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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International Journal of Mining and Geo-Engineering
Number of Followers: 0  

  This is an Open Access Journal Open Access journal
ISSN (Print) 2345-6930 - ISSN (Online) 2345-6949
Published by U of Tehran Homepage  [9 journals]
  • Tunnelling Induced ground settlement considering soil variability

    • Abstract: Ground settlement need to be predicted well so that necessary precautionary measures could be adopted. Ground deformation behaviour due to tunnel construction in inhomogeneous soil has been studied in the past few decades by many researchers. When tunnel-induced ground, settlement is predicted by considering average soil properties, it is likely to miss the true settlement characteristics and failure mechanism due to the inherent heterogeneity of the ground. In this paper, spatial variability of the ground is considered in the numerical analysis to simulate the ground settlement. A numerical model is developed using the Finite-Difference based numerical code FLAC3D to simulate tunnel construction with earth pressure balance (EPB) TBMs for a case study. Both 2D and 3D random fields are simulated in the numerical model. Results are systematically compared with some of the empirical and analytical methods for predicting ground settlement. Spatial distribution is found to have a significant effect on surface settlements and overall ground behaviour.
  • The mineral exploration of rare earth elements using the optimal sampling
           pattern in Baghak mine

    • Abstract: In current study, sampling from the Baghak anomaly in Sangan mines has been carried out based on radioactivity and radiation measurement methods. The goal of this study is to survey the presence or absence of such a relation (between rare earth and radioactive elements) in a skarn mine which is a different case study in central Iran. Mineralogical studies (based on optical and electronic microscopic observations), univariate and multivariate statistical investigations and geochemical analyses are applied. Results show that the Baghak anomaly is due to a significant amount of U, Ce, La and a high concentration of REEs. It seems that mineralization of Th and REEs occurred simultaneously with the formation of iron skarn, while uranium mineralization in hydrothermal form occurred in a secondary phase after the skarn iron mineralization. Finally, it could be acknowledged that in addition to presence of such a relation in the mineralization (central Iran mineralizations), there is an acceptable correlation between these elements in Baghak iron-skarn mineralization.
  • Development of a new system for improving blastability by using the Fuzzy
           Delphi AHP method

    • Abstract: Blastability is one of the most important and effective parameters in open pit mining, which is closely related to rock mass, environmental conditions and explosion systems. To investigate the blastability, many classification systems have been proposed so far, each of which has expressed some of the parameters affecting the blasting according to environmental conditions and based on empirical judgments. Therefore, the factors affecting the blastability can be identified and determined according to theories and environmental conditions. Due to the necessity and presentation of a classification system to investigate the blastability of the Sangan iron ore mines project, by studying and examining each of these factors, in this paper, this classification system was presented and introduced. For this purpose, according to the response received from a questionnaire sent to experts around the world and using the fuzzy Delphi Hierarchical Analysis (FDAHP) method, the weighting of each of the factors affecting the proposed classification system was performed and finally, a new classification system was introduced to optimize blastability classification.
  • Evaluating the efficiency of the Genetic algorithm in designing the
           ultimate pit limit of open-pit mines

    • Abstract: The large-scale open-pit mine production planning problem is an NP-hard issue. That is, it cannot be solved in a reasonable computational time. To solve this problem, various methods, including metaheuristic methods, have been proposed to reduce the computation time. One of these methods is the genetic algorithm (GA) which can provide near-optimal solutions to the problem in a shorter time. This paper aims to evaluate the efficiency of the GA technique based on the pit values and computational times compared with other methods of designing the ultimate pit limit (UPL). In other words, in addition to GA evaluation in UPL design, other proposed methods for UPL design are also compared. Determining the UPL of an open-pit mine is the first step in production planning. UPL solver selects blocks whose total economic value is maximum while meeting the slope constraints. In this regard, various methods have been proposed, which can be classified into three general categories: Operational Research (OR), heuristic, and metaheuristic. The GA, categorized as a metaheuristic method, Linear Programming (LP) model as an OR method, and Floating Cone (FC) algorithm as a heuristic method, have been employed to determine the UPL of open-pit mines. Since the LP method provides the exact answer, consider the basics. Then the results of GA were validated based on the results of LP and compared with the results of FC. This paper used the Marvin mine block model with characteristics of 53271 blocks and eight levels as a case study. Comparing the UPL value's three ways revealed that the LP model received the highest value by comparing the value obtained from GA and the FC algorithm's lowest value. However, the GA provided the results in a shorter time than LP, which is more critical in large-scale production planning problems. By performing the sensitivity analysis in the GA on the two parameters, crossover and mutation probability, the GA's UPL value was modified to 20940. Its UPL value is only 8% less than LP's UPL value.
  • 2D Inversion of magnetic and gravity data: a case study on Golgohar mine

    • Abstract: Because of the limitations of manipulating single geophysical data sets to interpret subsurface anomalies for many cases, it is required to combine geophysical data in order to decrease the ambiguity and non-uniqueness of the interpretation. Integration interpretation of two different geophysical data sets is one of the most common ways to integrate geophysical data and in this paper we want to utilize the combination of gravity and magnetic data for the Golgohar mine in Iran. This mining case is located in the Sanandaj-Sirjan zone in the province of Kerman. Gravity and magnetic data are interpreted using a MATLAB code written based on the damped weighted minimum length solution for which the model weighting is the product of the multiplying of compactness and depth weighting constraints. At first the inversion algorithm is applied on the synthetic case to investigate its reliability for practical application on the real data. Reconstructed models from the noise contaminated synthetic data are suggestive of productivity of the inversion algorithm. Ultimately, the algorithm is applied for the interpretation of the real data and the inversion results of both data sets shows a high correlation about the magnetite anomaly position horizontally and vertically. The results represent an anomaly with the depth ranges approximately from 25 to 130 m with horizontal extension of about 120 m from 280 to 400 m relative to the start of the interested profile.
  • A new approach to analyzing the type of moisture inside the filter cake of
           hematite concentrate

    • Abstract: Filters are widely used for dewatering in the mining industry. In general, different parameters affect vacuum filtration, such as solid percentage, vacuum level, particle size distribution, filter cloth, and chemical additives. These parameters can influence filtration properties such as cake moisture, throughput, and filter cloth lifetime. Moisture and throughput usually are used to determine the quality of filtration. In this study, new variables were used to express the filtration and characteristics of filter cake at a microscopic scale. The quality of filter cake can be precociously analyzed using void fraction and density of filter cake. The present study aimed to propose some new variables to properly analyze the filtration process, improve the filtration rate, and decrease the cake moisture of Gol-E Gohar iron ore concentrate. In this regard, a series of filtration experiments was implemented using laboratory-scale bottom and top feed vacuum filters. The results showed that an increase in the solid percentage decreased the void fraction from 0.45 to 0.40 and increased cake density from 0.30 to 0.33, respectively. Increasing the particle size increased the void fraction from 0.415 to 0.43. Furthermore, the type of structural or capillary moisture of the filter cake could be determined using a void fraction.
  • Physical modeling of soil arching around shallow tunnels in sandy grounds

