M. M Tahernejad; M. Ataei; R Khalokakaie
Abstract
Iran has high potential and unique stone reserves in terms of variety of color, texture, quality, and economic value; nevertheless, in spite of growing mine production during the past decade, in many instances this potential has been overlooked. Therefore it is necessary to investigate strategic factors ...
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Iran has high potential and unique stone reserves in terms of variety of color, texture, quality, and economic value; nevertheless, in spite of growing mine production during the past decade, in many instances this potential has been overlooked. Therefore it is necessary to investigate strategic factors of these mines. The purpose of this study is to evaluate and determine the best strategies for Iran’s quarries. To this end, the mines were analyzed using the Strengths, Weaknesses, Opportunities and Threats (SWOT) approach in combination with Fuzzy Analytic Hierarchy Process (FAHP). Firstly, an environmental analysis was performed and then the SWOT factors were identified. In this way, the sub-factors which have very significant effects on the mines were determined. Using the SWOT matrix, alternative strategies were developed. Subsequently, the strategies were prioritized and the best strategies for these mines were determined. The results show that conservative strategies are the best strategy group for Iran’s quarries.
Andisheh Alimoradi; Ali Moradzadeh; Mohammad Reza Bakhtiari
Abstract
This paper proposes a method for the prediction of pore size values in hydrocarbon reservoirs using 3D seismic data. To this end, an actual carbonate oil field in the south-western part ofIranwas selected. Taking real geological conditions into account, different models of reservoir were constructed ...
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This paper proposes a method for the prediction of pore size values in hydrocarbon reservoirs using 3D seismic data. To this end, an actual carbonate oil field in the south-western part ofIranwas selected. Taking real geological conditions into account, different models of reservoir were constructed for a range of viable pore size values. Seismic surveying was performed next on these models. From seismic response of the models, a large number of seismic attributes were identified as candidates for pore size estimation. Classes of attributes such as energy, instantaneous, and frequency attributes were included amongst others. Applying sensitivity analysis, we determined Instantaneous Amplitude and asymmetry as the two most significant attributes. These were subsequently used in our machine learning algorithms. In particular, we used feed-forward artificial neural networks (FNN) and support vector regression machines (SVR) to develop relationships between the known attributes and pore size values in a given setting. The FNN consists of twenty one neurons in a single hidden layer and the SVR method uses a Gaussian radial basis function. Compared with real values from the well data, we observed that SVM performs better than FNN due to its better handling of noise and model complexity.
Alireza Arab-Amiri; Fereydoun Sharifi; Abolghasem Kamkar-Rouhani
Abstract
The need for clean groundwater resources to have sustainable development in a country is undoubted. Due to the importance and high quality of karstic waters in supplying water in Iran especially in Shahrood city, it is attempted in this research work to recognize and explore karstic waters in southwest ...
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The need for clean groundwater resources to have sustainable development in a country is undoubted. Due to the importance and high quality of karstic waters in supplying water in Iran especially in Shahrood city, it is attempted in this research work to recognize and explore karstic waters in southwest of Tepal area, Shahrood. For this purpose, integration of the results obtained from the methods of vertical electrical sounding (VES) and resistivity profiling has been used in this research work. The VES surveys have been performed in 10 sounding points using the Schlumberger array with electrode separations of a maximum 500 meters. The resistivity profiling surveys using dipole-dipole electrode array with 75m electrode spacing and dipole steps 1 to 8 have been carried out along four lines having a length of more than four kilometers in the study area. Then, one-dimensional (1-D) modeling and interpretation of the sounding results using master curves and IX1D software, and two-dimensional (2-D) modeling and interpretation of the profiling results using Res2DINV have been made. As a result of the interpretation and integration of the results, karstic water zones in the study area have been recognized, and based on that, suitable locations for drilling to access and extract karstic groundwater have been introduced.
Omid Asghari
Abstract
Post-mineralization activities may cause difficulties in the process of ore modeling in porphyry deposits. Sungun, NW Iran, is one of the porphyry copper deposits, in which dyke intrusions have made ore modeling more complicated than expected. Among different kinds of dykes, two types were chosen and ...
