Exploration
Eid R. Abo-Ezz; El Sayed I Selim; Hatem Aboelkhair; Haytham Sehsah
Abstract
The bimodal hypsometry of the Arabian-Nubian Shield in the Neoproterozoic triggered the formation of post-amalgamation marine bains in the low-stand terranes of the Arabian shield (AS). The carbonate successions in the extraordinary marine basins in the AS are intruded by granite plutons of different ...
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The bimodal hypsometry of the Arabian-Nubian Shield in the Neoproterozoic triggered the formation of post-amalgamation marine bains in the low-stand terranes of the Arabian shield (AS). The carbonate successions in the extraordinary marine basins in the AS are intruded by granite plutons of different causative types, with major shear zones pathways. Therefore, the conditions for the formation of skarn deposits are mature at the contact of the carbonate succession with the causative granite plutons. Multidisciplinary approaches including ASTER data, Magnetic data, and geochemical data have been applied to the Murdama basin to locate the promising areas for skarn deposits. The Murdama basin has contrasting magnetic anomalies of different intensity at the contact between the Murdama limestone and the post-Murdama causative batholiths; significant magnetic anomalies exist at the contact with the Idah causative magmas. Lineaments related to the Najd fault system (NFS) exist eastward, where calc-silicate alteration-related minerals were evolved, with no clues for penetrative effect for such alteration activity along pathways related to the fracture system or at contact with the Abanat suite. Different spectral mapping techniques, including Spectral Information Divergence (SID), Spectral Angle Mapper (SAM), and Constrained Energy Minimization (CEM) confirm that the Idah suite is the predominant causative magma in the study area with highly evolved calc-silicate alteration-related minerals, such as wollastonite, garnet, and pyroxene. Meanwhile, The Idah suite has been identified as the main causative magma for other reduced skarn localities that have been recorded from the Murdama basin, i.e. the Qitan and An Nimriyah South. Alteration related mineral zones of kaolinite, chlorite, muscovite, and hematite are evolved alongside with calc-silicate minerals at the contact bewteen Idah suite, and the Murdama carbonate member. The geochemical data suggests reducing effect for the Idah suite at the contact between the Murdama carbonate succession and Idah plutons. These preliminary results of this study need detailed field investigations and geochemical explorations for the proposed skarn deposits in the Neoproterozoic molasse basins of the AS.
Exploration
Abdelrahem Khalefa Embaby; Sayed Gomaa; Yehia Darwish; Samir Selim
Abstract
This study aims to develop an empirical correlation model for estimating the uranium content of the G-V in the Gabal Gattar area, northeastern desert of Egypt, as a function of the thorium content and the total gamma rays. Using the recent MATLAB software, the effect of selecting tan-sigmoid as a transfer ...
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This study aims to develop an empirical correlation model for estimating the uranium content of the G-V in the Gabal Gattar area, northeastern desert of Egypt, as a function of the thorium content and the total gamma rays. Using the recent MATLAB software, the effect of selecting tan-sigmoid as a transfer function at various numbers of hidden neurons was investigated to arrive at the optimum Artificial Neural Network (ANN) model. The pure-linear function was investigated as the output function, and the Levenberg-Marquardt approach was chosen as the optimization technique. Based on 1221 datasets, a novel ANN-based empirical correlation was developed to calculate the amounts of uranium (U). The results show a wide range of uranium content, with a determination coefficient (R2) of about 0.999, a Root Mean Square Error (RMSE) equal to 0.115%, a Mean Relative Error (MRE) of -0.05%, and a Mean Absolute Relative Error (MARE) of 0.76%. Comparing the obtained results with the field investigation shows that the suggested ANN model performed well.
M. Rezaie; A. Moradzadeh; A. Nejati Kalate
Abstract
One of the most remarkable basis of the gravity data inversion is the recognition of sharp boundaries between an ore body and its host rocks during the interpretation step. Therefore, in this work, it is attempted to develop an inversion approach to determine a 3D density distribution that produces a ...
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One of the most remarkable basis of the gravity data inversion is the recognition of sharp boundaries between an ore body and its host rocks during the interpretation step. Therefore, in this work, it is attempted to develop an inversion approach to determine a 3D density distribution that produces a given gravity anomaly. The subsurface model consists of a 3D rectangular prisms of known sizes and positions and unknown density contrasts that are required to be estimated. The proposed inversion scheme incorporates the Cauchy norm as a model norm that imposes sparseness and the depth weighting of the solution. A physical-bound constraint is enforced using a generic transformation of the model parameters. The inverse problem is posed in the data space, leading to a smaller dimensional linear system of equations to be solvedand a reduction in the computation time. For more efficiency, the low-dimensional linear system of equations is solved using a fast iterative method such as Lanczos Bidiagonalization. The tests carried out on the synthetic data show that the sparse data-space inversion produces blocky and focused solutions. The results obtained for the 3D inversion of the field gravity data (Mobrun gravity data) indicate that the sparse data-space inversion could produce the density models consistent with the true structures.