    • Abstract: The distribution of earth pressure surrounding a tunnel is one of the most critical factors in designing tunnel support systems. In this study, a physical modeling setup has been designed and constructed to simulate the excavation procedure of a full-face circular tunnel. Silica sand was used with four different densities and three different cover-to-tunnel diameter ratios. The full-face excavation was simulated with a variation of tunneling-induced volume loss. The variations of earth pressure around the tunnel were measured by means of a series of miniature soil pressure cells. Particle Image Velocimetry (PIV), as a non-destructive image processing technique, was used to monitor the deformation of the soil surrounding the tunnel. The results obtained from both pressure cells and PIV showed that soil arching developed around the tunnel. As tunnel convergence increased, a loosened zone appeared above the tunnel, surrounded by a stress arch. It was discovered that there is a direct relationship between the height of the loosened zone and the depth of the tunnel. A linear equation has been established for the estimation of the height of the loosened zone, which has a direct influence on the design of the support system.
  • Implications on oil trapping in the Kifl field of Iraq through geophysical

    • Abstract: Potential field geophysical measurements were conducted at the west of Kifl region in central Iraq to image a plausible oil-trapping reservoir. Ground-based magnetometry and gravimetry surveys were conducted to investigate this region by covering an area of 16  24 km through designing a regular grid spacing of 250 m. After preprocessing potential field data, different filters were utilized to separate the residuals from the regional anomalies. The complicated tectonic setting of the studied area was imaged by recognition of the fault system through simulation of the magnetic and gravity anomalies, where it facilitates the configuration display of the oil-trapping mechanism. The geometry of a fault system was derived from parametric inversion of gravity data. The magnetic anomalies were extended with the trends of NS, NW and NE and reached to a maximum value of 55 nT. However, the gravity anomalies appeared with the same extensions and values ranging from -3.3 to 1.5 mGal. The intense magnetic susceptibility amount of the reservoir rocks is arising from chemical processes and iron-oxide ion replacements, accompanying with the migration and accumulation of hydrocarbon. Incorporating the results from the Euler’s depth estimation, parametric data modeling along with logging data assisted simultaneous modeling of the magnetic and gravity data. The 2D geological model of the subsurface layers at the Kifl area presents a graben-horst fault system within a thick sequence of sediment. Geological characteristics extracted from geophysical data modeling provided insightful information on the nature and essence of the hydrocarbon reservoirs in the Kifl area. It has formed through tectonic deformation and tension over the Arabian plate during Permian – Paleocene cycle. Hence, it can be concluded that aforementioned fault system has clearly divided the hydrocarbon reservoirs.
  • Development of new comprehensive relations to assess rock fragmentation by
           blasting for different open pit mines using GEP algorithm and MLR

    • Abstract: The fragment size of blasted rocks considerably affects the mining costs and production efficiency. The larger amount of blasthole diameter (ϕh) indicates the larger in blasting pattern parameters, such as spacing (S), burden (B), stemming (St), charge length (Le), bench height (K) and the larger the fragment size.  In this study, influence of blasthole diameter, blastability index (BI) and powder factor (q) on the fragment size were investigated. First, the relation between each of X20, X50 and X80 with BI, ϕh and q as the main critical parameters were analyzed by Table curve v.5.0 software to find better input variables with linear and nonlinear forms. Then, the results were analyzed by multivariable linear regression (MLR) procedure using SPSS v.25 software and gene expression programming (GEP) algorithm for prepared datasets of four open pit mines in Iran. Relation between each of X20, X50 and X80 with the combination of adjusted BI, ϕh and q were obtained by MLR procedure with good correlations of determination (R2) and less root mean square error (RMSE) values of (0.840, 1.4 cm), (0.874, 2.5 cm) and (0.823, 9.6 cm) respectively. Moreover, new models were developed to predict X20, X50 and X80 by GEP algorithm with better correlations of R2 and RMSE values (0.860, 1.3 cm), (0.913, 2.49 cm) and (0.923, 5.6 cm) respectively and good agreement with actual field results. The developed GEP models can be used as new relations to estimate the fragment sizes of blasted rocks.
  • A review on the extraction of vanadium pentoxide from primary, secondary,
           and co-product sources

    • Abstract: Vanadium is a strategic metal and its compounds are widely used in industry. Vanadium pentoxide (V2O5) is one of the important compounds of vanadium, which is mainly extracted from titanomagnetite, phosphate rocks, uranium-vanadium deposits, oil residues, and spent catalysts. The main steps of vanadium extraction from its sources include salt roasting, leaching, purification, and precipitation of vanadium compounds. In the hydrometallurgical method, first, the vanadium is converted to a water-soluble salt by roasting, and then the hot water is used to leach out salt roasted product and the leach liquor is purified by chemical precipitation, solvent extraction, or ion exchange processes to remove impurities. Then, a red cake precipitates from an aqueous solution by adjusting the conditions. To provide high pure vanadium pentoxide, it is necessary to treat the filtered red cake in ammonia solution. So, ammonium metavanadate (AMV) is precipitated, calcined, and flaked to vanadium pentoxide. In the pyrometallurgical method, vanadium-containing concentrate is smelted, and by forming titanium-containing slag and molten pig iron, oxygen is blown into pig iron in a converter or shaking ladles, and vanadium is oxidized to produce vanadium-rich slag. In the next step, the slag is roasted and treated by the hydrometallurgical process. In this paper, the industrial processes and novel developed methods are reviewed for the extraction of vanadium pentoxide.
  • Reservoir characterization and porosity classification using probabilistic
           neural network (PNN) based on single and multi-smoothing parameters

    • Abstract: Probabilistic neural network (PNN) is a feed-forward neural network using a smoothing parameter. We used PNN algorithm based on single and multi-smoothing parameters for multi-dimensional data classification. Using multi smoothing parameters, we implemented an improved probabilistic neural network (PNN) to estimate porosity distribution of a gas reservoir in North Sea. Comparing the results of implementing smoothing parameters which obtained from model-based optimization and particle swarm optimization (PSO) indicated the efficiency of PNN in characterizing the gas. Also results showed that while PSO algorithm was able to specify smoothing parameters with more precision, about 9%, but it was very time consuming. Finally, multi PNN based on PSO was applied to estimate porosity distribution of F3 reservoir. The results validated the main fracture or gas chimney of F3 reservoir with higher porosity. Also, gas bearing layers were highlighted by energy and similarity attributes.
  • Physical Model Simulation of Block Caving in Jointed Rock Mass

