F. Rastegar; H. R. Nejati; A. Ghazvinian; M. R. Hadei; A. Nazerigivi
Abstract
The tensile strength of rocks plays a noteworthy role in their failure mechanism, and its determination can be beneficial in optimizing the design of the rock structures. Schistose rocks due to their inherent anisotropy in different foliation directions show a diverse strength at each direction. The ...
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The tensile strength of rocks plays a noteworthy role in their failure mechanism, and its determination can be beneficial in optimizing the design of the rock structures. Schistose rocks due to their inherent anisotropy in different foliation directions show a diverse strength at each direction. The purpose of this work was to compare and assess the tensile strength of phyllite, which was obtained in direct and indirect tensile tests in different foliation directions. To this end, several phyllite specimens with different foliation angles (0º, 30º, 45º, 60º, and 90º) related to the loading axis (β) were prepared. Finally, the direct tensile test, diametrical and axial point load tests, Brazilian test, and Schmidt hammer test were conducted on 188 samples. The results of the experimental tests revealed that the maximum and minimum tensile strengths in direct tensile testing tension were directly related to the angles of 0º and 90º. Also it was observed that the Brazilian tensile strength overestimated the tensile strength. Furthermore, an exponential correlation was introduced between the direct tensile strength and the Brazilian tensile strength.
Lokeshwar Singh Dilta; Ravi Kumar Sharma
Abstract
This study highlights the results from a series of analytical model experiments that investigate the behaviour of a strip footing supported by hollow steel piles installed to stabilize a clay slope. The effects of changing the pile diameter, pile length, spacing between piles, slope angle, the position ...
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This study highlights the results from a series of analytical model experiments that investigate the behaviour of a strip footing supported by hollow steel piles installed to stabilize a clay slope. The effects of changing the pile diameter, pile length, spacing between piles, slope angle, the position of the pile row from the top of slope, and the footing placement are all examined. After determining the load-carrying capacity of unstabilized slopes, it is compared with the load-carrying capacity of stabilized slopes. The results are then analysed to see how each parameter affects the load carrying capacity of strip footing. The results of unstabilized cases reveal that the load carrying capacity of a footing decreases as the slope angle increases and increases when the footing is positioned away from the slope. In addition, the findings imply that by reinforcing clay slope with a sequence of hollow steel piles significantly enhances the load carrying capacity of strip footing. As the distance between piles is decreased and their length is increased, the bearing capacity of the footing increases, and this improvement is enhanced by increasing the diameter of the piles. When the row of pile is positioned away from the top of the slope, the footing’s load carrying capacity decreases. Also positioning the footing a quite distance apart from the crest slope shows reduction in bearing capacity ratio.
Rock Mechanics
E. Dadashi; A. Noorzad; K. Shahriar; K. Goshtasbi
Abstract
The utilization of the lining type in pressure tunnels is highly dependent on the geological and hydraulic conditions. There are two types of lining, namely concrete and steel lining but steel lining is one of the most expensive arrangements. To decrease the length of steel lining in these tunnels, the ...
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The utilization of the lining type in pressure tunnels is highly dependent on the geological and hydraulic conditions. There are two types of lining, namely concrete and steel lining but steel lining is one of the most expensive arrangements. To decrease the length of steel lining in these tunnels, the concrete lining, which prevents water seepage from the surrounding rock mass, is the appropriate alternative. In this work, a special attention is devoted to limit water losses in the concrete lining of pressure tunnel based on the critical reinforcing ratio in concrete lining. In order to evaluate the effect of internal water pressure on the permeability coefficient variation of the concrete lining and the surrounding rock mass, some simulations of reinforced concrete lining is implemented in the ABAQUS finite element software based on the coupled pore fluid-stress analysis. The results obtained indicate that although the critical reinforcing ratio has an important role in capturing the seepage flows and water losses, it is not sufficient to rely only on this parameter. However, among the various influential factors involved, a suitable arrangement of the reinforcement in the concrete lining should also be considered.
Exploitation
Feng Yang; Pengjie Li; Qiang Sun
Abstract
Large coal pillars result in significant resource waste. The high stress concentration within these pillars also creates safety hazards for the working face. To address this, a cooperative mining method for section coal pillars is proposed. This method is designed for seams with large inclination angles ...