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Post-mineralization activities may cause difficulties in the process of ore modeling in porphyry deposits. Sungun, NW Iran, is one of the porphyry copper deposits, in which dyke intrusions have made ore modeling more complicated than expected. Among different kinds of dykes, two types were chosen and the consequent geostatistical analyses were applied on. In this study, simple directional variograms were used for extracting relevant information from dyke systems on which the Sequential Indicator Simulations were applied consequently. One hundred realizations were produced on the simulation grid considering the anisotropy characteristics and E-type map has been provided averaging all realizations. Moreover, a binary state between dyke and non-dyke environments was produced putting threshold on the E-type grid node values to discriminate the ore from barren dykes. Hole-effect models were fitted to the empirical variograms perpendicular to the dyke strike. Dimensional information was elicited from these models and the results were compared with the previously carried out geological investigations, and finally a good numerical match was found between these two sources of information.
M. Hasani; Seyed M. J. Koleini; A. Khodadadi
Abstract
In the present work, the extraction of zinc from a sphalerite concentrate using sodium nitrate as an oxidant in a sulfuric acid solution was investigated. The effective parameters such as the temperature, sulfuric acid and sodium nitrite concentrations, stirring speed, particle size, and solid/liquid ...
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In the present work, the extraction of zinc from a sphalerite concentrate using sodium nitrate as an oxidant in a sulfuric acid solution was investigated. The effective parameters such as the temperature, sulfuric acid and sodium nitrite concentrations, stirring speed, particle size, and solid/liquid (S/L) ratio were analyzed. The dissolution rate increased with increase in the sulfuric acid and sodium nitrite concentrations and temperature but decreased with increase in the particle size and S/L ratio. Moreover, the stirring speed had a significant effect on the leaching rate. Under the optimum conditions, 74.11% of zinc was obtained. The kinetic data obtained was analyzed by the shrinking core model (SCM). A new SCM variant captured the kinetic data more appropriately. Based on this model, the activities of the reactants control the diffusion but the two concentrations affect the second order reaction rate or diffusion in both directions. At 75 ˚C, the R2 values in the surface chemical reactions and diffusion were 0.78 and 0.89, respectively. Using the new model, however, the R2 value 0.989 was obtained. The reaction orders with respect to [H2SO4], [NaNO3], S/L ratio, and particle size were 1.603, 1.093, ‒0.9156, and ‒2.177, respectively. The activation energy for the dissolution was 29.23 kJ/mol.
N. Aziz; A. Mirzaghorbanali
Abstract
Canister desorption is a widely used technique to measure the gas content of coal. The gas content data, when normalized to volume/weight and multiplied by coal seam mass, is used to estimate the gas in place in an area around the cored hole. However, the gas content and the percentage of each constituent ...
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Canister desorption is a widely used technique to measure the gas content of coal. The gas content data, when normalized to volume/weight and multiplied by coal seam mass, is used to estimate the gas in place in an area around the cored hole. However, the gas content and the percentage of each constituent are likely to be influenced by trapped air in the canister at the time of the coal enclosure and subsequent sealing. Freshly-cored coal samples were collected from three mines, mining coal from Bulli seam, Sydney Basin. The studied underground mines were Appin West, West Cliff, and Tahmoor. The research programme, spanning for a period of four years, focused only on the influence of the trapped air in the canister on the coal gas percentage of each constituent. It was found that the percentage of each coal gas constituent was influenced by the trapped air in the canister space. The effect of trapped air was extended to the component percentage of the gases in the crushed coal samples, normally used for the estimation of Q3.
Rock Mechanics
A. Turanboy; E. Ülker; C. B. Küçüksütçü
Abstract
The intersection lines between discontinuity surfaces and their intersection points on the visible surfaces of any engineering structure may be the instability indicators. This paper describes a new approach to modelling the intersecting lines and points that would provide the first evaluation of any ...
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The intersection lines between discontinuity surfaces and their intersection points on the visible surfaces of any engineering structure may be the instability indicators. This paper describes a new approach to modelling the intersecting lines and points that would provide the first evaluation of any instability in an engineering structure characterized by the failure modes. In this work, the intersection lines were grouped according to their direction either in the reverse or in the same direction as the dip of the slope. Furthermore, the intersection lines are grouped according to various ranges of the interior friction angle, which can be selected by the users in a computer application developed for this work. The orientation of the intersecting lines and the location of the exposed intersection points are defined and assigned as the scatter points. These exposed points are clustered to determine the centroid locations. The K-means clustering is used in this step. Finally, all these analyses are integrated in a logical order, and the results obtained are used to assess the instabilities on the slope surface. Experiments are carried out on a rock cut along the Konya-Antalya (Turkey) highway, which is composed of limestone, to demonstrate the performance and results of the approach. The locations of the possible failure zones in the critical range of the interior friction angle are defined both visually and numerically along the slope. Experiments show that the proposed method is very useful and easy to implement and yields practical preliminary evaluation results pertaining to instabilities according to the basic failure modes.