    • Abstract: Incorrect estimation of undercut dimensions in the block caving method can lead to the cessation of caving operations and loss of a large portion of deposits. Numerical modeling is one of the methods for determining the minimum caving span. Numerical and physical modeling methods are useful for an accurate understanding of caving operations. Accordingly, this research focused on investigating the performance of physical and numerical modeling in determining the effects of depth and joint orientation on the minimum required caving span for the initiation and propagation of caving. The physical model was made with 1.5*1.5 square meter dimensions and consisted of travertine blocks with 4*4 square centimeter dimensions. In addition, joints were modeled with dips of 0, 90, 45, 135, 30, and 120 degrees. The physical model could simulate ground stress conditions to great depths and show the behavior of the jointed rock mass in a two-dimensional space. Further, by capturing this behavior, it was possible to compare its result with UDEC software. The results demonstrated that the number of falling blocks and the height of the caving increase by increasing the dip. Furthermore, the formation of arches due to high horizontal stress stops the caving, which will occur again with the increasing span. Although the horizontal stresses and geometrical properties of the joints affect the shape of the caving area, its shape largely follows the dip and orientation of the rock mass joints. Poor draw control causes caved ore columns, which can lead to the formation of a stable arc. Finally, the height of the caved back increases in each span by increasing the depth while decreasing the dip of the joints.
  • Geoelectrical characterization of a landslide surface for investigating
           hazard potency, a case study in the Tehran- North freeway, Iran

    • Abstract: Landslide, as a geohazard issue, causes enormous threats to human lives and properties. In order to characterize the subsurface prone to the landslide which is occurred in the Tehran-North freeway, Iran, a comprehensive study focused on geological field observations, and a geoelectrical survey as a cost-effective and fast, non-invasive geophysical measurement was conducted in the area. As a result of road construction, problems in this region have increased. The Vertical Electrical Sounding (VES) investigation in the landslide area has been carried out by the Schlumberger array for data acquisition, implementing eight survey profiles varying in length between 60 and 130 m. Based on the electrical resistivity models through a smoothness-constrained least-square inversion methodology, the landslide structure (i.e., depth of the mobilized material and potential sliding surface) is better defined. The inferred lithological units, accompanied by stratigraphical data from a borehole and geological investigations for the prone landslide region, consisted of a discontinuous slip surface, having a wide range of resistivity, observed to be characterized by tuff with silt. Electrical resistivity values above 150 Ωm indicate a basement of weathered marlstone and sand. Values between 15 and 150 Ωm illustrate a shale-content layer with outcrops in the area that is the reason for movement. The sliding surface is at a depth of about 12 m. The method used in this study is a good candidate to investigate the risk of landslides in this region and can be applied to other landslide areas where borehole exploration is inefficient and expensive due to local complications.
  • Optimizing the exploratory drilling rig route based on the Multi-Objective
           Multiple Traveling Salesman Problem

    • Abstract: Exploratory drilling is one of the most important and costly stages of mineral exploration procedures, so the continuation of mining activities depends on the gathered data during this stage. Due to the importance of cost and time-saving in the performance of mineral exploration projects, the effective parameters for reducing the cost and time of drilling activities should be investigated and optimized. Road construction and the sequence of the drilling boreholes by drilling rigs are among these parameters. The main objectives of this research were to optimize the overall road construction cost and the difference in length drilled by each drilling rig. The problem has been modeled as a Multi-Objective Multiple Traveling Salesman Problem (MOmTSP) and solved by the Non-dominated Sorting Genetic Algorithm-II (NSGA-II). Finally; the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method has been used to find the optimal solution among the solutions obtained by the NSGA-II.
  • A numerical study on the influence of tunnel excavation on pile foundation

    • Abstract: Tunnel construction in cities faces many geotechnical challenges, and the effect on pile foundation is possibly one of the most complex ones. Most tall buildings in big cities mostly have pile foundations, and any tunnelling nearby might significantly influence those existing foundations. In the present study, a 3-dimensional Finite Element (FE) analysis has been carried out to investigate tunnelling effects on pile foundations. The investigation is done for a single pile with multiple stages of tunnel excavation where the pile foundations are assumed to reach below the base of the excavation of tunnelling. A tentative rate of excavation was also included in this investigation and found that a faster rate of excavation results in better performance of foundations affected by tunnelling. The study also extended to see the effect of tunnelling on pile groups. Attempts were made to compare the results with some of the previously published literature.
  • Effect of the chemical compounds of soil on the stability of excavation
           wall: A case study

    • Abstract: Chemical compounds of soils can remarkably affect the stability of the excavation wall. This is highlighted in soils with fine grain materials. Inter-particle chemical cementation (IPCC) increases soil cohesion and, in turn, provides more stable excavations. This study evaluates the effect of soil chemical compounds on the stability of an excavation excavated in the west of Iran, Kermanshah city. It adopted the 2D finite element method (2DFEM) to evaluate the physical stability of the excavation. In the excavation examined here, the maximum depth that could be excavated with no need for support was 36m. In contrast, according to simulation results, the maximum possible depth for an excavation with soil cohesion of 6kPa and friction angle of 33 degrees, derived from direct shear test, is 6m. As per the results of this investigation, iron oxide, aluminum oxide, and silicon oxide increase the soil's cohesion containing the clay mineral montmorillonite by 10 folds and increase its shear strength by 127%. 
  • Geometry determination of galleries and pillars in Chehel Koureh copper
           mine, Iran

    • Abstract: Chehel Koureh mine project is located 110 km NW of Zahedan in the southeast of Iran. Due to the great depth of ore deposits, the underground exploitation method was chosen. In this research, the geomechanical parameters were obtained using in situ tests and empirical formulas. The non-pillar continuous mining method (NPCM) was selected as the most appropriate method considering the shape of the ore body and rock mass strength conditions. As the rock mass is fractured and has semi-continuum characteristics, the stability analysis of the shape dimensions was carried out using FLAC 3D software. In the proposed method, a cylindrical pillar with a height of 3.8 meters was located above the stope. For the safety of the drilling machine room and stope roof, height accuracy was required. Five different pillar diameters (i.e., 3, 3.2, 3.4, 3.6, and 3.8 m) were analyzed by considering the critical height and plastic zone created around the pillar. For these five diameters, only the pillar with a diameter of 3 meters had a supercritical height. It was observed that for the pillar with a diameter of 3.8 m, no plastic zone was created and the safety factor for this pillar was obtained 1.11. Due to the restrictions for the application of the proposed mining method i.e. NPCM in Iran, the Miami method was considered as the alternative mining method applicable to the Chehel Koureh copper deposit. Then, the suitable dimensions for stope and pillar were determined by the same software. In the Miami method, there were three spans and two pillars at each stope before the recovery of pillars could be undertaken. The pillars with three widths of, i.e., 5, 6, and 8 meters were studied for the stability analysis. The results demonstrated that a plastic zone was not created only around the pillar with a width of 8 meters, and the safety factor for this pillar was obtained to be 1.56.
  • HEBF strategy: A hybrid evidential belief function in geospatial data
           analysis for mineral potential mapping

