Mineral Processing
Mohammad Reza Vashadi Arani; Seyed Mohammad Razavian
Abstract
The use of lithium-ion batteries has increased significantly in recent years due to their high energy density and the presence of valuable materials such as cobalt and nickel, making them an important source for secondary material recovery. However, recycling these batteries presents substantial safety ...
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The use of lithium-ion batteries has increased significantly in recent years due to their high energy density and the presence of valuable materials such as cobalt and nickel, making them an important source for secondary material recovery. However, recycling these batteries presents substantial safety risks, primarily from fire and explosion hazards caused by unwanted short circuits and high voltage components. These risks are especially pronounced during mechanical preparation, crushing, storage, and transportation, where damaged or improperly handled batteries can ignite or explode. To mitigate these hazards, rapid and controlled discharge of batteries before recycling is critical. Discharging using salt solutions is recognized as a simple, fast, and cost-effective method to reduce residual charge and minimize the risk of fire during subsequent handling. In this research, four different types of natural salts at various concentrations were tested, prioritizing the use of accessible, low-cost, and impure salts over pure laboratory-grade salts to enhance scalability and economic feasibility. Initial experiments involved direct immersion of batteries in salt solutions at concentrations of 10%, 15%, and 20% by weight. Among the complementary processes evaluated, the use of a high-speed magnetic stirrer, iron powder, and ultrasonic operations (ultrasonic bath and probe) were found to further reduce discharge time and help achieve target voltages more quickly. Notably, ultrasonic agitation at 28 kHz was particularly effective, significantly accelerating the discharge process and enabling the batteries to reach lower voltage thresholds such as 0.5 volts in a shorter time.
Exploitation
Hasan Ghasemzadeh; Hassan Madani; Farhang Sereshki; Sajjad Afraei
Abstract
One of the most prevalent risks in coal mines is spontaneous combustion (spon com) of coal, which is a major source of coal loss in these environments. Therefore, to avoid coal loss and preventing the potential risks, a criterion for predicting the spon com of coal is essential. The main purpose of this ...
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One of the most prevalent risks in coal mines is spontaneous combustion (spon com) of coal, which is a major source of coal loss in these environments. Therefore, to avoid coal loss and preventing the potential risks, a criterion for predicting the spon com of coal is essential. The main purpose of this work is to present a new model for predicting the spon com of coal potential using a decision tree technique, known as the Spon com of coal decision Tree (SCCDT). In this research work, after identifying the effectiveness of each parameter on the spon com of coal, several parameters were examined, including characteristics such as moisture, ash, pyrite, volatile matter, fixed carbon, mineralogy, and petrography. Subsequently, the primary phases of applying the decision tree model were analyzed, and the probability of the spon com of coal potential was determined based on intrinsic parameters. Finally, the mentioned parameters were categorized, and an appropriate model for classifying the spon com of coal potential was developed. In the SCCDT model, the spon com of coal potential was divided into three classes: low, medium, and high. The model was then applied to Parvadeh I to IV coal mines in Tabas. A comparison of the study's findings showed relatively good agreement with the SCCDT model. Using the proposed model can help to predict the spon com hazard and prevent the various life-threatening/mortal and financial risks.
M. Moghise; M. Pourrahim; B. Rezai; M. Gharabaghi
Abstract
This study aims to investigate and optimize the effects of the main parameters including the particle size, gravity and magnetic separation combination, high gradient magnetic separation, magnetic field intensity, shaking table slope, washing water flow, and electrostatic separation upon the rare earth ...
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This study aims to investigate and optimize the effects of the main parameters including the particle size, gravity and magnetic separation combination, high gradient magnetic separation, magnetic field intensity, shaking table slope, washing water flow, and electrostatic separation upon the rare earth element (REE) recoveries from iron mine waste. The electron microprobe showed that high amounts of REEs were distributed on the fluorapatite mineral, and hence, it was necessary to remove the high magnetic minerals by a low-intensity magnetic separation using a magnetic drum in an experimental procedure. A cyclic magnetic separator was used for the low-gradient magnetic separation. Moreover, a shaking table and an electrostatic separator were used to expand the recovery and grade of REEs. A combination of these methods was considered to optimize the REE recoveries based on the best combination including two steps of low magnetic separation, one step of medium intensity magnetic separation, a shaking table, and an electrostatic separator. Two low-intensity magnetic of 800 and 2000 gauss, one medium-intensity magnetic of 8000 gauss, a one-step shaking table with a water flow of 90 mL/s and a table slope of 3 degree, and one electrostatic separator of 25000 V with a blade angel of 20 degree had the best performance to separate REEs. The microscopic studies carried out showed that the monazite degree of freedom was between 75 and 105 micron. The results obtained showed that a particle size of ‒75 + 63 micron was a proper one to separate REEs. The total recovery and grade of the REE (Ce, La, Nd, Er, and Gd) concentrate obtained from the sample with a grade of 1499 ppm of REEs were 67.1 and 1.2%, respectively, at the optimum conditions. The results obtained showed that there was a direct relation between the phosphor grade and the REE recoveries, and that the REE recoveries increased by increasing the quantity of phosphor.