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Large coal pillars result in significant resource waste. The high stress concentration within these pillars also creates safety hazards for the working face. To address this, a cooperative mining method for section coal pillars is proposed. This method is designed for seams with large inclination angles and that are extremely close to overlying pillars. The technical principles are explained. First, FLAC3D simulation software was used to investigate the effect of the spacing between the lower roadway and the section coal pillar, which determined the optimal roadway position. Then, a coupled FLAC-PFC method was employed to optimize the coal drawing process parameters. The optimal scheme was analyzed to characterize roof deformation, stress distribution, and hydraulic support loads. An engineering case study demonstrates that a spacing greater than 18 m minimizes the influence of concentrated stress, resulting in limited deformation and improved roadway stability. The study investigates coal drawing under different sequences, port widths, and methods. The optimal process was identified as downward drawing, with a 1.5 m coal drawing port width and a two-wheel sequential method. This process achieves a drawing rate of 85.62% and a gangue content of 4.61%. Analysis shows that during the pillar drawing process, the concentrated stress on the roof plate is significantly reduced, with a maximum stress decrease of 21.1 MPa, effectively alleviating stress concentration. The total force on the section hydraulic support in fully mechanized caving is 1.6×10⁴ kN, while the force in the fully mechanized mining section is 1.4×10⁴ kN.
Mineral Processing
Rim Amata; Mohamed Bounouala; Ashraf Alsafasfeh; Amar Amata; Sofiane Bouabdallah
Abstract
The Djebel Onk region of Algeria faces a significant environmental concern, related to phosphate mining waste. Although these mining tailings contain relatively low quantities of valuable minerals, they still include up to 25% P₂O₅ in the particle size range of 0.25-1 mm (-1-+0.25), suggesting the ...
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The Djebel Onk region of Algeria faces a significant environmental concern, related to phosphate mining waste. Although these mining tailings contain relatively low quantities of valuable minerals, they still include up to 25% P₂O₅ in the particle size range of 0.25-1 mm (-1-+0.25), suggesting the potential for recovery and reuse. This research, based on the Bir El Ater area, explores the methods to recover phosphate-rich minerals, optimizing their reuse. Two techniques were explored: calcination, a heat treatment altering mineral chemistry, and electrostatic separation, which uses the electrical properties to separate minerals. The black phosphate tailings collected from the curved grids of wet processing were subjected to detailed analysis using Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), and X-Ray Fluorescence (XRF), to examine their mineralogical and chemical properties. The results showed a notable improvement in the P₂O₅ concentration, with electrostatic separation reaching a 30.03% content and an 89% recovery rate, while calcination achieved the 30.91% content with a 91% recovery rate. These results highlight the effectiveness of both methods in recovering phosphate from mining tailings, contributing to a better waste management, a more efficient resource use, and a reduced environmental footprint. They also suggest sustainable recovery pathways, especially for the regions facing water scarcity, where flotation is impractical. With the ability to achieve high recovery rates without chemical inputs, calcination and electrostatic separation stand out as environmentally sustainable options for global phosphate beneficiation.
Environment
H. Nikoogoftar; A. Hezarkhani
Abstract
In this paper, we aim to achieve two specific objectives. The first one is to examine the applicability of the Artificial Neural Networks (ANNs) technique in ore grade estimation. Different training algorithms and numbers of hidden neurons are applied to estimate Cu grade of borehole data in the hypogene ...
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In this paper, we aim to achieve two specific objectives. The first one is to examine the applicability of the Artificial Neural Networks (ANNs) technique in ore grade estimation. Different training algorithms and numbers of hidden neurons are applied to estimate Cu grade of borehole data in the hypogene zone of porphyry copper-gold deposit, Masjed-Daghi, East Azerbaijan Province (Iran). The efficacy of ANNs in function-learning and estimation is compared with ordinary kriging (OK). As the kriging algorithms smooth the data, their applicability in the pre-processing of data for fractal analysis is not conducive. ANNs can be introduced as an alternative for this kind of problem. Secondly, we aim to delineate the potassic and phyllic alteration regions in the hypogene zone of Cu-Au porphyry deposit based on the estimation obtained by the ANNs and OK methods, and utilize the Concentration-Volume (C-V) fractal model. In this regard, at first, C-V log-log is generated based on the ANN results. The plots are then used to determine the Cu threshold values for the alteration zones. To investigate the correlation between the geological model and C-V fractal results, the log ratio matrix is applied. The results obtained show that Cu values less than 0.38% from ANNs have more overlapped voxels with phyllic alteration zone by an overall accuracy of 0.72. Spatial correlation between the potassic alteration zones resulting from 3D geological modeling and high concentration zones in C-V fractal model show that Cu values greater than 0.38% have more voxels overlapped with the potassic alteration zone by an overall accuracy of 0.76. Generally, the results obtained show that a combination of the ANNs and C-V fractal methods can be a suitable and robust tool for quantitative modeling of alteration zones instead of the qualitative methods.