Exploitation
B. Ünver; M.S. Ünal
Abstract
A daunting mine disaster took place in 13 May 2014 at Soma and 301 men lost their lives. Brief information about the Eynez coal mine and some of the inherent characteristics of the field in terms of their effects on mining are presented. This paper basically concentrates on the factors that played an ...
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A daunting mine disaster took place in 13 May 2014 at Soma and 301 men lost their lives. Brief information about the Eynez coal mine and some of the inherent characteristics of the field in terms of their effects on mining are presented. This paper basically concentrates on the factors that played an important role in the occurrence of this disaster. Progress of mine fire, firefighting, and rescue activities were only given in basics. Mine fire started suddenly without giving any sign at the hearth of the mine. Sudden occurrence of mine fire and start location properties reveal that the root cause of this disaster was probably not directly related to spontaneous heating of coal. Analysis of roof caving mechanism, subsidence profiles, production history, and overall conditions in the mine showed that the mine fire most probably started as a result of a sudden caving above the nearby sealed out old production panels. Upon caving, pressure of the gas present in uncaved voids and unconsolidated goaf must have increased and gas must have overflown through abundant cracks towards the mine. Gas exuding under moderate pressure might possibly be ignited by a non-ex-proof belt conveyor drive motor starting the mine fire.
Rock Mechanics
A. Turanboy; E. Ülker; C. Burak Küçüksütçü
Abstract
Estimation of the possible instability that may be encountered in the excavation slope(s) during the planning and application steps of the rock excavation processes is an important issue in geoengineering. In this paper, a modelling method is presented for assessing the probability of wedge failure involving ...
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Estimation of the possible instability that may be encountered in the excavation slope(s) during the planning and application steps of the rock excavation processes is an important issue in geoengineering. In this paper, a modelling method is presented for assessing the probability of wedge failure involving new permanent or temporary slope(s) along the planned excavation direction. The geostructural rock slopes including wedge blocks are determined geometrically in the first step. Here, a structural data analysis system that includes a series of filterings, sortings, and linear equations used to reveal the necessary geometric conditions for the wedge form is developed and used. The second step involves the 3D visualization and Factor of Safety (FS) using the limit equilibrium analysis of wedges on both the actual and planned new excavation surfaces. The last step is the Monte Carlo simulation, which is used in assessing the instabilities on the actual and planned new excavation surfaces. These new slope surfaces that have not yet been excavated are called the virtual structures. As a result of this work, the mean and probabilistic FS variations in the planned excavation direction are obtained as profiles. We suggest the preliminary guidelines for the mean and probability of the wedge failure in the excavation direction. The model is tested on a motorway cut slope. The FS results obtained from the Monte Carlo simulation calculations are compared with the mean results and the changes are revealed with the reasons.
A. David Mwangi; Z. Jianhua; H. Gang; R. Muthui Kasomo; I. Mulalo Matidza
Abstract
The ultimate pit limit optimization (UPLO) serves as an important step in the mine planning process. Various approaches of maximum flow algorithms such as pseudo-flow and push-relabel have been used for pit optimization, and have given good results. The Boykov-Kolmogorov (BK) maximum flow algorithm has ...
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The ultimate pit limit optimization (UPLO) serves as an important step in the mine planning process. Various approaches of maximum flow algorithms such as pseudo-flow and push-relabel have been used for pit optimization, and have given good results. The Boykov-Kolmogorov (BK) maximum flow algorithm has been used in solving the computer vision problems and has given great practical results but it has never been applied in UPLO. In this work, we formulate and use the BK maximum flow algorithm and the push-relabel maximum flow algorithm in MATLAB Boost Graph Library within the MATLAB software in order to perform UPLO in two case studies. Comparing both case studies for the BK maximum flow algorithm and push-relabel maximum flow algorithm gives the same maximum pit values but the BK maximum flow algorithm reduces the time consumed by 12% in the first case and 16% in the second case. This successful application of the BK maximum flow algorithm shows that it can also be used in UPLO.