Rock Mechanics
M. Hosseini; A. R. Khodayari
Abstract
The fracture mechanics examines the development and expansion of cracks in solids and how they affect the deformation of materials. The stress intensity factors at the tip of the crack and the critical stress intensity factors or fracture toughness of materials are considered in the relevant criteria. ...
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The fracture mechanics examines the development and expansion of cracks in solids and how they affect the deformation of materials. The stress intensity factors at the tip of the crack and the critical stress intensity factors or fracture toughness of materials are considered in the relevant criteria. There are three main modes of applying forces to a crack including the tensile mode, shear mode, and mixed mode. Mode II fracture toughness, which is also called the shear mode, is an important parameter for investigating the rock behaviors. This parameter is used in many different areas such as mining and tunneling. Several methods have been proposed for determining the mode II fracture toughness. In this work, the Punch-True-Shear (PTS) test, standardized by the International Society for Rock Mechanics, was used to determine the fracture toughness while the confining pressure is present. The studied sample was the Lushan sandstone. In this work, notchd cylindrical specimens were prepared for PTS testing. In order to investigate the effect of confining pressure, some tests were conducted in the presence of the confining pressures of 0, 3, 5, 7, and 10 MPa, and to check the effect of temperature, some tests were conducted under 1, 5, and 10 heating and cooling cycles at 60, 100, and 150 ˚C as well as at the ambient temperature (25 °C). The confining pressure of 3 MPa was used in all the tests to examine the effect of temperature. The analyses results showed that with increase in the confining pressure, the mode II fracture toughness and the fracture energy would increase as well. By increasing the number of heating-cooling cycles, the mode II fracture toughness as well as the fracture energy would decrease leading to a reduced fracture toughness and energy for all the three modes of heating specimens up to 60, 100, and 150 ˚C. The effect of the number of heating-cooling cycles on reducing the fracture toughness and fracture energy was greater than the effect of temperature.
Exploitation
S. Tabasi; M. Kurdi; M. Bahrammanesh
Abstract
The objective of this work was to investigate the potential of three different kinds of Iranian peat and swamp soils as sources of organic matter (OM) in the Golestan Province, Northern Iran. Comparison of the peats was done in terms of the degree of humification on the von Post scale. Moreover, the ...
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The objective of this work was to investigate the potential of three different kinds of Iranian peat and swamp soils as sources of organic matter (OM) in the Golestan Province, Northern Iran. Comparison of the peats was done in terms of the degree of humification on the von Post scale. Moreover, the X-ray fluorescence, X-Ray Diffractometry, and Fourier transform infra-red (FT-IR) techniques were used to investigate their mineralogical and geochemical properties. Also a method was tested for the sequential extraction of OM from Suteh peat, in which the following organic solvents were utilised in sequence: (I) ethyl ether, (II) ethanol, (III) 1,4-dioxane, and (IV) n-hexane; each extract was analysed by FT-IR spectroscopy, and the residue was used in the next phase. The results obtained indicated that OMOM extracted during each step was different; nevertheless, some spectral features such as those attributable to lignin, carbohydrate, phenol, wax, and fats were common to all phases. Major absorbance spectra were related to specific extraction steps, namely polysaccharide, proteins, alkyne, humic acids, esters, aldehydes, and cellulose.
S. Najafi Ghoshebolagh; A. Kamkar Rouhani; A.R. Arab Amiri; H. Bizhani
Abstract
As many gold deposits are associated with sulfide zones, and the direct exploration of gold deposits using the geophysical methods is very difficult due to its low amount in the sub-surface, the direct exploration of sulfide zones by the geophysical electrical resistivity and induced polarization (IP) ...
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As many gold deposits are associated with sulfide zones, and the direct exploration of gold deposits using the geophysical methods is very difficult due to its low amount in the sub-surface, the direct exploration of sulfide zones by the geophysical electrical resistivity and induced polarization (IP) methods may lead to the indirect exploration of gold deposits. The gold deposit in the Kervian area is located in the Kurdistan shear zone, and is directly related to the sulfide, silica, and carbonate alteration units. After acquiring the resistivity and IP data, 2D modeling of the data is made in order to indirectly identify the gold-bearing zones in the surveyed area. As some of the identified geophysical anomalies indicating the sulfide zones may not be associated with the economic amounts of gold, in order to obtain an exploration pattern for the gold deposit in the studied area, a combination of the geophysical data modeling and interpretation results with the geological information and other exploratory data is used to reduce the uncertainty in identifying the gold-bearing zones in the studied area. Thus, modeling and interpretation of the geophysical data lead to identify the sub-surface anomalies as the locations of possible gold mineralization in the area, and then the drilling points are suggested in the area. Considering the geological studies and chemical analysis of the samples taken from the drilled boreholes crossing some of the geophysical anomalies, we conclude that the geophysical anomalies occurring inside the phyllite and carbonate units in the area can contain an economic amount of gold, and thus are recommended as the top priority for further exploration.
