Subjects -> MINES AND MINING INDUSTRY (Total: 82 journals)
 Showing 1 - 42 of 42 Journals sorted alphabetically American Mineralogist       (Followers: 16) Applied Earth Science : Transactions of the Institutions of Mining and Metallurgy       (Followers: 4) Archives of Mining Sciences       (Followers: 3) AusiMM Bulletin       (Followers: 1) BHM Berg- und Hüttenmännische Monatshefte       (Followers: 2) Canadian Mineralogist       (Followers: 7) CIM Journal Clay Minerals       (Followers: 9) Clays and Clay Minerals       (Followers: 5) Coal Science and Technology       (Followers: 4) Contributions to Mineralogy and Petrology       (Followers: 14) Environmental Geochemistry and Health       (Followers: 3) European Journal of Mineralogy       (Followers: 14) Exploration and Mining Geology       (Followers: 3) Extractive Industries and Society       (Followers: 2) Gems & Gemology       (Followers: 2) Geology of Ore Deposits       (Followers: 5) Geomaterials       (Followers: 3) Geotechnical and Geological Engineering       (Followers: 9) Ghana Mining Journal       (Followers: 3) Gold Bulletin       (Followers: 2) Inside Mining International Journal of Coal Geology       (Followers: 4) International Journal of Coal Preparation and Utilization       (Followers: 2) International Journal of Coal Science & Technology       (Followers: 1) International Journal of Hospitality & Tourism Administration       (Followers: 16) International Journal of Minerals, Metallurgy, and Materials       (Followers: 12) International Journal of Mining and Geo-Engineering       (Followers: 4) International Journal of Mining and Mineral Engineering       (Followers: 8) International Journal of Mining Engineering and Mineral Processing       (Followers: 6) International Journal of Mining Science and Technology       (Followers: 4) International Journal of Mining, Reclamation and Environment       (Followers: 6) International Journal of Rock Mechanics and Mining Sciences       (Followers: 9) Journal of Analytical and Numerical Methods in Mining Engineering Journal of Applied Geophysics       (Followers: 18) Journal of Central South University       (Followers: 1) Journal of China Coal Society Journal of China University of Mining and Technology       (Followers: 1) Journal of Convention & Event Tourism       (Followers: 6) Journal of Geology and Mining Research       (Followers: 10) Journal of Human Resources in Hospitality & Tourism       (Followers: 9) Journal of Materials Research and Technology       (Followers: 2) Journal of Metamorphic Geology       (Followers: 17) Journal of Mining Institute Journal of Mining Science       (Followers: 5) Journal of Quality Assurance in Hospitality & Tourism       (Followers: 6) Journal of Sustainable Mining       (Followers: 3) Journal of the Southern African Institute of Mining and Metallurgy       (Followers: 6) Lithology and Mineral Resources       (Followers: 4) Lithos       (Followers: 11) Mine Water and the Environment       (Followers: 6) Mineral Economics       (Followers: 2) Mineral Processing and Extractive Metallurgy : Transactions of the Institutions of Mining and Metallurgy       (Followers: 14) Mineral Processing and Extractive Metallurgy Review       (Followers: 5) Mineralium Deposita       (Followers: 4) Mineralogia       (Followers: 2) Mineralogical Magazine       (Followers: 1) Mineralogy and Petrology       (Followers: 5) Minerals       (Followers: 2) Minerals & Energy - Raw Materials Report       (Followers: 1) Minerals Engineering       (Followers: 14) Mining Engineering       (Followers: 7) Mining Journal       (Followers: 4) Mining Report       (Followers: 3) Mining Technology : Transactions of the Institutions of Mining and Metallurgy       (Followers: 4) Mining, Metallurgy & Exploration Natural Resources & Engineering Natural Resources Research       (Followers: 5) Neues Jahrbuch für Mineralogie - Abhandlungen       (Followers: 1) Physics and Chemistry of Minerals       (Followers: 4) Podzemni Radovi Rangeland Journal       (Followers: 4) Réalités industrielles Rem : Revista Escola de Minas Resources Policy       (Followers: 4) Reviews in Mineralogy and Geochemistry       (Followers: 5) Revista del Instituto de Investigación de la Facultad de Ingeniería Geológica, Minera, Metalurgica y Geográfica Rock Mechanics and Rock Engineering       (Followers: 9) Rocks & Minerals       (Followers: 5) Rudarsko-geološko-naftni Zbornik Transactions of Nonferrous Metals Society of China       (Followers: 9)
Similar Journals
 International Journal of Coal Science & TechnologyJournal Prestige (SJR): 2.063 Citation Impact (citeScore): 3Number of Followers: 1     Open Access journal ISSN (Print) 2095-8293 - ISSN (Online) 2198-7823 Published by SpringerOpen  [262 journals]
• Fluidized mining and in-situ transformation of deep underground coal
resources: a novel approach to ensuring safe, environmentally friendly,
low-carbon, and clean utilisation

