Subjects -> MINES AND MINING INDUSTRY (Total: 82 journals)
Showing 1 - 42 of 42 Journals sorted by number of followers
Stainless Steel World     Full-text available via subscription   (Followers: 18)
Journal of Applied Geophysics     Hybrid Journal   (Followers: 16)
Journal of Metamorphic Geology     Hybrid Journal   (Followers: 15)
International Journal of Hospitality & Tourism Administration     Hybrid Journal   (Followers: 14)
European Journal of Mineralogy     Hybrid Journal   (Followers: 12)
Journal of Geology and Mining Research     Open Access   (Followers: 11)
Contributions to Mineralogy and Petrology     Hybrid Journal   (Followers: 11)
Mineral Processing and Extractive Metallurgy : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 11)
Transactions of Nonferrous Metals Society of China     Hybrid Journal   (Followers: 10)
Journal of Human Resources in Hospitality & Tourism     Hybrid Journal   (Followers: 9)
Clay Minerals     Hybrid Journal   (Followers: 9)
Minerals Engineering     Hybrid Journal   (Followers: 9)
Lithos     Hybrid Journal   (Followers: 9)
International Journal of Minerals, Metallurgy, and Materials     Hybrid Journal   (Followers: 9)
Natural Resources Research     Hybrid Journal   (Followers: 8)
Geotechnical and Geological Engineering     Hybrid Journal   (Followers: 8)
Rock Mechanics and Rock Engineering     Hybrid Journal   (Followers: 7)
International Journal of Rock Mechanics and Mining Sciences     Hybrid Journal   (Followers: 6)
Canadian Mineralogist     Full-text available via subscription   (Followers: 6)
International Journal of Mining Engineering and Mineral Processing     Open Access   (Followers: 5)
Journal of Quality Assurance in Hospitality & Tourism     Hybrid Journal   (Followers: 5)
Mine Water and the Environment     Hybrid Journal   (Followers: 5)
International Journal of Mining and Mineral Engineering     Hybrid Journal   (Followers: 5)
Journal of the Southern African Institute of Mining and Metallurgy     Open Access   (Followers: 5)
Mining Engineering     Full-text available via subscription   (Followers: 5)
Resources Policy     Hybrid Journal   (Followers: 4)
International Journal of Mining Science and Technology     Open Access   (Followers: 4)
Reviews in Mineralogy and Geochemistry     Hybrid Journal   (Followers: 4)
Mineral Processing and Extractive Metallurgy Review     Hybrid Journal   (Followers: 4)
Applied Earth Science : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 4)
International Journal of Mining, Reclamation and Environment     Hybrid Journal   (Followers: 4)
International Journal of Coal Geology     Hybrid Journal   (Followers: 4)
Physics and Chemistry of Minerals     Hybrid Journal   (Followers: 4)
Journal of Convention & Event Tourism     Hybrid Journal   (Followers: 4)
Mineralium Deposita     Hybrid Journal   (Followers: 4)
Lithology and Mineral Resources     Hybrid Journal   (Followers: 3)
Journal of Sustainable Mining     Open Access   (Followers: 3)
International Journal of Coal Science & Technology     Open Access   (Followers: 3)
Mining Journal     Full-text available via subscription   (Followers: 3)
Ghana Mining Journal     Full-text available via subscription   (Followers: 3)
Geology of Ore Deposits     Hybrid Journal   (Followers: 3)
Rocks & Minerals     Hybrid Journal   (Followers: 3)
Environmental Geochemistry and Health     Hybrid Journal   (Followers: 2)
Journal of Mining Science     Hybrid Journal   (Followers: 2)
Geomaterials     Open Access   (Followers: 2)
Mineralogia     Open Access   (Followers: 2)
BHM Berg- und Hüttenmännische Monatshefte     Hybrid Journal   (Followers: 2)
Mining Technology : Transactions of the Institutions of Mining and Metallurgy     Hybrid Journal   (Followers: 2)
Extractive Industries and Society     Hybrid Journal   (Followers: 2)
International Journal of Coal Preparation and Utilization     Hybrid Journal   (Followers: 2)
Mineralogy and Petrology     Hybrid Journal   (Followers: 2)
Mining Report     Hybrid Journal   (Followers: 2)
Neues Jahrbuch für Mineralogie - Abhandlungen     Full-text available via subscription   (Followers: 2)
Archives of Mining Sciences     Open Access   (Followers: 2)
Journal of Materials Research and Technology     Open Access   (Followers: 2)
Gems & Gemology     Full-text available via subscription   (Followers: 1)
Journal of Analytical and Numerical Methods in Mining Engineering     Open Access   (Followers: 1)
Rangeland Journal     Hybrid Journal   (Followers: 1)
Revista del Instituto de Investigación de la Facultad de Ingeniería Geológica, Minera, Metalurgica y Geográfica     Open Access   (Followers: 1)
Journal of Central South University     Hybrid Journal   (Followers: 1)
Mineralogical Magazine     Hybrid Journal   (Followers: 1)
CIM Journal     Hybrid Journal  
Natural Resources & Engineering     Hybrid Journal  
Mining, Metallurgy & Exploration     Hybrid Journal  
Podzemni Radovi     Open Access  
Rudarsko-geološko-naftni Zbornik     Open Access  
Journal of Mining Institute     Open Access  
International Journal of Mining and Geo-Engineering     Open Access  
Journal of China Coal Society     Open Access  
Réalités industrielles     Full-text available via subscription  
Mineral Economics     Hybrid Journal  
Minerals     Open Access  
Gold Bulletin     Hybrid Journal  
Minerals & Energy - Raw Materials Report     Hybrid Journal  
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Minerals
Journal Prestige (SJR): 0.462
Citation Impact (citeScore): 2
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Online) 2075-163X
Published by MDPI Homepage  [84 journals]
  • Minerals, Vol. 12, Pages 936: Prediction of the Adaptability of Using
           Continuous Extraction and Continuous Backfill Mining Method to Sequestrate
           CO2-A Case Study

    • Authors: Yujun Xu, Liqiang Ma, Ichhuy Ngo, Yangyang Wang, Jiangtao Zhai, Lixiao Hou
      First page: 936
      Abstract: The consumption of coal resources has caused an increase in CO2 emissions. A scientific concept that can realize CO2 sequestration, the harmless treatment of solid wastes, and coal extraction under buildings, railways, and water bodies (BRW) is proposed. First, a novel CO2 mineralized filling body (CMFB) is developed by employing CO2 gas, fly ash, silicate additives, and cement. It is then injected into the mined-out mining roadways (MRs) of the continuous extracting and continuous backfill (CECB) mining method to ameliorate the overburden migration and thus extract the coal body under the BRW. The AHP-fuzzy comprehensive evaluation method was employed to construct a prediction model for the suitability of this concept. Subsequently, the evaluation model is generalized and applied to the Yu-Shen mining area. Each indicator affecting adaptability is plotted on a thematic map, and the corresponding membership degree is determined. The aptness for 400 boreholes distributed in the entire area was determined and a zoning map which divides the whole area into good, moderate, slightly poor, and extremely poor suitability was drawn. This paper puts forward a mathematical model for predicting the suitability of using CECB and CMFB to sequestrate CO2. Research results can provide references for determining the site of CO2 sequestration under the premise of maximizing the economic and ecological benefits, which is conducive to constructing ecological, green, and sustainable coal mines.
      Citation: Minerals
      PubDate: 2022-07-25
      DOI: 10.3390/min12080936
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 937: Recent Ostracod Fauna of the Western Ross
           Sea (Antarctica): A Poorly Known Ingredient of Polar Carbonate Factories

    • Authors: Gianguido Salvi, John B. Anderson, Marco Bertoli, Pasquale Castagno, Pierpaolo Falco, Michele Fernetti, Paolo Montagna, Marco Taviani
      First page: 937
      Abstract: Ostracoda are a minor but recurrent component of Southern Ocean marine carbonate factories, and their low-Mg calcitic skeletal mineralogy helps in ensuring a noteworthy post-mortem resilience. Our study, based upon surface sediment occurrences, contributes to the better definition of their distribution vs. potential controlling factors in Antarctic waters. The ostracod fauna from the Western Ross Sea Shelf appears dominated by Australicythere polylyca, Australicythere devexa, Xestoleberis rigusa, Loxoreticulatum fallax, Cativella bensoni, Austrotrachyleberis antarctica and Patagonacythere longiducta, colonizing a variety of shelf environments along a wide bathymetric range. The abundance and richness values correlate well to nutrient distribution and sediment supply, primarily related to the circulation of different oceanographic regimes affecting the floor of the Ross Sea Shelf. Circumpolar Deep Water could represent the main factor controlling the distribution of ostracods. Similar results (high abundance and richness in ostracod values) were also recorded in the Terra Nova Bay and in a nearby area characterized by warm water rich in nutrients and composed of water of circumpolar origin flowing from the open ocean southwards onto the continental shelf. Particulate Fe (pFe), in suspended particulate matter (SPM), and other particulate trace metals in TNB could support the hypothesis that biogenic iron may significantly contribute to the bioavailable iron pool, sustaining both primary production and ostracod fauna richness in this area.
      Citation: Minerals
      PubDate: 2022-07-25
      DOI: 10.3390/min12080937
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 938: Application of the Response Surface
           Methodology to Optimise the Leaching Process and Recovery of Rare Earth
           Elements from Discard and Run of Mine Coal

    • Authors: Harrar Hamza, Orevaoghene Eterigho-Ikelegbe, Abdulsalam Jibril, Samson Oluwaseyi Bada
      First page: 938
      Abstract: The supply shortage of rare earth elements (REEs) for use in numerous high-tech applications has become an incentive for the prospecting of REEs from coal and coal discard. In this study, an optimised leaching process for the recovery of REEs from coal using the Design Expert (DOE) is reported. Response surface methodology (RSM) was used to investigate the effect and to determine the optimal leaching parameters for the two non-calcined coal samples. An optimised REE leaching recovery of 18.95% and 41.35% was obtained for the non-calcined Run-of-Mine (ROM) coal and discard coal, respectively. This optimised recovery was obtained as the HCl concentration increased from 0.5 M to 2 M, leaching temperature increased from 30 °C to 50 °C, whilst the solid:liquid ratio decreased from 40 g/L to 10 g/L. Statistical analysis indicated that the leaching parameters studied were important and controlled the REE leaching recovery model. Optimisation results also indicate that the calcined coals at 700 °C have the highest leaching recovery of 94.73% (ROM) and 98.17% (discard), respectively. Calcination also increased the concentration of REEs in the ROM sample from 225 ppm to 347 ppm and discarded the sample from 245 ppm to 363 ppm at 700 °C. Given the effect of the lixiviants investigated, the leaching efficiency of HClO4 for REE recovery was significantly lower than HCl and HNO3 under optimal leaching conditions. The discard coal used in this study had a significantly higher potential for REE recovery than ROM coal because it had a higher REE abundance and greater recovery.
      Citation: Minerals
      PubDate: 2022-07-26
      DOI: 10.3390/min12080938
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 939: Comparative Study for Flue Dust
           Stabilization in Cement and Glass Materials: A Stability Assessment of
           Arsenic

    • Authors: Harshit Mahandra, Atefeh Azizitorghabeh, Ahmad Ghahreman
      First page: 939
      Abstract: Arsenic is a poisonous element and its super mobility can pose a major threat to the environment and human beings. Disposed arsenic-bearing waste or minerals over time may release arsenic into the groundwater, soil and then the food chain. Consequently, safe landfill deposition should be carried out to minimize arsenic bleeding. Cement-based stabilization/solidification and glass vitrification are two important methods for arsenic immobilization. This work compares the stability and intrinsic leaching properties of sequestered arsenic by cement encapsulation and glass vitrification of smelter high-arsenic flue dust (60% As2O3) and confirms if they meet or exceed the requirement of landfill disposition over a range of environmentally relevant conditions. The toxicity characterization leaching procedure (TCLP, 1311), synthetic precipitation leaching procedure (SPLP, 1312) and Australian standard (Aus. 4439.3) in short-term (18 h) and mass transfer from monolithic material using a semi-dynamic leaching tank (1315) in longer-term (165 days) were employed to assess arsenic immobility characteristic in three arsenic-cement (2%, 8.4% and 14.4%) and arsenic-glass (11.7%) samples. Moreover, calcium release from different matrices has been taken into consideration as a contributor to arsenic bleeding. Based on the USEPA guidelines, samples can be acceptable for landfilling only if As release is < 5 mg/L. Results obtained from short-term leaching were almost similar for both cement and glass materials. However, high calcium release was observed from the cement-encapsulated materials. The pH of leachates after the test was highly alkaline for encapsulated materials; however, in glass material it was near neutral or slightly acidic. Method 1315 tests made a huge difference between the two materials and confirmed that cement encapsulation is not the best method for landfilling arsenic waste due to the high arsenic and calcium release over time with alkaline pH. However, glass material has shown promising results, i.e., the insignificant release of arsenic over time with an acceptable change in pH value. Overall, arsenic sequestration in glass is a better option compared with the cement-based solidification process.
      Citation: Minerals
      PubDate: 2022-07-26
      DOI: 10.3390/min12080939
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 940: Impact of Stimulated Fractures on Tree-Type
           Borehole Methane Drainage from Low-Permeability Coal Reservoirs

    • Authors: Liang Zhang, Qingjie Qi, Xuexi Chen, Shaojie Zuo, Kai Deng, Ruiqing Bi, Jiamei Chai
      First page: 940
      Abstract: Tree-type hydraulic fracturing (TTHF) is a promising method applicable to the effective development of methane in low-permeability coal seams. However, a large-scale application of this technique is limited due to the unclear impact of stimulated fractures by TTHF on the effect of post-fracturing methane drainage. To address this issue, a multi-scale methane flow model of coupled thermo-hydro-mechanical (THM) processes in stimulated coal seams by TTHF was developed and verified against laboratory-based measurements. Using this proposed model, a systematic evaluation of the influence extent of hydraulic fractures connecting sub-boreholes in a tree-type borehole on the drainage effect under different fracture apertures, initial permeabilities of the cleat system, and remnant methane pressures was performed. Detailed simulated results showed that the presence of highly permeable fractures induced by TTHF greatly enhanced, as expected, the drainage efficiency of coal seam methane between the ends of adjacent sub-boreholes, and led to a significant increase in the homogeneity coefficient β. Furthermore, increasing the stimulated fracture aperture and initial cleat permeability or reducing the remnant methane pressure also resulted in a larger value of β, but in turn shortened the lead time of the tree-type borehole. The β’s growth rate for different investigated cases compared to identical simulations without stimulated fractures presented an overall trend of increasing at first and then slowly decreasing with sustained drainage time. Meanwhile, large-aperture hydraulic fractures and lower remnant methane pressure are more beneficial to the drainage effect of tree-type boreholes in the initial stages of drainage. These results portrayed herein can be employed to better understand how fractures generated by TTHF play a role in post-fracturing drainage programs and provide theoretical assistance in engineering applications.
      Citation: Minerals
      PubDate: 2022-07-26
      DOI: 10.3390/min12080940
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 941: Machine Learning Methods for Quantifying
           Uncertainty in Prospectivity Mapping of Magmatic-Hydrothermal Gold
           Deposits: A Case Study from Juruena Mineral Province, Northern Mato
           Grosso, Brazil

    • Authors: Victor Silva dos Santos, Erwan Gloaguen, Vinicius Hector Abud Louro, Martin Blouin
      First page: 941
      Abstract: Mineral prospectivity mapping (MPM), like other geoscience fields, is subject to a variety of uncertainties. When data about unfavorable sites to find deposits (i.e., drill intersections to barren rocks) is lacking in MPM using machine learning (ML) methods, the synthetic generation of negative datasets is required. As a result, techniques for selecting point locations to represent negative examples must be employed. Several approaches have been proposed in the past; however, one can never be certain that the points chosen are true negatives or, at the very least, optimal for training. As a consequence, methodologies that account for the uncertainty of the generation of negative datasets in MPM are needed. In this paper, we compare two criteria for selecting negative examples and quantify the uncertainty associated with this process by generating 400 potential maps for each of the three ML methods utilized (200 maps for each criterion), which include random forest (RF), support vector machine (SVM), and k-nearest neighbors (KNC). The results showed that applying a geological constraint to the creation of negative datasets reduced prediction uncertainty and improved overall model performance but produced larger areas of very high probability (i.e., >0.9) when compared to using only the spatial distribution of known deposits and occurrences as a constraint. SHAP values were used to find approximations for the importance of features in nonlinear methods, and kernel density estimations were used to examine how they varied depending on the negative dataset used to train the ML models. Prospectivity models for magmatic-hydrothermal gold deposits were generated using data from the shuttle radar terrain mission, gamma-ray, magnetic lineaments, and proximity to dykes. The Juruena Mineral Province, situated in Northern Mato Grosso, Brazil, represented the case study for this work.
      Citation: Minerals
      PubDate: 2022-07-26
      DOI: 10.3390/min12080941
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 942: Tectono-Thermal Events of Coal-Bearing Basin
           in the Northern North China Craton: Evidence from Zircon–Apatite
           Fission Tracks and Vitrinite Reflectance

    • Authors: Dongna Liu, Junwei Lin, Anchao Zhou, Fenghua Zhao, Rui Zhou, Yu Zou
      First page: 942
      Abstract: In order to further reveal the tectonic activity of the central and northern North China Craton (NCC) since late Paleozoic, the Datong coal-bearing basin was selected as the research object. The tectono-thermal events and uplifting cooling events of the basin were retrieved through zircon and apatite fission tracks and vitrinite reflectance measurements. The research shows that the Datong coal-bearing basin experienced three tectono-thermal events with ages of 245–207 Ma (middle–late Triassic), 179 ± 9 Ma (early Jurassic), and 140 Ma to 78 ± 11 Ma (middle–late Cretaceous), respectively. That just coincides with the lamprophyre activity, Kouquan fault activity, and Zuoyun basaltic andesite magmatic activity which surround the Datong coalfield. The basin also experienced three uplift events with the peak ages of 202 ± 18 Ma (late Triassic), 157 ± 7 Ma (late Jurassic), and 45 ± 3 Ma or 36 ± 3 Ma (middle Eocene), respectively. The Datong Permo-Carboniferous and Jurassic coal vitrinite reflectance proved that the average metamorphism temperature is 104–108 °C, even reaching 163–367 °C. The fission track results showed that the paleotemperature was even higher than 170–250 °C from 117 to 282 Ma and 80–120 °C from 20 to 68 Ma, in the Datong coal-bearing basin. The results show that the deep tectonic activities of the NCC were still active in the Mesozoic and even Cenozoic Paleogene.
      Citation: Minerals
      PubDate: 2022-07-26
      DOI: 10.3390/min12080942
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 943: 87Sr/86Sr Isotopic Ratio of Ferromanganese
           Crusts as a Record of Detrital Influx to the Western North Pacific Ocean

    • Authors: Keishiro Azami, Naoto Hirano, Jun-Ichi Kimura, Qing Chang, Hirochika Sumino, Shiki Machida, Kazutaka Yasukawa, Yasuhiro Kato
      First page: 943
      Abstract: In this study, the Sr isotope ratios (IRs; 87Sr/86Sr) of ferromanganese (Fe–Mn) crusts are analyzed through laser ablation inductively coupled plasma multiple-collector mass spectrometry. A sample collected from off Minamitorishima Island showed uniform Sr IRs (0.70906–0.70927) similar to that of present-day seawater with more than 36 mm thickness. Meanwhile, a detritus-rich sample collected from off northeast (NE) Japan showed a wide variation in Sr IRs (0.707761–0.709963). The Sr IR variation in the Fe–Mn crust from off NE Japan suggests detrital influx contributions from both the NE Japan arc (<0.708) and aeolian dust from China (>0.718). Detrital flux from the NE Japan arc increases from the bottom to middle layers, possibly due to the uplift of the Ou backbone range that occurred after ~2 Ma. The increased influx of the aeolian dust in the outer layer is attributable to global cooling in the Quaternary that increased the loess dust transportation from China to the western North Pacific Ocean. Meanwhile, the influence of the detrital influx on the sample from off Minamitorishima Island appeared to be negligible. The Sr IR analysis with high spatial resolution proposed in this study possibly improves the burial history of Fe–Mn nodules.
      Citation: Minerals
      PubDate: 2022-07-27
      DOI: 10.3390/min12080943
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 944: An Assessment of the Role of Combined Bulk
           Micro- and Nano-Bubbles in Quartz Flotation

    • Authors: Shaoqi Zhou, Yang Li, Sabereh Nazari, Xiangning Bu, Ahmad Hassanzadeh, Chao Ni, Yaqun He, Guangyuan Xie
      First page: 944
      Abstract: Bulk micro-nano-bubbles (BMNBs) have been proven to be effective at improving the flotation recovery and kinetics of fine-grained minerals. However, there is currently no research reported on the correlation between the properties of BMNBs and flotation performance. For this purpose, aqueous dispersions with diverse properties were created by altering preparation time (0, 1, 2, 3, 5, and 7 min), aeration rate (0, 0.5, 1, 1.5, and 2 L/min) and aging time (0, 0.5, 1, and >3 min). Micro- and nano-bubbles were characterized using focused beam reflection measurements (FBRM) and nanoparticle tracking analysis (NTA), respectively. The micro-flotation of quartz particles was performed using an XFG-cell in the presence and absence of BMNBs with Cetyltrimethylammonium bromide (CTAB) as a collector. The characterization of bubble sizes showed that the bulk micro-bubble (BMB) and bulk nanobubble (BNB) diameters ranged from 1–10 μm and 50–400 nm, respectively. It was found that the preparation parameters and aging time considerably affected the number of generated bubbles. When BNBs and BMBs coexisted, the recovery of fine quartz particles significantly improved (about 7%), while in the presence of only BNBs the promotion of flotation recovery was not significant (2%). This was mainly related to the aggregate via bridging, which was an advantage for quartz flotation. In comparison, no aggregates were detected when only nano-bubbles were present in the bulk solution.
      Citation: Minerals
      PubDate: 2022-07-27
      DOI: 10.3390/min12080944
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 945: Lithium Occurrence in Italy—An
           Overview