    • Abstract: In integrating geospatial datasets for mineral potential mapping (MPM), the uncertainty model of MPM can be inferred from the Dempster – Shafer rules of combination. In addition to generating the uncertainty model, evidential belief functions (EBFs) present the belief, plausibility and disbelief of MPM, whereby four models can be simultaneously utilized to facilitate the interpretation of mineral favourability output. To investigate the functionality and applicability of the EBFs, we selected the Naysian porphyry copper district located on the Urmia – Dokhtar magmatic belt in the northeast of the Isfahan city, central Iran. Multidisciplinary datasets- that are geochemical and geophysical data, ASTER satellite images, Quickbird and ground survey- were designed in a geospatial database to run MPM. Implementing the Dempster law through intersection (And) and union (OR) operators led to different MPM performances. To amplify the accuracy of the generated favourability maps, a combinatory EBFs technique was applied in three ways: (1) just OR operator, (2) just And operator, and (3) combination of And and OR operators. The plausibility map (as mineral favourability map) was compared to Cu productivity values derived from drilled boreholes, where the MPM accuracy of hybrid method was higher than each individual operator. Of note the success rate of hybrid method validated by 21 boreholes was about 84%, and it demarcates high favourability zones occupying 0.67 km2 of the studied area.
  • Thermoacidophilic bacteria isolated from Sarcheshmeh low-grade copper ore
           in chalcopyrite bioleaching from mineral tailing

    • Abstract: This research has focused on isolating and identifying different thermoacidophilic bacteria from a Sarcheshmeh low-grade copper ore and evaluating their ability of copper bioleaching from the mineral tailing. After the isolation of the bacteria, molecular identification was carried out based on the 16S rRNA gene sequences and drawing the phylogenetic tree. Then, the effect of the pH, pulp density, and composition of the media on the copper bioleaching was determined using the identified bacteria. The isolated strain (Strain SCM1) belonged to Delftia acidovorans with a 95.73% of identity. The optimal condition for the copper bioleaching was reported in a medium consisting of sulfur (10 g/L), glucose (10 g/L), yeast extract (2 g/L), and mineral tailing (5% wt/vol) at the pH of 2.00 at 50°C. Under this condition, the highest amount of copper (83%) was bioleached. It proves that the lately isolated strain can be effectively employed in the copper bioleaching process.
  • Application of adaptive neuro-fuzzy inference system for prediction of
           dissolved oxygen concentration in the gold cyanide leaching process

    • Abstract: An adaptive neuro-fuzzy inference system (ANFIS) model has been developed for the prediction of the dissolved oxygen concentration (DOC) as a function of the solution temperature (0-40oC), salinity based on conductivity (0-59000 µS/cm) and atmospheric pressure (600-795 mmHg). The data set was randomly divided into two parts, training and testing sets. 80% of the data points (80%=11556 datasets) were utilized for training the model and the remainder data points (20% =2889 datasets) were utilized for its testing. Several indices of performance such as root mean squared error (RMSE), mean absolute percentage error (MAPE) and coefficient of correlation (R) were used for checking the accuracy of data modeling. ANFIS models for prediction of DOC were constructed with various types of membership functions (MFs). The model with the generalized bell MF had the best performance among all of the given models. The results indicate that ANFIS is a powerful tool for the accurate prediction of DOC in the gold cyanidation tanks.
  • The Potential Sources of Bauxite in PirMishi Tash, Semnan Province,
           Northern Iran

    • Abstract: Tash bauxite mine is located approximately 6 km northeast of Tash village and 40 km northwest of Shahroud city in Semnan Province with coordinates of 36° 32′ N to 36° 37′ N and 54° 41′ E to 54° 48′ E. The actions of the orogenic phase of the former Cimmerian as well as the chemical and physical factors have caused the erosion of the basalts in the Shemshak sedimentary basin, which have resulted in the simultaneous deposition of the Shemshak molasses‌ and bauxite in Tash area. According to some geological evidence and the location of Elias rule, bauxites in the vicinity of Shemshak Formation shales, it is concluded that the clay minerals have played an important role in forming the bauxite deposits in this area. The results showed that the basalts were formed from the alkaline magma and then altered to the clay minerals. The rmaining immobile elements such as aluminum and residual iron formed Tash bauxite deposit. The investigation of thin sections designates that the studied ore contains ooidal, plitomorphic, allogeneic pizolite, coloform, and compressive dissolution tissues, which indicates the autochthonous origin. Pyrite, chalcopyrite, goethite, and hematite were also recognized. The mineralogical study, performed by the X-Ray diffraction method, led to the identification of minerals of anatase, boehmite, diaspore, chamosite, kaolinite, quartz, and hematite. Analysis of ore samples by the X-Ray fluorescence method and calculation of aggregation coefficient of trace elements and geochemical indicators along with geological evidence revealed the source rock could be from the mafic type.    
  • A proposed framework for estimating the environmental damage cost of
           mining activities in line with the goals of sustainable mining: a case
           study of Sungun-Ahar Copper Mine, Iran

    • Abstract: The growth of mining activities reduces the area covered by natural ecosystems and the value of ecosystem services (ES) provided by them. It is necessary to estimate the impacts of land-use changes on the ES value of the ecosystems located in the areas directly and indirectly influenced by mining activities as well as the cost of environmental damages inflicted on the ecosystems. Green mining makes it possible to develop a suitable and effective mechanism for the policymakers and planners to optimally and sustainably upgrade resources utilization. Estimating the cost of the environmental damage of mining activities would effectively preserve ES values and prevent the degradation of ecosystems. It is also an efficient approach in making effective decisions and plans for the restoration of mines. The recent study is the first research to investigate the relationship between mining activities and their impact on reducing/losing the value of ecosystem services by offering a comprehensive and specific framework. The total estimated cost of environmental damages inflicted on ecosystem services influenced by the mining activities in the Sungun Copper Mine was estimated at Int $ 7543232 (1734943 million IRR). This research aimed to develop a comprehensive framework for the stages involved in estimating the changes and losses inflicted on the values of ecosystem services provided by the ecosystems within the scope of direct and indirect effects of mining activities. This framework can help policymakers, stakeholders, and land use planners at regional and national levels preserve ecosystem services and make sustainability plans for the mining regions.
  • Constrained Vertex Optimization and Simulation of the Unconfined
           Compressive Strength of Geotextile Reinforced Soil for Flexible Foundation