• Abstract: Traditional coal mining and utilisation patterns are severely detrimental to natural resources and environments and significantly impede safe, low-carbon, clean, and sustainable utilisation of coal resources. Based on the idea of in situ fluidized coal mining that aims to transform solid coal into liquid or gas and transports the fluidized resources to the ground to ensure safe mining and low-carbon and clean utilisation, in this study, we report on a novel in situ unmanned automatic mining method. This includes a flexible, earthworm-like unmanned automatic mining machine (UAMM) and a coal mine layout for in situ fluidized coal mining suitable for the UAMM. The technological and economic advantages and the carbon emission reduction of the UAMM-based in situ fluidized mining in contrast to traditional mining technologies are evaluated as well. The development trends and possible challenges to this design are also discussed. It is estimated that the proposed method costs approximately 49% of traditional coal mining costs. The UAMM-based in situ fluidized mining and transformation method will reduce CO2 emissions by at least 94.9% compared to traditional coal mining and utilisation methods. The proposed approach is expected to achieve safe and environmentally friendly coal mining as well as low-carbon and clean utilisation of coal.
PubDate: 2019-06-17

• Computer simulation of coal organic mass structure and its sorption
properties

• Abstract: Structural model of C100H79O7NS coal organic mass was obtained within density functional theory in the localized orbital basis set using the B3LYP hybrid functional. The model was compared with the known experimental data for coal of different grades and its sorption properties were studied with respect to CH4, CO2 and H2O. It has been shown that macromolecule of coal organic mass has bulk structure with a pore inside it. Interaction between coal and CH4 molecules consists of typical physical adsorption with oligomer formation on the pore border, physical adsorption with elements of chemical adsorption was also observed between coal and H2O molecules. Interaction between coal and H2O molecules included both physical and chemical adsorbion.
PubDate: 2019-05-31

• Optimization of drill bit replacement time in open-cast coal mines

• Abstract: To gain a competitive edge within the international and competitive setting of coal markets, coal producers must find new ways of reducing costs. Increasing bench drilling efficiency and performance in open-cast coal mines has the potential to generate savings. Specifically, monitoring, analyzing, and optimizing the drilling operation can reduce drilling costs. For example, determining the optimal drill bit replacement time will help to achieve the desirable penetration rate. This paper presents a life data analysis of drill bits to fit a statistical distribution using failure records. These results are then used to formulate a cost minimization problem to estimate the drill bit replacement time using the evolutionary algorithm. The effect of cost on the uncertainty associated with replacement time is assessed through Monte-Carlo simulation. The relationship between the total expected replacement cost and replacement time is also presented. A case study shows that the proposed approach can be used to assist with designing a drill bit replacement schedule and minimize costs in open-cast coal mines.
PubDate: 2019-05-31

• Non-parallel double-crack propagation in rock-like materials under
uniaxial compression

• Abstract: Coalescence among fractures would have influence on the stability of rock masses. Deep understanding of mechanical behavior of fractured rock masses is an important mean to identify failure mechanism of geological disaster. In this study, crack propagation processing was studied through loading pre-fractured specimens of concrete block, termed as rock-like material, in uniaxial compression tests. New non-parallel double-crack geometry was introduced to observe crack coalescence. The flaw combinations are different from the normally used flaw configurations. In addition, ultrasonic detection tests were performed on the test blocks. The stress and strain data of these tests and characteristic parameters of sound wave were recorded. The stress-strain curves of each test block under the uniaxial compression test were drawn, relations among deformation characteristics and crack angle of the crack specimens, and their overall strength were analyzed. It is found that strength of the specimen decreases as crack inclination increases under two crack inclinations. The highest uniaxial compressive strength is found in the specimen with the cracks at the same angle in different directions. Based on description of the crack initiation location, crack surface and the ultimate failure patterns, failure modes of eight subtype for test blocks are divided into three categories. It is expected that the study results could be beneficial for engineering application of jointed rock masses.
PubDate: 2019-05-31