E. Koken; E. Başpınar Tuncay
Abstract
Andesites with a satisfactory quality have been mainly considered as dimension stones worldwide. However, practical approaches are required to evaluate the dimension stone quality due to the increasing demand for natural resources. This study presents detailed laboratory investigations on andesitic rocks ...
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Andesites with a satisfactory quality have been mainly considered as dimension stones worldwide. However, practical approaches are required to evaluate the dimension stone quality due to the increasing demand for natural resources. This study presents detailed laboratory investigations on andesitic rocks in NE Uşak, Turkey. For laboratory studies, representative rock blocks are obtained from unweathered (W0) to highly weathered (W3) rock masses. Laboratory test results demonstrate that progressive rock weathering has remarkable influences on the dry density (ρd), effective porosity (ne), pulse wave velocity (Vp), uniaxial compressive strength (UCS), flexural strength (FS), and Böhme abrasion value (AWR) of the andesitic rocks. Of the above parameters, ne seems to be the most affected rock property due to progressive rock weathering. Furthermore, based on the three-parameter Weibull distribution, andesitic rocks are evaluated for their use as cladding stones. A quantitative approach called the suitability index (SI) is proposed to quantify the quality of cladding stones for andesitic rocks, considering six different evaluation criteria (C1–C6). Two examples of SI calculations reveal the implementation of the proposed approach. The suitability of the proposed approach is also checked by Monte Carlo analysis, showing that the use of SI is suitable to quantify the cladding stone quality for the investigated andesitic rocks. However, the proposed approach should be improved by incorporating the mineralogical and textural characteristics into the SI calculations. Moreover, it should also be attempted to different andesitic rocks in order to observe the similarities or difficulties of quantifying the quality of cladding stones.
Maysam Abedi; Kiomars Mosazadeh; Hamid Dehghani; Ahmad MadanchiZare
Abstract
We have applied an automatic interpretation method of potential data called AN-EUL in unexploded ordnance (UXO) prospective which is indeed a combination of the analytic signal and the Euler deconvolution approaches. The method can be applied for both magnetic and gravity data as well for gradient surveys ...
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We have applied an automatic interpretation method of potential data called AN-EUL in unexploded ordnance (UXO) prospective which is indeed a combination of the analytic signal and the Euler deconvolution approaches. The method can be applied for both magnetic and gravity data as well for gradient surveys based upon the concept of the structural index (SI) of a potential anomaly which is related to the geometry of the anomaly sources. With AN-EUL method, both the depth and the approximate geometry (or SI) of the causative sources can be deduced. A realistic model for UXO to be simulated by a simple shape body is a prolate spheroid. The method is applied for both synthetic potential data assuming a collection of causative UXO sources replicating various sizes placed at different depths. In both cases, the estimated depth and the SI of the synthetic UXOs approximately correspond to the synthetic model parameters. The location detection of the causative sources is based upon the Blakely automatic picking algorithm. For both data sets, since the anomaly responses of the small UXOs are affected by noise, the estimated SI is a bit disturbed but the locations correspond to the real ones. The Blakely algorithm also identifies weak anomalies that are due to noise in data; thus, a post-processing of the estimated SI of the automatically detected sources may be needed to prevent false alarm sources in UXO exploration. Two field data sets have been provided to demonstrate the capability of the applied methods in UXO detection.
Prof R.N. Singh; O Aduvire; V.F Navarro Torres
Abstract
In the past, mining activities have generated major acid drainage sources, which usually carry dissolved metals that flow into the main rivers of the affected basins. The study looks at natural attenuation processes in local, sub-basin and basin areas, in the El Bierzo and Odiel basins of Spain, where ...
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In the past, mining activities have generated major acid drainage sources, which usually carry dissolved metals that flow into the main rivers of the affected basins. The study looks at natural attenuation processes in local, sub-basin and basin areas, in the El Bierzo and Odiel basins of Spain, where coal and metal mining activities were formerly conducted. In this study, sampling and in situ monitoring of pH, Eh, dissolved oxygen, conductivity, temperature, flow, turbidity, acidity, alkalinity, Fe2+, Fe3+ and total Fe were carried out during the hydrological cycle. Chemical analysis was also performed on water samples, following the water quality data of the ICA Network of the Spanish Environment Ministry for a period of 10 years. The results show that the main natural attenuation processes were: dilution by mixing with clean water, oxidation and hydrolysis of dissolved metals, reduction of anaerobic sulphates, and precipitation of secondary minerals.