    • Abstract: Extreme vertex design (EVD) provides an efficient approach to mixture experiment design whereby the factor level possesses multiple dependencies expressed through component constraints formulation. Consequently, the derived experimental points are within the center edges and vertices of the feasible constrained region. EVD was deployed for the modeling of the mechanical properties of the problematic clayey soil-geogrid blends. Geogrids are geosynthetic materials which possess an open mesh-like structure and are mostly used for soil stabilization. The geotextile materials present a geosynthetic and permeable layer to support the soil and foundation by improvement of its stiffness characteristics and at a cheaper cost to procure compared to other construction materials and possess unique light weight properties with greater strength improvement on the soil layer when used. Minitab 18 and Design Expert statistical software were utilized for the mixture design experiment computation; to fully explore the constrained region of the simplex, I-optimal designs with a special cubic design model were utilized to formulate the mixture component ratios at ten experimental runs. I-optimality and D-optimality of 0.39093 and 1747.474, respectively, were obtained with G-efficiency of 64.8%. The generated laboratory responses were taken together with the mixture ingredients’ ratio and taken as the system database for the model development. Statistical influence and diagnostics tests carried out on the generated EVD model indicate a good correlation with the experimental results. Graphical and numerical optimizations were incorporated using a desirability functions that ranged from 0 to 1, which helped to arrive at the optimal combination of the mixture components. 0.2% of geogrid, 9.8% of water, and 90 % of soil yielded the optimal solution with a response of 41.270kN/m2 and a desirability score of 1.0. Model simulation was further carried out to test the model’s applicability with the results compared with the actual results using student’s t-test and analysis of variance. The statistical results showed p-value>0.05 which indicates good correlation.
  • Failure modeling of alluvial foundations due to boiling: numerical
           modeling versus experiments

    • Abstract: The sheet piles are used below hydraulic structures to reduce seepage flow rate and hydraulic gradient at the outlet of such structures rested on permeable foundations. Up to now, for analysis of seepage under hydraulic structures much research work has been carried out in the form of numerical models. However, less field and laboratory works have been performed to study and compare boiling phenomena for evaluating of the numerical models. By simulating an experimental model of a sheet pile inserted in a sand foundation by computer code FLAC based on the finite difference method, the soil behavior mechanism flow has been investigated under seepage effect. The results indicate that computer code FLAC underestimated uplift pressures compared to the experimental data. In order to study the boiling, the soil treatment analyzed at the most critical condition as well. The numerical model presented in computer code FLAC, is properly able to simulate the soil and foundation behavior. Comparing the results obtained from numerical model with experimental data also confirms well, because this model predicts the boiling observations with reasonable accuracy and it was possible to predict heaving mechanism based on the stress analysis before performing the plan.
  • Comparison between the performance of four metaheuristic algorithms in
           training a multilayer perceptron machine for gold grade estimation

    • Abstract: Reserve evaluation is a very difficult and complex process. The most important and yet most challenging part of this process is grade estimation. Its difficulty derived from challenges in obtaining required data from the deposit by drilling boreholes, which is a very time consuming and costly act itself. Classic methods which are used to model the deposit are based on some preliminary assumptions about reserve continuity and grade spatial distribution which are not true about all kind of reserves. In this paper, a multilayer perceptron (MLP) artificial neural network (ANN) is applied to solve the problem of ore grade estimation of highly sparse data from zarshouran gold deposit in Iran. The network is trained using four metaheuristic algorithms in separate stages for each algorithm. These algorithms are artificial bee colony (ABC), genetic algorithm (GA), imperialist competitive algorithm (ICA) and particle swarm optimization (PSO). The accuracy of predictions obtained from each algorithm in each stage of experiments were compared with real gold grade values. We used unskillful value to check the accuracy and stability of each network. Results showed that the network trained with ABC algorithm outperforms other networks that trained with other algorithms in all stages having least unskillful value of 13.91 for validation data. Therefore, it can be more suitable for solving the problem of predicting ore grade values using highly sparse data.
  • Effect of Water Quality on Formation of Hydrogen Peroxide and Its Behavior
           on Flotation

    • Abstract: Water is one of the important parameters in flotation and represents 80–85% of the volume of mineral pulp processed in flotation circuits. In our recent studies revealed was found that sulphide minerals generated H2O2 in pulp liquid during wet grinding and also the solids when placed in water immediately after dry grinding but effect of type of water on the oxidation of pulp components and hence in deteriorating the concentrate grade and recovery in flotation has not been explored yet. In this study, effect of two types of water on formation of H2O2 as an oxidizing agent stronger than oxygen was investigated. process water is water that is used for a flotation processes in Bama Company. It was shown that process water generated 482 µM H2O2 but deionized water generated 16 µM. The result shows recovery of chalcopyrite in pH 6 is 60% and 40% in process water and deionized water respectively. Also, recovery of galena in pH 6 is 30% and 20% in process water and deionized water respectively.
  • Solving 2-D gravity inversion problems using a PDE model in geophysics

    • Abstract: Inverse modeling is one of the useful solutions to create a logical model with relationships between observed and measured values. In geophysical and subsurface investigations such as cavities or mineral explorations, solving inverse problems using problem physics in a partial differential equation (PDE) system is very important. In this research, COMSOL multiphysics’ optimization interface, combined with a PDE or physics interface, was used to solve inverse-modeling problems. Also, a framework is presented to solve undetermined inverse problems using COMSOL multiphysics’ optimization. COMSOL multiphysics does not include a gravity calculation module. However, since Poisson’s equation governs gravity and electrostatics, a gravity model can be created in the electrostatics module by changing the electrical permittivity value. We present a general adjoint state formulation which may be used in this framework and allows for faster calculation of sensitivity matrices in a variety of commonly encountered underdetermined problems. First of all, 2D inversion of gravity data has been run and validated in COMSOL multiphysics software using one synthetic model and synthetic data in a forward modeling process. Afterward, using real gravity data surveyed along a cross-section of the sinkholes in the NW of Abarkuh, the lateral structure and subsurface cavities were estimated. The inverted gravitational acceleration values, then cross-correlated with observed gravity data and available surface pieces of evidence such as sinkholes and circular structures. The results indicated that our COMSOL-based routines for the solution of PDE-basedinverse problems using adjoint states, while high in computational speed, can be used in modeling a wide range of physical systems governed by the partial differential equation laws and also can accurately discriminate between low-density contrast regions and background.
  • Aeromagnetic Mapping of Basement Structures and Gold Mineralization
           Characterization of Kirk range Area, Southern Malawi

    • Abstract: A high-resolution aeromagnetic survey was conducted in the Kirk Range region in southern Malawi with the goal of obtaining comprehensive geological and structural information. This newly collected data was analyzed and interpreted in order to gain a better understanding of the mode of occurrence of gold mineralization and related structural characteristics. To un-derstand the distribution of magnetic sources, many analytic approaches were applied to the aeromagnetic data, including reduction to the pole, Euler deconvolution, Spectrum analysis, Tilt and Vertical Derivatives filtering. Spectral analysis and Euler deconvolution were used to determine the depth of magnetic sources. The study reveals that the studied region is charac-terized by NE-SW and roughly E-W direction structures and that the gold occurrence is re-stricted within these structures, implying that mineralization is structurally controlled. These structures are found at depths of 200-1000 meters, according to Euler solutions produced from this work. Based on the calculated depths the structures controlling mineralization, in the Kirk Range are interpreted to occur at a depth range of 200 to 1000m and the structures trend in the NE-SW and E-W direction. However current gold mining is taking place at a fairly shallow depth of less than 50m and no gold mine has gone deeper than that. The struc-tural pattern and depth extent estimations show that gold mineralization in the Kirk range is expected to continue up to 1000 meters because the majority of the structures controlling mineralization in the region are located within that depth range. It is therefore recommended that future exploration should go deeper to a depth of about 200-1000 meters or more focus-ing on these NE-SW and E-W structures, because it is expected that at that depth range more mineralization should be intercepted.
  • A New Method for Determining Geochemical Anomalies: U-N and U-A Fractal