Exploration
Ashraf Ismael; Abdelrahem Khalefa Embaby; Faissal Ali; Hussin Farag; Sayed Gomaa; Mohamed Elwageeh; Bahaa Mousa
Abstract
The mineral resource estimation process necessitates a precise prediction of the grade based on limited drilling data. Grade is crucial factor in the selection of various mining projects for investment and development. When stationary requirements are not met, geo-statistical approaches for reserve estimation ...
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The mineral resource estimation process necessitates a precise prediction of the grade based on limited drilling data. Grade is crucial factor in the selection of various mining projects for investment and development. When stationary requirements are not met, geo-statistical approaches for reserve estimation are challenging to apply. Artificial Neural Networks (ANNs) are a better alternative to geo-statistical techniques since they take less processing time to create and apply. For forecasting the iron ore grade at El-Gezera region in El- Baharya Oasis, Western Desert of Egypt, a novel Artificial Neural Network (ANN) model, geo-statistical methods (Variograms and Ordinary kriging), and Triangulation Irregular Network (TIN) were employed in this study. The geo-statistical models and TIN technique revealed a distinct distribution of iron ore elements in the studied area. Initially, the tan sigmoid and logistic sigmoid functions at various numbers of neurons were compared to choose the best ANN model of one and two hidden layers using the Levenberg-Marquardt pure-linear output function. The presented ANN model estimates the iron ore as a function of the grades of Cl%, SiO2%, and MnO% with a correlation factor of 0.94. The proposed ANN model can be applied to any other dataset within the range with acceptable accuracy.
K. Sultan shah; M. H. bin Mohd Hashim; H. Rehman; K. S. bin Ariffin
Abstract
Indirect tensile testing is used in order to investigate the effect of particle morphology (shape and size) on the various weathering grade sandstone fracture characteristics. Several fracture characteristics are discussed in depth in this work including the fracture length (FL), fracture deviation area ...
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Indirect tensile testing is used in order to investigate the effect of particle morphology (shape and size) on the various weathering grade sandstone fracture characteristics. Several fracture characteristics are discussed in depth in this work including the fracture length (FL), fracture deviation area (FDA), fracture angle (FA), and fracture maximum deviation distance (FMDD). A tabletop microscope (TTM) is used to measure the particle morphology. The image analysis techniques induce the uncertainty-related particle shape and size. Therefore, the Monte Carlo simulation (MCS) is used in order to incorporate the inherent uncertainties-related particle morphology. The results obtained reveal that the sandstone fracture angle presents an unclear relationship with the particle shape and size. The effect of particle size on FL is completely obvious, and FL increases with the particle size. In contrast, the particle shape and size have an unclear relationship with the fracture characteristics. Furthermore, the sandstone porosity affects the fracture characteristics, which increase with the weathering grade. Moreover, the findings reveal that the Monte Carlo simulation is a viable tool for integrating the inherent uncertainties associated with the particle shape and size.
Abderrahim Ayad; Saad Bakkali
Abstract
In Sidi Chennane, Central Morocco, the cost of phosphate mining is often influenced by problems bound to the existence of sterile bodies called derangements. These bodies consisting of a waste rocky material affect the sedimentary phosphate series, and thus disturb the phosphate extraction process. In ...
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In Sidi Chennane, Central Morocco, the cost of phosphate mining is often influenced by problems bound to the existence of sterile bodies called derangements. These bodies consisting of a waste rocky material affect the sedimentary phosphate series, and thus disturb the phosphate extraction process. In this work, we attempt to analyze and quantify the economic impact of these sterile bodies on the cost of phosphate mining in Sidi Chennane. The work is carried out through a prototype model prepared as a real mining trench, using data collected during our internships in the Sidi Chennane mining field. The results of this work show that the cost of removing derangements increases the cost of phosphate mining for the entire cycle of production, drilling, blasting, ripping, dozing, loading, and hauling. It is concluded, therefore, that the outcomes of this work are of great importance for obtaining an accurate understanding of phosphate mining when confronted derangements. This can be adapted to analyze and interpret such similar structures in phosphate mines around the world (e.g. Taïba phosphate mine in Senegal).
A. Ghanizadeh Zarghami; K. Shahriar; K. Goshtasbi; A. Akbari Dehkharghani
Abstract
Calculation of the specific charge and specific drilling before a blasting operation plays a significant role in the design of a blasting pattern and the reduction of the final extraction cost of minerals. In this work, the information from the Sungun, Miduk and Chah-Firouzeh copper mines in Iran was ...