• Effect of occurrence mode of heavy metal elements in a low rank coal on
volatility during pyrolysis

• Abstract: The harmful trace elements will be released during coal utilization, which can cause environment pollution and further endangering human health, especially for heavy metal elements. Compared to combustion, the release of heavy metal elements during coal pyrolysis process, as a critical initial reaction stage of combustion, has not received sufficient attention. In the present paper, a low rank coal, from Xinjiang province in China, was pyrolyzed in a fixed bed reactor from room temperature, at atmospheric pressure, with the heating rate of 10 °C/min, and the final pyrolysis temperature was from 400 to 800 °C with the interval of 100 °C. The volatility of heavy metal elements (including As, Hg, Cd and Pb) during pyrolysis process was investigated. The results showed the volatility of all heavy metal elements increased obviously with increasing temperature, and followed the sequence as Hg > Cd > As > Pb, which was mainly caused by their thermodynamic property and occurrence modes in coal. The occurrence modes of heavy metals were studied by sink-and-float test and sequential chemical extraction procedure, and it can be found that the heavy metal elements were mainly in the organic and residual states (clay minerals) in the raw coal. And most of the organic heavy metals escaped during the pyrolysis process, the remaining elements were mainly in the residual state, and the elements in Fe–Mn state also tended to remain in the char.
PubDate: 2019-05-27

• In situ Raman imaging of high-temperature solid-state reactions in the
CaSO 4 –SiO 2 system

• Abstract: The deposition of mineral phases on the heat transfer surfaces of brown coal power plants may have a negative effect on power plant boilers. The paragenesis of these deposits contains information about the actual temperature prevailed during the combustion of lignite, if the temperature-dependences of distinct mineral transformations or reactions are known. Here, we report results of a sintering study (to ~ 1100 °C) with samples containing anhydrite, quartz, and gehlenite, which are typical components of Rhenish lignite ashes. Thermal decompositions and solid-state reactions were analyzed (1) in situ and (2) both in situ and after quenching using confocal hyperspectral Raman imaging. This novel application of confocal Raman spectroscopy provides temperature- and time-resolved, 2-dimensional information about sintering processes with a micrometer-scale resolution. In the course of the sintering experiments with anhydrite and quartz with a weight ratio of 2:1 both polymorphs wollastonite and pseudowollastonite were identified in situ at about 920 and 1000 °C, respectively. The formation of pseudowollastonite was thus observed about 120 °C below the phase transition temperature, demonstrating that it can form metastably. In addition, $$\alpha_{L}^{\prime }$$ -Ca2SiO4 was identified at about 1100 °C. In samples containing equal weight fractions of anhydrite and quartz that were quenched after firing for 9 h at about 1100 °C, β-Ca2SiO4 (larnite) crystallized as rims around anhydrite grains and in direct contact to wollastonite. We furthermore observed that, depending on the ratio between quartz and anhydrite, wollastonite replaced quartz grains between 920 and 1100 °C., i.e., the higher the quartz content, the lower the formation temperature of wollastonite.
PubDate: 2019-05-27

• Advances in the chemical leaching (inorgano-leaching), bio-leaching and
desulphurisation of coals

• Abstract: Coal still remains an important source of power generation world over. Along with its usage, comes unwanted generation of noxious gas emissions, toxic metal releases into wastewater and other pollutants which ultimately lead to environmental concerns. So cleaning of coal through physical or chemical processes becomes utmost important. There are several coals which cannot be cleaned by physical beneficiation techniques to produce low ash cleaner coals. Such coals can be cleaned only through chemical cleaning techniques. The present paper reviews the chemical demineralisation and desulphurisation of coals over the years using various inorganic and organic acids, alkalis, oxidants, leachants and various acids and alkali-acid combinations to reduce the ash and sulphur contents in coals. As high as 90% demineralisation and desulfurization could be achieved with the use of these cheap inorganic acids as compared to the expensive solvents used for solvent extraction processes, a parallel approach of cleaning and refining coals.
PubDate: 2019-05-24