    • Abstract: Undoubtedly, determining the threshold of anomalies and separating geochemical anomalies from background is one of the most important stages of minerals exploration. In the discussion of the separation of geochemical anomalies from background, there are different methods that structural methods have shown much greater efficiency than nonstructural methods. Among structural methods (methods that consider the position and location of samples), U-statistic and fractal methods have a special place. In this study, by using the algorithm of the abovementioned methods and combining them with each other, a new method as U values fractal model (U-N and U-A) is introduced at the first time. Then, the proposed method is employed to determine the boundaries of background and anomalous populations (about the gold (Au) and arsenic (As) elements in Susanvar district). Results show that in U-N and U-A fractal models, the first fracture boundary is much clearer and more accurate than previous fractal models (C-N and C-A) in the same condition. In U-N model, due to the nature of the U method algorithm, there is a discontinuity as exact threshold between background and anomaly that in U-A model, this does not exist due to the homogenization of U values. In this method, the exact threshold between background and anomaly is determined by U-statistic method and by its combination with the fractal method, in each population, sub-populations are identified more accurately and simply than concentration fractal model. Finally, lithogeochemical map of the study area is provided for Au and As which has been prepared using U-N and U-A fractal methods. In these maps (especially the prepared maps by U-A model), the delineated Au-As mineralization is closely associated with the defined Au ore indications in the study area.
  • Removal of copper ions from dilute sulfuric acid solutions: Effect of
           solution composition and applied potential

    • Abstract: Removal of copper from synthesized and real dilute sulfuric acid solutions was investigated. Effects of copper and iron concentrations and applied potential were studied. In pure copper solutions, increasing the Cu (II) concentration from 1000 to 5000 mg.L-1 increased the copper recovery from about 30-300% depending on the cathode potential and decreased the energy consumption by about 30%. Also, with increasing the acid concentration from 15 to 50 g.L-1 an about 25% increase in copper recovery and a 30% decrease in energy consumption were observed. The addition of Fe (II) to the solution improved the ionic conductivity and so that the copper recovery. The specified energy consumption for the real leaching solutions increased to 31-47
  • Using the mass-radius method to quantify the disturbed zones in Sidi
           Chennane mine through geoelectrical images

    • Abstract: This paper presents a new approach to quantify the rate of the disturbances within the phosphate series in an area of 50 hectares located in Sidi Chennane deposit, Ouled Abdoun, Morocco. The proposed approach consists in applying the mass-radius fractal method on the geo-electrical images to estimate the fractal dimension FD as an index of the rate of the disturbances. The result of this study shows a strong correlation between the measured disturbed surfaces displayed on the studied geo-electrical images and their corresponding fractal dimensions. The calculated FD’s values were found in the range of 2.081 to 2.719 and correspond to the range of the disturbances rates of 4.1 % to 17.7 % respectively. Therefore, the highest fractal dimension values reveal a high rate of disturbances and vice-versa. This analysis has confirmed that the fractal dimension may offers significant implications to distinguishing between the phosphate deposit at high disturbances rate and the deposit at low disturbances rate. This may lead to important implications for the mining engineers to obtain an accurate phosphate reserve estimate and make the best exploration and exploitation planning in Sidi Chennane mine.
  • Comparison of clayey soil characteristics treated with lime and water base

    • Abstract: This paper presents results of laboratory tests to explicate the mechanism of the Poly Vinyl Acetate (PVA) and hydrated lime on the engineering properties of the treated soil. Soil improvement is a time and cost saving method that enables unsatisfactory in-situ materials to obtaining higher strength, obviating the need for costly excavation and replacement with suitable material. Laboratory test, including consistency limits, compaction, unconfined compressive strength (UCS), and direct shear tests were carried out on treated soils. The results show that the addition of 4% PVA and 6% lime can improve soil properties, but lime had higher UCS on long period. Moreover, optimum percentage of PVA has a small effect on the cohesion and UCS of treated soil, but its effect on friction angle is significant.
  • Selective precipitation of iron from multi-element PLS produced by
           atmospheric leaching of Ni-Co bearing laterite

    • Abstract: Laterites are the main resources of oxidized nickel in the world. Nickel and cobalt are embedded in limonite laterites within the goethite structure. Therefore, the removal of iron ions will lead to the simultaneous precipitation of iron, nickel, and cobalt. In our previous study investigating atmospheric leaching of laterite ore using sulfuric acid with the addition of NaCl to the solution, we determined the optimal parameters to minimize the co-dissolution of iron. Based on the determined optimum conditions, a PLS was prepared. In the current study, the effect of pH on iron precipitation from the PLS was investigated using sodium hydroxide as a neutralizing agent. Results indicated that a pH=4 can result in the highest removal of iron from the leaching solution (around 90%) while minimizing loss of nickel and cobalt. The SEM analysis revealed ferrihydrite as the most important mineral in the final precipitation obtained at pH=4. Results of this study can be used for benchmarking more efficient methods for iron removal from the solution and improving the dissolution kinetics of nickel and cobalt.
  • Model development for prediction of autogenous mill power consumption in
           Sangan iron ore processing plant

    • Abstract: The variables including ore hardness based on the SAG power index (SPI), particle size of mill product (P80), trunnion pressure of the mill free head (p) and working time period of mill liner (H) were considered as variables for development of an adequate model for the prediction of autogenous (AG) mill power consumption in Sangan iron ore processing plant. The one-parameter models (SPI as variable) showed no adequate precision for the prediction of Sangan AG mill power consumption. Two-parameter models (SPI and P80 as variables), proposed by Starkey and Dobby, showed no adequate precision for the Sangan AG mill power consumption. Nonetheless, by exerting an adjustment factor in the model (0.604513 which obtained by what-if analysis using Solver Add-Ins program), the model precision increased significantly (an error of 7.11%). Finally, a four-parameter model in which the Sangan AG mill power consumption is predicated as a function of SPI, P80, p, and H was developed. Hence, initially the relationship between the mill power consumption and each of the variables was obtained and then the four-parameter model was developed by summation of these four equations and applying a similar coefficient of 0.25 for all of them. This model was modified through finding the best coefficients by what-if analysis using solver Add-Ins program through minimizing the ARE error function. The error function for the training and testing data sets was determined to be 2.93% and 2.39%, respectively.
  • Microwave-Assisted Leaching for Copper Recovery from the Chalcopyrite
           Concentrate of Sarcheshmeh Copper Complex