    • Authors: Andrea Dini, Pierfranco Lattanzi, Giovanni Ruggieri, Eugenio Trumpy
      First page: 945
      Abstract: Italy has no record of Li production, even though it is well known for its outstanding Li mineral specimens from the Elba Island pegmatites. Because of the current geopolitical situation, the opportunity for a systematic appraisal of resources is evident. Most European Li production comes from deposits associated with Late Paleozoic magmatic rocks. In Italy, such rocks occur extensively in Sardinia and Calabria, but their potential for Li is unknown, and deserves a more systematic exploration. Also of potential interest are the Permo–Triassic spodumene pegmatites in the Austroalpine units of the Central Alps. The Tertiary pegmatites (Elba Island and Central Alps) contain Li minerals, but do not appear large enough to warrant bulk mining. However, we notice that Tertiary–Quaternary magmatic rocks of the Tuscan and Roman magmatic provinces have systematically higher Li contents than those recorded in normal arc igneous rocks worldwide. Specifically, Tuscan granites contain up to 350 μg/g Li, mostly hosted by biotite (up to 4000 μg/g Li); the Capo Bianco aplite (Elba Island) contains up to 1000 μg/g. There are other small Li occurrences associated with Mn deposits and metabauxites, and there is a hypothetical potential for sediment-hosted deposits in the post-orogenic Lower Permian Alpine basins. However, the most promising potential seems to be associated with subsurface fluids. High-enthalpy fluids in geothermal fields may contain up to 480 mg/L Li. Lower-temperature thermal waters may also contain significant Li (>10 mg/L). Moreover, a visionary, but not impossible, perspective may consider a deep injection of water to interact with, and extract Li from, magmatic rocks.
      Citation: Minerals
      PubDate: 2022-07-27
      DOI: 10.3390/min12080945
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 946: Paleoenvironmental and Bio-Sequence
           Stratigraphic Analysis of the Cretaceous Pelagic Carbonates of Eastern
           Tethys, Sulaiman Range, Pakistan

    • Authors: Shuja Ullah, Irfan U. Jan, Muhammad Hanif, Khalid Latif, Mohibullah Mohibullah, Mahnoor Sabba, Aqsa Anees, Umar Ashraf, Hung Vo Thanh
      First page: 946
      Abstract: The Cretaceous pelagic carbonate succession, i.e., Goru Formation was studied in the Chutair Section, Sulaiman Range, representing part of the eastern Tethys for the paleoenvironment and bio-sequence stratigraphy. Eight planktonic foraminiferal biozones are identified which include: 1. Muricohedbergella planispira Interval Zone; 2. Ticinella primula Interval Zone; 3. Biticinella breggiensis Interval Zone; 4. Rotalipora appenninica Interval Zone; 5. Rotalipora cushmani Total Range Zone; 6. Whiteinella archeocretacea Partial Range Zone; 7. Helvetoglobotruncana helvetica Total Range Zone; and 8. Marginotruncana sigali Partial Range Zone representing Albian-Turonian age. The petrographic studies revealed five microfacies: 1. Radiolarians-rich wacke-packestone microfacies; 2. Radiolarians-rich wackestone microfacies; 3. Planktonic foraminiferal wacke-packestone microfacies; 4. Planktonic foraminiferal wackestone microfacies; and 5. Planktonic foraminiferal packestone microfacies; indicating deposition of the Goru Formation in outer-ramp to deep basinal settings. Based on the facies variations and planktonic foraminiferal biozones, the 2nd and 3rd order cycles are identified, which further include six transgressive and five regressive system tracts. The sea level curve of the Goru Formation showed fluctuation between outer-ramp and deep-basin, showing the overall transgression in the 2nd order cycle in the study area, which coincides with Global Sea Level Curve; however, the 3rd order cycle represents the local tectonic control during deposition of the strata.
      Citation: Minerals
      PubDate: 2022-07-27
      DOI: 10.3390/min12080946
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 947: Effects of Magmatic-Hydrothermal Activities
           on Characteristic of Source Rocks from Beipiao Formation in the Jinyang
           Basin, NE China

    • Authors: Shuo Deng, Sumei Li, Shouliang Sun, Ziyan Hao, Menghua Qin, Yongfei Li
      First page: 947
      Abstract: The Jinyang Basin is a typical volcanic-sedimentary basin, located in the southern peripheral area of the Songliao Basin. Hydrothermal activity is often closely related to the intrusion or eruption of magma. It was recently suggested that dolomite in the Jurassic Beipiao Formation was formed under the influence of magmatic-hydrothermal activity and magmatic-hydrothermal activity might have impacts on the organic matter of the source rocks. No investigation has been aimed at the effect of magmatic-hydrothermal activities on the accumulation of organic matter in the Beipiao Formation source rocks and a comprehensive study is urgent, which would be indicative in unravelling the accumulation mechanism of organic matter and useful in further petroleum exploration. To provide important insights into these issues, we carried out a detailed investigation of geological and geochemical analysis for Wolong (WL) and Dongkuntouyingzi (DK) outcrop shales from the Lower Jurassic Beipiao Formation in the Jinyang Basin. The hydrothermal indicator discrimination diagram (Zn-Ni-Co triangular plot) and rare earth element anomalies (δEu and δCe) indicate that the formation of WL samples is associated with hydrothermal activity, but DK is not. The TOC values suggest that most of the WL and DK samples are good to very good and fair to good source rocks, respectively. The Ro values suggest that both WL (Ro = 1.17%) and DK (Ro = 1.01%) samples have entered the oil-generating stage, and WL samples were influenced by the magmatic activity with higher maturity. The biomarkers such as high steranes/hopanes, high 4-methyl steranes/C29 steranes, low Pr/Ph values and high gammacerane index suggest that WL samples were deposited in an anoxic-prone saline environment with significant contributions of algal sources. Contrarily, the DK samples were deposited in oxic-prone and freshwater paleolake with significant contributions of terrigenous organic matter. The magmatic-hydrothermal activities in the Wolong area brought numerous nutrients to the lake basin, which may facilitated the reproduction of aquatic organisms. At the same time, the magmatic-hydrothermal activities increased the salinity of water and promoted the formation of a water reducing environment, which provided an excellent environment for the preservation and enrichment of organic matter. Therefore, the magmatic-hydrothermal activities in the Wolong area promoted the formation of organic-rich source rocks and the hydrocarbon generation process.
      Citation: Minerals
      PubDate: 2022-07-27
      DOI: 10.3390/min12080947
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 948: Recovery of Rare Earth Elements from Mining
           Tailings: A Case Study for Generating Wealth from Waste

    • Authors: Luver Echeverry-Vargas, Luz Marina Ocampo-Carmona
      First page: 948
      Abstract: The growing demand for rare earth elements (REE) driven by their applications in modern technologies has caused the need to search for alternative sources of these elements as their extraction from traditional deposits is limited. A potential source of light rare earth elements (LREE) may be the monazite present in the mining waste generated in the Bagre-Nechí mining district in Colombia due to the processing of sands containing alluvial gold. Consequently, in this research, a systematic evaluation has been carried out for the extraction of Ce, La, and Nd from a leach liquor obtained from monazite present in alluvial gold mining tailings. The leaching process carried out with HCl indicated the recovery of approximately 90% of La and Nd and ∼60% of Ce; the solvent extraction tests of these elements showed that increasing the contact time and pH of the leaching liquor positively affects the extraction of lanthanum, cerium, and neodymium, achieving extractions close to 100% with D2EHPA and to a lesser extent with Cyanex572. McCabe–Thiele diagrams for extraction with D2EHPA indicated the requirement of three stages for the extraction of Ce, La and Nd.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080948
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 949: On the Isomorphism of Sodium at the M(2)
           Site in Eudialyte-Group Minerals: The Crystal Structure of Mn-Deficient
           Manganoeudialyte and the Problem of the Existence of the M(2)Na-Dominant
           Analogue of Eudialyte

    • Authors: Sergey M. Aksenov, Nikita V. Chukanov, Igor V. Pekov, Yulia V. Nelyubina, Dmitry A. Varlamov, Lia N. Kogarko
      First page: 949
      Abstract: Sodium plays an important role in the crystal structures of eudialyte-group minerals given that it can occupy different crystallographic sites. Predominantly, it distributes between the N(1–5) sites situated in the large cavities of the heteropolyhedral framework. Rarely, Na occupies split sites of the M(2) microregion where it can predominate over other elements (predominantly Mn, Fe2+, and Fe3+). The crystal structure of the Mn-deficient manganoeudialyte from the Lovozero alkaline complex (Kola Peninsula, Russia) has been refined. The trigonal unit–cell parameters are: a = 14.1848(2) Å, c = 30.4726(3) Å, V = 5309.90(11) Å3. The sample is a rare example of a high-sodium and high-calcium representative of the eudialyte group with Fe + Mn < 2 apfu. The idealized formula is Na14Ca6[(Mn,Fe)2Na]Zr3Si2[Si24O72]O(OH)·2H2O with bivalent components, Mn2+ and Fe2+, dominating at the M(2) site. The regularities of isomorphism involving M(2)Na in EGMs and the problem of the existence of the M(2)Na-dominant analogue of eudialyte are discussed. The new data obtained in this work confirm the previous conclusion that the complete isomorphism between Ca-deficient and Ca-rich members of the eudialyte group cannot be realized in frames of a single-space group (R3m, R-3m or R3). Thus, the existence of the M(2)Na analogue of eudialyte remains questionable.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080949
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 950: A Modeling Approach for Beach-Bar Sand
           Reservoirs Based on Depositional Mode and Sandbody Volume

    • Authors: Wanbing Li, Shaohua Li, Quangong Qu, Huafeng Zhang, Junying Zhao, Mengjiao Dou
      First page: 950
      Abstract: Beach-bar sand in lacustrine facies represents one of the most significant reservoirs. Depending on the depositional characteristics, it can be further divided into two different sedimentary microfacies, beach sand and the bar sand. Favorable reservoirs are often developed in bar sand. The lower section of the upper part of the 4th member of the Shahejie Formation in the Gao89-1 block is a typical nearshore shallow water beach-bar deposit. Oil distribution is influenced by lithofacies and physical properties. In order to better characterize the heterogeneity within beach-bar sandbodies, a modeling method based on the depositional mode and sandbody volume is proposed. Firstly, a sandbody model is established. On this basis, an algorithm for distinguishing between beach and bar sand based on vertical thickness is proposed. The model is post processed based on the sandbody volume to remove unreasonable sandbodies. The method allows for a more realistic three-dimensional geological model of the beach-bar sands in the study area than the classical two-point geostatistical, object-based, and multi-point simulation method. A facies-controlled modeling approach is used to establish a petrophysical property model on this foundation; the result shows that the property models better reflect the characteristics of the petrophysical distribution in the Gao89-1 block.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080950
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 951: Coal and Gangue Active Identification Method
           Using Microwave Irradiation-Infrared Detection

    • Authors: Chuang Liu, Hani S. Mitri, Huamin Li
      First page: 951
      Abstract: In the process of the longwall top coal caving method, automatic distinction between coal and gangue at the working face is one of the most critical factors for the success of the operation. An active coal and gangue identification method using microwave irradiation combined with infrared detection is proposed in this paper. Coal and gangue are irradiated with microwave to actively enhance the external differences between them, and then the quantitative data of the difference are quickly collected by a noncontact infrared thermal imager, to perform identification of coal and gangue. Using theoretical analysis and laboratory experiments, the physical and chemical properties of coal and gangue are analyzed in order to reveal the thermal sensitivity of coal and gangue to microwave irradiation. The influences of the coal and gangue particle size, microwave irradiation time and microwave frequency on the thermal sensitivity to microwave irradiation are investigated. The experimental results show that the average temperature rise in coal is approximately 1.5 times that in gangue material under the same microwave irradiation conditions. This supports the feasibility of this identification method, and provides theoretical and experimental bases for achieving rapid and accurate identification of coal and gangue in top coal caving operations.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080951
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 952: Zircon U-Pb Ages and Geochemistry of the
           Granite in the Xintianling Tungsten Deposit, SE China: Implications for
           Geodynamic Settings of the Regional Tungsten Mineralization

    • Authors: Wu Yang, Min Zhang, Jun Yan, Xiaocui Chen
      First page: 952
      Abstract: The Xintianling tungsten deposit is a super-large deposit in the Nanling tungsten–tin mineralization belt, which is genetically associated with the early-stage hornblende-biotite monzonitic granite of Qitianling pluton. The orebodies predominantly occur as veins and lenses within skarn rocks between Xintianling granite and limestone (Shidengzi group). In this work, whole-rock major and trace elements and zircon U–Pb ages of the Xintianling granite were studied in an attempt to investigate the geochronological framework, petrogenesis, tectonism, and metallogenesis with regard to the deposit. The petrographic and geochemical analyses indicated that the Xintianling granite consists of three intrusive units of medium- and coarse-grained biotite granite, fine-grained biotite granite, and granite porphyry, of which the biotite granite was strongly associated with mineralization. Biotite granite rocks are highly K-calc-alkaline and weakly peraluminous, with A/CNK ratios ranging from 0.99 to 1.05. Late-granite porphyry is aluminum-supersaturated with a high evolution degree, whose geochemical characteristics suggest that it is either an I- or S-type granite. LA-ICP-MS zircon U-Pb dating revealed that medium- and coarse-grained biotite granite (162.3 ± 1.2 Ma, MSWD = 1.3), fine-grained biotite granite (161.8 ± 1.3 Ma, MSWD = 1.8), and granite porphyry (154.3 ± 1.6 Ma, MSWD = 2.4) formed in the late Jurassic. The emplacement of the Qitianling A-type granite and associated tungsten-tin polymetallic mineralization is a continuous evolution process, and they are products of the large-scale mineralization of the Nanling in the middle–late Jurassic (150–160 Ma). Under the tectonic setting of the Mesozoic lithospheric extension, asthenosphere upwelling along deep-fault, intensive mantle–crust interaction processes probably provide not only the high heat flow, but also partly mantle-derived material for large-scale W-Sn-polymetallic mineralization in this area.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080952
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 953: Age of the Tuchengzi Formation in Western
           Liaoning Province and the Jurassic–Cretaceous Boundary from the
           Continuous Core Records of Well YD1, Jinyang Basin

    • Authors: Shou-Liang Sun, Shu-Wang Chen, Zhong-Jie Yang, Tao Zhang, Yong-Fei Li, Ji-Chang Zhu, Huai-Chun Wu, Tian-Tian Wang, Yue-Juan Zheng, Qiu-Hong Ding
      First page: 953
      Abstract: The Tuchengzi Formation is widely distributed in western Liaoning Province with a clear top and bottom. It is the focal area for the delineation of the terrestrial Jurassic–Cretaceous boundary in China. Based on continuous core samples taken from well YD1, detailed lithostratigraphic sequences and zircon uranium–lead (U-Pb) dating were used to investigate the Tuchengzi Formation. The zircon U-Pb ages of the tuff samples taken from the First and Third Members of the Tuchengzi Formation ranged from 153.8 to 137.16 Ma, indicating that they were formed in the late Middle Jurassic–Early Cretaceous. Dating results from the bottom of the Second Member of the Tuchengzi Formation indicate that the sedimentary time of the stratum is no later than 145.7 ± 2.1 Ma. We concluded that the Jurassic–Cretaceous boundary of the Jinyang Basin in western Liaoning province may be located at the interface at a depth of 464 m in well YD1. This conclusion is consistent with the Jurassic–Cretaceous boundary that has been presumed by other researchers based on paleontological assemblage features found in recent years, and can provide useful geological marker beds for the future study of the terrestrial Jurassic–Cretaceous boundary. In addition, the authors also systematically sorted the potential development areas and layers of the terrestrial Jurassic–Cretaceous boundary line, which may also provide useful geological marker beds for the future study of the terrestrial Jurassic–Cretaceous boundary.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080953
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 954: Allanite in Variscan Post-Collisional
           Lamprophyre Dykes from Les Guilleries (NE Iberia) as a Part of Rare Earth
           Element Recycling in Collisional Orogens

    • Authors: Esteban Mellado, Mercè Corbella, Andrew Kylander-Clark
      First page: 954
      Abstract: Recent studies of Late Permian calc-alkaline lamprophyre dykes located in the Les Guilleries Paleozoic massif of the Catalan Coastal Range have revealed that allanite is present as the main REE-bearing accessory phase, which is the object of this study. The lamprophyre dykes are amphibole–plagioclase-dominated spessartites with a wide variety of accessory phases, including titanite, ilmenite, allanite, fluorapatite, spinel, zircon, and sulfides, and show complex alteration textures related to secondary albite, chlorite, epidote, titanite and calcite. The allanite crystal composition, analyzed by SEM-EPMA and LA-ICP-MS, evidences the solid solution between epidote and allanite with a ferriallanite component, similar to what is found in Variscan post-collisional granitoids from western Europe. However, heterogeneity in crystal shapes, sizes, type of zoning, dissolution embayment textures, growth of epidote coronas, mineral paragenesis, and the unique geochemical characteristics of allanite crystals suggest multiple crystallization events. At least two types of allanite–epidote composite grains have been identified: allanite Type I, with regular allanite–epidote core-to-rim zoning and a secondary allanite rim; and allanite Type II, with anhedral allanite cores surrounded by epidote coronas. Additionally, irregular zoning, complex dissolution textures and REE redistribution suggest the occurrence of deuteric and/or post-magmatic processes, which are also common in Variscan post-collisional plutons from the Catalan Coastal Range and nearby Paleozoic massifs. Multivariate statistical analyses of major elements in allanite–epidote composite grains show a relationship between major textural and geochemical variations for three out of ten principal components, mainly related to cationic substitutions between ferriallanite-(Ce) and epidote, but also involving Mn and Ti(REE3+ + Fe2+ + Ti4+ + Mg2+ + Mn2+ = Al3+ + Ca2+ + Fe3+). The allanite U-Pb-Th- weighted mean age of 265 ± 15 Ma (MSWD = 0.57) is roughly similar to the age of emplacement of the lamprophyres in the upper crust in the mid–late Permian, and coincides with the period following the main tectonometamorphic and magmatic events of the post-collisional evolution in the Catalan Coastal Range. Th/U and La/Sm ratios suggest a metamorphic origin for most allanite grains, but a combination of metamorphic processes prior to partial melting, early–late magmatic crystallization, and/or post-magmatic hydrothermal processes is the most plausible explanation to account for the diversity of allanite grains in Les Guilleries lamprophyres.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080954
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 955: The Numerical Simulation and
           Characterization of Complex Fracture Network Propagation in Multistage
           Fracturing with Fractal Theory

    • Authors: Peng Zhang, Chunsheng Pu, Xian Shi, Zhiqian Xu, Zhengqin Ye
      First page: 955
      Abstract: To investigate complex fracturing and the influencing factors of simultaneous fracture propagation in horizontal wells, a three-cluster fracture propagation model that is controlled by fracture surface displacement parameters is established. When performing multistage fracturing on reservoirs with a relatively high development degree of natural fractures, staged multicluster fracturing in horizontal wells is one of the commonly used technical methods for volume fracturing. Two frequently encountered problems are multifracture extension and interfracture stress interference between fractures. The characteristics of the coal mechanics parameters of coalbed methane (CBM) blocks in northwestern China are analyzed by probability statistics to obtain the elastic modulus and Poisson’s ratio. With the interactive development environment of the MATLAB-PYTHON-FEM platform, a numerical model of fracture network expansion under the staged fracturing of horizontal wells is constructed. The stress interference level between fractures and the fractal expansion mechanism of fracture networks are analyzed under different influencing factors, including the fractal dimensions of natural joints, fracturing fluid pumping rate, and inhomogeneity coefficient of the in situ stress.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080955
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 956: Study on the Characteristics of Acoustic
           Emission Quiet Period in Rocks with Different Elastic Modulus

    • Authors: Kui Zhao, Wenkai Wu, Peng Zeng, Cong Gong
      First page: 956
      Abstract: To study the characteristics of the quiet period of acoustic emission (AE) during the rock failure process, rock models with an abnormal elastic modulus were established based on PFC2D. The calibration of the mesoscopic parameters was performed by the macroscopic mechanical parameters of granite samples obtained in uniaxial compression tests. An abnormal area of 2 × 100 mm2 was set at the center of the model and had two to six times the elastic modulus of the normal area. The evolution law of cracks and the characteristics of the AE quiet period were analyzed in detail. The main conclusions are as follows: (1) The axial stress of the abnormal area rises to the maximum value before the occurrence of the main fracture; in the AE quiet period, the axial stress in the abnormal area of elastic modulus increased by 2%–5%, then decreases rapidly after the AE quiet period. (2) As the elastic modulus increases, the interval time of the AE quiet period is prolonged by one to five times. Furthermore, many cracks occurred mainly in the abnormal area, and then a few cracks were generated before the AE quiet period. Cracks mainly focus on the elastic modulus abnormal area and propagate beyond the normal area after the AE quiet period. (3) The Z value is used as the indicator of the significance of the AE quiet period, and it changes with the elastic modulus of the abnormal area. The Z value without an abnormal area is the minimum of 1.1, and the elastic modulus of the abnormal area was set to three times the normal area, the Z value reaches the maximum of 6.08, and the Z value changes with the elastic modulus. The distribution of different elastic modulus is an important factor concerned with the characteristics of the AE quiet period.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080956
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 957: Difficulties and Recent Achievements in
           Flotation Separation of Fluorite from Calcite—An Overview