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Calculation of the specific charge and specific drilling before a blasting operation plays a significant role in the design of a blasting pattern and the reduction of the final extraction cost of minerals. In this work, the information from the Sungun, Miduk and Chah-Firouzeh copper mines in Iran was assessed, and it was found that there was a significant relationship between the specific charge and specific drilling and the hole diameter, bench height, uniaxial compressive strength and joint set orientation. After finding a technical and economic model to calculate the specific charge and specific drilling, this model was tested on the Sungun copper mine. Due to the insufficient consideration during the design of a blast pattern and because of the high hardness of the rocks in some parts of the mine, lots of destructive events such as boulders, back break, bench toe, high specific charge and high specific drilling, fly rock, and ground vibration in the blast operations were observed. The specific charge and specific drilling were found to be the most important technical and economic parameters involved in designing a blasting pattern, and they were found to play an important role in reducing the blasting cost. The blasting cost could be largely controlled by the accurate examination and computation of these parameters. An increase in the rock strength and the angle between the bench face and the main joint set would increase the specific charge and specific drilling. On the other hand, a specific charge and a specific drilling would decrease when the hole diameter increased in every range of the uniaxial compressive strength.
Exploitation
Babatunde Adebayo; Blessing Olamide Taiwo; BUSUYI THOMAS AFENI; Aderoju Oluwadolapo Raymond; Joshua Oluwaseyi Faluyi
Abstract
The quarry operators and managers are having a running battle in determining with precision the rate of deterioration of the button of the drill bit as well as its consumption. Therefore, this study is set to find the best-performing model for predicting the drill bit button's wear rate during rock drilling. ...
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The quarry operators and managers are having a running battle in determining with precision the rate of deterioration of the button of the drill bit as well as its consumption. Therefore, this study is set to find the best-performing model for predicting the drill bit button's wear rate during rock drilling. Also, the rate at which drill bit buttons wear out during rock drilling in Ile-Ife, Osogbo, Osun State, and Ibadan, Oyo State, Southwest, Nigeria was investigated. Artificial Neural Network (ANN), Adaptive Neuro-Fuzzy Inference System (ANFIS), and adaptive moment Estimation-based Long Short-Term Memory (LSTM) machine learning approaches were used to create models for estimating the bit wear rate based on circularity factor, rock grain size, equivalent quartz content, uniaxial compressive strength, porosity, and abrasive properties of the rock. The performance of the models was measured using a new error estimation index and four other convectional performance estimators. The analysis of performance shows that the adaptive moment estimation algorithm-based LSTM model did better and more accurately than the other models. Thus, the LSTM models presented can be used to improve drilling operations in real-life situations.
Environment
Ahmed Amara Konate; Djénébou Bourama Sangare; Baba Faradji N'diaye; N'dji dit Jack Dembele
Abstract
Artisanal gold mining (AGM) is one of Mali's most significant economic activities. This activity become a serious environmental concern because of the chemicals used for AGM. The artisanal gold processing method uses a significant amount of water. The operating waste, often toxic by chemical mercury, ...
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Artisanal gold mining (AGM) is one of Mali's most significant economic activities. This activity become a serious environmental concern because of the chemicals used for AGM. The artisanal gold processing method uses a significant amount of water. The operating waste, often toxic by chemical mercury, is discharged or drained into watercourses. This study describes the main actors and the different methods of exploration, extraction, and processing of gold by artisanal miners, as well as their perception of environmental impacts. The methodology adopted is based on surveys and observations conducted at the Lollè and Sinty sites. The results show that no mining legislative rules were applied. Still, non-standard customary rules for a very long time. AGM has a particular organizational chart that actors manage. This study shows that AGM can cause health and environmental problems, especially with the use of chemicals, contamination of water resources, land degradation, and destruction of fauna and flora. Analysis of water samples shows that the mercury concentration at Lollè exceeds the WHO standard, while most mercury concentrations at Sinty are below this standard. The geomorphology of the study area shows a watershed with an area of 88.40 km2 with four orders of the hydrographic network in Lollè and 404.02 km2 with five orders in Sinty. While the slopes range from very weak to strong, and the study areas are practically flat. This study will provide accurate information to policy-makers for implementing environmental management strategies in a manner that miners can understand and evaluate.
Rock Mechanics
Tanya Thakur; Kanwarpreet Singh; Abhishek Sharma
Abstract
Landslides affecting life and property losses has become a serious threat in various countries worldwide which highlights the importance of slope stability and mitigation. The methods and tools employed for slope stability analysis, ranging from traditional limit equilibrium methods to worldly-wise numerical ...