H. Mansouri; M. A. Ebrahimi Farsangi
Abstract
A linear superposition method was used for modeling the time history of the production blast vibrations and optimizing the blast sequence to reduce vibration levels in Sar-Cheshmeh copper mine, Kerman, Iran. A single-hole blast for modeling and two double-hole blasts with time delays of 25 and 65 ms ...
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A linear superposition method was used for modeling the time history of the production blast vibrations and optimizing the blast sequence to reduce vibration levels in Sar-Cheshmeh copper mine, Kerman, Iran. A single-hole blast for modeling and two double-hole blasts with time delays of 25 and 65 ms between two holes for modeling validation were carried out. The generated vibrations were measured at seven points with different distances and directions around the blasts. These records contain information about the complex mechanism of seismic energy radiation from an explosive source as well as the filtering effect of the signal travel path. Totally, 40 seismograms were synthesized (3 components for each point) for two blasts using the linear superposition method. The results obtained presented a good correlation between the synthetic and measured seismograms. Also, a comparison was made between the measured peak particle velocities (PPVs) and those obtained from the scaled-distance method and linear superposition modeling. This shows the merits of linear superposition modeling to predict PPVs. Moreover, the recorded seismograms of the single-hole blast were used to simulate the vibrations produced by a production blast at seven points. Furthermore, by using a systematic variation of firing delay in the modeling procedure, the effect of delay on the production blast vibrations was studied. The production blast simulations showed that for Sar-Cheshmeh copper mine, the blasts carried out with the inter-row delays more than 40 ms can significantly reduce vibration levels.
A. Mirzaghorbanali; N. Aziz
Abstract
The load transfer mechanisms of cable bolts differ from those for normal rebar bolts. The cable bolts used in mines are basically steel strands with different constructions depending on the number of wires or elements and the way they are laid. Tendon bolts (rebar and cable) are normally evaluated for ...
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The load transfer mechanisms of cable bolts differ from those for normal rebar bolts. The cable bolts used in mines are basically steel strands with different constructions depending on the number of wires or elements and the way they are laid. Tendon bolts (rebar and cable) are normally evaluated for their strength and load transfer properties. The tendon strength can be evaluated by the tensile failure tests, while the load transfer strength is evaluated by the pull and shear strength tests. Short Encapsulation Pull Testing (SEPT) is normally used to study the load transfer capacities of tendons, and it can be undertaken in both the laboratory and in situ. A new apparatus known as Minova Axially Split Embedment Apparatus (MASEA) was used to study load-displacement characteristics of smooth versus spiral profile cable bolts. Minova Stratabinder grout was used for encapsulating 400-mm long 19 wire 22-mm diameter superstrand cable in embedment units. The anchorage of the cable on the two sides of the embedment apparatus were intentionally installed at different lengths to allow the cable to be pulled out from one side of the anchorage. The spiral wire strand cable bolts achieved a higher peak pull-out load at a minimum displacement in comparison with the smooth surface wire strand. The peak pull out force increased with the age of encapsulation grout. The use of MASEA was easier to assemble and test at a short period of time, thus allowing the quick and repeated tests undertaken.
M. Anselme Kamga; S. Nzali; C. O. Olatubara; A. Adenikinju; E. A. Akintunde; M. P. Kemeng; F. W.D. Nguimatsia; E. A. Ndip; C. Fuanya
Abstract
Cameroon has a strong geological potential for a number of mineral resources that, if well managed, could support economic growth. The country contains potentially large deposits of iron ore, gold, bauxite, diamond, limestone, nickel, and gemstones, and indices of other numerous minerals and precious ...