    • Authors: Junwei Huang, Qiwu Zhang, Hongchao Li, Chao Wang
      First page: 957
      Abstract: As an important strategic non-metallic mineral resource, fluorite has been widely used in various industrial fields, such as metallurgy, optics and semiconductor manufacturing, as well as fluorine-related chemical engineering. Since the major gangue minerals of fluorite ore are silicate and carbonate ones, flotation is the main beneficiation method for the concentration. Compared with the relatively easy operation for silicate-type fluorite ore, fluorite concentration from calcite has always been the most difficult challenge in the field of mineral processing. In this review, analyses of the fundamental reasons for the difficulties of flotation separation of fluorite from calcite are performed, from the similar surface properties of both calcium minerals to the deterioration by the interference of dissolved ions in the pulp during grinding and flotation. Recent achievements in the flotation separation of fluorite from calcite as the main contents are comprehensively summarized, covering all aspects of flotation reagents of collectors, depressants and modifiers. Finally, successful examples of industrial practices forfluorite and calcite flotation separation are introduced. This overview provides a detailed and comprehensive reference source for the current research status of fluorite and calcite flotation separation, and some suggestions for future research are provided.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080957
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 958: Advances on Exploration Indicators of
           Mineral VNIR-SWIR Spectroscopy and Chemistry: A Review

    • Authors: Yan Zhou, Tiangang Wang, Feipeng Fan, Shizhong Chen, Weimin Guo, Guangfu Xing, Jiandong Sun, Fan Xiao
      First page: 958
      Abstract: Establishing exploration vectors to infer the properties of ore-forming fluids, locate blind ore bodies with the aid of visible to near-infrared (VNIR) and short-wave infrared (SWIR) spectroscopy, and infer the chemistry of minerals, is a new research interest for economic geology. Common alterations and clay minerals, including sericite, chlorite, epidote, alunite, kaolinite, tourmaline, etc., are ideal objects for the study of exploration indicators due to their sensitivity to variations in the nature of hydrothermal fluid. The diagnostic spectral feature and chemistry vary spatially and systematically with physicochemical change. VNIR spectroscopy can characterize the REE-bearing clay minerals directly. Obtaining spectral or chemical parameters with the aid of VNIR-SWIR spectroscopy, electron probe micro-analyzer (EPMA) or laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) can help to establish exploration vectors. This paper systematically summarizes recent advances in mineral exploration indicators (MEIs) of VNIR-SWIR spectroscopy and chemistry, and compares them in different regions or deposits. We found that some MEI spatial variation trends are random, even the same type of deposit can show an opposite trend. The controlling factors that limit the application of the established MEIs are vague. Conducting further research on petrology and mineralogy with the aids of observation under microscopy, X-ray diffraction (XRD), TESCAN Integrated Mineral Analyzer (TIMA), and EPMA are suggested to discover alteration mineral assemblage, alteration stages, and behaviors of “the pathfinder elements” related to mineralization. Based on the above research, the physicochemical properties of ore-forming fluids and their control over MEIs can be inferred. Refining the theoretical basis is critical to understanding and popularization of spectral and chemical MEIs.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080958
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 959: Velocity Structure and Cu-Au Mineralization
           of the Duobaoshan Ore District, NE China: Constrained by First-Arrival
           Seismic Tomography

    • Authors: Zongdong Pan, Hesheng Hou, Wei Fu, Xiaofan Deng, Jiaduo Zhang, Hengcheng Ying
      First page: 959
      Abstract: The genesis of deeply buried deposits in the Duobaoshan ore district, the largest porphyry-related Cu-Mo-Au ore field in northeastern China, is not well understood and their exploration is lacking because the fine velocity structure of this region is not comprehensively understood. Herein, first-arrival seismic travel times were picked along a deep seismic reflection profile and inverted using the tomographic method to obtain a detailed velocity profile of the upper 2900 m of the crust beneath this region. The profile showed that the velocity varied from 1900 to 6100 m/s and that the crust was subdivided into five parts by two low-velocity (2500–4000 m/s) blocks. Based on previous studies, the boundaries between the high-speed and low-speed bodies were interpreted as hidden fractures, and the 5000–6100 m/s parts were interpreted as concealed granite bodies in these sections. Porphyry copper deposits in the Duobaoshan ore district were related to the occulted granite bodies, and epithermal Au deposits were associated with the occulted fracture zones. Comprehensive evaluation of hydrothermal activity, regional magnetic anomalies, and deposit distribution indicated that the hidden fractures served as channels for ore-related magmas. Combining previous research on the Duobaoshan ore district with our results of the high-velocity interface, we infer that the prospecting range of the Tongshan deposit is below the depth of 1000 m.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080959
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 960: Metal–Metal Correlation of Biodegraded
           Crude Oil and Associated Economic Crops from the Eastern Dahomey Basin,
           Nigeria

    • Authors: Saeed Mohammed, Mimonitu Opuwari, Salam Titinchi, Lilburne Cyster
      First page: 960
      Abstract: The presence of heavy metals in plants from oil sand deposits may reflect mineralization resulting from petroleum biodegradation. Petroleum composition and heavy metal analyses were performed using thermal desorption gas chromatography and atomic absorption spectrophotometry on oil sand and plant root samples from the same localities in the Dahomey Basin. The results from the oil sand showed mainly heavy-end hydrocarbon components, humps of unresolved complex mixtures (UCM), absences of C6-C12 hydrocarbon chains, pristane, and phytane, indicating severe biodegradation. In addition, they showed varying concentrations of vanadium (2.699–7.708 ppm), nickel (4.005–11.716 ppm), chromium (1.686–5.733 ppm), cobalt (0.953–3.223 ppm), lead (0.649–0.978 ppm), and cadmium (0.188–0.461 ppm). Furthermore, these heavy metals were present in Citrus, Theobroma Cacao, Elaeis guineensis, and Cola. The chromium, nickel, vanadium, lead, cobalt, and cadmium concentrations in the Citrus were 7.475, 4.981, 0.551, 0.001, 0.806, and 0.177 ppm, respectively. For the Theobroma Cacao, the concentrations of chromium, nickel, vanadium, lead, cobalt, and cadmium were 7.095, 16.697, 2.151, 0.023, 3.942, and 0.254 ppm. Elaeis guineensis also showed the presence of chromium (32.685 ppm), nickel (32.423 ppm), vanadium (11.983 ppm), lead (0.190 ppm), cobalt (4.425 ppm), and cadmium (0.262 ppm). The amounts of chromium, nickel, vanadium, lead, cobalt, and cadmium in the Cola were 9.687, 9.157, 0.779, 0.037, 0.695, and 0.023 ppm. The World Health Organization’s (WHO) safe and permissible limits for Cd (0.003 ppm), Cr (0.1 ppm), Ni (0.05 ppm), and Pb (0.1 ppm) in agricultural soils were all exceeded in the oil sand. The presence of these metals in the oil sands and their uptake by the plants could potentially be toxic, resulting in high mortality. The metal–metal correlation of the plant’s rootsto the oil sand indicates the nonanthropogenic origin of the heavy metals, which leads to the conclusion that their source is related to the hydrocarbon accumulation in the Afowo sand.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080960
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 961: The Heavy Mineral Map of Australia: Vision
           and Pilot Project

    • Authors: Patrice de Caritat, Brent I. A. McInnes, Alexander T. Walker, Evgeniy Bastrakov, Stephen M. Rowins, Alexander M. Prent
      First page: 961
      Abstract: We describe a vision for a national-scale heavy mineral (HM) map generated through automated mineralogical identification and quantification of HMs contained in floodplain sediments from large catchments covering most of Australia. The composition of the sediments reflects the dominant rock types in each catchment, with the generally resistant HMs largely preserving the mineralogical fingerprint of their host protoliths through the weathering-transport-deposition cycle. Heavy mineral presence/absence, absolute and relative abundance, and co-occurrence are metrics useful to map, discover and interpret catchment lithotype(s), geodynamic setting, magmatism, metamorphic grade, alteration and/or mineralization. Underpinning this vision is a pilot project, focusing on a subset from the national sediment sample archive, which is used to demonstrate the feasibility of the larger, national-scale project. We preview a bespoke, cloud-based mineral network analysis (MNA) tool to visualize, explore and discover relationships between HMs as well as between them and geological settings or mineral deposits. We envisage that the Heavy Mineral Map of Australia and MNA tool will contribute significantly to mineral prospectivity analysis and modeling, particularly for technology critical elements and their host minerals, which are central to the global economy transitioning to a more sustainable, lower carbon energy model.
      Citation: Minerals
      PubDate: 2022-07-28
      DOI: 10.3390/min12080961
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 962: Petrogenesis of the Early Cretaceous
           Zhouguan Granodiorite in Jiaodong Peninsula: Evidence from Mineralogy,
           Geochemistry, Geochronology, and Sr-Nd Isotopes

    • Authors: Naijie Chi, Zuozhen Han, Ruicong Tian, Chuan’e Liu, Wei Shan, Yuqiang Xiong, Zengsheng Li, Yufeng Xie, Min Li, Xiufeng Wang
      First page: 962
      Abstract: The Jiaodong Peninsula is the most important gold mineralization area in China, and the formation of gold deposits is closely related to granitoids. The isotopic ages of the Early Cretaceous granodiorites in the northwestern Jiaodong Peninsula are concentrated in the range of 111~123 Ma, and are coeval with the formation of the gold deposits in the area. However, the studies on the geotectonic settings of the granodiorites, especially their petrogenesis and relationship with gold deposits in the northwestern Jiaodong Peninsula, are scarce. Based on field and petrographic observations, geochemistry, EPMA analysis, zircon U-Pb chronology, and Sr-Nd isotopes of the Early Cretaceous Zhouguan granodiorite in the Jiaodong area, the formation age of Zhouguan granodiorite is determined as 115 Ma ± 0.77 Ma; the analysis of EPMA shows that biotite is mainly composed of Fe-biotite and Mg-biotite, with its MgO content ranging from 9.797% to 11.635%. The crystallization temperature of biotite is in the range of 500 °C~625 °C and the emplacement depth of the rock mass is 3.98~8.71 km. The amphibole in the mass mainly includes magnesiohornblende, pargasite, and magnesiosadanagaite; among them, the former two are of crustal origin, while magnesiosadanagaite is of mantle origin. The crystallization pressure and depth of the former two are in the range of 0.75~3.02 kbar and 2.81~11.4 km, respectively, while the crystallization pressure and depth for the latter is 4.64 kbar and 17.53 km, respectively. The (87Sr/86Sr) values range from 0.710424 to 0.711074 and the (143Nd/144Nd) values range from 0.511530 to 0.511808. The parental magma of the Zhouguan granodiorite is highly oxidized with high-water content that is favorable for Au enrichment. Combined with the Nb-Y and Yb-Ta diagrams, a model describing the formation of Zhouguan granodiorite is proposed.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080962
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 963: Study on the Phase Transition from Quartz to
           Coesite under High Temperature and High Pressure

    • Authors: Dongsheng Ren
      First page: 963
      Abstract: Quartz is an important component of the Earth. In this study, experiments were conducted at temperatures between 600 to 700 °C, confining pressures between 1.5 and 1.8 GPa, and differential stress conditions. It was found that coesite production is closely related to differential stress, reaction time, and reaction temperature, with coesite formation being a multifactorial coupling process.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080963
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 964: Ore Genesis of the Toudaochuan Gold Deposit
           in Central Jilin Province, NE China: Constraints from Fluid Inclusions and
           C–H–O–S–Pb Isotopes

    • Authors: Jingmou Li, Yunsheng Ren, Qun Yang, Xinhao Sun
      First page: 964
      Abstract: The Toudaochuan gold deposit is a recently discovered lode gold deposit in Central Jilin Province. Gold ore bodies are dominantly controlled by NE-trending fault. The major hydrothermal period can be further divided into the quartz–pyrite stage (stage I), quartz–gold–polymetallic sulfides stage (stage II, major gold mineralization stage), and quartz–carbonate stage (stage III). Primary fluid inclusions (FIs) identified in quartz at different hydrothermal stages include liquid-rich aqueous FIs (L-type), CO2 FIs (C-type, including CO2-bearing C1-type FIs and CO2-rich C2-type FIs), and minor vapor-rich aqueous FIs (V-type). Microthermometry studies on different fluid inclusions indicate that the original ore-forming fluids belonged to the CO2–H2O–NaCl system characterized by a moderate–low temperature and low salinity in stages I and II, and they finally evolved into a H2O–NaCl system characterized by low temperature and low salinity in stage III. Fluid immiscibility is considered to be the key ore-forming mechanism. The initial ore-forming fluid was originated from magmatic water and was mixed with meteoric water in the later stage. The S and Pb isotope data suggest that the ore metal materials were derived from the mixed source of mantle and crust. Based on all the above data, therefore, it can be proposed that the Toudaochuan gold deposit is a mesothermal magmatic–hydrothermal gold deposit.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080964
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 965: Research on the Stability Mechanism of the
           Surrounding Rock of Gob-Side Entry Retaining by Roof Cutting in Dianping
           Coal Mine

    • Authors: Zi-min Ma, Yan-jun Wang, Long Huang, Hao-hao Wang, Jiong Wang, Zhao-xuan Wang, Yan-long Wang, Bo-tao Wang
      First page: 965
      Abstract: According to the movement characteristics of the surrounding rock of the gob-side entry retaining by roof cutting (GERRC), the structural evolution mechanism and stability control countermeasures are studied in this paper. Taking the roof cutting and bulking as the core point, the movement process of the surrounding rock of GERRC is divided into five stages: roof cutting, dynamic pressure support, gangue bulking, double arch roadway support, and roadway formation. Combined with mechanical analysis, the roof pressure of the mechanical model of the short-arm beam formed by roof cutting is calculated, and the roof breaking criterion is obtained, which provides a basis for roof control design and reasonable support strength calculation. A structural model of double-arch roadway protection under the action of hydrostatic roof cutting and gangue bulking was established, and the mechanism of roadway formation stability was studied. The gob-side bulking gangue and short-arm beam are formed by roof cutting, and the solid coal seam forms the immediate balance arch, the bulking gangue in goaf, articulated transfer rock beam, and solid coal seam forms the main balance arch. The two together are called double balance arch. With the support of the double-balanced arch on the overlying rock strata, the roadway below is located in the low-stress zone, which ensures the stability of the roadway surrounding rock. Through mechanical analysis and field observation, the law of bulking and deformation and mechanical characteristics of gob-side gangue in the above structural model are analyzed, and the reasonableness of the structural model of the double-arch guard lane is verified through numerical simulation of the cut top into lanes. and the reasonableness of the structural model of double-arch protection in GERRC is verified by using numerical simulation. In this paper, a mechanical double-arch model has been developed that allows us to understand the mechanism of stress transfer of roof cutting roadway from the perspective of a dynamic balance of roadway surrounding rock and overlying rock strata, helping us to specify efficient support countermeasures.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080965
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 966: Secondary Minerals from Minothem
           Environments in Fragnè Mine (Turin, Italy): Preliminary Results

    • Authors: Yuri Galliano, Cristina Carbone, Valentina Balestra, Donato Belmonte, Jo De Waele
      First page: 966
      Abstract: The Fragnè mine, located in the Lanzo valley in the municipality of Chialamberto (Turin, Piedmont Region), represented the most important regional site for Fe–Cu sulfide exploitation over a period of more than eighty years (1884–1965). The entire mining area is part of a structural complex in the Lower Piedmont Unit of the Western Alps, characterized by the presence of amphibolite, metabasite (“prasinite”), and metagabbroic rocks. In particular, the pyrite ore deposit occurs as massive mineralizations within interlayered metabasites and amphibolites. In this work, we describe secondary minerals and morphologies of minothems from the Fragnè mine that are found only in abandoned underground works, such as soda straws, normal and jelly stalactites and stalagmites, jellystones, columns, crusts, blisters, war-clubs, and hair, characterized by different mineralogical associations. All minothems were characterized by minerals formed during acid mine drainage (AMD) processes. Blisters are composed only of schwertmannite, war-clubs by schwertmannite, and goethite with low crystallinity and hair by epsomite and hexahydrite minerals. Jelly stalactites and stalagmites are characterized by schwertmannite often in association with bacteria, while solid stalactites and stalagmites are characterized by jarosite and goethite. The results indicate that the mineralogical transformation from schwertmannite to goethite observed in some minothems is probably due to aging processes of schwertmannite or local pH variations due to bacterial activity. On the basis of these results, we hypothesize that all the jelly samples, in association with strong bacterial activity, are slowly transformed into more solid goethite, and are thus precursors of goethite stalactites.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080966
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 967: Geochronology, Geochemistry, and Lu-Hf
           Isotopic Compositions of Monzogranite Intrusion from the Chang’anpu
           Mo Deposit, NE China: Implications for Tectonic Setting and Mineralization
           

    • Authors: Jian Zhang, Yanchen Yang, Shijiong Han, Wukeyila Wutiepu
      First page: 967
      Abstract: The Chang’anpu Molybdenum deposit occurs in the monzogranite intrusions in the Lesser Khingan Mountains-Zhangguangcai Mountains metallogenic belt. Previous work focused on the study of deposits, including geological characteristics, mineralization time, S-Pb isotope, etc. However, systematic petrogeochemical study of monzogranite intrusion and comparative analysis with other porphyry deposits in the region are lacking. Three monzogranite dating samples yield LA-ICP-MS zircon weighted mean 206Pb/238U ages of 174.7 ± 1.3 Ma, 174.9 ± 1.4 Ma, and 174.3 ± 1.8 Ma, respectively, indicating that the magmatism occurred in the middle Jurassic of Mesozoic. The 14 monzogranite samples show alkali rich and relatively high silica content (up to 84.39%) with the differentiation index (DI) ranges from 86 to 96, showing that monzogranite have been subjected to fractional crystallization during its evolution; the depletion of Ba, Sr, P, Nb, Ti, and Eu also indicates that the rock has undergone crystallization fractionation, the monzogranite belong to the highly fractionated I-type. Positive εHf(t) values (6.72–8.85) and young TDM2 (551–673 Ma) of the monzogranite indicate that the formation of Chang’anpu monzogranite intrusion is related to the partial melting of juvenile lower crust, originated from the Mesoproterozoic depleted mantle. The magmatism and related Mo mineralization in the Chang’anpu deposit occurred in an active continental margin setting associated with westward subduction of the Paleo-Pacific plate beneath the Eurasian plate.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080967
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 968: Two Epochs of Mineralization of Orogenic
           Gold Deposit in the East Kunlun Orogenic Belt: Constraints from Monazite
           U–Pb Age, In Situ Sulfide Trace Elements and Sulfur Isotopes in
           Wulonggou Gold Field

    • Authors: Zheming Zhang, Qingdong Zeng, Tong Pan, Hailin Xie, Zhanhao Wei, Hongrui Fan, Jinjian Wu, Kuifeng Yang, Xinghui Li, Gaizhong Liang
      First page: 968
      Abstract: The Wulonggou Gold Field is one of the giant gold fields in the East Kunlun Orogenic Belt, northwestern China. Previous studies mainly focused on elementary mineral isotopic studies, fluid inclusions, and geological features in the Wulonggou Gold Field. In this study, we report some research on the precise age and the specific ore-forming process of the WGF: the hydrothermal monazite U–Pb ages; the way of gold precipitation; the composition, evolution, and source of ore-forming fluids of the Wulonggou Gold Field. Finally, we demonstrate a link between two-stage hydrothermal events and sequential episodes of crust-derived magmas, with implications for gold metallogeny in the East Kunlun Orogenic Belt. There are four hydrothermal stages that are recognized: a quartz–pyrite stage (stage 1), a quartz–pyrite–arsenopyrite–chalcopyrite stage (stage 2), a quartz–galena–sphalerite–pyrite stage (stage 3) and a quartz–stibnite–carbonate stage (stage 4). The monazite U–Pb ages of the Huanglonggou and Hongqigou deposits in the Wulonggou Gold Field were 422.2 ± 2.4 Ma and 236.7 ± 3.7 Ma, respectively, which support the opinion of two epochs of mineralization. Stages 1 and 2 are the main gold mineralization stages, wherein Au and As have a close genetic relationship. The Hongqigou and Huanglonggou deposits seem to have been formed in different metallogenic events due to the contrast on the trace element compositions in pyrite. The sources of the ore-forming materials and fluids of the Hongqigou and Huanglonggou deposits show apparent characteristics of orogenic gold deposit, and the magmatic events during Paleozoic and Mesozoic have an important contribution to the formation of the gold deposits. The gold deposits in the Wulonggou Gold Field can be interpreted as an orogenic gold system related to two-epoch tectonic–magmatic events.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080968
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 969: Application of Raman Spectroscopy for
           Studying Shocked Zircon from Terrestrial and Lunar Impactites: A
           Systematic Review

    • Authors: Dmitry A. Zamyatin
      First page: 969
      Abstract: A highly resistant mineral, zircon is capable of preserving information about impact processes. The present review paper is aimed at determining the extent to which Raman spectroscopy can be applied to studying shocked zircons from impactites to identify issues and gaps in the usage of Raman spectroscopy, both in order to highlight recent achievements, and to identify the most effective applications. Method: Following PRISMA guidelines, the review is based on peer-reviewed papers indexed in Google Scholar, Scopus and Web of Science databases up to 5 April 2022. Inclusion criteria: application of Raman spectroscopy to the study of shocked zircon from terrestrial and lunar impactites. Results: A total of 25 research papers were selected. Of these, 18 publications studied terrestrial impact craters, while 7 publications focused on lunar breccia samples. Nineteen of the studies were focused on the acquisition of new data on geological structures, while six examined zircon microstructures, their textural and spectroscopic features. Conclusions: The application of Raman spectroscopy to impactite zircons is linked with its application to zircon grains of various terrestrial rocks and the progress of the electron backscatter diffraction (EBSD) technique in the early 2000s. Raman spectroscopy was concluded to be most effective when applied to examining the degree of damage, as well as identifying phases and misorientation in zircon.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080969
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 970: Flotation Separation of Covellite and
           Enargite via Oxidation Treatment