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Landslides affecting life and property losses has become a serious threat in various countries worldwide which highlights the importance of slope stability and mitigation. The methods and tools employed for slope stability analysis, ranging from traditional limit equilibrium methods to worldly-wise numerical modeling techniques. It focuses on the importance of accurate and reliable data collection, including geotechnical investigations, in developing precise slope stability assessments. Further, it also addresses challenges associated with predicting and mitigating slope failures, particularly in dynamic and complex environments. Mitigation strategies for unstable slopes were systematically reviewed of different researchers, encompassing both traditional and innovative measures. Traditional methods, such as retaining walls and drainage systems, the mitigation strategies were explored, emphasizing both preventive measures and remedial interventions. These include the implementation of engineering solutions such as slope structures, and Matrix Laboratory (MATLAB) techniques along with the comprehensive analysis of four prominent slope stability assessment tools: Rock Mass Rating (RMR), Slope Mass Rating (SMR), and the Limit Equilibrium Method (LEM). The comparative analysis of these tools highlights their respective strengths, limitations, and areas of application, providing researchers, authors, and practitioners with valuable insights to make informed choices based on project-specific requirements. To ensure the safety and sustainability of civil infrastructure, a thorough understanding of geological, geotechnical, and environmental factors in combination with cutting-edge technologies is required. Furthermore, it highlights the important role that slope stability assessment and mitigation play a major role in civil engineering for infrastructure development and mitigation strategies.
Rock Mechanics
Manthri Rakesh; Ashish Kumar Dash; Sunny Murmu
Abstract
India's growing energy demand has intensified the need for efficient and safe coal extraction methods, particularly in underground mining, where mechanized depillaring using Continuous Miner (CM) technology has gained prominence. This study explores the critical role of Cut-Out Distance (COD) in optimizing ...
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India's growing energy demand has intensified the need for efficient and safe coal extraction methods, particularly in underground mining, where mechanized depillaring using Continuous Miner (CM) technology has gained prominence. This study explores the critical role of Cut-Out Distance (COD) in optimizing production and ensuring safety during mechanized depillaring operations. COD, defined as the stable drivage length that can be cut without support, directly impacts productivity, roof stability, and operational safety. Despite its importance, there are no standardized guidelines for determining COD in Indian coal mines, leading to trial-and-error practices that compromise efficiency and safety. This paper reviews global and domestic practices, highlighting the inadequacies in existing methods for COD estimation. It identifies key factors influencing COD, including Rock Mass Rating (RMR), roof elasticity, geological conditions, and machinery capabilities. The work also examines case studies of strata control failures in Indian coal mines, highlighting the consequences of improper strata assessment in mines. The research work advocates for the development of standardized guidelines tailored to Indian mining conditions by integrating numerical simulations and machine learning tools for precise COD estimation. A flow chart of methodology for the development of guidelines is proposed; the findings aim to enhance safety, reduce accidents, and improve productivity, paving the way for sustainable growth in India's underground coal mining sector.
Mineral Processing
Sajad Kolahi; Mohammad Jahani Chegeni; Asghar Azizi
Abstract
In Part 2 of this research work, five types of liners, i.e. wave, step, step@, ship-lap, and ship-lap@, are examined. These liners all have similar connected lifters with different volumes. Their difference is in the width, height, and type of the lifter profile. All the five liner types, from 8 to 64 ...
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In Part 2 of this research work, five types of liners, i.e. wave, step, step@, ship-lap, and ship-lap@, are examined. These liners all have similar connected lifters with different volumes. Their difference is in the width, height, and type of the lifter profile. All the five liner types, from 8 to 64 lifters, are simulated using the Discrete Element Method (DEM). In this research work, for the first time, data from the sum of the kinetic and potential energies of individual balls (79,553 particles) are used to find the appropriate range for the number of lifters. In other words, the kinetic and potential energies of all particles within the system (inside the ball mill) are the basis for determining the appropriate number of lifters. The results suggest that for the wave liner, the appropriate range of the number of lifters is between 8 and 16, for the step, step@, and ship-lap liners; it is between 12 and 20, and for the ship-lap@ liner, it is between 8 and 20. In fact, using the data on the kinetic and potential energies of the balls inside the mill, it is possible to determine the appropriate range of the number of lifters, which is done for the first time in this study. In general, it is suggested that the data on the kinetic and potential energies of the balls can be used to determine the number of mill lifters, and unlike what has been done. So far, by other researchers, the number of mill lifters should not be determined solely by using its diameter or the dimensions of the lifters. Also the effect of mill-rotation direction on the values of kinetic and potential energies in step and ship-lap liners is investigated. It is shown that the step@ and ship-lap@ liners transfer more energy to the balls than the step and ship-lap liners, and have a suitable direction of rotation.