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Cameroon has a strong geological potential for a number of mineral resources that, if well managed, could support economic growth. The country contains potentially large deposits of iron ore, gold, bauxite, diamond, limestone, nickel, and gemstones, and indices of other numerous minerals and precious metals. Despite its geological wealth, mining has never played a major role in Cameroon’s economic development. A study on the state of sustainable development and environmental challenges in the Cameroon mining sector permits the identification of key points for improvement in order to position the country towards achieving a sustainable mining industry in the future. This paper reviews the mining potential, stakeholder participation, legislation, and mining policy in Cameroon mining industry. The methodology involves a single case study focused on the review of sustainable development in the Cameroon mining industry up to date. It includes scientific studies, and reports of ministries and support organizations, national laws, and regulations related to the area of study. Also the corporate sustainability reports of mining companies and mining stakeholders are analyzed. This research work covers the latest developments in terms of the institutional and regulatory frameworks for mining and the environment in the country, history of mining in Cameroon, and evolution and issues of the Environmental and Social Impact Assessment (ESIA) system in the mining sector until 2016. The work concludes with an identification of the current challenges of implementing sustainable development in mining as well as future directions that research works on this area should take.
K. Sultan Shah; M. H. Bin Mohd Hashim; K. Sh. Bin Ariffin
Abstract
The particles within the rock samples are present in extensive ranges of shapes and sizes, and their characterization and analysis exist with a considerable diversity. The prior research works have appraised the significance of the particle shape types and their effects on the geotechnical structures ...
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The particles within the rock samples are present in extensive ranges of shapes and sizes, and their characterization and analysis exist with a considerable diversity. The prior research works have appraised the significance of the particle shape types and their effects on the geotechnical structures and deficiencies by evaluating the uncertainty-related rock particle shape descriptors (PSDs). In this work, the Monte Carlo simulation (MCS) is used in order to present a framework to integrate the inherent uncertainty associated with PSDs. A tabletop microscope is used to measure the primary particle shape distribution for the sandstone samples. An open-source processing tool, ImageJ, is used in order to analyze PSDs. The probabilistic distribution of PSDs is acquired using MCS according to the relative frequency histogram of the input parameters. Additionally, a probabilistic sensitivity analysis is performed in order to evaluate the importance of the input parameters in PSDs. The sensitivity analysis results demonstrate that the major axis and area are the most influential parameters involved. The simulation results obtained have revealed that the proposed framework is capable of integrating the inherent uncertainties related to the particle shape.
Exploitation
I. M. Jiskani; F. I. Siddiqui
Abstract
Faults are the most critical tectonic factors in geological structures, which have major economic impacts on mining economics. Thus it is necessary to understand faults in order to identify the actual risks and complications associated with mining. In the preliminary investigation of the Sonda-Jherruck ...
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Faults are the most critical tectonic factors in geological structures, which have major economic impacts on mining economics. Thus it is necessary to understand faults in order to identify the actual risks and complications associated with mining. In the preliminary investigation of the Sonda-Jherruck coalfield, 3D geological modeling was not performed. The purpose of this work was to perform fault orientation modeling in order to document pre-mine planning information and discuss the obstacles that may cause problems in mine planning and development stages. Using the drill hole data, 3D fault models based on the calculation of dip angle and dip direction were established. In the first step, surface models of coal seams were established by applying the triangulation method to the coal seam roof elevations. Then an appropriately oriented grid was overlain to regularize the data and to find the unknown points. The calculation of dip and dip direction was done using an algorithm. The models showing the variation in the dip and dip direction were generated using the inverse distance squared weighted (ID2W) interpolation technique. The generated 3D models were compared with the pre-existing fault lines (based on the aerial map). An attempt was made to create comprehensive models that demonstrate a better understanding of the faults in the studied area.
Exploration
F. Mirsepahvand; M.R. Jafari; P. Afzal; M. A. Arian
Abstract
The goal of this research work is to recognize the metallic mineralization potential in the Ahar 1:100,000 sheet (NW Iran) using the remote sensing data based on determination of the alteration zones. This area is located in the Ahar-Arasbaran metallogenic zone as a significant metallogenic zone in Iran ...
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The goal of this research work is to recognize the metallic mineralization potential in the Ahar 1:100,000 sheet (NW Iran) using the remote sensing data based on determination of the alteration zones. This area is located in the Ahar-Arasbaran metallogenic zone as a significant metallogenic zone in Iran and Caucasus. In this research work, the Landsat-7 ETM+ and advanced space borne thermal emission and reflection radiometer (ASTER) multispectral remote sensing data was interpreted by the least square fit (LS-Fit), spectral angle mapper (SAM), and matched filtering (MF) algorithms in order to detect the alteration zones associated with the metallic mineralization. The results obtained by these methods show that there are index-altered minerals for the argillic, silicification, advanced argillic, propylitic, and phyllic alteration zones. The main altered areas are situated in the SE, NE, and central parts of this region.