    • Authors: Yonggang Gan, Rongdong Deng, Quanjun Liu
      First page: 970
      Abstract: The flotation separation of enargite from copper sulfide minerals is difficult owing to the similar floatability and reagent adsorption characteristics of these minerals. In this study, the effect of oxidation treatment using NaClO flow with FeCl3 on the flotation separation of covellite and enargite was systematically investigated. Micro-flotation tests and contact angle measurements indicated that the addition of NaClO and FeCl3 increased the hydrophobicity difference between covellite and enargite. The bench-scale flotation test results show that the bulk copper concentrate could be separated into two products: a low-arsenic-containing (0.46%) and a high-arsenic-containing (5.18%) copper concentrate. X-ray photoelectron spectroscopy and scanning electron microscopy revealed that the oxidization treatment of NaClO caused the accumulation of oxides on the covellite surface, but not on the enargite surface. The varying precipitation of ferric hydroxide on the surfaces of covellite and enargite further exacerbated the difference in the hydrophilicity of these minerals. Thus, a possible method for separating enargite from covellite was obtained through oxidation treatment using NaClO and FeCl3.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080970
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 971: Paleoproterozoic Mineralization of the
           Lijiapuzi Gold Deposit in the Liaodong Peninsula, NE China: Constraints
           from 40Ar-39Ar Age, S-Pb Isotopes, and In Situ Analyses

    • Authors: Yan Zhao, Peng Zhang, Hongzhi Yang, Linlin Kou, Zhongwei Bi, Zhongzhu Yang, Jiang Chen
      First page: 971
      Abstract: A Paleoproterozoic 40Ar/39Ar age, interpreted as the gold metallogenic epoch of the Lijiapuzi deposit in NE China, is reported in this paper. The ore body of this deposit is hosted in the marbles and schists of the Paleoproterozoic Dashiqiao Formation and exhibits parallel development to the foliation of the country rocks. Coexisting auriferous pyrite and tremolite can be observed both in the field and under a microscope, revealing the presence of hydrothermal activity in the deposit. The δ34S composition of the auriferous pyrite varies from +8‰ to +12.3‰, indicating a sedimentary origin. The auriferous pyrite and host marble have similar Pb isotopic ratios, indicating the contribution of Paleoproterozoic sediments to gold mineralization. Furthermore, in situ S and trace element analyses of the auriferous pyrite reveal that the main gold mineralization stage was Py2, which coexists with radial tremolite. 40Ar/39Ar dating of these tremolite samples yields a plateau age of ~1851.23 Ma, with similar isochronal and inverse isochronal ages. The Paleoproterozoic gold metallogenesis, together with the contemporary Pb-Zn, boron, graphite, and magnetite mineralization, constitute an important mineralogenetic series during the evolution of the Jiao-Liao-Ji orogeny in the Liaodong Peninsula.
      Citation: Minerals
      PubDate: 2022-07-29
      DOI: 10.3390/min12080971
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 972: Investigation of the Effect of Electrolytes
           on the Breakaway of Air Bubbles at an Underwater Capillary Using
           High-Speed Cinematography and Passive Acoustic Techniques

    • Authors: Pengbo Chu, Ronghao Li, Mark Lepage, Kristian Waters
      First page: 972
      Abstract: Saline water froth flotation has received increasing attention in recent years due to sustainability-related concerns. Although the presence of electrolytes in these flotation systems is known to produce the desired bubble swarms, i.e., a macroscopic observation, the fundamental mechanism through which the solutes produce such an effect at the microscopic level remains obscure. For example, there is no agreed mechanism (i.e., break-up or coalescence—two major bubble formation mechanisms) of how the effect is achieved. Not only is understanding the impact of electrolytes on the bubble formation mechanisms a fundamental question, but it can also provide insight into the design of more efficient air dispersing mechanisms for saline flotation systems. Previous studies have demonstrated that electrolytes can inhibit coalescence, but their potential impact on break-up remains vague, which is the focus of this study. It is hypothesized that electrolytes have an impact on break-up, and by isolating break-up from coalescence, the effects of electrolytes on break-up can be revealed. A break-up-only bubble formation system was built. Under this condition, any impact from the electrolytes on the produced bubble can be attributed to an impact on break-up. High-speed cinematography and a passive acoustic technique were employed to capture the bubble size, acoustic frequency, and damping ratio during the break-up process. Under the quasi-static condition, an increase in the electrolyte concentration increased the bubble size produced via break-up, contradicting the common observations made for bubble swarms. The break-up imparted an initial capillary wave to the bubble surface, which is correlated with the bending modulus of the air/water interface affected by the electrolytes. No direct correlation was observed between the acoustic damping ratio and that of the capillary wave, suggesting that the electrolytes affect the break-up via a different mechanism from that by surfactants.
      Citation: Minerals
      PubDate: 2022-07-30
      DOI: 10.3390/min12080972
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 973: Study on the Basic Characteristics of Iron
           Ore Powder with Different Particle Sizes

    • Authors: Zezheng Li, Yifan Li, Yuanshuai Duan, Aimin Yang, Zhenghan Xu, Jianming Zhi
      First page: 973
      Abstract: In order to study in depth the differences in basic characteristics between iron ore fines commonly used by a steel company, and guide the sintering performance plant to choose the best ore allocation method, experimental studies on the basic characteristics of seven iron ore powders of three sizes were carried out using micro-sintering equipment, mainly including assimilation properties, liquid phase fluidity, and bonding phase strength. The results of the research showed that with the increase of the iron ore powder particle size, the assimilation of the seven iron ore powders showed an overall decreasing trend, deteriorating fluidity and decreasing bonding phase strength. Among them, the overall fluidity of iron ore powder A was poor, and the fluidity of iron ore powder B varied greatly between different particle grades, and the fluidity of iron ore powder C was more balanced and its bonding phase strength was high, while the overall bonding phase strength of iron ore powders B and E was low. The results of the study provide a theoretical basis for optimal ore allocation in sintering plants.
      Citation: Minerals
      PubDate: 2022-07-30
      DOI: 10.3390/min12080973
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 974: Origin of Podiform Chromitites in the Sebuku
           Island Ophiolite (South Kalimantan, Indonesia): Constraints from Chromite
           Composition and PGE Mineralogy

    • Authors: Arifudin Idrus, Federica Zaccarini, Giorgio Garuti, I Gusti Ngurah Kusuma Wijaya, Yoseph Calasanctius Amita Swamidharma, Christoph Bauer
      First page: 974
      Abstract: The presence of PGM associated with the podiform chromitites in the Jurassic–Cretaceous ophiolite of Sebuku Island (South Kalimantan, Indonesia) is reported for the first time. Two types of chromitite have been recognized; one with high-Cr composition (Cr/(Cr + Al) > 0.7) occurs in the deep mantle, the other, high-Al (Cr/(Cr + Al) < 0.6), is located close to the Moho transition zone. The TiO2-Al2O3 relations indicate affinity to IAT and MORB, for the high-Cr and high-Al chromitites, respectively. However, both are believed to have formed by mantle/melt reaction and differentiation of a magma characterized by an initial IAT composition related to an SSZ. Primary magmatic inclusions (<10 μm) of laurite characterized by Ru/Os chondritic ratio are the only PGM found in the high-Cr chromitites, indicating crystallization from undifferentiated magma, at low fS2 in the mantle. In contrast, the high-Al to chondrite, suggesting the increase of fS2 in the evolved melt. Besides laurite, the high-Al chromitite contains a complex assemblage of secondary PGM (Pt-Fe, garutiite, iridium, ruthenium–magnetite aggregates, zaccariniite and unnamed Ru and Mn oxides). These secondary PGM have an irregular shape and occur exclusively in the chlorite matrix sometimes associated with Mn-Ni-Fe-Cr hydroxides. They are interpreted to have formed by desulfuration of primary interstitial PGM sulfides or to have precipitated from secondary fluids during low T alteration. The relative abundance of PPGE in the high-Al chromitite is interpreted as a result of PGE fractionation during differentiation of the parent melt of the chromitites.
      Citation: Minerals
      PubDate: 2022-07-30
      DOI: 10.3390/min12080974
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 975: High-Resolution Transmission Electron
           Microscopy Study of a Powder River Basin Coal-Derived Fly Ash

    • Authors: James C. Hower, Debora Berti, Christopher R. Winkler, Dali Qian, Nicolas J. Briot
      First page: 975
      Abstract: Examination of a fly ash derived from the combustion of a low-S, subbituminous Powder River Basin coal by Scanning Electron Microscopy (SEM) and High-resolution Transmission Electron Microscopy (HRTEM), both supplemented by Energy-dispersive X-ray spectroscopy (EDS), showed that the fly ashes were dominated by amorphous phases, Ca-rich plagioclase feldspars, Mg-rich phases, complex Ca-Mg-Al-Si-Ti-Fe grains, and trace amounts of REE-rich particles. Many of the particles were rimmed by a Ca-S, possibly a sulfate. HRTEM-EDS examination of a REE-rich particle proved it to be a mix of light- and heavy-rare earth minerals mixed with amorphous phases.
      Citation: Minerals
      PubDate: 2022-07-30
      DOI: 10.3390/min12080975
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 976: Uranium in Source Rocks: Role of Redox
           Conditions and Correlation with Productivity in the Example of the
           Bazhenov Formation

    • Authors: Nadezhda Khaustova, Elena Kozlova, Polina Maglevannaia, Andrey Voropaev, Evgenia Leushina, Mikhail Spasennykh
      First page: 976
      Abstract: The paper reports comprehensive analysis of different factors affecting uranium content in oil source rocks and the relationship between uranium content and productivity of source rocks. The analysis of data for 13 wells of the Bazhenov Formation (Western Siberia, Russia) was carried out. The uranium content of the rocks was measured by gamma-ray spectrometry on core samples. In order to analyze factors affecting uranium accumulation in source rocks, we studied content and characteristics of organic matter (Rock-Eval pyrolysis), and also mineral, element, and isotope composition of rocks. We have shown that redox conditions at the sedimentation stage have the most pronounced impact on the uranium accumulation in the rocks of the Bazhenov Formation. It was also shown that productive intervals, containing increased amounts of mobile hydrocarbons, are characterized by low (<20 ppm) concentration of uranium. However, the intervals, containing phosphorite minerals may show better reservoir properties and oil saturation at higher concentration of uranium. The analysis of correlations and relationships between uranium content and Rock-Eval pyrolysis indexes (oil saturation index and productivity index) enabled formulation of criteria for selection of oil-saturated intervals using the spectral gamma and pulsed neutron spectroscopy log data.
      Citation: Minerals
      PubDate: 2022-07-31
      DOI: 10.3390/min12080976
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 977: Comparative Analysis of Theoretical,
           Observational, and Modeled Deformation of Ground Subsidence: The Case of
           the Alhada Pb-Zn Mine

    • Authors: Liming He, Jiuyang Cai, Wang Cao, Yachun Mao, Honglei Liu, Kai Guan, Yabo Zhou, Yumeng Wang, Jiashuai Kang, Xingjie Wang, Panke Pei
      First page: 977
      Abstract: In this study, the probability integral method, Synthetic Aperture Radar Interferometry (InSAR), and the Okada dislocation model were collaboratively used to analyze deformation in the Alhada Pb-Zn mine. The predicted deformation values of the subsidence centers in three subsidence areas were 107 mm, 120 mm, and 83 mm, respectively, as predicted using the probability integral method. The coherent scatterer InSAR technique was used to analyze the time-series deformation of the mining area, and the same subsidence center locations and similar deformation values were observed. The Okada dislocation model was used to invert the optimal parameters of the underground-mining ore body causing the surface subsidence, indicating that the surface subsidence is mainly caused by the mining of ore bodies in the 888 and 848 middle sections. We further simulated ground deformation using the multi-source Okada model. The results showed that the predicted and modeled deformations are highly correlated with the observed deformation. Through the analysis and comparison of the InSAR results, it was concluded that the three subsidence areas do not threaten the stability of the main buildings in the mining area. Using theoretical, observational, and modeling methods, the development and evolution of the subsidence area in mines can be established, which could provide basic data for subsidence control work and guarantee mine production safety.
      Citation: Minerals
      PubDate: 2022-07-31
      DOI: 10.3390/min12080977
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 978: Ore Genesis of the Dongping Gold Deposit in
           the Northern Margin of North China Craton: Constraints from In-Situ Major,
           Trace Elemental Analysis of Magnetite and Pyrite

    • Authors: Chengyang Wang, Jiajia Yu, Yunsheng Ren, Junkang Zhao, Zhenjun Sun
      First page: 978
      Abstract: The Zhangxuan district in North China, also known as Northwestern Hebei “Golden Triangle,” develops many intrusion-hosted lode-gold deposits. The Dongping gold deposit in the Zhangxuan district is well known for its unique hosting of rocks and ore mineral assemblages. Magnetite and pyrite are common minerals that widely exist in ores of the Dongping deposit. To get a better understanding of the evolution of the ore-forming fluids responsible for mineralization, we report on an integrated study on the electron microprobe analysis (EMPA) and laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) analysis of magnetite and pyrite from the deposit. The major results are as follows: The magnetite grains from the Dongping deposit show a variable content of major and trace elements such as Ti, Al, Si, Fe, Mn, Cr, Na, V, and Co, and the majority of the magnetite contain low Ti contents, revealing potential properties of hydrothermal magnetite. The flat time-resolved signals of LA-ICP-MS imply that the majority of trace elements in magnetite exist in the form of isomorphism, except for some incompatible trace elements. Magnetites from the Dongping deposit have compositional characteristics of hydrothermal origins, and the genetic discriminant diagrams of Ti–V, Ti–Ni/Cr or (Ca + Al + Mn)–(Ti + V) show that they may be originated from magma differentiated hydrothermal solutions. Co, Ni in pyrite from Dongping mainly enter the lattice via isomorphism, and Cu, Zn, Ag, W, Sn, Au, Pb, and Bi are partitioned into pyrite as micro/nano- mineral inclusions. The Co, Ni content, and the Ni/Co ratios, indicated that the temperature of the ore-forming fluids has decreased from Py-1 to Py-2, and the enrichment of Au in Py-2 may be related to the cooling and boiling of the fluids.
      Citation: Minerals
      PubDate: 2022-07-31
      DOI: 10.3390/min12080978
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 979: Characteristics and Genesis of Alkaline
           Lacustrine Tight Oil Reservoirs in the Permian Fengcheng Formation in the
           Mahu Sag, Junggar Basin, NW China

    • Authors: Yong Tang, Zhengxiang Lv, Wenjun He, Yuanhua Qing, Xiuzhang Song, Qinming Cao, Yongxin Qian, Tao Zhu, Na Li, Xiang Li
      First page: 979
      Abstract: Through optical microscopic examination, scanning electron microscope analysis, whole rock X-ray diffraction analysis, X-ray fluorescence spectrum analysis, carbon and oxygen isotope analysis, and temperature measurement of fluid inclusions, the characteristics and formation mechanism of the alkaline lacustrine tight oil reservoirs of the Permian Fengcheng Formation in the Mahu Sag of the Junggar Basin have been systematically studied, and a genetic model has been proposed. Porosity of tight oil reservoirs of the Fengcheng Formation in the Mahu Sag is mostly less than 4%, with permeability mostly less than 0.1 mD. The lithology of the Fengcheng Formation in the Mahu Sag is mainly tuff, and the authigenic minerals mainly consist of feldspar, quartz, dolomite, and salt minerals (e.g., shortite, trona). The authigenic feldspar and quartz of the Fengcheng Formation in the Mahu Sag mainly originate from devitrification of volcanic glass in pyroclastic rocks. Reservoir space is dominated by dissolution pores of feldspar and salt minerals, followed by intercrystalline pores among feldspar, quartz, and other minerals formed by devitrification. Fractures are mainly comprised of shrinkage fractures, structural fractures, and bedding seans. The Permian Fengcheng Formation was mainly formed in an alkaline lake in the Mahu Sag, and the alkaline lacustrine sedimentary setting plays a decisive role in the formation of the tight oil reservoirs of the Fengcheng Formation. Volcanic glass in the tight oil reservoirs was generally devitrified within the alkaline lacustrine diagenetic fluid in the early diagenetic stage, and the devitrified micropores become an important reservoir space. Feldspars and salt minerals were mainly dissolved by acidic fluids generated by burial thermal evolution of the alkaline lacustrine source rocks of the Fengcheng Formation in the Mahu Sag, which produces the most developed dissolution pores in the tight oil reservoir. The abnormal high pressure formed by the early hydrocarbon generation and expulsion of the alkaline lacustrine source rocks in the Fengcheng Formation is one of the main reasons for porosity preservation. In the alkaline lake sedimentary environment of the Fengcheng Formation, widespread dolomitization and precipitation of a large number of salt minerals in the early diagenetic stage resisted partial compaction, which not only effectively protected early porosity, but also provided material conditions for dissolution porosity enhancement.
      Citation: Minerals
      PubDate: 2022-07-31
      DOI: 10.3390/min12080979
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 980: Pascoite Minerals and Potential Application
           of NMR Spectroscopy

    • Authors: Craig C. McLauchlan, Beth Trent-Ringler, Debbie C. Crans
      First page: 980
      Abstract: The 20 minerals encompassing the pascoite family of decavanadate isopolyanion-containing [V10O28]6− minerals include a few minerals, such as rakovanite, that have been described as containing a protonated decavanadate anion. Rakovanite was originally assigned the formula Na3[H3V10O28]•15H2O and now is redefined with an ideal formula (NH4)3Na3[V10O28]•12H2O. Nuclear magnetic resonance (NMR) and particularly 51V NMR spectroscopy is an informative method used to describe the protonation state and speciation in both solid and solution states of materials in the chemical and life sciences. However, 51V NMR spectroscopy has not yet been used experimentally to distinguish the protonation state of the decavanadate ion of leaching solutions and thus contributing to the discussion regarding the controversial protonation states of decavanadate ions in gunterite, rakovanite, and nashite. In contrast, the morphology and crystal structure for apatites, vanadinite, pyromorphite, and mimetite was related to 207Pb NMR chemical shifts, assisting in describing the local environments of these minerals. NMR spectroscopy could be a useful method if used in the future for decavanadate-containing minerals. Currently, partial reduction of two Pascoite minerals (caseyite and nashite) is proposed and accordingly could now effectively be investigated using a different magnetic resonance technique, EPR spectroscopy.
      Citation: Minerals
      PubDate: 2022-08-01
      DOI: 10.3390/min12080980
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 981: Rare Element Enrichment in Lithium Pegmatite
           Exomorphic Halos and Implications for Exploration: Evidence from the
           Leinster Albite-Spodumene Pegmatite Belt, Southeast Ireland

    • Authors: Renata Barros, David Kaeter, Julian F. Menuge, Thomas Fegan, John Harrop
      First page: 981
      Abstract: Pegmatitic deposits of critical metals (e.g., Li, Ta, Be) are becoming increasingly significant, with growing interest in understanding metal enrichment processes and potential vectors to aid the discovery of new resources. In southeast Ireland, the Leinster pegmatite belt comprises several largely concealed Li-Cs-Ta albite-spodumene-type pegmatites. We carried out detailed mineralogical characterization and whole-rock geochemical analyses of six drill cores intersecting pegmatite bodies and their country rocks. Exomorphic halos 2–6 m thick, enriched in Li, Rb, Be, B, Cs, Sn and Ta, are identified in both mica schists and granitic rocks adjacent to spodumene pegmatites. Metasomatism in wall rocks visible to the naked eye is restricted to a few tens of centimeters, suggesting country rock permeability plays a key role in the dispersion of these fluids. We propose that halos result from the discharge of rare element-rich residual fluids exsolved near the end of pegmatite crystallization. Halo geochemistry reflects the internal evolution of the crystallizing pegmatite system, with residual fluid rich in incompatible elements accumulated by geochemical fractionation (Be, B, Cs, Sn, Ta) and by auto-metasomatic resorption of spodumene and K-feldspar (Li, Rb). The possibility of identifying rare-element enrichment trends by analysis of bedrock, stream sediments and soils brings opportunities for mineral exploration strategies in Ireland and for similar albite-spodumene pegmatites worldwide.
      Citation: Minerals
      PubDate: 2022-08-01
      DOI: 10.3390/min12080981
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 982: Characterization of Atmospheric Deposition
           as the Only Mineral Matter Input to Ombrotrophic Bog

    • Authors: Valentina Pezdir, Martin Gaberšek, Mateja Gosar
      First page: 982
      Abstract: Ombrotrophic peatlands contain a very small percentage of mineral matter that they receive exclusively from atmospheric deposition. Mineral matter deposited on the Šijec bog was characterized using scanning electron microscopy coupled with energy dispersive spectroscopy (SEM/EDS). We collected solid atmospheric deposition from snow, rainwater, and using passive samplers. Samples were collected at average atmospheric conditions and after two dust events. Size, morphology, and chemical composition of individual particles were determined. We distinguished four main particle groups: silicates, carbonates, organic particles, and Fe-oxyhydroxides. Silicate particles are further divided into quartz and aluminosilicates. Proportions of these groups vary between samples and between sample types. In all samples, silicate particles predominate. Samples affected by dust events are richer in solid particles. This is well observed in passive deposition samples. Carbonates and organic particles represent smaller fractions and are probably of local origin. Iron-oxyhydroxides make up a smaller, but significant part of particles and are, according to their shape and chemical composition, of both geogenic and anthropogenic origin. Estimated quantity and percentage of main groups vary throughout the year and are highly dependent on weather conditions. Dust events represent periods of increased deposition and contribute significantly to mineral matter input to peatlands.
      Citation: Minerals
      PubDate: 2022-08-02
      DOI: 10.3390/min12080982
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 983: Authigenic Gypsum Precipitation in the ARAON
           Mounds, East Siberian Sea