M. Kor; E. Abkhoshk; Kh. Gharibie; S. Z. Shafaei
Abstract
An attempt has been made in this paper to investigate the effect of particle size distribution on coal flotation kinetics. The effect of particle size (Ps) on kinetics constant (k) and maximum theoretical flotation recovery (RI) was investigated while other operational parameters were kept constant. ...
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An attempt has been made in this paper to investigate the effect of particle size distribution on coal flotation kinetics. The effect of particle size (Ps) on kinetics constant (k) and maximum theoretical flotation recovery (RI) was investigated while other operational parameters were kept constant. The relationship between flotation kinetics constant and theoretical flotation recovery with particle size was estimated with nonlinear equations. Analysis of variance showed that the effect of particle size on the kinetics constant was statistically significant at 95% confidence level. However, it was not significant on maximum theoretical flotation recovery (RI). Different regression methods were conducted in order to model the effect of coal particle size on flotation kinetics. Results indicated that the quadric regression method gave better prediction of the cumulative recovery for different particle size fractions. The correlation coefficient (R2) values of this model were 0.99, 0.996, 0.98, 0.98 and 0.97 for average of particle sizes of 37.5 µm, 112.5 µm, 225 µm, 400 µm and 625 µm respectively.
A. H. Ansari; K. Alamdar
Abstract
Potential field methods such as gravity and magnetic methods are among the most applied geophysical methods in
mineral exploration. A high-resolution technique is developed to image geologic boundaries such as contacts and faults.
Potential field derivatives are the basis of many ...
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Potential field methods such as gravity and magnetic methods are among the most applied geophysical methods in
mineral exploration. A high-resolution technique is developed to image geologic boundaries such as contacts and faults.
Potential field derivatives are the basis of many interpretation techniques. In boundary detection, the analytic signal
quantity is defined by combining the values of horizontal and vertical derivatives. The outlines of the geologic
boundaries can be determined by tracing the maximum amplitudes of analytic signal. However, due to superposition
effects, in some cases that a variety of sources are adjacent, the detected boundaries are blurred. To overcome this
problem, this study used enhanced analytic signal composed of the nth- order vertical derivative of analytic signal. The
locations of its maximum amplitudes are independent of magnetization direction and geomagnetic parameters. This
technique is particularly suitable when interference effects are considerable and when remanent magnetization is not
negligible. In this paper this technique has been applied to gravity data of southwest England. Using this method, five
granites outcrops and their separating faults are enhanced accurately.
P. Masoudi; B. Tokhmechi; A. Zahedi; M. Ansari Jafari
Abstract
Distinguishing productive zones of a drilled oil well plays a very important role for petroleum engineers to decide where to perforate to produce oil. Conventionally, net pay zones are determined by applying a set of cut-offs on perophysical logs. As a result, the conventional method finds productive ...
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Distinguishing productive zones of a drilled oil well plays a very important role for petroleum engineers to decide where to perforate to produce oil. Conventionally, net pay zones are determined by applying a set of cut-offs on perophysical logs. As a result, the conventional method finds productive intervals crisply. In this investigation, a net index value is proposed, then; diffusivity equation is utilized to calculate the proposed index value. The new net determination method is applied on the interval of Sarvak Formation of two datasets of two nearby wells. The best advantage of this newly developed net determination method is its fuzzy output. Fuzzy net pay determination is valuable in grading pay zones and not classifying all productive zones in a single class. Another advantage of the proposed net determination method is its higher accuracy in identifying productive zones in comparison with cut-off based method.
Mineral Processing
Chourouk MENIAI; Mohamed BOUNOUALA; Raouf CHAABIA; CHAHRA SIFI; Rim AMATA
Abstract
Phosphate mining at Djebel Onk (Tébessa, Algeria) generates large volumes of solid wastes that occupy land, release dust, and contaminate surrounding environments. This study aims to characterize and valorize two types of dry tailings, namely +15 mm screening rejects and fines from pneumatic separation ...