H. Sabeti; A. Moradzadeh; F. Doulati Ardejani; A. Soares
Abstract
Stochastic seismic inversion is a family of inversion algorithms in which the inverse solution was carried out using geostatistical simulation. In this work, a new 3D stochastic seismic inversion was developed in the MATLAB programming software. The proposed inversion algorithm is an iterative procedure ...
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Stochastic seismic inversion is a family of inversion algorithms in which the inverse solution was carried out using geostatistical simulation. In this work, a new 3D stochastic seismic inversion was developed in the MATLAB programming software. The proposed inversion algorithm is an iterative procedure that uses the principle of cross-over genetic algorithms as the global optimization technique. The model perturbation towards the objective function is performed recurring to direct sequential simulation and co-simulation. This new algorithm was applied to a synthetic dataset with and without noise. The results obtained for the inverted impedance were satisfactory in both cases. In addition, a real dataset was chosen to be applied by the algorithm. Good results were achieved regarding the real dataset. For the purpose of validation, blind well tests were done for both the synthetic and real datasets. The results obtained showed that the algorithm was able to produce inverted impedance that fairly matched the well logs. Furthermore, an uncertainty analysis was performed for both the synthetic and real datasets. The results obtained indicate that the variance of acoustic impedance is increased in areas far from the well location.
J. Jurković; E. Babajić; T. Muhić – Šarac; M. Kolar; A. Kazlagić
Abstract
Oxidation of sulfide-containing ores is the main cause of Acid Mine Drainage (AMD), which is an environmental problem associated with both the abandoned and active mines. Iron-bearing sulfide minerals can be oxidized and form mine waters with high sulfate content, low pH, high electrical conductivity, ...
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Oxidation of sulfide-containing ores is the main cause of Acid Mine Drainage (AMD), which is an environmental problem associated with both the abandoned and active mines. Iron-bearing sulfide minerals can be oxidized and form mine waters with high sulfate content, low pH, high electrical conductivity, high redox potential, and high concentrations of iron, aluminum, and other heavy metals. In the process of AMD, precipitation of poorly crystalized oxy-hydroxides of iron with a large active surface can occur. On the surface of iron oxy-hydroxide, the precipitated particulate matter, anions, and cations (metals) could be adsorbed. Mine waters can contain a certain amount of precious metals that can also be adsorbed onto an iron particulate matter surface, which is investigated in this research work. In this work, the samples of iron oxy-hydroxide particulate matter at abandoned gold mine waste in Bakovići (Central Bosnia and Herzegovina) are used. Several parameters including pH, water content, particle size distribution, sulfate content, electrical conductivity, redox potential, and amounts of gold, silver, and iron are measured on the selected mine waste samples. The results obtained indicate that significant amounts of gold (average: 6.8 mg/kg) and silver (average: 7.13 mg/kg) are present in the iron precipitate. Adsorption of precious metals onto the iron oxy-hydroxide surface is strongly pH-dependent. At a very low pH value, desorption of precious metals is favorite. Thus, precious metals are only partially adsorbed onto the iron oxy-hydroxide surface.
Mineral Processing
M. Naderi; Seyed Z. Shafaie; M. Karamoozian; Sh. Gharanjik
Abstract
In this work, the parameters affecting the recovery of copper from the low-grade sulfide minerals of Sarcheshmeh Copper Mine were studied. A low-grade sulfide ore was used with a copper grade of 0.25%, which was about 28% of the mineral oxide, and the sulfide minerals made up the rest. Much more sulfide ...
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In this work, the parameters affecting the recovery of copper from the low-grade sulfide minerals of Sarcheshmeh Copper Mine were studied. A low-grade sulfide ore was used with a copper grade of 0.25%, which was about 28% of the mineral oxide, and the sulfide minerals made up the rest. Much more sulfide minerals were found to be pyrite and most of the gangue minerals were quartz, anorthite, biotite, and muscovite. In order to investigate, simultaneously, the solids (10 to 20%) and acidity (1.5 to 2.5) and shaking (110 to 150 rpm), the separation of bacteria from Sarcheshmeh Copper Mine was carried out. After adjustment of the sample, bio-leaching tests were performed in accordance with the pattern defined by the software DX7 in shaking flasks, and the Cu recovery was modeled and optimized using the response surface methodology. The influential parameters were comprehensively studied. The central composite design methodology was used as the design matrix to predict the optimal level of these parameters. Then the model equation was optimized. The results obtained showed that increasing solids (from 10 to 20%) was bad for bacteria. The highest copper recovery was equivalent to 69.91%, obtained after 21 days at 35 degrees using the Acidi Thiobacillus Ferrooxidans bacteria and a K9 medium with a pulp density of 10% and pH 1.5.