    • Authors: Hyo Jin Koo, Jeong Kyu Jang, Dong Hun Lee, Hyen Goo Cho
      First page: 983
      Abstract: Authigenic gypsum has been observed in marine methane hydrate-bearing sediments throughout the last decade. However, changes in mineral composition and gypsum precipitation in methane emission environments have not yet been reported in the Arctic. Expeditions aboard R/V ARAON revealed several mound structures described as active seeps, which were given the name ARAON Mounds (AMs). Core sediments from the AMs provide an excellent opportunity to research authigenic mineral production in the Arctic methane environment. We identified sedimentary units and investigated the mineral composition of gravity cores from the AMs and a background site. The background core ARA09C-St13, obtained between the mound structures, contains five sedimentary units that extend from the Chukchi Rise to Chukchi Basin, and core sediments from the AMs contain three sedimentary units in the same order. The fundamental difference between AMs and the background site is the lack of dolomite and abundance of gypsum in AMs. This gypsum precipitated authigenically in situ based on its morphological features. Precipitation was more closely associated with the absence of dolomite than the location of the sulfate–methane transition according to the vertical distribution of gypsum in the sediment. Chemical weathering and gypsum overgrowth were confirmed on dolomite surfaces recovered from the AMs, suggesting that dolomite dissolution is the primary source of Ca for gypsum precipitation. Dissolution of biological carbonates and ion exclusion may provide Ca for gypsum precipitation, but this mechanism appears to be secondary, as gypsum is present only in sedimentary units containing dolomite. The main sources of sulfate were inferred to be oxidation of H2S and disproportionation of sulfide, as no sulfide other than gypsum was observed. Our findings reveal that gypsum precipitation linked to methane emission in the Arctic Ocean occurs mainly in dolomite-rich sediments, suggesting that gypsum is a suitable proxy for identifying methane hydrate zones in the Arctic Ocean.
      Citation: Minerals
      PubDate: 2022-08-02
      DOI: 10.3390/min12080983
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 984: The Effects of Soil Porosity and Mix Design
           of Volcanic Ash-Based Geopolymer on the Surface Strength of Highly Wind
           Erodible Soils

    • Authors: Hamid Reza Mohebbi, Akbar A. Javadi, Alireza Saeedi Azizkandi
      First page: 984
      Abstract: Surface stabilization of loose, non-cohesive, and fine soils has always been a challenging task for geotechnical engineers. These soils show meager mechanical behavior and are very vulnerable to wind erosion. Many attempts have been made to combat wind erosion of soils. These attempts, including a variety of soil surface amendment methods, have faced complications in terms of financial efficacy, reduced long-term behavior at elevated temperatures, and limitations in stabilization of a wide range of soil types. The application of geopolymers for surface stabilization is a novel approach, which has its own challenges in terms of selecting an appropriate precursor type, mix design, and preparation method. This study evaluated the challenges of using volcanic ash (VA)-based geopolymer, through the 1 Phase (1P) method for stabilization of two silty and sandy soils. A series of uniaxial compressive strength (UCS) and penetrometer tests were performed on cylindrical specimens and soil surface-treated samples, respectively, to evaluate the resistance of treated samples with different porosities. Moreover, the rheological behavior of geopolymer paste having various binder-to-activator ratios is discussed. The available rheological characteristics of geopolymer in this study fit well with the Bingham model. It was found that, despite the minimal crust thickness formed on the topsoil, significant surface resistance is acquired. The results show notable performance of the 1P method for surface amendment of both the silty and sandy soil samples.
      Citation: Minerals
      PubDate: 2022-08-02
      DOI: 10.3390/min12080984
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 985: Origin of Historical Ba-Rich Slags Related
           to Pb-Ag Production from Jihlava Ore District (Czech Republic)

    • Authors: Jaroslav Kapusta, Zdeněk Dolníček, Ondra Sracek, Karel Malý
      First page: 985
      Abstract: The aim of this study was to characterize historical slags which originated during silver production from the Jihlava ore district, Czech Republic. The area was among the head producers of silver within the Lands of the Czech Crown in 13th–14th centuries. The mined ores had complex composition, being formed mostly by pyrite, sphalerite, galena, chalcopyrite, and accessory silver-rich minerals such as silver-bearing tetrahedrite (freibergite) or pyrargyrite, with gangue represented by quartz and Mn-rich carbonates or baryte. Large volumes of slags with contrasting composition were generated during the Pb-Ag production. Altogether, two main types of slags were identified in the district. The first type is characterized by high BaO contents (up to 34.5 wt.%) and dominancy of glass, minor quartz, and accessory amounts of Ba-rich feldspar (up to 93 mol.% of Cls), metal-rich inclusions, Ba-Pb sulphates and only rare pyroxene, wollastonite and melilite. The composition of the second group belongs to fayalitic slags containing glass, Fe-rich olivine, accessory pyroxene, feldspar, quartz, and inclusions of various metallic phases. Fluxes were derived from gangue (quartz, carbonates, baryte) or local host rocks for both types of slag. The calculated viscosity indexes reflect (with minor exceptions) medium-to-high effectivity of metal separation. Smelting temperatures were estimated from a series of ternary plots; however, more reliable estimates for both types of slags were obtained only from experimental determination of melting temperature and calculations using bulk/glass compositions (~1100–1200 °C).
      Citation: Minerals
      PubDate: 2022-08-02
      DOI: 10.3390/min12080985
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 986: Prediction of the Mechanical Performance of
           Cemented Tailings Backfill Using Ultrasonic Pulse Velocity Measurement

    • Authors: Xichun Tian, Wenbin Xu
      First page: 986
      Abstract: Cemented tailings backfill (CTB), prepared by a mixture of tailings, binder, and water in a certain proportion, is widely applied to mines worldwide for ground support and tailings disposal. The prediction of the mechanical properties of CTB during the whole consolidation process is of great practical importance. The objective of this paper focuses on the investigation of the prediction of the mechanical performance of CTB based on the ultrasonic pulse velocity (UPV) method. The CTB samples prepared with different binder-to-water (b/w) ratios, as well as solid content were monitored by the UPV method during the curing age of 28 days. The evolution of dynamic shear modulus and dynamic elasticity modulus properties of CTB samples were studied by UPV monitoring. Meanwhile, uniaxial compressive strength (UCS) and microstructure tests were performed on CTB samples at curing times of 3, 7, and 28 days. The results showed that the UPV development follows a trend that increases fast at early curing ages and then becomes stable at the 10 d curing age. UPV and UCS increased with the increase in b/w, solid content, and curing age. From the results of microstructure tests, the increase in UPV is attributed to the low porosity and compact structure due to the increase in the b/w ratio and solid content. For the purpose of predicting the UCS of CTB utilizing UPV monitoring, the empirical equations for the relationship between UCS and UPV of CTB with variation b/w ratios and solid content were regression analyses. F-tests, as well as t-tests, were used to check the validity of the equations, which indicate that higher calculated values for CTB to predicted UCS by means of the UPV method. The main finding of this paper shows that the UPV monitoring method can be an effective way to predict the mechanical property of CTB in the field and is non-destructive and effective.
      Citation: Minerals
      PubDate: 2022-08-03
      DOI: 10.3390/min12080986
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 987: Sepiolite and Other Authigenic Mg-Clay
           Minerals Formation in Different Palustrine Environments (Madrid Basin,
           Spain)

    • Authors: Juan Emilio Herranz, Manuel Pozo
      First page: 987
      Abstract: Lithofacies belonging to mud-flat and palustrine deposits (lake margin) in the Miocene of the Madrid Basin (Spain) have been studied. Four lithofacies corresponding to mud flat (1 and 3) and palustrine (2 and 4) deposits have been differentiated. Units 1 and 3 consist mainly of mudstones and carbonates (calcretes and diolocretes). The clay fraction is dominated by trioctahedral smectite (up to 79%) with illite and kaolinite as minor components. The d(060) spacing value shows reflections at 1.52 and 1.50 Å indicating also the presence of dioctahedral phyllosilicates. Unit 2 consists predominantly of lutites (claystones), locally with carbonate and chert nodules. The clay fraction is dominated by sepiolite (up to 96%) with variable contents of smectite and subordinate illite. The d(060) spacing value shows reflections at 1.51 and 1.52 Å indicating trioctahedral clay minerals. Unit 4 consists mostly of carbonates (limestones) with mudstone and lutite inserts. The clay fraction shows different contents of sepiolite, palygorskite and dioctahedral smectite. The analysis of a selection of trace elements (Cr, Co, Th, La, Sc) has allowed us to determine the characteristics of the source area as dioritic, somewhat different from those of the nearby materials from the Batallones sector. Sepiolite shows FWHM values ranging between 0.68 and 1.10 (2θ), indicating “low crystallinity sepiolite”. Differences in the conditions of formation of magnesian smectite and palygorskite have been observed in the mud-flat and palustrine deposits. The formation of sepiolite mainly by neoformation in palustrine deposits with different hydrochemistry is remarkable, leading to differences in fibre size and crystallinity of the fibrous clay mineral. Authigenic transformation processes from previous Al-rich phases would be responsible for the formation of saponite and palygorskite in mud flat and palustrine environments, with different pH conditions.
      Citation: Minerals
      PubDate: 2022-08-03
      DOI: 10.3390/min12080987
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 988: Potential Toxicity of Natural Fibrous
           Zeolites: In Vitro Study Using Jurkat and HT22 Cell Lines

    • Authors: Michele Betti, Maria Gemma Nasoni, Francesca Luchetti, Matteo Giordani, Michele Mattioli
      First page: 988
      Abstract: An emerging problem for human health is the exposure to non-regulated mineral fibers with an asbestos-like crystal habit, particularly fibrous zeolites. This study aimed to determine if and how selected fibrous zeolites (erionite, mesolite, and thomsonite) induce toxicity effects on two different in vitro cellular models, the adherent murine hippocampal (HT22) and human immortalized T lymphocyte (Jurkat) cell lines. Before proceeding with the cellular tests, the three zeolite samples were investigated using scanning electron microscopy–energy-dispersive spectroscopy and X-ray powder diffraction techniques. The cells were treated with 0.1 µM and 1 µM of fibrous erionite, mesolite, and thomsonite for 12, 24, and 48 h. Results showed a cytotoxic effect of erionite in both cellular models and revealed different toxic behaviors of the mesolite and thomsonite fibers, suggesting other potential mechanisms of action. The outcome of this study would be a first step for further research on fine biochemical interactions of zeolite fibers with cells and future in vivo investigations.
      Citation: Minerals
      PubDate: 2022-08-03
      DOI: 10.3390/min12080988
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 989: Extreme Alteration of Chevkinite-(Ce) by
           Pb-CO2-Rich Fluids: Evidence from the White Tundra Pegmatite, Keivy
           Massif, Kola Peninsula

    • Authors: Ray Macdonald, Bogusław Bagiński, Marcin Stachowicz, Dmitry Zozulya, Jakub Kotowski, Petras Jokubauskas
      First page: 989
      Abstract: An unusual hydrothermal alteration scheme was presented for chevkinite-(Ce) from the White Tundra pegmatite (2656 ± 5 Ma), Keivy massif, Kola Peninsula. Pb-CO2-rich fluids initially removed REE and Y from the chevkinite-(Ce), with enrichment in Pb and U. PbO abundances reaching 17.35 wt%. Continued alteration resulted in the altered chevkinite-(Ce) being progressively transformed to a Pb-Ti-Fe-Si phase, which proved, upon EBSD analysis, to be almost totally amorphous. Pb enrichment was accompanied by a loss of LREE, especially La, relative to HREE, and the development of strong positive Ce anomalies. A notably U-rich aeschynite-(Y), with UO2 values ≤7.67 wt%, crystallized along with the chevkinite-(Ce). Aeschynite-(Y) with a lower UO2 value (3.91 wt%) and bastnäsite-(Ce) formed during alteration. The formation of bastnäsite-(Ce) rather than cerussite, which might have been expected in a high Pb-CO2 environment, is ascribed to the fluids being acidic.
      Citation: Minerals
      PubDate: 2022-08-03
      DOI: 10.3390/min12080989
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 990: Modes of Occurrence of Critical Metal
           Elements (Li, REEs and Other Critical Elements) in Low-Grade Bauxite from
           Southern Shanxi Province, China

    • Authors: Shangqing Zhang, Fenghua Zhao, Dongna Liu, Lei Zhao, Xiaohui Zhang, Junwei Lin, Haiyu Dong, Shuang Zhao, Xuefei Liu, Minjie Zan
      First page: 990
      Abstract: The low-grade bauxite in southern Shanxi Province, China is enriched in multiple critical metal elements, including Li, Ga, V, Se, and rare earth elements (REEs), which have reached the standard of comprehensive utilization as independent deposits or associated resources. Even more importantly, identifying the modes of occurrence of these critical elements is essential for designing technologies to extract critical metals from bauxite ores. This study used a combination of direct (X-ray diffraction, scanning electron microscopy–energy dispersive X-ray spectroscopy, and micro-X-ray fluorescence spectrometer), and indirect (size sieving method, float-sink experiment, and correlation analysis) methods to effectively reveal the distribution of critical elements in the different identified mineral phases. The results regarding the low-grade bauxite are as follows: Li was mainly hosted in cookeite as an independent mineral; Ga was mainly associated with diaspore; anatase is the main carrier mineral for V; REEs were present in the low-grade bauxite in multiples modes of occurrence, the most common of which were goyazite, and to a lesser extent, florencite; Se primarily occurs in sulfides. This study contributes to the development and utilization of these essential metal resources in bauxite by providing a useful reference.
      Citation: Minerals
      PubDate: 2022-08-04
      DOI: 10.3390/min12080990
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 991: Genesis of the Halılar
           Metasediment-Hosted Cu-Pb (±Zn) Mineralization, NW Turkey: Evidence
           from Mineralogy, Alteration, and Sulfur Isotope Geochemistry

    • Authors: Demet Kiran Yildirim
      First page: 991
      Abstract: This study contributes to our understanding of the evolution of Halılar Cu-Pb (±Zn) mineralization (NW Turkey) based on mineralogical and geochemical results and sulfur isotope data. The study area represents local Cu-Pb with some Zn brecciated-stockwork vein type mineralization along the NE–SW fault gouge zone at the lower boundary of the Sakarkaya and Düztarla granitoid rocks. Two main zones, consisting of sericite–quartz–chlorite ± kaolinite ± pyrite (i.e., zone-1) and calcite–epidote–albite ± chlorite ± sericite (i.e., zone-2), were observed within the central ore mineral zone at the mining site. Different mineralization assemblages were recorded; the main ore mineral contains chalcopyrite, galena, pyrite, and sphalerite within alteration zone-1, and the oxidation/supergene mineralization includes covellite and goethite. The mass balance calculations show that the samples of zone-1 show an increase in SiO2, Fe2O3, K2O, and LOI along with Ag, As, Cu, Mo, Pb, S, Sb, and Zn, reflecting high pyritization with sericitization and silicification. On the other hand, the samples from zone-2 are rich in CaO; Na2O; P2O5; TiO2; LOI; and carbon-reflecting calcite, epidote, and albite alterations. A uniform magmatic sulfur source of Halılar sulfides is suggested by their mean δ34S value of −1.62‰. Furthermore, the primary metal source is metasediments and intrusive Düztarla granitoid magmatism. These observations suggest that the Halılar metasediment-hosted Cu-Pb (±Zn) mineralization was formed by epigenetic hydrothermal processes after sedimentation/diagenesis and metamorphism.
      Citation: Minerals
      PubDate: 2022-08-04
      DOI: 10.3390/min12080991
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 992: Editorial for Special Issue “Risk
           Assessment, Management and Control of Mining Contamination”

    • Authors: Elizabeth J. Lam, Antonio Bernardo-Sánchez, Violetta Sokoła-Szewioła
      First page: 992
      Abstract: The exploitation of mineral resources around the world has always been a matter of controversy among governments, production companies, and organized society, giving rise particularly to conflicts about environmental matters [...]
      Citation: Minerals
      PubDate: 2022-08-04
      DOI: 10.3390/min12080992
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 993: Genesis of the Wuzhutang Granite and
           Associated W–Sn–Be Mineralization in the Xuebaoding Mining
           Area, Sichuan Province, China

    • Authors: Hongzhang Dai, Denghong Wang, Xin Li, Shanbao Liu, Chenghui Wang, Yan Sun
      First page: 993
      Abstract: The Xuebaoding W–Sn–Be mining area, located in the Songpan–Garze orogenic belt in western China, is known for producing large, colorful, euhedral crystals of scheelite, cassiterite, and tabular beryl. Zircon LA-ICP-MS U–Pb dating of the Wuzhutang granite yields a concordia age of 218.96 ± 2.1 Ma, and a weighted mean 206Pb/238U age of 218.98 ± 1.12 Ma. Cassiterite LA-MC-ICPMS dating of the quartz vein bearing beryl, cassiterite, and scheelite, yields a concordant age of 213.5 ± 1.7 Ma. These observations indicate that magmatic activities and mineralization on the western side of the Zibaishan dome occurred during the late Indosinian, prior to their occurrence on the eastern side of the dome, reflecting the fact that the granite may have undergone two epochs of magmatic evolution and metallogenic processes. Geochemical analysis revealed that the Wuzhutang granite has relatively high A/CNK (average: 1.05) and differentiation index (DI; 81.16~85.88) values, and that they are enriched in W, Sn, Be, Li, and Cs. Unlike the Pukouling and Pankou granites, the Wuzhutang granite contains a certain amount of plagioclase and relatively high contents of Ba (633~1007 ppm) and Sr (334~411 ppm). Sr–Nd–Pb isotope values (87Sr/86Sr(t) = 0.70747–0.70865, εNd(t) = −6.35 to –4.34, 206Pb/204Pb = 18.186–18.3, 207Pb/204Pb = 15.556–15.592, and 208Pb/204Pb = 38.268–38.432) indicate a Mesoproterozoic basement origin for the Wuzhutang granite. We suggest the three granites belong to a peraluminous magma system and were derived by partial melting of the upper crust, the magma of the Wuzhutang granite originated from a deeper source and exhibits a lower degree of differentiation than that of the Pankou and Pukouling granites.
      Citation: Minerals
      PubDate: 2022-08-05
      DOI: 10.3390/min12080993
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 994: Study of the Crystallographic Distortion
           Mechanism during the Annealing of Kaolinite

    • Authors: Qiuyu Zeng, Jun Xie, Wei Zhou, Jinbo Zhu, Liangliang Liu, Jianqiang Yin, Wenliang Zhu
      First page: 994
      Abstract: The distortion process of kaolinite annealed from 25 °C to 550 °C for different holding times can be characterized using a thermogravimetric/differential scanning calorimeter (TG/DSC) for thermal analysis, X-ray diffraction (XRD) for establishing the crystal structure, the Fourier transform infrared spectrum (FTIR) for identifying the functional groups, and a scanning electron microscope (SEM) for establishing the microstructure. Dehydroxylation is the main reaction during annealing from 25 °C to 550 °C and leads to kaolinite crystal distortion. A stable crystal structure during distortion was obtained by optimizing the bulk phase with quantum chemistry. Then, the crystal structure was studied by using ab initio multiple scattering calculations for X-ray absorption of the fine structure (XAFS). The results of X-ray absorption near the edge structures (XANES) determined that peak shifts and intensity phases slightly increased. The crystal structure distortion of kaolinite during annealing can be explained by the experimental and simulation results. This work provides theoretical support for identifying kaolinite with different degrees of distortion and has the potential for further developments in coal gangue separation.
      Citation: Minerals
      PubDate: 2022-08-05
      DOI: 10.3390/min12080994
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 995: Constraints on the Genesis of the Shuangwang
           Gold Deposit in Qinling Orogen, Central China: Evidence from In Situ Trace
           Element and Sulfur Isotope

    • Authors: Junjie Yang, Xingke Yang, Jianbo Li, Hujun He, Huixia Chao, Pengfei Yi
      First page: 995
      Abstract: The Shuangwang gold deposit, with more than 70 tons of Au, is located in the Fengxian-Taibai ore concentration area in the Qinling Orogen of central China, hosted in a Northwest-trending breccia belt. Fragments of the breccia body are cemented by ankerite, albite, quartz, calcite, and pyrite. Four metallogenic stages are identified in mineral paragenesis: quartz-albite, ankerite-pyrite-albite, pyrite-quartz-calcite, and fluorite-anhydrite. Pyrite, as the main gold-bearing mineral, was formed in the syn-ore and post-ore stages, which are analyzed for trace elements. The experimental results show that Au (0.02 to 11.68 ppm), As (198.45 to 5502.86 ppm), Ag (0.00 to 1.56 ppm), Co (0.02 to 1002.75 ppm), Ni (0.15 to 646.30 ppm), Cu (0.00 to 64.76 ppm), Sb (0.00 to 4.67 ppm), Zn (0.23 to 260.59 ppm), Pb (0.00 to 10.42 ppm), Se (0.00 to 386.24 ppm), and Bi (0.00 to 47.72 ppm) are enriched in syn-ore pyrite much more than in post-ore pyrite, especially arsenic. The high arsenic content and rapid crystallization of pyrite may be the main reasons for precipitation of gold. δ34SV-CDT values of pyrite formed in stage II (PyII) vary from 11.1 to 15.2‰ (mean = 12.9‰), while those for pyrite formed in stage III (PyIII) vary from 11.1 to 13.5‰ (mean = 12.0‰). In situ sulfur isotope analysis indicates that sulfur of the Shuangwang deposit comes from the wallrock, mixed with sulfur from magma.
      Citation: Minerals
      PubDate: 2022-08-06
      DOI: 10.3390/min12080995
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 996: Effect of Calcium Ion on the Flotation of
           Fluorite and Calcite Using Sodium Oleate as Collector and Tannic Acid as
           Depressant