K. Seifpanahi Shabani; A. Vaezian
Abstract
In the environment, two main sources of heavy metals are natural backgrounds derived from parent rocks and anthropogenic contamination including mineral industrial wastes, tailing damps of sulfide mines, agrochemicals, and other outputs of industrial activities and factories. In this work, the physico-chemical ...
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In the environment, two main sources of heavy metals are natural backgrounds derived from parent rocks and anthropogenic contamination including mineral industrial wastes, tailing damps of sulfide mines, agrochemicals, and other outputs of industrial activities and factories. In this work, the physico-chemical aspects of the magnetic Nano- mineral surfaces are studied in contrast to acid mine drainage using the multi- -analytical techniques XRF, XRD, BET, SEM, TEM, FT-IR, and AFM before and after adsorption of toxic elements. According to the results obtained, the FT-IR analysis presents a suitable curve, showing that the adsorption site of the sorption is filled with Ni(II) and Cd(II) ions. The results obtained show that the adsorption reaction is due to the high removal of the toxic elements from acid mine drainages.
Sh. Rezaei; A. Imam Ali Pour
Abstract
In the recent years, according to the difficulty of accurately measuring parameters and demarcation of earth sciences, attempts have been made to simplify the natural events for better investigation using geo-modelling. Modeling with intelligent methods is one of the new methods that has been considered ...
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In the recent years, according to the difficulty of accurately measuring parameters and demarcation of earth sciences, attempts have been made to simplify the natural events for better investigation using geo-modelling. Modeling with intelligent methods is one of the new methods that has been considered in this field in the recent years. In this work, the intelligent method of adaptive neural-fuzzy inference system (ANFIS) is used to predict the elements of lead and zinc located in the Guard Kooh area, north of Yazd province in Iran. Descriptive statistics of data and correlation matrices of studied elements are obtained using the SPSS software. After the data is standardized, imported to the MATLAB software, and the lead and zinc elements are predicted using the ANFIS-SCM method. In this method, 70% of the data (175 samples) are set as the training data, and the rest (75 samples) are set as the test data, which are randomly selected. Using the obtained results, it is found that the grade of the estimated elements in the studied area has a good accuracy and a high correlation with the grade of the analyzed elements. As a result, the ANFIS-SCM intelligent method is a useful and accurate method for estimating the lead and zinc elements.
M. Mirzaie; P. Afzal; A. Adib; E. Rahimi; Gh. Mohammadi
Abstract
Detection of mineralized zones based on ores and gangues is important for mine planning and excavation operation. The major goal of this research work was to determine the zones based on ores and gangues by a combination of fractal and factor analysis in the Chah Gaz iron ore (Central Iran). The Concentration-Volume ...
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Detection of mineralized zones based on ores and gangues is important for mine planning and excavation operation. The major goal of this research work was to determine the zones based on ores and gangues by a combination of fractal and factor analysis in the Chah Gaz iron ore (Central Iran). The Concentration-Volume (C-V) fractal method was carried out for Fe, P and S, which indicated that the main mineralized zones consisted of the Fe, S, and P values ≥ 57%, ≤ 0.4%, and ≤0.3%, respectively. Factor analysis categorized variables in two groups including factor 1 (F1) and factor 2 (F2) for ore and gangue, respectively. The C-V fractal modeling on the derived factors showed four zones for F1 and F2. Based on the correlation among the results of fractal modeling on the elements and factors, the first and second zones of F1 were proper for exploitation. Furthermore, the last and first zones of F1 and F2 could be assumed as the main waste for mining excavation.
Vivek Sharma; Pardeep Kumar; Ravi Kumar Kumar Sharma
Abstract
Himachal Pradesh state is located in seismically active western Himalayas (India) and its seven districts are in seismic zone V and other in zone IV as per the seismic code of India. Ninety% area of Hamirpur district, the studied area, lies in zone V. Peak ground acceleration (PGA) is one of the most ...