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Phosphate mining at Djebel Onk (Tébessa, Algeria) generates large volumes of solid wastes that occupy land, release dust, and contaminate surrounding environments. This study aims to characterize and valorize two types of dry tailings, namely +15 mm screening rejects and fines from pneumatic separation (TSV), in order to reduce their environmental impact and recover residual phosphate. Samples were analyzed using particle size distribution, atomic absorption spectrometry (AAS), X-ray diffraction (XRD), and scanning electron microscopy coupled with energy-dispersive spectroscopy (SEM/EDS). Treatment tests included calcination (laboratory furnace, 700–1000 °C, 15–30 min) and direct flotation (Denver-type cell, with oleic acid and phosphoric acid as reagents).The results show that the +15 mm rejects and TSV fines contain 21.42 % and 23 % P₂O₅, respectively, while the richest fraction (-0.5 + 0.25 mm) reaches 28.99 % P₂O₅ with 1.01 % MgO. Calcination at 1000 °C for 30 minutes produced concentrates with 33.51 % P₂O₅ and near-complete CO₂ removal, whereas direct flotation yielded concentrates of ≈ 30 % P₂O₅ with MgO < 1 %. The novelty of this work lies in the combined application of calcination and flotation, which demonstrates their complementarity for efficient recovery of phosphate from dry tailings. These results confirm the potential for phosphate valorization while reducing environmental impacts and supporting more sustainable mining practices.Keywords: Phosphate, mining wastes, calcination, flotation, environmental management, Djebel Onk
A Igder; Ali Akbar Rahmani; Ali Fazlavi; Mohammad Hossein Ahmadi; Mohammad Hossein Ahmadi Azqhandi; Mohammad Hassan Omidi
Abstract
The main objective of the present study is to investigate the feasibility of using Carboxymethyl chitosan magnetic nanoparticles (CCMN) for the adsorption of Cd2+. The study also reports important parameters, which affect the adsorption process, i.e., pH, adsorbent dose, contact time and concentration ...
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The main objective of the present study is to investigate the feasibility of using Carboxymethyl chitosan magnetic nanoparticles (CCMN) for the adsorption of Cd2+. The study also reports important parameters, which affect the adsorption process, i.e., pH, adsorbent dose, contact time and concentration of Cd2+, using Box-Behnken designs. Firstly, functional carboxymethyl chitosan magnetic nanoparticles (about 33 nm) was prepared by chemical coprecipitating and characterized by means of scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier Transform infrared spectroscopy (FTIR). Then, CCMN was used as the adsorbent for the treatment of effluent. The ANOVA result of the full model shows that pH, adsorbent dosage and metal concentration had a significant effect on metal removal. In addition, this parameters indicates which contact time variable does not have a significant effect (p>0.05).
Saeed Alishahi; Ahmad Darban; Mahmood Abdollahi
Abstract
Since a high toxicity of cyanide which use as a reagent in the gold processing plant, thiosulfate has been recognized as a environmental friendly reagent for leaching of gold from ore. After gold leaching process it's important for recovery of gold from solution using adsorption or extraction methods, ...
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Since a high toxicity of cyanide which use as a reagent in the gold processing plant, thiosulfate has been recognized as a environmental friendly reagent for leaching of gold from ore. After gold leaching process it's important for recovery of gold from solution using adsorption or extraction methods, One of these methods is activated carbon.The loading of gold from industrial thiosulfate solution that obtained from Zarshuran gold plant-Takab-Iran, onto activated carbon have been investigated. The affecting variables of the adsorption of gold on the carbon included, temperature, concentration of gold, size of activated carbon, pH and the ratio of amount of activated carbon to the volume of solution. The results have shown that at low concentration of gold, effective loading can be achieved at pH 10.5. The size of activated carbon has a significant effect on the loading of gold. In this research the recovery of gold on activated carbon has been predicted using artificial neural network. For this purpose temperature, pH, the proportion of solution volume to weight of activated carbon, gold concentration and time of adsorption were taken as input parameters, whereas, the recovery of gold on activated carbon from thiosulfate solution was considered as an output parameter. The network with LMBP algorithm with two hidden layer were used and the topology 5-4-13-1 showed the best ability for prediction.Moreover sensitive analyze were indicated parameters pH and temperature have substantial influence on adsorption.
M. Fakhrerad; A. Nejati Kalateh; S. Ghomi
Abstract
Coastal Fars gravimetry project in Fars province was carried out to find the buried salt domes and to determine characteristics of faults in this area. The Lavarestan structure was covered by 4203 gravimetry stations in a regular grid of 1000*250 m. Depth structural model of this anticline made in previous ...
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Coastal Fars gravimetry project in Fars province was carried out to find the buried salt domes and to determine characteristics of faults in this area. The Lavarestan structure was covered by 4203 gravimetry stations in a regular grid of 1000*250 m. Depth structural model of this anticline made in previous studies was based on geological evidences and structural geology measurements. In order to have a complete coverage of Lavarestan anticline, 4 profiles with appropriate intervals were selected on gravity data for further processing and interpretation. 2D inverse modeling was performed on these profiles using Encome Modelvision and Encome PA software. Geometrical and physical parameters of each layer were changed step by step and forward gravity calculations were repeated until we reached a desirable fitting between observed and calculated gravity anomaly. The results of 2D gravity modeling were focused on Lower Paleozoic and Kazerun (cap rock) top horizon, also the underground contour map was extracted from seismic data after interpretation. The results show appropriate correlation between the underground contour map of 2D gravity modeling and interpretation of seismic data.