    • Authors: Yupeng Qian, Xuan Qiu, Tiewei Shen, Yangyang Huai, Bin Chen, Zhen Wang
      First page: 996
      Abstract: In the flotation of semi-soluble minerals such as calcite and fluorite, Ca2+ is one of the common dissolved components influencing the collector adsorption behaviors on the mineral surfaces. However, there is very limited research focusing on how the dissolved Ca2+ affects the separation of fluorite and calcite. In the study, with sodium oleate (NaOL) as a collector and tannic acid (TA) as a depressant, a flotation test, zeta potential measurement, and adsorption experiment in the presence of Ca2+ were conducted. Flotation tests indicated that in the presence of Ca2+, fluorite and calcite were both significantly depressed by TA, leading to difficulty in the separation of the two minerals. It was also found that the depression effect on fluorite flotation was minimized with a high concentration of NaOL. Zeta potential measurement and the adsorption experiment results are consistent with the flotation results, revealing that it is only in the low concentration of NaOL that the flotation of fluorite was depressed by TA in the presence of Ca2+. Specifically, in the low concentration of NaOL, TA adsorbed on the fluorite surface and depressed the flotation of fluorite due to the preferential interaction between NaOL and Ca2+ in the solution leading to a shortage in the effective NaOL in the solution. In the high concentration of NaOL, the adsorbed TA on the fluorite surface was displaced by the excessive NaOL in the solution; hence, the flotation of fluorite was recovered. In contrast, TA always hinders the interaction of NaOL with calcite regardless of the presence and absence of Ca2+ and NaOL, hence, depressing the flotation of calcite. The study presented that a high concentration of NaOL may mitigate the negative effect of Ca2+ on the fluorite surface and improve the separation of fluorite from calcite.
      Citation: Minerals
      PubDate: 2022-08-06
      DOI: 10.3390/min12080996
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 997: Orebody Modeling Method Based on the Coons
           Surface Interpolation

    • Authors: Zhaohao Wu, Lin Bi, Deyun Zhong, Ju Zhang, Qiwang Tang, Mingtao Jia
      First page: 997
      Abstract: This paper presents a surface modeling method for interpolating orebody models based on a set of cross-contour polylines (geological polylines interpreted from the raw geological sampling data) using the bi-Coons surface interpolation method. The method is particularly applicable to geological data with cross-contour polylines acquired during the geological and exploration processes. The innovation of this paper is that the proposed method can automatically divide the closed loops and automatically combine the sub-meshes. The method solves the problem that it is difficult to divide closed loops from the cross-contour polylines with complex shapes, and it greatly improves the efficiency of modeling based on complex cross-contour polylines. It consists of three stages: (1) Divide closed loops using approximate planes of contour polylines; each loop is viewed as a polygon combined with several polylines, that is the n-sided region. (2) After processing the formed n-sided regions, Coons surface interpolation is improved to complete the modeling of every single loop (3) Combine all sub-meshes to form a complete orebody model. The corresponding algorithm was implemented using the C++ programing language on 3D modeling software. Experimental results show that the proposed orebody modeling method is useful for efficiently recovering complex orebody models from a set of cross-contour polylines.
      Citation: Minerals
      PubDate: 2022-08-06
      DOI: 10.3390/min12080997
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 998: Quantitative Characterization and
           Controlling Factors of Shallow Shale Reservoir in Taiyang Anticline,
           Zhaotong Area, China

    • Authors: Kai Ma, Bing Zhang, Siyu Wen, Xiaoyang Lin, Yan Wang, Kai Yang
      First page: 998
      Abstract: Pore and its structural characteristics are key parameters affecting shale gas reservoir development. Accurate quantitative characterization of shale pore and its structural characteristics is of great significance for evaluating shale reservoir state. In this study, 15 shallow marine shale samples were collected in Well Y108. X-ray diffraction results indicate that brittle minerals are the most common components in shale. In this paper, various pore types are classified and characterized by scanning electron microscope images. The total porosity of shale measured by the mercury intrusion method is between 3.2% and 6.5%. In addition, a petrophysical model is established to calculate matrix porosity and fracture. The results of this model are consistent with the measured porosity. Three key parameters (VTOC > VBri > VClay) were obtained. The low-pressure N2/CO2 adsorption experiment allows for the analysis of pore volume, specific surface area, and pore size. Finally, it was determined that the primary pore types and primary shale gas reservoir space in shallow marine shale are mesopores and micropores. The impact of shale constituents on pores and their structural properties is also covered in this work. The results indicate that the enrichment of total organic carbon and brittle minerals is conducive to the development of shallow marine shale pore-fracture system. Additionally, there is a positive linear relationship between matrix porosity, pore volume, specific surface area, average pore diameter, and surface porosity.
      Citation: Minerals
      PubDate: 2022-08-08
      DOI: 10.3390/min12080998
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 999: Data Quality in Geochemical Elemental and
           Isotopic Analysis

    • Authors: Balaram Vysetti, Satyanarayanan Manavalan
      First page: 999
      Abstract: Appropriate sampling, sample preparation, choosing the right analytical instrument, analytical methodology, and adopting proper data generation protocols are essential for generating data of the required quality for both basic and applied geochemical research studies. During the last decade, instrumental advancements, in particular further developments in ICP-MS, such as the use of tandem ICP-MS, high-resolution mass spectrometry to resolve several interferences, and the use of the second path with a collision/reaction cell in multi-collector ICP-MS (MC-ICP-MS) to effectively resolve interferences, have brought in remarkable improvements in accuracy and precision in both elemental and isotopic analyses. The availability of a number of well-characterized geological certified reference samples having both elemental and isotopic data-enabled matrix-matching calibrations and contributed to the quality and traceability of the geochemical data in several cases. There have been some developments in the sample dissolution methods also. A range of quality issues related to sampling, packaging and transport, powdering, dissolution, the application of suitable instrumental analytical techniques, calibration methods, accuracy, and precision are addressed which are helpful in geochemical studies.
      Citation: Minerals
      PubDate: 2022-08-08
      DOI: 10.3390/min12080999
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1000: Pervasive Listwaenitization: The Role of
           Subducted Sediments within Mantle Wedge, W. Chalkidiki Ophiolites, N.
           Greece

    • Authors: Alkiviadis Sideridis, Petros Koutsovitis, Basilios Tsikouras, Christos Karkalis, Christoph Hauzenberger, Federica Zaccarini, Pavlos Tsitsanis, Christina Vasiliki Lazaratou, Vasilios Skliros, Dionisios Panagiotaras, Dimitrios Papoulis, Konstantin Hatzipanagiotou
      First page: 1000
      Abstract: Listwaenitization processes have significantly altered the mantle section of the West Chalkidiki ophiolites, generating the second largest magnesite deposit in Greece. Although research studies have been conducted in the region, the post-magmatic processes, and especially the geotectonic settings under which listwaenitization took place, remain unclear. In this study, minerals and rocks were studied applying XRD, clay fraction, SEM, EMPA, ICP-MS, INAA, LA-ICP-MS, and thermodynamic modeling. The results revealed that alteration processes significantly affected the mantle wedge peridotite protoliths leading to the following chemical changes (a) SiO2 increase with decreasing MgO, (b) Cs, Pb, As, and V enrichments, (c) limited alteration of magnesiochromite hosted within listwaenitized chromitites and (d) enrichment in PPGE and Au in listwaenitized chromitites and desulfurized laurite. Alteration was induced by fluids deriving from subducted Mesozoic sediments, represented by the Prinochori Formation or chemically similar formations. The final product of completely silicified peridotite (silica listwaenite) is thermodynamically stable in Earth-surface conditions, with dolomite and phyllosilicates transforming into clay minerals. Based on detailed petrographical observations, peridotites were subjected to serpentinization, and subsequently, serpentine interacted with CO2, silica and calcium-bearing fluids, leading to its transformation into amorphous rusty-silica mass and/or tremolite.
      Citation: Minerals
      PubDate: 2022-08-08
      DOI: 10.3390/min12081000
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1001: HabitEst3D: A User-Friendly Software for
           Estimating Mixed Crystal Habits from Two-Dimensional Sections in Igneous
           Rocks

    • Authors: Jie Li, Zong-Feng Yang, Yu Wang
      First page: 1001
      Abstract: Crystal habit in igneous rocks provides a window to understand magmatic processes or reveal crystallization environments. Generally, we can obtain the two-dimensional (2D) crystal habits directly from the thin section, which is easy to access. However, the three-dimensional (3D) habit cannot be directly observed in thin sections and needs the stereological conversion from 2D habits. Statistical methods have been developed for stereological conversion, but they cannot identify mixed habits. Our study uses the distributions of the cut-sections of pre-set habits to match the unknown sample and enumerates habit combinations to find the best-match results for mixed habits. The specialized program, HabitEst3D, is developed according to our model in this study. The program is written in Python and is a cross-platform with a user-friendly graphical interface. The input data are the aspect ratio of 2D sections. After setting the parameters, the program finds the best-match estimations fitting the sample, visualizes the results, and saves them in multiple file formats. The program is robust and is not sensitive to outliers to obtain more accurate results. It traverses all possible combinations and needs memory and time but effectively explores the mixed crystal habits in the sample, contributing to investigating magmatic processes in more detail.
      Citation: Minerals
      PubDate: 2022-08-08
      DOI: 10.3390/min12081001
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1002: Petrogenesis and Tectonic Implication of
           the Hongtaiping High-Mg Diorite in the Wangqing Area, NE China:
           Constraints from Geochronology, Geochemistry and Hf Isotopes

    • Authors: Siyu Lu, Yunsheng Ren, Qun Yang, Yujie Hao, Xuan Zhao
      First page: 1002
      Abstract: This study presents new data from zircon U–Pb dating and Hf isotope analysis, as well as whole-rock major- and trace-element compositions of the Hongtaiping high-Mg diorite in the Wangqing area of Yanbian, NE China. Laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) zircon U–Pb dating gives an eruption age of ca. 267 Ma for the high-Mg diorite. These samples have MgO contents of 13.30% to 16.58% and high transition metal element concentrations, classified as sanukite. Their rare earth element (REE) contents range from 45.2 to 68.4 ppm and are characterized by slightly positive Eu anomalies (Eu/Eu* = 1.08–1.17). They show enrichment in light REEs (LREEs) and depletion in heavy REEs (HREEs), with LREE/HREE ratios = 6.54–6.97 and (La/Yb)N values = 7.24–8.08. The Hongtaiping high-Mg diorite is enriched in Rb, U, K, and Sr, but depleted in Th, Nb, and Ta. High MgO contents, Mg# values, and transition metal element concentrations imply that the magma experienced insignificant crystallization fractionation and crustal contamination. Relatively homogenous positive Hf isotopic values indicate that the original magma was generated by the partial melting of a depleted mantle wedge that was metasomatized by subducting slab fluids. The magma was generated by the moderate degree partial melting (20%–30%) of a garnet lherzolite source. Combined with previous studies, this shows that the high-Mg diorite was formed by the northward subduction of the Paleo-Asian oceanic plate during the Middle Permian.
      Citation: Minerals
      PubDate: 2022-08-08
      DOI: 10.3390/min12081002
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1003: Desorption of REEs from Halloysite and
           Illite: A Link to the Exploitation of Ion-Adsorption RE Ore Based on Clay
           Species

    • Authors: Sen Qiu, Huashan Yan, Bengen Hong, Qibang Long, Jie Xiao, Fujian Li, Lichao Tong, Xiaowen Zhou, Tingsheng Qiu
      First page: 1003
      Abstract: The adsorption/desorption characteristics for light and heavy rare earth elements (REEs) on halloysite and illite (which are beneficial for the utilization of ion-adsorption RE ore) were systematically investigated and compared. Additionally, halloysite and illite were fully charactered by XRD, SEM, microscope, zeta potential, nitrogen adsorption–desorption isotherms and buffer pH to build the relationship between adsorption/desorption mechanisms and the minerals’ properties. The results of experiments show that the adsorption rate of halloysite is higher than illite, although they are both very fast and follow the pseudo-second-order kinetic model. The adsorption capacity of halloysite and illite increases with an increase in adsorption pH and remains constant when pH is higher than 4. Due to the narrow interlamellar spacing of halloysite and the fact that it is a nanotube, RE ions are adsorbed only through electrostatic attraction, whereas the adsorption and desorption pH have a significant effect on the recovery of RE ions from illite, because of the diverse adsorption mechanism. The results illustrated that the structure and surface properties of clays are also the key factors that affect RE ions leaching.
      Citation: Minerals
      PubDate: 2022-08-08
      DOI: 10.3390/min12081003
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1004: The Early Cretaceous Granitoids and
           Microgranular Mafic Enclaves of Sanguliu Pluton, the Liaodong Peninsula:
           Implications for Magma Mixing and Decratonic Gold Mineralization in the
           Eastern North China Craton

    • Authors: Taotao Wu, Cong Chen, Dongtao Li, Yan Zhao, Chunqiang Zhao, Yongheng Zhou
      First page: 1004
      Abstract: Some Early Cretaceous granitoids characterized by abundant mafic microgranular enclaves (MMEs) formed by magma mixing have been associated with gold deposits in the eastern North China Craton (NCC). However, the genetic connection of magma mixing with gold mineralization remains unclear. The zircon U–Pb ages and in situ Lu-Hf isotopic compositions, whole-rock major- and trace-element and Sr–Nd–Pb isotopic compositions, as well as EPMA biotite compositions, were presented for the Sanguliu granodiorite and enclaves in the Liaodong Peninsula in order to obtain insights into the spatial and temporal distribution, and internal connection of magma mixing with the decratonic gold deposits in the eastern NCC. The Sanguliu granodiorite yielded coeval formation ages with the enclaves (~123 Ma), and their acicular apatites and plagioclase megacrysts suggest that the enclaves were formed by mixing between mafic and felsic magmas. Geochemically, the Sanguliu granodiorite is high-K calc-alkaline I-type granite, with an initial 87Sr/86Sr ratio of 0.70552 to 0.71470 and strongly negative εNd(t) (−11.4 to −21.3) and zircon in situ εHf(t) values (−15.1 to −25.4), indicating that the felsic magmas were ancient lower crust with the involvement of mantle-derived materials. Meanwhile, the enclaves have high MgO (4.18 to 6.17 wt.%), Cr (45.91 to 290.04 ppm), and Ni (19.65 to 88.18 ppm) contents, with high Mg# values of 50 to 57 at intermediate SiO2 contents (53.68 to 55.78 wt.%), highly negative εNd(t) values (mostly −18.42 to −22.03), and in situ zircon εHf(t) values (−18.6 to −22.7), indicating that the mafic magma was mainly derived from the enriched lithospheric mantle. Furthermore, the biotites from the Sanguliu granodiorite clustered between the MH and NNO buffers in the Fe2+–Fe3+–Mg diagram. This, combined with the high Ce/Ce* ratios (1.30 to 107.18) of the zircons, indicates that the primary magmas forming the Sanguliu granodiorite had a high oxygen fugacity, which is favorable for gold mineralization. These findings, together with previous studies of the Early Cretaceous granitoids with enclaves in the eastern NCC, suggest that magma mixing commonly occurred during 110–130 Ma and is temporally, spatially, and genetically related to decratonic gold systems in eastern NCC.
      Citation: Minerals
      PubDate: 2022-08-09
      DOI: 10.3390/min12081004
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1005: Improving the Efficiency of Downhole
           Uranium Production Using Oxygen as an Oxidizer

    • Authors: Bayan Rakishev, Zhiger Kenzhetaev, Muhametkaly Mataev, Kuanysh Togizov
      First page: 1005
      Abstract: The features occurring during borehole uranium mining in deposits with low filtration characteristics, as well as the conditions and reasons for the reduction of geotechnological parameters of uranium mining by the well are considered in this study. Core material samples were taken from the productive horizon of the Chu-Sarysui province deposit and granulometric compositions were established. The contents of uranium, aluminum, calcium, magnesium, iron and carbonate minerals in the samples were determined by atomic emission spectroscopy. The X-ray phase analysis method established the features and quantitative and qualitative characteristics of ore-containing minerals. A special technique has been developed for conducting experiments in laboratory conditions using core samples, where the intensity of uranium leaching in tubes is determined. The results of laboratory studies are analyzed and discussed and graphs are constructed, to show the dependencies of change in: the filtration coefficients of Kf; the uranium content in solution; the extraction coefficient; and the specific consumption of sulfuric acid on the values of L:S (the ratio of liquid to solid) in the experiments. The effectiveness of using a mild acidity regime, with the addition of oxygen as an oxidizer, is determined and shown. The values of the uranium content in the productive solution, with the addition of oxygen as an oxidizer, reached 220 mg/L, which exceeds the design parameters. The results of uranium extraction from ore show a positive trend, reaching 68%, with L:S from 1.7 to 3.0, low acidity values and the addition of oxygen as an oxidizer. The specific consumption of sulfuric acid reaches the minimum values when using leaching solutions with reduced acidity of 26 kg/kg. The obtained results, on the flow rate of the solution in the tube, the extraction of uranium from ore and the specific consumption of sulfuric acid, indicate a decrease in sedimentation in a porous medium and increased filtration characteristics, with reduced acidity values in the leaching solution.
      Citation: Minerals
      PubDate: 2022-08-10
      DOI: 10.3390/min12081005
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1006: Corded Ware and Contemporary
           Hunter-Gatherer Pottery from Southeast Lithuania: Technological Insights
           through Geochemical and Mineralogical Approaches

    • Authors: Eglė Šatavičė, Gražina Skridlaitė, Inga Grigoravičiūtė-Puronienė, Aivaras Kareiva, Aušra Selskienė, Sergej Suzdalev, Gailė Žalūdienė, Ričardas Taraškevičius
      First page: 1006
      Abstract: A geochemical and mineralogical approach was used to analyze 3rd millennium BCE pottery from Southeast Lithuania that is attributed to the foreign Corded Ware Culture and local hunter-gatherers. SEM-EDS, XRF, XRD, and FTIR were used to study the peculiarities of the pottery and to develop hypotheses about the raw material and technology choices present. The amounts of ten major elements in the bulk and clay matrix compositions (XRF, SEM-EDS) and eleven trace analytes in the bulk compositions (XRF) were compared with the Clarke values and tested to highlight the significance (Mann–Whitney U and Wilcoxon Matched Pairs Tests) of the differences in the elemental quantities between the clay matrix and bulk compositions, and between the lighter and darker clay matrixes. These also revealed the advantage of Ward’s clustering method using the City-block distance of bulk compositions as a tool for inter-correlating ceramics in attributing them to specific communities and locations. The XRD, FTIR, and SEM-EDS mineralogical analyses indicated a predominance of iron-rich illite clay, quartz, and alkali feldspar, in addition to very low to medium firing temperatures. All of the pottery samples consisted of hydromicaceous clay from local Quaternary glacial sediments that contain weathered granitoid fragments.
      Citation: Minerals
      PubDate: 2022-08-10
      DOI: 10.3390/min12081006
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1007: A Comparison of the Fine-Grinding
           Performance between Cylpebs and Ceramic Balls in the Wet Tumbling Mill

    • Authors: Ningning Liao, Caibin Wu, Jianjuan Li, Xin Fang, Yong Li, Zhongxiang Zhang, Wenhang Yin
      First page: 1007
      Abstract: This study investigated the effect of grinding media on the fine-grinding performance in the wet tumbling mill. Comparative experiments between cylpebs and ceramic balls were conducted in a laboratory wet ball mill under various conditions, such as different total masses, total surface areas, and total numbers. The results indicated that ceramic balls produce a slightly smaller instantaneous breakage rate than cylpebs due to their small bulk density at the same charge volume. However, a larger instantaneous breakage rate can be obtained by ceramic balls with the same total mass due to the larger surface area. According to experiments related to the total surface area and total number of ceramic balls, it was found that the fine grinding of ceramic balls also needs to meet a certain break force, which is mainly determined by the diameter of the ceramic balls. Moreover, two models were developed to use ceramic balls instead of cylpebs as fine-grinding media in the wet tumbling mill based on the ball size and the ratio of the total mass of cylpebs. Cylpebs can be replaced by ceramic balls with 1.16–1.75 times the diameter of cylpebs, taking up only 76%–83% of the total weight of cylpebs. When the charge volume of cylpebs is between 20% and 35% in the wet ball mill, cylpebs can be replaced by ceramic balls of the same single mass, with the total weight of the ceramic balls being only 74%–77% of that of the cylpebs.
      Citation: Minerals
      PubDate: 2022-08-11
      DOI: 10.3390/min12081007
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1008: Genesis of the Dongpuzi Gold Deposit in the
           Liaodong Peninsula, NE China: Constraints from Geology, Fluid Inclusion,
           and C–H–O–S–Pb Isotopes

    • Authors: Cong Chen, Taotao Wu, Deming Sha, Dongtao Li, Zhongzhu Yang, Jing Zhang, Qingqing Shang
      First page: 1008
      Abstract: The Dongpuzi deposit is an epithermal gold deposit located in the southern margin of the Shaozihe volcanic fault basin in the Liaodong Peninsula. On the basis of fluid inclusion and C–H–O–S–Pb isotope data, a metallogenic model is established for the Dongpuzi deposit. The mineralization at the Dongpuzi deposit has experienced quartz–pyrite (I), quartz–sulfide (II), and quartz–calcite (III) stages. The quartz from ore stage II has liquid-dominated aqueous inclusions, which have homogenization temperatures ranging from 113 to 162 °C and salinities varying from 3.2 to 9.6 wt% NaCl equiv. The quartz from the quartz–calcite stage has decreasing homogenization temperatures (106~143 °C) and salinities (2.7~6.9 wt% NaCl equiv.). The fluid inclusion data indicate that the gold ores were precipitated from low-temperature and low-salinity solutions, with an obvious decrease in temperature and salinity from ore stages II to III. The calculated δ18Owater values for the quartz of ore stage II range from −14.71‰ to −13.31‰, and the corresponding δDwater values range from −103.3‰ to −96.1‰, indicating that the ore-forming fluids could be of a meteoric origin. The calcite from ore stage III has δ13CV-PDB values of −4.5‰ to −4.2‰ and δ18OV-SMOW values of +7.0‰ to +7.4‰, indicating a mantle source for the carbon. The pyrite yielded δ34S values of +4.1‰ to +6.6‰ and Pb isotopes consistent with those of the host trachyte porphyry and volcanic rocks of the Xiaoling Formation, which suggests that the S and Pb in gold ores were dominantly derived from the host trachyte porphyry and volcanic rocks of the Xiaoling Formation, with some combination of Paleoproterozoic metamorphic rocks of the Gaixian Formation. These results, together with the ore geology, indicate that the Dongpuzi deposit is a typical low-sulfidation epithermal gold deposit with important ore-forming materials input from the host trachyte porphyry, volcanic rocks of the Xiaoling Formation, and Paleoproterozoic metamorphic rocks of the Gaixian Formation. The Dongpuzi deposit was formed under an extensional setting related to the Early Cretaceous lithospheric extension and thinning of the eastern North China Craton.
      Citation: Minerals
      PubDate: 2022-08-11
      DOI: 10.3390/min12081008
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1009: The Impact of Detrital Minerals on
           Reservoir Flow Zones in the Northeastern Bredasdorp Basin, South Africa,
           Using Core Data