    • Abstract: Microwave applications in mining and process metallurgy have been the subject of many studies over the past two decades. This paper reviews microwave-assisted leaching of copper from high-grade sulfide concentrate of the Sarcheshmeh copper complex. Response surface methodology (RSM) is used to optimize the leaching process. In this research, leaching experiments were carried out in a multi-mode cavity and times in the presence of varying concentrations of H2O2 with microwave assistance after the leaching process parameters including type and concentration of the oxidizing agent, NaCl concentration, and leaching temperature, were optimized using Taguchi orthogonal array design method. The conventional leaching experiments were also performed to evaluate the influence of microwave radiation. It has been recognized that microwave technology has great potential to improve the extraction efficiency of metals in terms of both reductions in required leaching time and the recovery of valuable metals. Under the optimized conditions, the leaching efficiencies of copper were 75.3% and 42.5% in 3 hours by microwave assistance and conventional leaching methods, respectively.
  • Prediction of rockburst in water conveyance tunnel: A case study of Gelas

    • Abstract: At the presence of undesirable geological conditions, including rock masses with high overburden, crushed zones and faults, folds, dikes and other abnormalities, rockburst has become a critical safety problem in Gelas tunnel, a water conveyance tunnel, wherein some sections overlying strata exceed 600 m. The main goal of this study is to determine the possibility of rockburst and its level along the second part of the Gelas tunnel. In order to study the mechanisms of rockburst occurrence in Gelas tunnel, measurements of in situ stress, geological investigation, uniaxial compression tests, and analytical approaches are carried. So, in this study, some analytical approaches, including Linear elastic index, Tangential stresses criterion, Brittleness coefficient of rocks, and method of stresses are used to predict rockburst in 17 sections of the tunnel path. The average result shows that all the selected sections in the tunnel path have the potential of occurring rockburst at a range of low to moderate. About 65 percent of the sections are exposed to moderate risk of rockburst occurrence; and the remaining 35 percent are exposed to low risk of rockburst occurrence. The comparison between applied methods shows a lack of consensus conformity among them. The brittleness coefficient of rocks method turned out to be as the most conservative approaches for predicting rockburst occurrence since by this approach most of the sections in the tunnel path are susceptible to high risk of rockburst occurrence. According to the average result, fault and Dolomitic zones with high overburden have the highest risk of rockburst occurrence.
  • Modeling the Effect of the Striker Geometry on the Wave Propagation
           Pattern in the Split-Hopkinson Pressure Bar Test Using the Discrete
           Element Method

    • Abstract: Split Hopkinson Pressure Bars (SHPB) test is widely used among the various methods for investigating the dynamic behavior of rocks at high strain rates. Various factors affect the waveform and the results of this test. In this study, the aim was to investigate the effect of geometrical parameters of striker including the effect of shape, length, and impact cross-section width (ICSW) on the waveform induced in the SHPB test using numerical modeling. For this purpose, in the first stage, the required information including geometrical properties and the required micro-parameters have been collected from two laboratory and numerical modeling studies. Then, the initial model was constructed using the discrete element numerical method (DEM), and its results were compared with laboratory and numerical results. Evaluation of the effect of striker shape demonstrated that SS strikers have induced a semi-sinusoidal wave and CS strikers have induced a quasi-rectangular wave. Among the waveform properties, the wavelength was strongly related to the geometric properties of the strikers in both CS and SS types in a way that was directly related to the striker’s length and inversely related to the ICSW. On the other hand, the maximum amplitude is directly related to the striker’s length and ICSW in both CS and SS types. According to the results, the use of SS strikers is more appropriate according to the waveform, and its geometric properties can be determined according to the problem requirement, using numerical modeling results.
  • Modeling of Unconfined Compressive Strength and Young's Modulus of
           Lime and Cement Stabilized Clayey Subgrade Soil using Evolutionary
           Polynomial Regression (EPR)

    • Abstract: In this study, the evolutionary polynomial regression (EPR) method has been employed to develop simple models with reasonable accuracy to predict the compressive strength and Young's modulus of the lime/cement stabilized clayey subgrade soil. For this purpose, the different specimens with the various cement and lime contents, at three moisture contents (dry side, wet side, and optimum moisture content) were fabricated and were cured for 7, 14, 21, 28 and, 60 days to conduct the unconfined compressive strength (UCS) test. According to the test results, a dataset consisting of 75 records for each additive was prepared. Results of this study show that the R2 value of the developed model for predicting UCS of cement-stabilized clay soil is equal to 0.96 and 0.95 for training and testing sets, respectively. These two values for lime-stabilized soil are 0.91 and 0.87, respectively. Moreover, the R2 for predicting Young's modulus of cement-stabilized clay soil is equal to 0.90 and 0.89 for training and testing set, respectively. These two values for predicting Young's modulus of lime-stabilized soil are 0.88 and 0.94, respectively. The sensitivity analysis showed that for the Portland cement stabilized clayey subgrade, the percentage of the Portland cement and moisture content are the most significant parameters for predicting the UCS and Young's modulus, respectively. In contrast, for the lime-stabilized clayey subgrade soil, the most important parameters are the moisture content and the UCS, respectively.
  • Photogrammetry and Monte Carlo Simulation based statistical
           characterization of rock mass discontinuity parameters

    • Abstract: Discontinuities within the rock mass are present in a wide range of networks. Their characterization and analysis exist with considerable diversity. Prior research appraises the significance of mechanical discontinuities and their effect on geotechnical structures and deficient with integral discontinuities. The variability and uncertainty related to rock mass discontinuity parameters such as spacing, persistence and aperture size cannot be present in a single value; it exhibits variability between specific range values. The use of a statistical method to present the discontinuity parameters provides a basis for Monte Carlo (MC) based stochastic modeling of discontinuity parameters to evaluate the stability of rock mass. The road cut slope of Bukit Merah, Malaysia, was investigated using close-range photogrammetry. Details of high precision rock mass discontinuities (mechanical and integral) parameters such as spacing, persistence and aperture were captured. To evaluate the best fit distribution for discontinuity parameters, Chi-Square test, Modified Kolmogorov Smirnov (K-S) and Anderson-Darling tests were employed. According to the findings, the discontinuity spacing is subjected to a lognormal distribution. In contrast, discontinuity persistence and aperture size followed loglogistic distribution. Furthermore, the Monte Carlo simulation (MCS) is a promising approach for assessing the variability and uncertainty of discontinuity parameter relationships.
  • Weathering Induced Brazilian Tensile Strength and Fracture Characteristics
           of Sandstone and their Prevailing Mutual Association