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Himachal Pradesh state is located in seismically active western Himalayas (India) and its seven districts are in seismic zone V and other in zone IV as per the seismic code of India. Ninety% area of Hamirpur district, the studied area, lies in zone V. Peak ground acceleration (PGA) is one of the most important seismic response parameters in structural seismic design, largely influenced by the sub-soil and input seismic motion characteristics. In the present work, the primary objective is to identify the areas in the district that are prone to amplification of peak ground acceleration and can be delineated for infrastructural planning. Peak ground acceleration is one of the most important parameters used in seismic design of the structures. It is estimated using the computer programme ProShake, wherein the soil parameters from 181 borehole profiles up to 30 m depth and software in-built standard earthquake input motions of magnitude 6.9, 7.0, and 7.2 used as the input parameters. The output peak ground acceleration range from 0.24 g to 0.72 g at the ground surface and from 0.21 g to 0.54 g at a depth of 10 m. There is an attenuation of peak ground acceleration at 30 m depth. The estimation of peak ground acceleration will play an important role in delineating the starta having higher peak ground acceleration amplification. This information can be effectively used for planning of important infrastructure projects like hospitals, educational institutions, and commercial establishments in an economical way in the studied area.
Rock Mechanics
Mounius Bashir; Manendra Singh; Krishna Kotiyal
Abstract
Among all methods for ground improvement, stone columns have become more popular recently, owing to their simple construction and plentiful availability of raw materials. However, in relatively softer soils, ordinary stone columns (OSCs) experience significant bulging owing to the minimal confinement ...
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Among all methods for ground improvement, stone columns have become more popular recently, owing to their simple construction and plentiful availability of raw materials. However, in relatively softer soils, ordinary stone columns (OSCs) experience significant bulging owing to the minimal confinement offered by the surrounding soil. This necessitates the introduction of reinforcements in the stone column, to enhance their strength in such circumstances. The subject of this investigation was the assessment of the behavior of horizontally reinforced stone columns (HRSCs), introduced in layered soil, under the raft foundation. The soil material included was idealised using an isotropic linearly elastic fully plastic model with a Mohr-Coulomb failure criterion. There are a total of six separate factors required by the Mohr-Coulomb criterion. These include cohesion (c), the soil's dry unit weight (γd), the Poisson ratio (μ), the angle of internal friction (φ), the angle of dilatancy (ψ), and the Young's modulus of elasticity (E). At the very beginning, the load-settlement response of unreinforced soil was evaluated followed by a comparative study between square and triangular arrangements of stone columns, at different spacings, under the raft, to arrive at the configuration that encounters minimal settlements and lateral deformations. Furthermore, circular discs of suitable geogrid material were introduced along the length of the stone column. The elastic behaviour of geogrids is governed by two properties: tensile modulus and yield strength. The load-settlement behavior and lateral deformations of the resulting reinforced stone columns, with OSCs were compared. Furthermore, the spacing between the circular discs of geogrids was kept at D/2, D, 2D, and 3D, where D is the diameter of the stone column. According to the findings of an investigation conducted using FEM software, the performance of a granular pile group that is laid out in the shape of a triangle encounters much less lateral deformation and settlement than the square arrangement. The results also show that the performance of HRSCs was way better than those of OSCs, under the same in-situ soil conditions.
Mineral Processing
Ashraf Alsafasfeh; Anum Razzaq; Abeer Sajid; Maryam Nazir; Muhammad Badar Hayat; Mirza Zaid
Abstract
Palygorskite (PAL), also known as attapulgite, is a clay mineral prized for its nanorod-like silicate structure and fibrous morphology. The traditional PAL purification methods often involve wet gravity separation techniques such as sedimentation and screening, which require significant water usage and ...
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Palygorskite (PAL), also known as attapulgite, is a clay mineral prized for its nanorod-like silicate structure and fibrous morphology. The traditional PAL purification methods often involve wet gravity separation techniques such as sedimentation and screening, which require significant water usage and pose sustainability challenges, especially in the water-scarce regions. This work introduces a novel, environmentally sustainable dry beneficiation method for PAL. A large PAL sample with 41.7% content and 10% moisture was crushed, ground using a pin mill, and classified into three particle size fractions:-0.088 mm + 0.066 mm, -0.066mm +0.044 mm, and -0.044 mm. These fractions were treated with an air classifier. A Box-Behnken experimental design was employed to investigate the effects of particle size, shutter opening, and motor speed on the classification efficiency. The optimal parameters for grade were 400 rpm motor speed, shutter opening of 1 mm, and feed size of -0.066 mm + 0.044 mm. For the recovery, the optimal conditions were 1200 rpm motor speed, shutter opening of 2.5 mm, and feed size of -0.044 mm. The most favorable balance of grade (67.8%) and recovery (53.2%) was achieved with a motor speed of 1200 rpm, shutter opening of 4 mm, and feed size of -0.066 mm + 0.044 mm. The work concludes that air classification significantly enhances the PAL beneficiation process, with a 50% increase in grade, and recommends exploring the low shear grinding techniques for further improvement.