• Geochemistry and multivariate statistical evaluation of major oxides,
trace and rare earth elements in coal occurrences and deposits around Kogi
east, Northern Anambra Basin, Nigeria

• Abstract: The Cretaceous Mamu Formation coal samples located within the Northern Anambra Basin were collected, analysed and interpreted using multivariate statistical approach to determine the major, trace and rare elements association with a view to determine the source of the terrestrial rocks, palaeoweathering/climatic conditions and tectonic setting. The dominant oxides such as SiO2, Al2O3, Fe2O3, TiO2 and CaO were identified in the coal to suggest terrigenous origin. The ratio of SiO2/Al2O3 of 4.8 suggests that the coal was formed from low land peat associated with freshwater continental marine or blackish water with low salinity as indicated by Sr/Ba and CaO + MgO/K2O + Na2O ratios. The major oxides also revealed stable condition of deposition, low degree of tectonic setting but constant subsidence in the basin. The condition of deposition was acidic in nature as indicated by TiO2/Zr plot. Based on the abundance of Zr, Zn, Ba, Ni, Co, Sr, V, and Y, moderate salinity, sub-oxic to oxic bottom water condition was prevalent and also indication of marine influence. Based on the ratios of La/Yb; La/Sm and Gd/Yb, LREE has higher enrichment than HREE. Humid climatic conditions were observed at the coal formation stage while weak laterization to kaolinization was also evidence.
PubDate: 2019-05-13

• Effects of inherent alkali and alkaline earth metals on nitrogen
transformation during steam gasification of Shengli lignite

• Abstract: This work evaluated the effects of inherent alkali and alkaline earth metals on nitrogen transformation during steam gasification of Shengli lignite at the temperature of 873–1173 K in a fluidized-bed/fixed-bed quartz reactor. The results indicated that the alkali metal Na and alkaline earth metals Ca, Mg in coal have different effects on inherent nitrogen transformation to NH3, HCN and char-N during the lignite steam gasification. Specifically during the steam gasification of Shengli lignite, Na and Ca, Mg not only catalyze the inherent nitrogen conversions to NH3, but also promote the secondary reactions of the nascent char-N as well as the generation of NH3 from the generated HCN, meanwhile they also inhibited the inherent nitrogen conversion to HCN and char-N. The presence of Na, Ca and Mg hindered the formation of oxidized nitrogen (N-X) functional groups, but enhanced pyridinic nitrogen (N-6) and quaternary nitrogen’s (N-Q) formation in char.
PubDate: 2019-04-27

• Analysis of the influence of groundwater and the stress regime on bolt
behaviour in underground coal mines

• Abstract: The service failure of rock bolts and cable bolts are frequently reported issues in underground coal mines. Whilst numerous experimental investigations concerned with the service failure of bolts have been conducted, numerical modelling offers an alternative approach in evaluating the factors contributing to service failures of bolts in underground mines. In this study, analysis of the influence of groundwater and tensile stress on bolts in underground coal mines was studied through the numerical modelling of a grouted bolt in the immediate roadway roof. Bolt tensile stress and groundwater dripping rates in the immediate roadway roof were analysed using a package based on finite element method to assess the effect of coal roof thickness and claystone bands, as main contributors of known service failures of bolts in roadways of underground coal mines. Increasing coal roof thickness was found to increase bolt dripping rates. Probable location of stress corrosion cracking (SCC) occurrence was established through examining the shift and increase in maximum bolt tensile stress that was exhibited along the bolt length with increasing coal roof thickness. Claystone bands situated at the top and centre horizon of a grouted bolt produced lower bolt dripping rates compared with scenarios with no claystone bands. Intersecting claystone bands at the centre horizon of a bolt for a fully grouted bolt could increase the likelihood of SCC corrosion and bolt failure by contributing to microbial corrosion processes and grout fracturing by tensile stress. This study improves the understanding the bolt failure associated with the presence of groundwater and changing stress environments, which in turn is imperative in formulating strategies to mitigate support element failures and improve the ground support viability.
PubDate: 2019-04-27