Gh. Mojarradi; R. Rezaei; A. Ketabi
Abstract
This descriptive analytical survey was aimed to study the negative impacts of mine exploitations carried out in the rural regions of the Tekab Township located in Iran. The statistical population of the studied areas consisted of all the heads of the rural households in the villages located in the vicinity ...
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This descriptive analytical survey was aimed to study the negative impacts of mine exploitations carried out in the rural regions of the Tekab Township located in Iran. The statistical population of the studied areas consisted of all the heads of the rural households in the villages located in the vicinity of the mines in the Tekab Township (N=2680). According to the Cochran formula, a sample size of 220 was selected using a stratified random sampling technique (n=220). A questionnaire was used to collect the data required. The validity of the questionnaire used was confirmed by a panel of experts. A pilot study was conducted to establish the reliability of the instrument used. The Cronbach’s alpha coefficient for the main scale of the questionnaire including the negative effects of the mine exploitations was equal to 0.94. The results obtained from the factor analysis revealed that five factors including the environmental, social, economic, cultural, and hygiene factors explained 60.19% of the total variances of the negative impacts of the mine exploitations in the rural regions of the Tekab Township.
Rock Mechanics
M. T. Hamzaban; H. Memarian; J. Rostami
Abstract
Rock abrasivity is an essential factor for selecting cutting tools, estimating tool wear and life, and ultimately, matching various mechanized excavation systems with a given geologic condition. It also assists engineers to determine economic limits of different cutting tools and machines used in civil ...
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Rock abrasivity is an essential factor for selecting cutting tools, estimating tool wear and life, and ultimately, matching various mechanized excavation systems with a given geologic condition. It also assists engineers to determine economic limits of different cutting tools and machines used in civil and mining projects. The Cerchar abrasion test is a simple and most widely used method for rock abrasivity assessments. However, it has some shortcomings to describe the steel-rock interaction during the cutting process. In this work, two new parameters are used to describe the pin-rock interaction in the Cerchar abrasion test and to evaluate the efficiency of the rock scratching process. A set of 41 different rock samples are tested by a newly developed testing device. The device provides a more precise control of the testing operational parameters, and measures the applied frictional force on the pin and its horizontal and vertical displacements on the sample surface. The results obtained are used to calculate the Modified Cerchar Abrasion Index (MCAI) and the Scratch Energy Index (SEi), as two newly developed parameters. The accuracy of the calculated parameters is discussed. Our investigations show that MCAI has closer correlations with rock mechanical parameters than CAI, and therefore, has a higher potential to estimate the rock cutting tool wear in tunneling applications. Also SEi shows sensible correlations with sample hardness and mechanical properties. The results obtained show that SEi can be used to compare the efficiency of various pin hardnesses to create scratches on various rock samples, and could be used as a determinative parameter in selecting the cutting tool hardness.
M. Rezaee Rad; Sh. Shahhoseini; M. Janfada; H. A. Mirzaee; P. Kelidari
Abstract
Low grade diasporic bauxite in the Jajarm mine with an A/S (Al2O3/SiO2) ratio of 2.3 is not usable in the Bayer process at Jajarm Alumina Complex. Due to the severe interlocking effect between the diaspore and aluminosilicate minerals (Chamosite and Kaolinite) and iron-containing minerals in a microcrystal ...
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Low grade diasporic bauxite in the Jajarm mine with an A/S (Al2O3/SiO2) ratio of 2.3 is not usable in the Bayer process at Jajarm Alumina Complex. Due to the severe interlocking effect between the diaspore and aluminosilicate minerals (Chamosite and Kaolinite) and iron-containing minerals in a microcrystal matrix, the thermo-chemical treatment, which is independent from micro-mineralogy, was chosen for bauxite desilication. Five parameters affecting the process and their interactions were investigated using the Taguchi experimental design method. The results obtained showed that there was an interaction between the furnace temperature and the leaching time. Moreover, the optimum values for the parameters involved in the thermo-chemical treatment were determined to be a furnace temperature of 950 °C, a furnace residence time of 90 min, a leaching agent (soda) concentration of 150 g L-1, and a leaching time of 120 min, where the solid content (in leaching) had no effect. Moreover, a model was proposed using the Dx7 software to predict the A/S ratio. The ratio was predicted to be 7.52 at the optimum conditions, whereas in the experiments carried out under the same conditions, it was obtained to be 6.96 ± 0.2, which means a 59% decrease in silica and an increase in the A/S ratio of up to 3 times with 80% weight recovery.