Exploitation
S. Saadat
Abstract
Motivated by the recent successful results of using GIS modeling in a variety of problems related to the geosciences, some knowledge-based methods were applied to a regional scale mapping of the mineral potential, special for Cu-Au mineralization in the Feyz-Abad area located in the NE of Iran. Mineral ...
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Motivated by the recent successful results of using GIS modeling in a variety of problems related to the geosciences, some knowledge-based methods were applied to a regional scale mapping of the mineral potential, special for Cu-Au mineralization in the Feyz-Abad area located in the NE of Iran. Mineral Prospectivity Mapping (MPM) is a multi-step process that ranks a promising target area for more exploration. In this work, five integration methods were compared consisting of fuzzy, continuous fuzzy, index overlay, AHP, and fuzzy AHP. For this purpose, geological maps, geochemical samples, and geophysics data were collected, and a spatial database was constructed. ETM + images were used to extract the hydroxyl and iron-oxide alterations, and to identify the linear and fault structures and prospective zones in regional scale; ASTER images were used to extract SiO2 index, kaolinite, chlorite, and propylitic alterations in a district scale. All the geological, geochemical, and geophysical data was integrated for MPM by different analysis. The values were determined by expert knowledge or logistic functions. Based upon this analysis, three main exploration targets were recognized in the Feyz-Abad district. Based on field observation, MPM was proved to be valid. The prediction result is accurate, and can provide directions for future prospecting. Among all the methods evaluated in this work, which tend to generate relatively similar results, the continuous fuzzy model seems to be the best fit in the studied area because it is bias-free and can be used to generate reliable target areas.
Mineral Processing
S. Shahraki; M. Karamoozian; A. Azizi
Abstract
Sulfur is one of the most significant impurities in coal, which reduces the quality of coal and also results in environmental pollution. This work was aimed to investigate the removal of sulfur from coal by the leaching method employing parameters expected to affect the removal rate such as acid concentration ...
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Sulfur is one of the most significant impurities in coal, which reduces the quality of coal and also results in environmental pollution. This work was aimed to investigate the removal of sulfur from coal by the leaching method employing parameters expected to affect the removal rate such as acid concentration (10-30%), temperature (40-80 °C), and reaction time (40-100 min). A response surface methodology using Box-Behnken design was employed to maximize, model, and evaluate the factors affecting the desulfurization process. The results obtained indicated that the desulfurization value increased with increase in the acid concentration, temperature, and reaction time. A quadratic model with a high correlation coefficient (R2=0.98) is proposed and developed for the relationship between the removal value and the influential factors. The modeling results demonstrated that the significance degree of factors was in the order of acid concentration>temperature>reaction time. It was also found that the maximum desulfurization (about 87%) could be obtained under the optimal conditions of acid concentration=25%, temperature=80 °C, and leaching time=84 minutes.
Exploitation
H. Moini; F. Mohammad Torab
Abstract
Kriging is an advanced geostatistical procedure that generates an estimated surface or 3D model from a scattered set of points. This method can be used for estimating resources using a grid of sampled boreholes. However, conventional ordinary kriging (OK) is unable to take locally varying anisotropy ...
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Kriging is an advanced geostatistical procedure that generates an estimated surface or 3D model from a scattered set of points. This method can be used for estimating resources using a grid of sampled boreholes. However, conventional ordinary kriging (OK) is unable to take locally varying anisotropy (LVA) into account. A numerical approach has been presented that generates an LVA field by calculating the anisotropy parameters (direction and magnitude) in each cell of the estimation grid. After converting the shortest anisotropic distances to Euclidean distances in the grid, they can be used in variography and kriging equations (LVAOK). The ant colony optimization (ACO) algorithm is a nature-inspired metaheuristic method that is applied to extract image features. A program has been developed based on the application of ACO algorithm, in which the ants choose their paths based on the LVA parameters and act as a moving average window on a primary interpolated grid. If the initial parameters of the ACO algorithm are properly set, the ants would be able to simulate the mineralization paths along continuities. In this research work, Choghart iron ore deposit with 2,447 composite borehole samples was studied with LVA-kriging and ACO algorithm. The outputs were cross-validated with the 111,131 blast hole samples and the Jenson-Shannon (JS) criterion. The obtained results show that the ACO algorithm outperforms both LVAOK and OK (with a correlation coefficient value of 0.65 and a JS value of 0.025). Setting the parameters by trial-and-error is the main problem of the ACO algorithm.
M. Fooladi; F. Ghadimi; Seyed J. Sheikh Zakariaee; H. Rahimpour Bonab
Abstract
In this work, we determine the factors affecting soil erosion and its effect on dust formation around the Mineral Salts Company in Mighan playa of Arak. Seventy samples are randomly sampled from a depth of 10 cm above the ground around Mighan playa. Some factors involved (e.g. sample aggregation, lime, ...