• Prediction of face advance rate and determination of the operation

• Abstract: A new approach for prediction of face advance rete (FAR) prior to mining operation and determination of the operation efficiency after mining operation in retreat longwall mining panel is presented based upon the concepts of rock engineering system (RES). For this purpose, six longwall panels considered in Parvadeh-I coal mine. Seven major effective parameters on FAR was selected including coal mine roof rating, gas propagation, safety factor of longwall face, ratio of joint spacing to cutting depth at longwall face, longwall face inclination, panel width, floor rock mass rating. To performance evaluation of the presented model, the relationship between the average vulnerability indexes of advance operation with FAR was determined in considered panels with coefficient of determination (R2) equal to 0.884 that indicate relatively acceptable correlation and compatibility. Investigations of the research indicated that it is possible to determine the actual operation efficiency under fair conditions by a RES-based model. The inevitable reduction of FAR for each longwall panel was determined by presented model that the difference amount between the maximum possible practical face advance rate (FARmpp) and recorded actual face advance rate (FARa) indicate the operation efficiency. Applied approach in this paper can be used to prediction of FAR in retreat longwall mining panel for same conditions that can have many benefits, including better and more accurate planning for the sales market and mine operation. Also, presented method in this paper can be applied as a useful tool to determination of actual operation efficiency for other sections and extraction methods in coal mines.
PubDate: 2019-04-10

• Fire monitoring in coal mines using wireless underground sensor network
and interval type-2 fuzzy logic controller

• Abstract: From the view of underground coal mining safety system, it is extremely important to continuous monitoring of coal mines for the prompt detection of fires or related problems inspite of its uncertainty and imprecise characteristics. Therefore, evaluation and inferring the data perfectly to prevent fire related accidental risk in underground coal mining (UMC) system are very necessary. In the present article, we have proposed a novel type-2 fuzzy logic system (T2FLS) for the prediction of fire intensity and its risk assessment for risk reduction in an underground coal mine. Recently, for the observation of underground coal mines, wireless underground sensor network (WUSN) are being concerned frequently. To implement this technique IT2FLS, main functional components are sensor nodes which are installed in coal mines to accumulate different imprecise environmental data like, temperature, relative humidity, different gas concentrations etc. and these are sent to a base station which is connected to the ground observation system through network. In the present context, a WUSN based fire monitoring system is developed using fuzzy logic approach to enhance the consistency in decision making system to improve the risk chances of fire during coal mining. We have taken Mamdani IT2FLS as fuzzy model on coal mine monitoring data to consider real-time decision making (DM). It is predicted from the simulated results that the recommended system is highly acceptable and amenable in the case of fire hazard safety with compared to the wired and off-line monitoring system for UMC. Legitimacy of the suggested model is prepared using statistical analysis and multiple linear regression analysis.
PubDate: 2019-04-01

• The creep compaction behavior of crushed mudstones under the step loading
in underground mining

• Abstract: The crushed rocks are used as a filling material in mined-out areas of underground mining. Compared with the man-made filling materials, the crushed rocks exhibit higher compressibility and lower stability, which may result in instability of surrounding rock and surface subsidence. To study the creep compaction behavior of crushed mudstones, a series of creep tests are conducted. The investigations show that the creep compaction behavior of crushed mudstones is highly dependent on the original grain composition and axial stress applied on the samples. The samples with more large particles are easier to deform at initial loading stage for more large voids existed in the samples, and exhibit greater stability than those with smaller particles when the axial stress less than the bearing capacity of “framework structure”. When the axial stress is higher than 20 MPa, the influences of grain composition on deformability of crushed mudstones are weakened after the samples experience repeated compression. At lower stress level, the creep behavior prefers to occur in the samples with smaller particles, which is mainly caused by particles flow without significant particle breakage. As the axial stress increases, the single-sized sample with smaller particle size and the well-graded sample with larger Talbol power exponent n present more unstable under the constant stress. In addition, the filling of the residual intergranular voids by small particles formed by crushing and splitting behavior is the main cause of creep deformation. Lastly, a creep equation of crushed mudstones is obtained in this paper, which can agree with the experimental results in good.
PubDate: 2019-03-08

• Spontaneous combustion liability of coal and coal-shale: a review of
prediction methods