    • Authors: Mimonitu Opuwari, Moses Okon Ubong, Simamkele Jamjam, Moses Magoba
      First page: 1009
      Abstract: The present study uses core data to group reservoirs of a gas field in the Bredasdorp Basin offshore South Africa into flow zones. One hundred and sixty-eight core porosity and permeability data were used to establish reservoir zones from the flow zone indicator (FZI) and Winland’s methods. Storage and flow capacities were determined from the stratigraphy-modified Lorenz plot (SMLP) method. The effects of the mineralogy on the flow zones were established from mineralogy composition analyses using quantitative X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). Results reveal five flow zones grouped as high, moderate, low, very low, and tight reservoir rocks. The high flow zone is the best reservoir quality rock and has porosity and permeability values ranging from 12 to 20% and 100 to 1000 mD. The high and moderate zones contribute more than 60% of each well’s flow capacities. The moderate and low flow zone extends laterally to all the wells. The tight flow zone is an impervious rock and has the lowest rock quality with porosity and permeability values less than 8% and 1 mD, respectively. This zone contributes less than 1% to flow capacity. The impact of minerals on flow zones is evident in plagioclase and muscovite content increases. An accompanied decrease in quartz content is observed, which implies that low plagioclase content ≤4% and muscovite content of ≤1% corresponds to the low, moderate, and high flow zones, while plagioclase content of ≥4% and muscovite content of ≥1% belong to the tight flow zone. Consequently, the quantity of plagioclase and muscovite can be used as a proxy to identify better quality reservoir rocks. The diagenetic process that reduces the rock quality can be attributed to quartz overgrowth and the accumulation of mica flakes in the pore spaces. In contrast, the fracture in the high flow zone is the reservoir quality enhancing process. The flow zones are generally controlled by a combination of facies and diagenetic factors.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081009
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1010: Production of Refractory Materials Using a
           Renewable Source of Silicon Dioxide

    • Authors: Abdurassul Zharmenov, Svetlana Yefremova, Baimakhan Satbaev, Nurgali Shalabaev, Serik Satbaev, Sergey Yermishin, Askhat Kablanbekov
      First page: 1010
      Abstract: Organization of environmentally-friendly production of refractory materials based on the principles of cost-effective use of energy and material resources through use of energy-saving technologies and replacement of natural raw materials with industrial and agricultural waste is gaining relevance. Scientists are increasingly interested in creating high-temperature materials using silica of plant origin. Its source is rice husk, a multi-tonnage waste from rice production. Organo-mineral in its nature, rice husk determines the uniqueness of the structure and properties of the materials obtained from it. Use of this waste allows us to produce porous, high-strength silicon carbide refractories with properties corresponding to classical analogs, while benefiting from environmental, economic and technological aspects. The lack of industrial production of refractories using rice husk ash, despite the positive results of scientific research, indicates insufficient study of the issue with certain gaps in this area. This review is intended to help researchers to identify existing problems and outline further actions necessary to ensure that the scientific results are implemented in production.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081010
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1011: Gold Recovery from Sulfide Concentrates
           Produced by Environmental Desulfurization of Mine Tailings

    • Authors: Olivier Allard, Mathieu Lopez, Isabelle Demers, Lucie Coudert
      First page: 1011
      Abstract: Environmental desulfurization is gaining attention as an efficient approach to manage sulfidic mine tailings by separating sulfide minerals from tailings. While extensive research has been done to reuse desulfurized tailings in mine site reclamation, the responsible management or potential of valorization of desulfurization concentrates did not receive as much attention. The objective of this study was to evaluate the potential to recover Au from desulfurization concentrates originating from active gold mine sites. Desulfurization concentrates were produced by froth flotation of tailings and characterized. Cyanidation tests and gravity separation experiments were performed on the concentrates. Desulfurization concentrates, mostly composed of fine particles, contained high amounts of S (between 23.0 and 34.5% S) and variable contents of Au (between 0.7 and 1.9 g/t). Mineralogical characterization by SEM showed that 99% of Au-bearing particles were locked, mainly in pyrite (94%). Cyanidation allowed the recovery of 13 to 78% of Au, depending on the desulfurization concentrate. Low Au-bearing particles liberation, and possibly the presence of Cu, were identified as parameters negatively affecting the Au recovery. Gravity separation was poorly efficient (<50%) in recovering Au, which is quite consistent with physical (small particle size) and mineralogical characterizations. A desulfurization concentrate reprocessing flowsheet is proposed.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081011
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1012: Deep Learning Optimized Dictionary Learning
           and Its Application in Eliminating Strong Magnetotelluric Noise

    • Authors: Guang Li, Xianjie Gu, Zhengyong Ren, Qihong Wu, Xiaoqiong Liu, Liang Zhang, Donghan Xiao, Cong Zhou
      First page: 1012
      Abstract: The noise suppression method based on dictionary learning has shown great potential in magnetotelluric (MT) data processing. However, the constraints used in the existing algorithm’s method need to set manually, which significantly limits its application. To solve this problem, we propose a deep learning optimized dictionary learning denoising method. We use a deep convolutional network to learn the characteristic parameters of high-quality MT data independently and then use them as the constraints for dictionary learning so as to achieve fully adaptive sparse decomposition. The method uses unified parameters for all data and completely eliminates subjective bias, which makes it possible to batch-process MT data using sparse decomposition. The processing results of simulated and field data examples show that the new method has good adaptability and can achieve recognition with high accuracy. After processing with our method, the apparent resistivity and phase curves became smoother and more continuous, and the results were validated by the remote reference method. Our method can be an effective alternative method when no remote reference station is set up or the remote reference processing is not effective.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081012
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1013: Spectral Analysis of Ceres’ Main
           Linear Features

    • Authors: Andrea Longobardo, Filippo Giacomo Carrozzo, Anna Galiano, Jennifer E. C. Scully, Rutu Parekh, Ernesto Palomba, Maria Cristina De Sanctis, Eleonora Ammannito, Andrea Raponi, Federico Tosi, Mauro Ciarniello, Francesca Zambon, Edoardo Rognini, Maria Teresa Capria, Carol A. Raymond, Christopher T. Russell
      First page: 1013
      Abstract: Linear features are very common on asteroid surfaces. They are generally formed after impact and provide information about asteroid evolution. This work focuses on a mineralogical and spectral analysis of the main linear features on the 1/Ceres surface, having both tectonic (Samhain Catena’s pit chains) and geomorphic origins, i.e., generated by ejecta material (Occator ejecta, Dantu’s secondary radial chains, secondary radial chains generated from the Urvara impact). The analysis is based on spectral parameters defined by the Dawn’s VIR imaging spectrometer data, as albedo and depths of the bands centered at approximately 2.7, 3.1, 3.4 and 3.9 mm. The geomorphic linear features show spectral variations with respect to the surroundings, i.e., ammoniated phyllosilicates band depth shallowing is caused by the presence of material originating in a different region or dehydration caused by impact. The Samhain Catena does not show any mineralogical variation, due to its tectonic origin. The spectral behavior of Ceres’ linear features is similar to that observed on other asteroids (Vesta, Eros) and can be diagnostic in discerning the origin of linear features. Then, we searched spectral signatures of organics in the Samhain Catena region, since they are expected to form at depth due to internal processes: the absence of such signatures indicates that either they form at a larger depth or that their subsurface distribution is uneven.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081013
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1014: Enhanced Stability of Scorodite in Oxic and
           Anoxic Systems via Surface Coating with Hydroxyapatite and Fluorapatite

    • Authors: Sônia D. F. Rocha, Lydia Katsarou, George P. Demopoulos
      First page: 1014
      Abstract: With the objective of enhancing the stability of scorodite, its encapsulation with hydroxyapatite (Ca5(PO4)3OH) (HAP) and fluorapatite (Ca5(PO4)3F) (FAP) surface coatings, the two most stable of the calcium phosphates, inert to pH and redox potential variations, are presented in this work. The experimental work includes: (1) determination of the metastable zone for HAP and FAP precipitation, (2) the synthesis of crystalline scorodite under atmospheric conditions using hydrothermal scorodite seed and its characterization, (3) the coating of scorodite with hydroxyapatite and fluorapatite with supersaturation-controlled heterogeneous crystallization, and (4) the long-term stability of the encapsulated scorodite solids. Hydroxyapatite and fluorapatite were prepared with homogeneous precipitation from a metastable solution to which reagents were added at a controlled flow rate. Crystalline scorodite was produced with seeding precipitation and encapsulated with a direct apatite (HAP or FAP) deposition that was controlled by adjusting the pH and reagent addition. The stability tests in oxic and anoxic environments over the pH range of 5–9 showed the release of arsenic from the apatite-coated scorodite to be much lower than from naked scorodite, thereby demonstrating that apatite-based encapsulation of hazardous materials is technically feasible and merits further consideration for development into an arsenic stabilizing technology.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081014
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1015: Chlorine-Deficient Analog of Taseqite from
           Odikhincha Massif (Russia): Genesis and Relation with Other Sr-Rich
           Eudialyte-Group Minerals

    • Authors: Victor A. Zaitsev, Nikita V. Chukanov, Sergey M. Aksenov
      First page: 1015
      Abstract: Eudialyte-group minerals are important accessory minerals of peralkaline rocks of nepheline-syenite massifs and alkaline–ultramafic complexes. Here, we report the complex study of a eudialyte-group mineral (EGM) from peralkaline pegmatite of the alkaline-ultrabasic Odikhincha massif (Polar Siberia). The chemical composition of the studied EGM is intermediate between those of taseqite and eudialyte, with small admixtures of other members of the eudialyte group. The crystals of EGMs were formed during the postmagmatic stage in the temperature range of 300–350 °C and partly replaced by late eudialite along cracks during the zeolite stage (~230 °C). The chemical compositions, structural features and mineral association of the studied EGM are similar to those of Sr-Nb-dominant EGM found in other nepheline-syenite massifs, such as Khibiny, Lovozero and Pilansberg. The EGM studied in this work is a Cl-deficient taseqite variety (“monochlore taseqite”), which differs from “dichlorotaseqite” (found only in the Ilimaussaq massif) by a lower amount of chlorine.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081015
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1016: Reducing Negative Effects of Oxidation on
           Flotation of Complex Cu–Zn Sulfide Ores

    • Authors: Seda Özçelik, Zafir Ekmekçi
      First page: 1016
      Abstract: Surface oxidation of the sulfide minerals negatively affects the flotation performance, i.e., the selectivity and even the recoveries at heavy oxidation conditions. Oxidation may take place during the formation of the ore, during mining and stockpiling, and during the flotation process. Stockpiling of large amounts of ore is a common practice in mine sites for blending the process–plant feed. However, a long stockpiling time may cause severe surface oxidation of the complex sulfide ores, particularly the complex Cu–Zn sulfide ores containing secondary copper minerals, which resulted in loss of Cu–Zn selectivity and copper recovery. A complex Cu–Zn sulfide ore was used to investigate effects of stockpile time on flotation performance and to determine the most efficient mitigation method to restore the flotation performance. Batch-scale flotation tests were performed on a heavily oxidized sample using sulfidization, high intensity conditioning, and their combination. The results showed that sulfidization desliming and stage addition of depressants during flotation was the most effective method for producing a copper concentrate from oxidized ores.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081016
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1017: Experimental Study on the Interaction
           

    • Authors: Wei Liang, Ke Li, Jiashun Luo, Yalei Zhe, Mengtang Xu, Fushou Feng
      First page: 1017
      Abstract: Backfilling is commonly used in underground mines to improve the stability of overlying strata. The performance of the backfill and its interaction with surrounding rock are the key issues in backfill mining research. In this paper, the displacement and stress field evolution characteristics of the overlying strata in backfill mining were analyzed by a physical model, as well as the interaction between the backfill and surrounding rock. The research results show that when backfill mining is employed, the backfill mass and the unexcavated rock mass jointly bear the loads of the overlying strata. The loads of the overlying strata are transferred to the dense backfill mass and the surrounding rock. The stress in the near-field area of the surrounding rock increases and stabilizes gradually. The backfill mass improves the stress distribution state and reduces the stress concentration of the surrounding rock, which is conducive to preventing the progressive damage of the overlying strata. In addition, the backfill mass excavation has a significant influence on the stability of the overlying strata and the surrounding rock stress field. The backfill mass is a passive force-bearing structure that can effectively manage the deformation of the overlying strata and the phenomenon of underground pressure.
      Citation: Minerals
      PubDate: 2022-08-12
      DOI: 10.3390/min12081017
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1018: AFM Image Analysis of the Adsorption of
           Xanthate and Dialkyl Dithiophosphate on Chalcocite

    • Authors: Jinhong Zhang, Wei Zhang
      First page: 1018
      Abstract: Atomic force microscopy (AFM) has been applied to study the adsorption morphology of various collectors, i.e., potassium ethyl xanthate (KEX) and potassium amyl xanthate (PAX) and Cytec Aerofloat 238 (sodium dibutyl dithiophosphate), on chalcocite in situ in aqueous solutions. The AFM images show that all these collectors adsorb strongly on chalcocite. Xanthate adsorbs mainly in the form of insoluble cuprous xanthate (CuX), which binds strongly with the mineral surface without being removed by flushing with ethanol alcohol. This xanthate/chalcocite adsorption mechanism is very similar to the one obtained with the xanthate/bornite system; while it is different from the one of the xanthate/chalcopyrite systems, for which oily dixanthogen is the main adsorption product on chalcopyrite surface. On the other hand, dibutyl dithiophosphate adsorbs on chalcocite in the form of hydrophobic patches, which can be removed by rinsing with ethanol alcohol. AFM images show that the adsorption of collectors increases with increasing adsorption time and collectors’ concentration. In addition, increasing the solution pH to 10 does not prevent the adsorption of xanthate and Aerofloat 238 on chalcocite and the result is in line with the fact that chalcocite floats well in a wide pH range up to 12 with xanthate and dialkyl dithiophosphate being used as collectors. The blending collectors study shows that xanthate and dialkyl dithiophosphate can co-adsorb with both insoluble cuprous xanthate and oily Cu(DTP)2 (Cu dibutyl dithiophosphate) on a chalcocite surface. The present study helps to clarify the flotation mechanism of chalcocite in industry practice using xanthate and dialkyl dithiophosphate as collectors.
      Citation: Minerals
      PubDate: 2022-08-13
      DOI: 10.3390/min12081018
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1019: Fulvic Acid from Chestnut Forest as an
           Added Qualities to Spring Water: Isolation and Characterization from
           Fiuggi Waters

    • Authors: Enrica Allevato, Vittorio Vinciguerra, Silvia Rita Stazi, Francesco Carbone, Cristiano Zuccaccia, Giuseppe Nano, Rosita Marabottini
      First page: 1019
      Abstract: The aquifer of “mineral” water, historically known for its curative properties, is an identifying characteristic of the Anticolana valley. This area hosted a coppice chestnut forest for a long time. Under the forest, there is an important aquifer, historically renowned and widely recognized for preventing renal stone formation and or facilitating their expulsion. This mineral water pre- vents the formation of calcium oxalate and phosphate crystals in the kidney and promotes their dissolutions through soluble calcium complexes. The forest environment soil is particularly rich in humification products owing to the interaction of the rainwater–litter–soil system. The fulvic fraction is soluble in water under all pH conditions and enriches the water basin. We aimed to test these hypotheses and assess how the coppice chestnut forest is involved in fulvic acid production. Fulvic fractions isolated and purified from soil samples and mineral water (550 μg L−1) were analyzed by GC-MS, FTIR, and NMR. Data from different sources were compared, showing sufficient similarities to state that the fulvic acids isolated from the water come from the processes that take place between the stems and the chestnut litter. The chestnut forest provides enrichment to water quality, which is a distinctive piece of information in defining water enhancement strategies, establishing soil management and designating sustainable forest management.
      Citation: Minerals
      PubDate: 2022-08-13
      DOI: 10.3390/min12081019
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1020: Research on the Mechanical Properties of
           Flexible Material Backfilling Wall in Gob-Side Entry Retaining

    • Authors: Dongdong Pang, Yong Zhou, Xingang Niu, Kai He, Chuanming Li, Zhongqi Chen
      First page: 1020
      Abstract: In order to solve the problems of the uneven deformation of Gangue Filled Wall and the difficulty of large-scale promotion of roadway side support, and to achieve the purposes of direct disposal of coal mine waste, reducing costs, and protecting the environment, the failure mechanics model of the bagged gangue was established, and the mechanical action relationship between longitudinal external load and transverse external load of gangue woven bag was deduced. Through the uniaxial compression test of large-scale flexible backfill (coal gangue of different particle sizes), it was obtained that when the strain is 0.2, the bearing capacity of particles with particle sizes between 0 and 10 mm is greater than 5 MPa, and when the strain is 1.27, the bearing capacity of particles with particle thicknesses between 10 and 20 mm is greater than 0 mpa, which meets the requirements of resistance value and resistance growth rate of gob side entry. In the “load deflection” test of backfill (gangue) samples, it was found that the maximum failure load of wet shotcrete is greater than that of dry shotcrete, and the wet shotcrete can withstand greater deformation under the same load conditions. Through the analysis of the experimental results of “flexural strength thickness” and “maximum failure load thickness”, it was finally determined that the thickness of the spray layer with good flexibility and sufficient support force is controlled at about 80 mm.
      Citation: Minerals
      PubDate: 2022-08-13
      DOI: 10.3390/min12081020
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1021: Carbothermic Reduction Roasting of Cathode
           Active Materials Using Activated Carbon and Graphite to Enhance the
           Sulfuric-Acid-Leaching Efficiency of Nickel and Cobalt

    • Authors: Youngjin Ahn, Wonbeom Koo, Kyoungkeun Yoo, Richard Diaz Alorro
      First page: 1021
      Abstract: Carbothermic reduction-roasting tests of NCM (nickel, cobalt, and manganese) cathode active materials with carbon sources such as activated carbon and graphite followed by sulfuric acid leaching were performed to investigate the effects of roasting temperature, molar mixing ratio of cathode active materials and carbon sources, and type of cathode active materials. When the virgin NCM622 materials were roasted with activated carbon, the peaks of Ni and Co metals were observed in the XRD data. The leaching efficiencies of Li, Ni, Co, and Mn increased to over 99.9% within 120 min in all samples roasted at 600 °C–900 °C, but, at the beginning of leaching, the leaching efficiencies increased more slowly with increasing roasting temperature. The leaching efficiencies of Ni and Co decreased with decreasing the molar mixing ratio of active cathode materials and carbon sources, but the leaching efficiencies were more than 99.9% in all ratios. These results indicate that roasting can enhance the leaching of cathode active materials and improve the conventional leaching process using hydrogen peroxide.
      Citation: Minerals
      PubDate: 2022-08-14
      DOI: 10.3390/min12081021
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1022: Quantitative Evaluation of Faults by
           Combined Channel Wave Seismic Transmission-Reflection Detection Method

    • Authors: Yanhui Wu, Guowei Zhu, Wei Wang, Mengbo Zhang, Zhen Gao
      First page: 1022
      Abstract: The quantitative detection of faults using the channel wave seismic method has been a major but challenging area of interest. In this study, we adopted an effective technical process to evaluate fault attribution. First, we use integrated transmission and reflection channel wave information to improve the accuracy of extraction velocity. Then, the location of the fault is determined by the elliptical tangent offset method, and feature extraction and fault location extension determination are achieved through logistic regression and a neural network. This is combined with the prior geological information, the fractional dimension D to the quantitative analysis of the fault throw. Data regarding the 4203 working face of a mine in Shanxi, China, are considered as an example. Two groups of faults were predicted, with the location error in the f30 fault position as 6.7 m. In addition, the f29 fault throw first increased, and then gradually decreased from the return airway to the haulage gateway. These predicted results have been drill-verified and were used to modify the original design. The proposed method has good stability and promising application prospects for fault evaluation.
      Citation: Minerals
      PubDate: 2022-08-14
      DOI: 10.3390/min12081022
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1023: Hyperbolic Secant Subsidence Prediction
           Model under Thick Loose Layer Mining Area