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In this work, we determine the factors affecting soil erosion and its effect on dust formation around the Mineral Salts Company in Mighan playa of Arak. Seventy samples are randomly sampled from a depth of 10 cm above the ground around Mighan playa. Some factors involved (e.g. sample aggregation, lime, organic matter, pH, Na, K, Ca, and electrical conductivity) are determined and compared with the statistical parameters such as the correlation matrix and cluster analysis in order to determine the erosion rate in each sample based on the soil properties. The results obtained show that soil salinity, as a major factor in erosion, causes soil depletion and degradation in the area. Also a high amount of sand in the environment causes the soil texture instability. The factors such as the amount of gravel, organic matter, and K are the main erosion inhibiting factors, which have little effect on the majority of the samples. The organic matter content in most samples is less than 4%, and does not have much effect on erosion. The amount of clay in the samples is less than 10%, and has no effect on the adhesion of soil texture. The main factor affecting the erosion rate is EC and Na in the soil. The inhibitors such as gravel, organic matter, K, and clay amount in the samples can be considered as a protective or reducing factor in erosioning. Rising in the mentioned factors in the soil causes a lack of density and instability in the soil, and increases the rate of soil erosion. The results of this work show that addition of soil erosion increases the amount of fine-grained soil, and dust is a result of increased production. Also the presence of mineral salt in the area increases the production rate of dense soil, and as a result, rises the amount of dust produced in the area. Therefore, we need to stabilize mining soil, and prevent dust generation around the Mineral Salts Company.
M. Shenavar; M. Ataee-pour; M. Rahmanpour
Abstract
Production scheduling in underground mines is still a manual process, and achieving a truly optimal result through manual scheduling is impossible due to the complexity of the scheduling problems. Among the underground mining methods, sub-level caving is a common mining method with a high production ...
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Production scheduling in underground mines is still a manual process, and achieving a truly optimal result through manual scheduling is impossible due to the complexity of the scheduling problems. Among the underground mining methods, sub-level caving is a common mining method with a high production rate for hard rock mining. There are limited studies about long-term production scheduling in the sub-level caving method. In this work, for sub-level caving production scheduling optimization, a new mathematical model with the objective of net present value (NPV) maximization is developed. The general technical and operational constraints of the sub-level caving method such as opening and developments, production capacity, sub-level mining geometry, and ore access are considered in this model. Prior to the application of the scheduling model, the block model is processed to remove the unnecessary blocks. For this purpose, the floating stope algorithm is applied in order to determine the ultimate mine boundary and reduce the number of blocks that consequently reduces the running time of the model. The model is applied to a bauxite mine block model and the maximum NPV is determined, and then the mine development network is designed based on the optimal schedule.
Alankrit Walia; Amrit Kumar Roy
Abstract
The complex geography of the Himalayan mountain range, along with the natural circumstances that already exist and the ways in which people have influenced and intervened in the region- makes various regions of the range vulnerable to slope instability. The slope stability of the area that is the subject ...
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The complex geography of the Himalayan mountain range, along with the natural circumstances that already exist and the ways in which people have influenced and intervened in the region- makes various regions of the range vulnerable to slope instability. The slope stability of the area that is the subject of this work is evaluated in Palampur, which is in the Kangra district of Himachal Pradesh. The primary objective of this work is to ensure that the slope remains stable so that the nearby three-sided residential structures and the highway remain protected. After the site visit, the geo-technical studies, which include testing in the form of bore holes and in the laboratory, are carried out. After evaluating the geo-technical technical report, the next step in the process is to begin the analysis of the slope's stability. In order to do an analytical analysis of the slope stability, the area has been subdivided into three portions, and labelled A-A, B-B, and C-C, respectively. Using the numerical modelling approaches, the mitigation design parameters for the area and the circular slip failure are computed. These calculations are based on the geo-technical characteristics of the studied area that have been specified. The factor of safety is calculated for both the natural and stable scenarios by the program. Because of this, some preventative steps and a few improvements are suggested.
Yeluri Sesha Choudary; Karan Singh; T S Ramesh Babu; Garikapati Deepthi
Abstract
The efficiency of geo-polymer mortar is analyzed by replacing fine aggregates with different ratios of copper slag and crumb rubber. Properties such as flow value, setting time, strengthening properties, density, and water absorption are studied for different factors, i.e. molarities of sodium hydroxide ...