• Abstract: This study presents a review of the various methods to predict the spontaneous combustion liability of coal and coal-shale. The relative propensity of coal to undergo self-heating can be established by different methods. These methods are well established in their usage, but the fact that no particular test method has become a standard to predict the spontaneous combustion liability indicates that doubt still exists as to the validity of all of them. The underlying principle of all the tests is that the more readily the coal undergoes exothermic oxidation, the more liable it is to self-heat. Comprehensive studies that centres on the international position on research being conducted by academics, different research institutes and industries on spontaneous combustion of coal and coal mine fires were evaluated. Relationships between the geochemical analysis (proximate and ultimate analysis, forms of sulphur, petrographic properties, X-ray diffraction and X-ray fluorescence) and spontaneous combustion testing methods (numerical and experimental approaches) used to predict the spontaneous combustion liability of coal were reviewed. The combination of these tests provides a better understanding of the mechanism that controls the spontaneous combustion phenomena. However, irrespective of the extensive studies that have been conducted over time, spontaneous combustion is still a major problem in the coal value chain.
PubDate: 2019-03-05

• Water-conserving mining influencing factors identification and weight
determination in northwest China

• Abstract: Water-conserving mining is an effective way to alleviate the contradiction between fragile ecological environment and high-intensity coal mining in the arid and semi-arid region of northwest China. It needs to consider the engineering and geological conditions, hydrogeological conditions and mining methods of coal seams. From the three aspects, this paper systematically analyzes the influencing factors and establishes an identification model with multi-level structures. The model includes three primary factors (including the engineering and geological conditions, hydrogeological conditions and mining methods), nine secondary factors (including overlying strata thickness, aquiclude, mining parameters and etc.), sixteen third-tier factors (including the faults, aquiclude thickness and effective mining height and etc.) and twelve fourth-tier factors (including the fault throw exponent, aquiclude permeability and coal pillar sizes and etc.). On the basis, the analytic hierarchy process is used to build the judgment matrix and obtain the weight of each influencing factor. The results indicate that the overlying strata thickness, aquiclude and effective mining height are the most important factors among the primary factors of engineering and geological conditions, hydrogeological conditions and mining methods, respectively. The research results could provide theoretical references for the water-conserving mining of coal resources in northwest China.
PubDate: 2019-03-01

• Bioleaching of trace elements and rare earth elements from coal fly ash

• Abstract: Coal fly ash originated from coal combustion has high concentrations of metals. If suitable leaching techniques are identified, then coal fly ash could serve as a useful source of valuable minerals including rare earth elements (REEs). In this study, three microbial strains, Candida bombicola, Phanerochaete chrysosporium and Cryptococcus curvatus were tested on their performance of leaching trace elements and REEs from fly ash. Through comparing mineral loss and leaching efficiencies resulting from indirect leaching or use of the culture supernatant, C. bombicola was identified to be the best leading to the highest mineral loss and extracting efficiencies of trace elements and REEs among the three strains. The highest mineral loss observed from using the supernatant of this yeast strain was 59.7%. Among all trace elements, As and Mo had the highest leaching efficiency of 80.9% and 79.5%, respectively. The same leaching test led to 67.7% of Yb and 64.6% of Er dissolved from the ash. This study, thus, demonstrated that bioleaching is feasible for leaching metals out of fly ash. The C. bombicola strain deserves further investigation due to its robust actions on metal leaching.
PubDate: 2019-03-01

• Pyrolysis characteristics and kinetics of Indian low rank coal using
thermogravimetric analysis

• Abstract: The present research work deals with the thermogravimetric analysis (TGA) and kinetic analysis of three typical Indian low rank coals selected from Indian coal mines at various temperature ranges. Experiments were performed at four different heating rate (50, 100, 150, 200 K/min) for three typical Indian low rank coal samples in a nitrogen atmosphere from temperature range 30–950 °C. The peak of temperature and mass loss for Indian low rank coal were evaluated. Current study also deals for the utilization and the behaviour of Indian low rank coal during the pyrolysis by using TGA. The activation energy for Indian low rank coal were calculated based on TGA data by using Friedman Method. Corresponding calculated mean value of activation energy for Indian low rank coal is found 49.132 kJ/mol. These experimental results help to explain and predict the behaviour of Indian low rank coal in practical applications.
PubDate: 2019-03-01