    • Abstract: This paper evaluates the variation and relationship of Brazilian tensile strength and fracture characteristics of sandstone under different weathering grades. Brazilian tensile strength experiments were performed on Fresh and slightly weathered sandstone specimens using an automated compression measuring machine UTC-5431. Image-based fracture characterization was carried out using public domain open-source software ImageJ. Furthermore, SPSS and Microsoft Excel were used to analyze the relationship between Brazilian tensile strength and fracture characteristics. Results demonstrate that sandstone tensile strength decreases as fracture maximum deviation distance (FMDD), fracture deviation area (FDA) and fracture length (FL), and weathering grades increases. Additionally, fracture deviation distance, fracture deviation area, and fracture length increase with an increase in weathering grade. The correlation results revealed that the tensile strength of fresh sandstone has a strong relationship with FMDD, FDA, and FL. Whereas, in the case of slightly weathered sandstone, BTS has a strong correlation with FMDD and FDA. Whereas multiple regression analysis shows that BTS has a strong relationship with fracture characteristics. Therefore, estimating the fracture characteristics of sandstone using its tensile strength is convenient, however, the sensitivity of sandstone strength properties and fracture characteristics to weathering must be acknowledged.
  • Evaluation of Scale and Loading Direction Effects on Strength and

    • Abstract: Determining strength and deformation of jointed rock masses is an inevitable part of geomechanical projects. Strength and deformability of a rock mass with stochastic joint sets is conceivably anisotropic and is mainly controlled by joints mechanical and geometrical properties. In this paper, strength and deformation behavior of jointed rock masses has been evaluated at Tazareh coal mine, Iran. Field mappings through scanline method have been used to collect joints spatial features on rock surfaces. A statistical evaluation has been carried out on field data using Dips software. Then, geomechanical properties of intact blocks have been measured conducting uniaxial compressive strength test. Finally, the rock mass is modelled using 3DEC, and its behavior is analyzed in some cases with different loading directions and block sizes to obtain representative elementary volume (REV) based on strength and deformation, respectively.
  • Utilization of Calcium Rich Mine Wastes and Bone Ash for the Improvement
           of California Bearing Ratio (CBR) of Soft Soil

    • Abstract: The aim of this experimental study is to investigate the effects of the addition of mine wastes and bone ash on some geotechnical properties of soft soil. The properties investigated include modified proctor compaction characteristics, California bearing ratio (CBR), uniaxial compression strength (UCS), internal friction angle (ϕ), maximum high density and maximum moisture contents of a characteristic soft soil. The study evaluated the ability of self-cementing properties of iron ore tailings, steel slag and coal ash which are by-product wastes from mining activities and bone ash at low proportion replacements to soft soil to improve the bearing capacity of the soil. The use of these calcium rich waste materials to stabilise and improve the bearing capacity of soil is a cost efficient and environmentally friendly disposal method of handling wastes. The candidate wastes, coal ash, bone ash, iron ore tailing, and steel slag were used to stabilise the soil separately at 0.5%, 1%, 1.5%, 2% and 2.5% replacements with soft soil. Based on performance tests conducted, considerable increase in the soil maximum dry density, compaction, UCS and CBR values were observed at different percentages of the additives. The results show that iron ore tailing is the candidate additive with highest property value of CBR of 11 over the soft soil of 7.5. Iron ore tailings also give maximum dry density and maximum moisture content values of 2500.73Kg/m3 and 22.45% respectively higher than other additives. All the candidate additives show improvement in properties evaluated over the soft soil. Therefore, these mine wastes can be used to enhance the stability of earthy materials of structural foundation such as highways, railways, embankments, reclamation and backfill etc. at low percentage replacements.
  • Estimation of mining time-span to improve the solution time in long-term
           production planning

    • Abstract: – Long-term production planning in open-pit mines is a precedence-constraint knapsack problem. A spatial representation of the mining region (called the block-model) is the primary input of mine planning models. One should note that as the number of blocks and periods to be planned increases, the number of decision variables increases. This paper presents a fast yet straightforward algorithm to reduce binary variables in open-pit mine production planning models. The algorithm considers mining capacity, processing capacity, and pit deepening rate to estimate the time-span within which a block is mineable. This paper applies the algorithm in 12 different cases. The number of blocks varies from 1000 to 240000, and the mining periods range from 6 to 30 years. According to the results, this algorithm is helpful for problem size reduction.
  • The Influence of Thermal breakage on Physio-mechanical behavior of Ghulmet
           Marble North Pakistan

    • Abstract: Geotechnical engineering applications comprises high temperature such as deep geological disposal of nuclear waste, exploitation of geothermal process, etc. High temperature and thermal environments can affect the mechanical properties of building materials used in civil engineering (concrete, building rock, steel, etc.). The constant action of regular thermal changes in situations of excess temperature is the main source of the alteration of marble in monumental and artistic buildings. In this study, the effect of both the specimen size and temperature on the physio-mechanical characteristics of dolomitic marble has been investigated. The temperature range selected was 20-600°C. It was observed that the color of samples changes with temperature rise. The Uniaxial compression strength (UCS), P-wave velocity (Vp) and Young’s modulus decreased with temperature rise. While the peak strain increases with temperature. The UCS and the peak strain showed a decreasing trend at the high diameter specimens. In the case of 43mm diameter specimens the peak stress reduced from 60MPa-26MPa with a rise in temperature from 20-600°C. While at the same temperature range the peak strain was observed as 1.7-3.3 and Young’s modulus was 34-8GPa. For 75mm diameter, the peak stress is reduced to 17MPa when the temperature rises to 600°C and Young’s modulus decreased to 4GPa while the peak strain increased from 2.3 to 3.9. The pulse velocity decreased from 2.75 km/s to 0.8km/ and the porosity value increased from 0.9 to 1.5%.
  • Influence of fabric and mineralogy on the mechanics of dolomitic rocks

    • Abstract: A detailed study into engineering mechanics of rocks is very crucial due to their nature and widespread applications as well as the fact that they are encountered in daily activities of practising engineers and designs and constructions are made in and/or on them. A comprehensive investigations have been made into influence of fabric and mineralogy on the behaviour of dolomitic rock by conducting series of laboratory tests. Also, extensive analyses have been made to determine suitable indices to predict parameters needed for engineering design and construction particularly at the beginning of projects when data may not be readily available. The parameters considered were porosity, rebound hardness, strength and modulus and the indices considered were fabric (particle shape, packing density) and mineralogical indices (quartz and dolomite). The rock is characterised by low porosity (0.64-1.50%), medium durability (65.4-73.3%), heterogeneous and sub-angular particles (0.60-0.77) with very few voids. The mineralogy comprises quartz (0-64%), dolomite (10-87%) and other minerals. The strength varies from low to relatively high strength (12-43 MPa). The variability of parameters and indices of dolomitic rock is low except for quartz. Although mineralogy has little influence on porosity of samples, fabric and mineralogy have significant influence on mechanics of dolomitic rock. It is very interesting to observe that fabric and mineralogical indices can be used to predict physical and mechanical parameters of dolomitic rock based on significant regression statistics. The fabric and mineralogical indices are suitable and are recommended for practitioners working on the materials.
School of Mathematical and Computer Sciences
Heriot-Watt University
Edinburgh, EH14 4AS, UK
Tel: +00 44 (0)131 4513762

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