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The efficiency of geo-polymer mortar is analyzed by replacing fine aggregates with different ratios of copper slag and crumb rubber. Properties such as flow value, setting time, strengthening properties, density, and water absorption are studied for different factors, i.e. molarities of sodium hydroxide (8, 10, and 12 M), various ratios of alkali-activator solution (1, 2, and 3), and the effect of pre-treating rubber. The results indicate that the increase in molarity increases the compressive strength, setting time, and flow value of mortar. It is observed that NaOH of 12 M and an alkali activator ratio of 2 show high compressive strength, which is 71.79 N/mm2. The rubber treated with alkali improves the bonding between the binder and the rubber, which leads to an increase in the material's strength by 7% for 1 hour and 10% for 24 hours, and density by about 1.5%. It is suggested that the optimum mix with 50% copper slag, 10% rubber with pre-treatment for a period of 1 hour, 12 M NaOH, and alkali activator ratio 2 provide excellent results among all mixes. In conclusion, the findings indicate that the produced mortar contributes to economic and ecological improvement.
A. Abdollahipour; M. Fatehi Marji; H. Soltanian; E. A. Kazemzadeh
Abstract
The permeability and coupled behavior of pore pressure and deformations play an important role in hydraulic fracturing (HF) modeling. In this work, a poroelastic displacement discontinuity method is used to study the permeability effect on the HF development in various formation permeabilities. The numerical ...
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The permeability and coupled behavior of pore pressure and deformations play an important role in hydraulic fracturing (HF) modeling. In this work, a poroelastic displacement discontinuity method is used to study the permeability effect on the HF development in various formation permeabilities. The numerical method is verified by the existing analytical and experimental data. Then the propagation of a hydraulic fracture in a formation with a range of permeabilities is studied. The time required for propagation of an HF to 10 times its initial length is used to compare the propagation velocity in the formations with different permeabilities. The results obtained show that the HF propagation can be significantly delayed by a permeability less than almost 10-9 D. Also the effect of HF spacing on the propagation path is studied. It was shown that the stress shadowing effect of HFs remained for a longer spacing than in the elastic model due to the required time for fluid leak-off in the formation. Also the propagation angles are higher in the poroelastic model predictions than the elastic model. Therefore, it is proposed to use the poroelastic model when studying multi-HF propagation in order to avoid errors caused by neglecting the pore fluid effects on the HF propagation paths.
Z. Rezaei; M. Ataee-pour; H. Madani
Abstract
Providing a fresh and cool airflow in underground mines is one of the main concerns during mining. Destruction of support systems, the presence of undesirable objects in the airway and distortion of airflow are the parameters involved that would result in pressure loss, which would affect the ventilation ...
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Providing a fresh and cool airflow in underground mines is one of the main concerns during mining. Destruction of support systems, the presence of undesirable objects in the airway and distortion of airflow are the parameters involved that would result in pressure loss, which would affect the ventilation network. There are a lot of research works about the ventilation network planning that consider the confidence in the planning but how reliable are these designs? These questions can be answered using the quantitative reliability evaluation. For the reliability evaluation of mine ventilation network, tunnel resistance and flow rate changes for all branches are considered as the reliability indices and criteria. This paper describes a stepwise method for evaluation of the underground coal mine network reliability associated with major losses using the cut set method. The reliability of the entire network is achieved by the reliability of every single component. The proposed model is implemented by the Takht coal mine. The Takht mine ventilation network probability of failure is in the range of 19-100% so reliability is in the range of 0-81% for the entire ventilation network.
Exploration
Marco Antonio Cotrina-Teatino; Jairo Jhonatan Marquina-Araujo; Jose Nestor Mamani-Quispe; Solio Marino Arango-Retamozo; Johnny Henrry Ccatamayo-Barrios; Joe Alexis Gonzalez-Vasquez; Teofilo Donaires-Flores; Maxgabriel Alexis Calla-Huayapa
Abstract
This work aimed to categorize mineral resources in a copper deposit in Peru, using a machine learning model, integrating the K-prototypes clustering algorithm for initial classification and Random Forest (RF) as a spatial smoother. A total of 318,443 blocks were classified using geostatistical and geometric ...
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This work aimed to categorize mineral resources in a copper deposit in Peru, using a machine learning model, integrating the K-prototypes clustering algorithm for initial classification and Random Forest (RF) as a spatial smoother. A total of 318,443 blocks were classified using geostatistical and geometric variables derived from Ordinary Kriging (OK) such as kriging variance, sample distance, number of drillholes, and geological confidence. The model was trained and validated using precision, recall, and F1-score metrics. The results indicated an overall accuracy of 97%, with the measured category achieving 98% precision and an F1-score of 0.98. The total estimated tonnage was 5,859.36 Mt, distributed as follows: 1,446.13 Mt (measured), 2,249.22 Mt (Indicated), and 2,164.01 Mt (Inferred), with average copper grades of 0.43%, 0.33%, and 0.31% Cu, respectively. Compared to the traditional geostatistical methods, this hybrid approach improves classification objectivity, spatial continuity, and reproducibility, minimizing abrupt transitions between categories. The RF model proved to be a robust tool, reducing classification inconsistencies and better capturing geological uncertainty. Future studies should explore hybrid models (K-means with RF, ANN with K-Prototypes, gradient boosting, and deep learning) and incorporate economic variables to optimize decision-making in resource estimation.