    • Authors: Jinman Zhang, Yueguan Yan, Huayang Dai, Liangji Xu, Jiewei Li, Ruirui Xu
      First page: 1023
      Abstract: In China, as a major resource, coal has made great contributions to national energy security and social development. The mining of coal resources can cause surface subsidence damage, and in particular, the mining of coal resources in thick loose layer mines is the most serious. How to accurately predict the surface subsidence caused by coal mining in thick loose layer mines has become an urgent problem to be solved. To solve this problem, numerical simulations based on the measured data were used to reveal that the thickness of the loose layer is the intrinsic mechanism that affects the value of the surface subsidence and the large range of subsidence. On this basis, the hyperbolic secant function is used as the influence function of unit mining to derive the expected model of subsidence under thick loose layer conditions: the hyperbolic secant subsidence prediction model. Compared with the probability integral method, the hyperbolic secant subsidence prediction model’s prediction accuracy RMSE value is improved by 38%. The hyperbolic secant subsidence prediction model can realize accurate estimation of the subsidence value in the thick loose layer mine area. This greatly enriches the mining subsidence prediction theory and provides a scientific basis for the assessment of surface damage and ecological environment restoration after coal seam mining under a thick loose seam mining area.
      Citation: Minerals
      PubDate: 2022-08-14
      DOI: 10.3390/min12081023
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1024: Preiswerkite: A First Occurrence in Marble
           Hosting Gem Spinel Deposits, Luc Yen, Vietnam

    • Authors: Vladimir G. Krivovichev, Katherine A. Kuksa, Pavel B. Sokolov, Olga Yu. Marakhovskaya, Andrey A. Zolotarev, Vladimir N. Bocharov, Tatyana F. Semenova, Maria E. Klimacheva, Geir Atle Gussiås
      First page: 1024
      Abstract: We report a new occurrence of preiswerkite, the rare sodium analog of eastonite, the trioctahedral mica, from marble-hosted noble spinel deposits of the Luc Yen district, northern Vietnam. It is found in marble for the first time. The preiswerkite is anhedral and associated with phlogopite, aspidolite, sadanagaite, pargasite, spinel, corundum, dolomite and calcite. The average compositions of preiswerkite is (Na0.88Ca0.08K0.01)Σ0.97(Mg2.29Al0.72Fe0.04)Σ3.05)[(Al1.95Si2.05)Σ4.00O10](OH)2. The compositions of preiswerkite have a narrow range of Mg# values (0.96–0.99) and define a preiswerkite-aspidolite solid-solution series. Compared with other occurrences, the Luc Yen preiswerkite has a low iron content, which attains 0.09 atoms per formula unit (1.53 wt.% FeO). The formation of preiswerkite is favored by the proportion of Mg, Al and Si in the precursor rocks and the increased activity of sodium and H2O in the fluid phase.
      Citation: Minerals
      PubDate: 2022-08-15
      DOI: 10.3390/min12081024
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1025: Investigation of the Deformation Failure
           Occurring When Extracting Minerals via Underground Mining: A Case Study

    • Authors: Xuanting Liu, Congxin Chen, Xiumin Liu, Kaizong Xia, Tianlong Wang
      First page: 1025
      Abstract: Metal mines mined using the sublevel caving method often exhibit various environmental problems on the ground surface. This can affect the safety of the production process in the mining area. A numerical model using Universal Distinct Element Code has been established to investigate deformation failure giving rise to this underground mining. The calculations are combined with in-situ monitoring data collected over a period of 10 years. The results indicate that the strata movement in the footwall can be divided into two stages: an arch caving development stage and post arch caving development stage. Mining disturbance is the main cause of caving in the arch caving development stage. The overlying strata experience ‘caving–stability–caving’, leading to the formation of an ‘arch-shaped’ caving pattern. In the post arch caving development stage, flexural-toppling deformation occurs in the strata in the direction of the collapse pit due to the tectonic stress present and high dip angles of the discontinuities. Through-going failure surface has been analyzed by studying the plastic state and displacement of elements. The formation of through-going failure surface is related to the flexural-toppling deformation and stress concentration caused by mining activities. Based on the different failure mechanisms, an efficient partition has been proposed such that the footwall can be divided into a stable zone, flexural-toppling failure zone, compression and slipping-toppling failure zone, and shear-slipping failure zone. The results are a useful reference when applied to the Chengchao Iron Mine and other similar metal mines.
      Citation: Minerals
      PubDate: 2022-08-15
      DOI: 10.3390/min12081025
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1026: U–Pb Zircon Ages and Geochemistry of
           the Wuguan Complex and Liuling Group: Implications for The Late Paleozoic
           Tectonic Evolution of the Qinling Orogenic Belt, Central China

    • Authors: Ming Guan, Jiahao Li, Guoqing Jia, Shenglian Ren, Chuanzhong Song
      First page: 1026
      Abstract: The tectonic evolution of the Qinling orogen is key to understanding the process of convergence between the North China Block (NCB) and the South China Block (SCB). The Wuguan Complex and Liuling Group, situated along the southern margin of the Shangnan–Danfeng suture zone (SDSZ) between the North Qinling Terrane (NQT) and the South Qinling Terrane (SQT), are important indicators of the late Paleozoic tectonic evolution of the Qinling orogen. In this paper, the detrital zircon U–Pb geochronology and geochemical analysis of the Wuguan Complex and Liuling Group are carried out. Detrital zircons from two metasedimentary rock samples of the Liuling Group yield a major age peak at 460 Ma and two subordinate peaks at 804 Ma and 920 Ma, with a few older grains having formed between 1000–2549 Ma. One metasedimentary rock sample of the Wuguan Complex has a similar age spectrum as that of the Liuling Group, which shows the main age peak at 440 Ma and two subordinate peaks at 786 and 927 Ma, indicating all detrital zircon age results have the same source area. Geochemical analyses suggest that the sedimentary rocks of the Liuling Group and part of the Wuguan Complex were deposited in the tectonic setting of the continental island arc (CIA), while the geochemical characteristics of the other group of sedimentary rocks of the Wuguan Complex indicate the mixing of basic rock sources. The protolith of garnet amphibolite and hornblende schist, which were collected from the Wuguan Complex, were classified as andesite and basalt, with the nature of arc andesite and oceanic island basalt, respectively. In combination with regional data, we suggest that the Liuling Group and the Wuguan Complex were deposited in a fore-arc basin. Additionally, the Wuguan Complex was subsequently incorporated into the tectonic mélange by the northward subduction of the Paleo-Qinling Ocean. Zircons from the subduction-related metamorphic igneous rocks in the Wuguan Complex yielded a weighted mean age of 365 ± 19 Ma, indicating that the Paleo-Qinling Ocean between the SQT and NQT was still subducted at the end of Devonian.
      Citation: Minerals
      PubDate: 2022-08-15
      DOI: 10.3390/min12081026
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1027: A New Image Processing Workflow for the
           Detection of Quartz Types in Shales: Implications for Shale Gas Reservoir
           Quality Prediction

    • Authors: Sen Guo, David Misch, Reinhard F. Sachsenhofer, Yanming Zhu, Xin Tang, Weichen Bai
      First page: 1027
      Abstract: A shale lithofacies scheme is commonly used to characterize source rock reservoirs of the Lower Cambrian Niutitang Formation. However, this classification ignores that individual components such as quartz may have different origins, potentially affecting reservoir quality. The main objective of this article is, therefore, to present a refined scheme for lithofacies and an image processing workflow for the detection of quartz types in the Niutitang Formation shales from the Jiumen outcrop in the Guizhou Province (Upper Yangtze Basin, SW China). In order to do so, a combination of bulk density, optical and scanning electron microscopy and image analysis was used. The shale lithology was macroscopically classified into seven major categories and nineteen subcategories. Subsequently, the shales were investigated at the microscopic level, mainly focusing on quartz types and microstructural variations. Afterwards, the workflow to calculate the weight per unit volume (1 cm3) of the quartz types was presented, i.e., firstly, by calculating the weight of mineral matter by subtraction of the measured weight of organic matter from the bulk shale; secondly, by calculating the weight of total quartz in bulk shale from the weight of mineral matter and its proportion calculated from X-ray diffraction data; thirdly, by calculating the weight of detrital quartz and non-detrital quartz with energy dispersive X-ray mapping, image processing and quartz density; finally, by calculating the weight of clay-sized quartz by subtracting of the weight of detrital and non-detrital quartz from the weight of the total quartz. The bulk quartz content was found to be dominated by clay-sized quartz, which may mainly control the mesopore volume available for gas storage and, hence, the shale gas reservoir development.
      Citation: Minerals
      PubDate: 2022-08-16
      DOI: 10.3390/min12081027
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1028: LA-ICP-MS Trace Element Composition of
           Sphalerite and Galena of the Proterozoic Carbonate-Hosted Morro Agudo
           Zn-Pb Sulfide District, Brazil: Insights into Ore Genesis

    • Authors: Colin Aldis, Gema R. Olivo, Samuel Morfin
      First page: 1028
      Abstract: The metal-rich Vazante-Paracatu Mineral Belt, in central Brazil, hosts the Zn-Pb sulfide Morro Agudo District in the Mesoproterozoic (1.3–1.1 Ga) upper carbonate sequence of the Vazante Group. The Morro Agudo district is comprised of the Morro Agudo deposit and the Bento Carmelo, Sucuri, and Morro do Capão occurrences. This carbonate sequence also hosts the Fagundes, Ambrósia and Bonsucesso Zn-Pb sulfide deposits (northern part) and the zinc silicate Vazante and North Extension deposits (southern part). The structurally controlled, stratabound and stratiform styles of mineralization in the Morro Agudo orebodies have been variably classified as sedimentary exhalative, Irish-type and Mississippi Valley-type. In this study, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) spot analyses of sphalerite and galena from the Morro Agudo district revealed that red sphalerite (interpreted as the last stage) has higher Fe and Mn and lower Bi, Co, Cu, Ge, Hg, Tl compared to the other types of sphalerite, whereas the first generation of galena (Gn-I) is enriched in Ag, Cd, and Se and depleted in Cu and Mn relative to later galena (Gn-II). Mineral paragenesis and principal component analysis (PCA) of ore mineral composition suggest that the Morro Agudo, Sucuri and Morro do Capão mineralized zones formed by similar processes involving Zn-Pb mineralizing fluids with various compositions, comprising two main elemental associations: (1) Fe, As, In, Mn, Sb, Ag; and (2) Cd, Bi, Co, Ga, and Se. Bento Carmelo is distinguished in PCA by its unique dolomite-hosted sphalerite composition with elevated concentrations of Cu, Ge, Hg and likely formed from distinct fluids or processes. Temperatures of the mineralizing fluids for the Morro Agudo district range from 82 to 320 °C, calculated based on the trace element composition of sphalerite. The styles of mineralization and ore compositions are consistent with MVT deposits; however, fluid temperatures are hotter than typical MVT mineralizing fluids and may reflect a higher geothermal gradient or active advective fluid flow during the Brasiliano orogeny.
      Citation: Minerals
      PubDate: 2022-08-16
      DOI: 10.3390/min12081028
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1029: Features of Arsenic Distribution in the
           Soils of Potash Mines

    • Authors: Tatiana Karavaeva, Elena Menshikova, Pavel Belkin, Vyacheslav Zhdakaev
      First page: 1029
      Abstract: The purpose of the present study is to analyse the distribution of arsenic in the soils of the Verkhnekamskoe potassium salt deposit (Perm Krai, Russia). The danger of arsenic pollution is determined by its high toxicity and carcinogenic hazard. Being a technophilic element, arsenic enters the environment primarily as a result of mining activities. Mining and processing sites for arsenic-containing ores are the most prone to technophilic arsenic accumulation. Solid wastes from potash production also contain elevated concentrations of arsenic. The content of arsenic in soils was determined by inductively coupled plasma mass spectrometry (ICP-MS). Statistical methods were used to analyse the features of arsenic distribution in soils of background areas and potash mining areas near production facilities. Three types of landscapes were studied within each territory, which were each distinguished by the leading processes of substance migration. Arsenic concentrations in both the background areas and the potash mining territories vary considerably, ranging from n × 10−1 to n × 10. The study found no statistically significant differences in arsenic concentrations in soils of potash mining areas and background areas. Arsenic concentrations in soils from various types of landscapes also do not differ statistically. Arsenic concentrations in soils of saline areas were found to be higher than in the rest of the territories. Outside of saline areas, the identified patterns of arsenic distribution in the soils of the Verkhnekamskoe potassium salt deposit indicate that potash operations are not a determinant in the technophilic accumulation of arsenic.
      Citation: Minerals
      PubDate: 2022-08-16
      DOI: 10.3390/min12081029
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1030: Corrosion of Carbon Steel in Extreme
           Environments by Acid Mine Water: Experimental Study of the Process Using a
           Factorial Analysis Tool

    • Authors: Juan Carlos Fortes, Javier Castilla-Gutierrrez, Aguasanta Sarmiento, José Antonio Grande
      First page: 1030
      Abstract: Acid mine drainage (AMD) is a process resulting from mining activity, which has a potential degrading effect on metallic materials used in machinery and structural installations, mainly carbon steel composites. This work shows how steel is affected and degraded by AMD, as well as the physicochemical changes that occur in the solvent as a consequence of the metal corrosion process. For this purpose, thirty specimens were immersed in AMD for thirty weeks and were removed once per week, observing the changes that had occurred both in the metal and in the solvent to which it was exposed. The results show a material degradation with a loss of weight and alterations in the acid drainage with an increase in pH, total dissolved solids (TDS) and modifications in the rest of the solvent characteristics. The data from the measurements of the plates under study, together with the physicochemical data of the resulting reagent solution, were integrated into matrices for subsequent graphical–statistical processing using Statgraphics Centurion software, a powerful tool for exploratory data analysis, statistical summary, analysis of variance, statistical control, multivariate analysis, time series, etc., and which allows the different variables studied to be classified into categories or proximity ratios.
      Citation: Minerals
      PubDate: 2022-08-16
      DOI: 10.3390/min12081030
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1031: Sulfur Isotopic Composition of Gypsum from
           Paleocene, Northwest China: Implications for the Evolution of Eastern
           Paratethys Seawater

    • Authors: Jun Wang, Yangtong Cao
      First page: 1031
      Abstract: The sulfate isotope record of marine sedimentary sulfate through time has been used successfully to determine global variations in the composition of seawater sulfate. The variations in the sulfur isotope composition of marine sulfate reflect changes in the global sulfur cycle and are also closely related to changes in the atmospheric oxygen cycles. However, data for the Paleocene are very sparse and the stratigraphic evolution of the sulfur isotope composition of seawater is poorly constrained due to the small number of samples analyzed. The Yarkand Basin, as a northeastern part of the eastern Paratethys ocean with the trumpet-shaped bay, in which a suite of evaporitic sequences named the Aertashen Formation was continuously developed in the Paleocene and was principally composed of massive gypsum interbedded fragmental rocks. The values of sulfur isotopic composition are from 12.2‰ to 20.6‰ (δ34 SCDT or δ34 SVCDT) and the mean is 17.7‰ in 97 gypsum samples in the basin. Three gradually increasing trends of sulfur isotopic curves reflect that enrichment of δ34 S occurred in seawater sulfate, and indicate oxidation of seawater sulfide. These may hint to at least three oxidation events or the bacterial reduction of seawater sulfide that occurred in the Paleocene, and that three oxygen-enriched events or the biological sulfur cycle might exist in this epoch. The sulfur isotopic composition (δ34 SCDT or δ34 SVCDT) in the seawater of the northeastern part of the eastern Paratethys ocean was about 15.0‰ to 20.6‰, and averaged 17.9‰ in the Paleocene. Combined with the previous global sulfur isotopic composition of seawater, the final range of global sulfur isotopic composition of seawater might be from 15.0‰ to 21.0‰, with 17.9‰–18.3‰ the average in the Paleocene, so the variations in the sulfur isotope composition of Paleocene seawater sulfate are reconstructed and supplemented.
      Citation: Minerals
      PubDate: 2022-08-16
      DOI: 10.3390/min12081031
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1032: Mechanical Behavior Characteristics and
           Energy Evolution Law of Coal Samples under the Influence of Loading
           Rate—A Case Study of Deep Mining in Wudong Coal Mine

    • Authors: Xingping Lai, Chong Jia, Feng Cui, Ganggui Feng, Mengqi Tian, Yifei Li, Cheng Zong
      First page: 1032
      Abstract: In order to clarify the mechanical properties and energy changes of coal samples under the influence of mining depth, a mechanical test analysis method to determine that the increase in mining depth increases the loading rate has been developed. Taking the Wudong Coal Mine as an example, a mechanical test analysis of coal samples is carried out. The results show that the surface deformation and failure of coal samples in the loading process presents four stages. That is, the evolution process of ‘complete coal sample’–‘partial failure-failure extension’–‘overall instability’. The maximum temperature of a coal sample when it is destroyed shows an obvious nonlinear increasing trend with the increase in loading rate. With the increase in loading rate, the strength and elastic modulus of coal samples decrease gradually. The cumulative total energy and elastic energy of coal samples are linearly positively correlated with the loading rate. The research results provide ideas for rational control of mining intensity and determination of productivity in steeply inclined thick coal seams for deep mining.
      Citation: Minerals
      PubDate: 2022-08-16
      DOI: 10.3390/min12081032
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1033: Vermiculite Modified with Fe3+ Polyhydroxy
           Cations Is a Low-Cost and Highly Available Adsorbent for the Removal of
           Phosphate Ions

    • Authors: Fernando H. do Nascimento, Jorge C. Masini
      First page: 1033
      Abstract: This paper demonstrates that intercalating Na+ homoionic vermiculite with Fe3+ polyhydroxy cations (1:1 molar ratio OH− to Fe3+) significantly improved the affinity of the clay mineral-based sorbent toward phosphate. Kinetic experiments revealed that adsorption is fast, approaching an equilibrium within about 200 min of contact time, and that the rate-limiting step is the intraparticle diffusion. Adsorption isotherms fitted to the Freundlich equation and a two-site Langmuir model, consistent with the heterogeneity of adsorption sites. The separation factor derived from the Langmuir constant revealed that the adsorption was favorable and even irreversible for high-affinity minor adsorption sites. The adsorption capacity was 299 ± 63 μmol·g−1 (9.3 ± 2.1 mg P·g−1), a value similar to several other clay-based phosphate adsorbents. Application to reservoir water spiked with 10 mg·L−1 in P removed about 71% of the available phosphate.
      Citation: Minerals
      PubDate: 2022-08-17
      DOI: 10.3390/min12081033
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1034: A Position Fixing Method for Near-Bottom
           Camera Data on the Seafloor

    • Authors: Xinyu Shi, Shijuan Yan, Chuanshun Li, Gang Yang, Yue Zhao, Dewen Du, Qiukui Zhao, Xiangwen Ren, Fengdeng Shi
      First page: 1034
      Abstract: The submarine camera system is one of the most effective detection methods for detecting seabed hydrothermal sulfide. The position fixing of camera equipment is generally achieved by the ultra-short baseline (USBL) positioning systems. The dynamic changes in the marine environment and the loss of acoustic signals lead to many abnormal points in the USBL positioning data. The existing methods cannot perform position fixing correction for USBL positioning data with many scattered abnormal points. This paper selects and focuses on the seabed camera data of the XunMei mineralization area acquired from the China South Atlantic voyage and employs the DTW optimization algorithm to solve this problem. This method is implemented based on Python language and an ArcGIS technical environment, and a total of 97,469 topographic profiles with 10 m spacing are extracted from the topographic data of the object area with 1m accuracy. Moreover, the highest similarity (95.9%) is obtained between the bathymetric profile of the camera survey line and the above topographic profile. The results indicate that the proposed algorithm is fast and effective, and the positioning correction accuracy of the deep-sea near-bottom camera data can reach the meter level (determined by the topographic data accuracy). Moreover, the solution can provide services for accurately position fixing near-bottom exploration equipment and its exploration data. It can also solve the problem of underwater position fixing problem that a GPS cannot solve.
      Citation: Minerals
      PubDate: 2022-08-17
      DOI: 10.3390/min12081034
      Issue No: Vol. 12, No. 8 (2022)
       
  • Minerals, Vol. 12, Pages 1035: Geochemical Data Mining by Integrated
           Multivariate Component Data Analysis: The Heilongjiang Duobaoshan Area
           (China) Case Study

    • Authors: Zhonghai Zhao, Kai Qiao, Yiwen Liu, Jun Chen, Chenglu Li
      First page: 1035
      Abstract: The Heilongjiang Duobaoshan area is located at the confluence of the Great Xing’an Range and the Lesser Xing’an Range, and the area has undergone a complex magmatic and tectonic evolutionary history resulting in a complex and diverse geological background for mineralization. As a result of this geological complexity and the multi-period nature of mineralization, the geochemical data of the area are usually not satisfied with a single statistical distribution form, so traditional statistical methods cannot adequately explore and identify the distribution of deep-seated information in the geochemical data. Based on the above problems, this paper adopts a multivariate component data analysis method to process 14 mass fraction data elements, namely Ag, As, Au, Bi, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, W, and Zn, in the 1:50,000 soil geochemical data from the Duobaoshan area of Heilongjiang. The spatial distribution and internal structural characteristics of raw, logarithmic transformation and isometric logarithmic ratio (ILR) transformed data were compared using exploratory data analysis (EDA); robust principal component analysis (RPCA) was applied to obtain the PC1 and PC2 principal component combinations associated with mineralization, and a spectrum–area (S–A) fractal model was further used to decompose the geochemical anomalies of the PC1 and PC2 principal component combinations as composite anomalies. The results show the following: (i) The data transformed by the isometric logarithmic ratio (ILR) eliminate the influence of the original data closure effect, and the spatial scale of the data is more uniform; the data are approximately normally distributed, based on which RPCA can be applied to better explore the correlation between elements and the pattern of co-associated combinations. (ii) The S–A method was further used to decompose the composite anomalies of the PC1 and PC2 principal component combination in the study area. The anomalous and background fields of the screened-out PC1 and PC2 principal component combinations reflect anomalous information on mineralization dominated by Au mineralization. Moreover, the anomaly and background information after extraction were in good agreement with the known Au deposits (points), and many geochemical anomalies with prospecting potential were obtained in the periphery, providing a theoretical basis and exploration focus for the next step in the searching and exploring of the study area.
      Citation: Minerals
      PubDate: 2022-08-17
      DOI: 10.3390/min12081035
      Issue No: Vol. 12, No. 8 (2022)
       
 
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