K.M. Tanguturi; R.S. Balusu
Abstract
It is necessary to obtain a fundamental understanding of the goaf gas flow patterns in longwall mine in order to develop optimum goaf gas drainage and spontaneous combustion (sponcom) management strategies. The best ventilation layout for a longwall underground mine should assist in goaf gas drainage ...
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It is necessary to obtain a fundamental understanding of the goaf gas flow patterns in longwall mine in order to develop optimum goaf gas drainage and spontaneous combustion (sponcom) management strategies. The best ventilation layout for a longwall underground mine should assist in goaf gas drainage and further reduce the risk of sponcom in the goaf. Further, in the longwall panel, regulators are installed in the maingate (MG) seals to control the gas migration on the MG side and the mine operators frequently encountered with seals leakage problems leading to abnormal gas contents in the tube bundles. Extensive parametric studies were carried out to investigate the effects of ventilation layouts, regulators, and seals leakages on the goaf gas distribution using the Computational Fluid Dynamics (CFD) techniques. The results of various CFD simulations are presented and discussed in detail in this paper.
Rock Mechanics
M. Akhyani; R. Mikaeil; F. Sereshki; M. Taji
Abstract
Predicting the wear performance of circular diamond saw in the process of sawing hard dimensional stone is an important step in reducing production costs in the stone sawing industry. In the present research work, the effective parameters on circular diamond saw wear are defined, and then the weight ...
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Predicting the wear performance of circular diamond saw in the process of sawing hard dimensional stone is an important step in reducing production costs in the stone sawing industry. In the present research work, the effective parameters on circular diamond saw wear are defined, and then the weight of each parameter is determined through adopting a fuzzy rock engineering system (Fuzzy RES) based on defining an accurate Gaussian pattern in fuzzy logic with analogous weighting. After this step, genetic algorithm (GA) is used to determine the levels of the four major variables and the amounts of the saw wear (output parameter) in the classification operation based on the fixed, dissimilar, and logarithmic spanning methods. Finally, a mathematical relationship is suggested for evaluation of the accuracy of the proposed models. The main contribution of our method is the novelty of combination of these methods in fuzzy RES. Before this work, all Fuzzy RESs only use simple membership functions and uniform spanning. Using GA for spanning and normal distribution as membership function based upon our latest work is the first work in fuzzy RES. To verify the selected proposed model, rock mechanics tests are conducted on nine hard stone samples, and the diamond saw wear is measured and compared with the proposed model. According to the results obtained, the proposed model exhibits acceptable capabilities in predicting the circular diamond saw wear.
J. Manyepa; V. Patson Mutambo
Abstract
Designing suitable extraction methods for mining randomly occurring pocket formation of gemstones has never been easy at the Musakashi emerald mine due to the limited geological information. In order to improve the productivity as well as the recovery, in this work, we undertake a detailed ...
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Designing suitable extraction methods for mining randomly occurring pocket formation of gemstones has never been easy at the Musakashi emerald mine due to the limited geological information. In order to improve the productivity as well as the recovery, in this work, we undertake a detailed geological survey (airborne, surface mapping, geochemical sampling, and trenching activities), and review, analyze, and establish the appropriate extraction methods, and conduct the economic viability of the mining emeralds in the Musakashi area. A total of 51 holes are drilled in order to define the mineralization and estimate the mineral resource for the rubble ore and the in-situ ore zones using the Surpac Geovia software. The diamond drilling unravels the existence of an alteration zone enveloping the shales in an area of 150m by 100m. The emerald is localized within these reaction zones, and is estimated to extend to a depth of about 20–30m below the surface. The total mineral resource stands at 345, 290 grams for the rubble ore and 123,870 grams for the discordant veins. From the geological information obtained, a trial pit design is established with a target of increasing recovery of emeralds from the current 10 kg to 100 kg per year.