Environment
Podicheti Ravi Kiran; Ramchandar Karra
Abstract
Opencast coal mines play a crucial role in meeting the energy demands of a country. However, the operations will result in deterioration of ambient air quality, particularly due to particulate emissions. The dispersion of particulate matter will vary based on the mining parameters and local meteorological ...
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Opencast coal mines play a crucial role in meeting the energy demands of a country. However, the operations will result in deterioration of ambient air quality, particularly due to particulate emissions. The dispersion of particulate matter will vary based on the mining parameters and local meteorological conditions. There is a need to establish a suitable model for predicting the concentration of particulate matter on a regional basis. Though a number of dispersion models exist for prediction of dust concentration due to opencast mining, machine learning offers several advantages over traditional modeling techniques in terms of data driven insights, non-linearity, flexibility, handling complex interactions, anomaly detection, etc. An attempt has been made to assess the dispersion of particulate matter using machine learning techniques by considering the mining and meteorological parameters. Historical data comprising of mine working parameters, meteorological conditions, and particulate matter pertaining to one of the operating opencast coal mines in southern India has been utilized for the study. The data has been analyzed using different machine learning techniques like bagging, random forest, and decision tree. The performance metrics of test data are compared for different models in order to find the best fit model among the three techniques. It is found that for PM10, many of the times bagging technique gave a better accuracy, and for PM2.5, decision tree technique gave a better accuracy. Integration of mine working parameters with meteorological conditions and historical data of particulate matter in developing the model using machine learning techniques has helped in making more accurate predictions.
R. Aram; M. Abdollahi; P. Pourghahramani; M. Mohseni; A. Khodadadi Darban
Abstract
In this research work, the solubility of sphalerite concentrate due to mechanical activation in planetary ball mill in both the wet and dry modes is investigated, and the parameters of mean particle size, BET specific surface area, SEM, and XRD are analyzed. The results of the particle size analysis ...
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In this research work, the solubility of sphalerite concentrate due to mechanical activation in planetary ball mill in both the wet and dry modes is investigated, and the parameters of mean particle size, BET specific surface area, SEM, and XRD are analyzed. The results of the particle size analysis and BET specific surface area show that the size of particles for the non-activated sample decrease from 51 to 30 microns but the BET specific surface area increase from 0.17 m2/g to 1.03 m2/g for the residue and feed samples. In the wet and dry mode mechanical activation, the mean particle size and BET specific surface area in the residue samples are reduced relative to the leaching feed. The results of the micro-structure characterization also show that the amorphization of the residue compared to the leaching feed increases in both modes of mechanical activation. The crystallite size and lattice strain of the activated samples in the residue increase and decrease compared to the leaching feed, respectively.
V. Heydarnoori; M. H. Khosravi; M. Bahaaddini
Abstract
The cavability assessment of rock mass cavability and indicating the damage profile ahead of a cave-back is of great importance in the evaluation of a caving mine operation, which can influence all aspects of the mine operation. Due to the lack of access to the caved zones, our current knowledge about ...
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The cavability assessment of rock mass cavability and indicating the damage profile ahead of a cave-back is of great importance in the evaluation of a caving mine operation, which can influence all aspects of the mine operation. Due to the lack of access to the caved zones, our current knowledge about the damage profile in caved zones is very limited. Among the different approaches available, physical modelling can provide a useful tool for assessment of the cave propagation and understanding the cave-back mechanism. Despite the general belief of the continuous damage profile ahead of a cave, the recent studies have shown a different mechanism of banding fracture. In order to investigate the caving mechanism ahead of a cave, a base friction apparatus is designed in this work. The base friction powder is used as the modelling material for physical testing, where its strength properties is significantly dependent on its unit weight. The effects of the material’s unit weight and the undercutting process on the cavability and cave-back height are studied. The experimental results undertaken in this research work clearly confirm the banding fracture mechanism in the caved zone, rather than continuous yielding. The effect of the undercutting sequence on the cave-back height is investigated through three different scenarios of symmetric undercutting with a gradual increase in span, symmetric undercutting with a sudden increase in span, and asymmetric undercutting. The results obtained show that the ground deformation is significantly dependent on the undercutting sequence, where choosing a greater undercutting span results in a faster cave propagation and smaller accessible undercut spans.