• Modeling of liquid hydrocarbon products from syngas

• Abstract: The modeling of hydrocarbon selectivity and CO conversion of the Fischer–Tropsch synthesis over Fe–Ni/Al2O3 catalyst by using coupled artificial neural networks (ANN) and design of experiment (DOE) approaches were investigated. The variable parameters for modeling consisted of the pressure range between 2 and 10 bar and the temperature range of 523–573 K. After training of data by ANN and determination of DOE points by central composite design (CCD), the results were compiled together for producing simulated data used in the response surface method (RSM). The RSM was used as an applied mathematics model to demonstrate the CO conversion and selectivity of hydrocarbons dependence on the CO hydrogenation conditions. The results indicated that CO conversion and $$C_{5}^{ + }$$ selectivity increased with rising both temperature and pressure. The methane selectivity showed upward trend as the temperature increased. It also increased by decreasing pressure. Finally, the optimization of the catalytic process was carried out and conditions with maximum desired product were obtained. A comparison of experimental values and RSM values show that the RSM equations are able to predict the behavior of experimental data.
PubDate: 2019-03-01

• The characteristic and evolution of coal-forming swamp in Hanshuiquan
district, Santanghu Coalfield, Xinjiang, NW China, during the Middle
Jurassic: evidence from coal petrography, coal facies and sporopollen

• Abstract: Santanghu Coalfield is the largest integrated coalfield exploration area in China. The major coal seams developing in Xishanyao Formation (Middle Jurassic) are the high-quality steam coals characterized by large thickness, favorable horizontal continuity and high coal quality. In this paper, twenty-two samples were collected from the three typical boreholes in Hanshuiquan district, representing the 11 coal seam sequences (7#, 8#, 9#, 13#, 14#, 15#, 17#, 18#, 19#, 20#, 22#), respectively. The petrographic characteristics of the coal-bearing sequence in Xishanyao Formation were firstly summarized systematicly, and then the coal-forming swamp characteristics and succession mechanism of the coal seam in Xishanyao Formation were defined by analyzing the samples. The maceral composition, structure, geochemical and geophysical characteristics of coal are included in original genetic criteria of coal-forming swamp analysis. And the composition of coal petrography, maceral and microlithotype are the most frequently used parameters. Coal is composed of microscopic constituents and inorganic substances. The Xishanyao Formation maceral mainly consists of vitrinite (65.74%–97.01%), inertinite (1.93%–34%), and the exinite shows the mode of regular change. The coal-forming swamp in Xishanyao Formation possesses the characteristics of mainly marsh, wet forest swamp facies, and shallow water covered forest swamp facies, and a few of coal seams distribute in the deep water covered forest swamp facies. In addition, the sporopollens in Xishanyao Formation are mainly Pinaceae evergreen broad leaf and needle-leaved plants, Osmundaceae, Cyatheaceae and Lygodiaceae, indicating that the warm and humid tropic-subtropical climate conductive to the persistent growth of coal-forming plants in the Middle Jurassic. The coal-forming swamp shows the characteristics of vertically upward fluctuation through the periodic transition. It indicates a shallow-deep-shallow change process of the water covered depth in the swamp. This is the principal factor for the formation of the high-quality and continuous coal seam in Hanshuiquan district, Santanghu Coalfield.
PubDate: 2019-03-01

• Dynamic simulation of the effect of time-dependent variation of pH on
response variable of the tailing thickener of coal washing plant

• Abstract: Dynamic simulation approach can be used for understanding the nonlinear behavior in mineral processing circuits. In this study, the gel point, the main parameters of batch flux density function and the main parameters of effective solid stress were determined at different conditions (pH, flocculant dosage and particle size). Therefore, the main parameters of phenomenological model of sedimentation and thickening were determined as a function of particle size, pH and flocculant dosages using the result of experimental tests and Curve expert professional software. Then, the dynamic simulation was carried out for the industrial thickener of coal washing plant and the time-dependent variation of response variables was investigated by time-dependent variation of pH of input feed to thickener using the obtained equations. It was observed that it is possible to predict the thickener behavior as a function of time for time dependent variation of pH of input feed to the thickener of coal washing plant using obtained equations that it was not possible using phenomenological model of thickener alone.
PubDate: 2019-03-01

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