S. Moghaddam; S. Dezhpasand; A. Kamkar Rohani; S. Parnow; M. Ebrahimi
Abstract
Protection of water resources from contamination and detection of the contaminants and their treatments are among the essential issues in the management of water resources. In this work, the time-lapse electrical resistivity tomography (ERT) surveys were conducted along 7 longitudinal lines in the downstream ...
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Protection of water resources from contamination and detection of the contaminants and their treatments are among the essential issues in the management of water resources. In this work, the time-lapse electrical resistivity tomography (ERT) surveys were conducted along 7 longitudinal lines in the downstream of the Latian dam in Jajrood (Iran), in order to detect the contamination resulting from the direct injection of a saltwater solution in to the saturated zone in the area. To investigate the pollutant quantities affecting the resistivity of this zone, the temperature and electrical conductivity measurement were carried out using a self-recording device during 20 days (before and after the injection). The results obtained from the self-recording device measurements and ERT surveys indicated that in addition to the salt concentration changes in water, the resistivity changes in the saturated zone were dependent on other factors such as the lithology and absorption of contaminants by the subsurface layers. Furthermore, the expansion of contamination toward the geological trend, sedimentation, and groundwater flow direction of the area were shown.
A. Abdollahipour; M. Fatehi Marji; A. R. Yarahmadi Bafghi; J. Gholamnejad
Abstract
Hydraulic fracturing (HF), as a stimulation technique in petroleum engineering, has made possible the oil production from reservoirs with very low permeability. The combination of horizontal drilling and multiple HF with various perforation angles has been widely used to stimulate oil reservoirs for ...
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Hydraulic fracturing (HF), as a stimulation technique in petroleum engineering, has made possible the oil production from reservoirs with very low permeability. The combination of horizontal drilling and multiple HF with various perforation angles has been widely used to stimulate oil reservoirs for economical productions. Despite the wide use of HF, there are still ambiguous aspects that require more investigation. Therefore, optimizing the geometry of the initial fractures using numerical methods is of high importance in a successful HF operation. Different geometrical parameters of the initial HF cracks including patterns, spacings, crack lengths, and perforation phase angles were modeled using the higher order displacement discontinuity method (HODDM) in horizontal and vertical oil wells. Several well-known issues in HF such as crack interference and crack arrest were observed in certain patterns of the HF cracks. Also the best possible arrangements of the HF cracks were determined for a better production. The results obtained were verified by the in-situ measurements existing in the literature. In addition, the best perforation phase angle in vertical wells was investigated and determined.
M. Mokhtarian Asl; J. Sattarvand
Abstract
Production planning of an open-pit mine is a procedure during which the rock blocks are assigned to different production periods in a way that leads to the highest net present value (NPV) subject to some operational and technical constraints. This process becomes much more complicated by incorporation ...
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Production planning of an open-pit mine is a procedure during which the rock blocks are assigned to different production periods in a way that leads to the highest net present value (NPV) subject to some operational and technical constraints. This process becomes much more complicated by incorporation of the uncertainty existing in the input parameters. The commodity price uncertainty is among the most significant factors, whose effects cannot be mitigated through further exploration or investigation. The present work introduced a new approach for integration of the commodity price uncertainty into long-term production planning of open-pit mines. The procedure involves solving the problem by the integer programming method based on a series of economic block models that are realized based on the sampled prices from commodity price distribution function using the median Latin hypercube sampling method. The results obtained showed that the new methodology is able to reduce the risks and the net present value of the new approach at a confidence level 80% more than the conventional methods.
M. Doustmohammadi; A. Jafari; O. Asghari
Abstract
Water inflow is one of the most important challenges in the underground excavations. In addition to inducing working conditions and environmental problems, it decreases the stability and quality of the surrounding rocks. The direct method of measuring rock mass hydraulic conductivity consists of drilling ...
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Water inflow is one of the most important challenges in the underground excavations. In addition to inducing working conditions and environmental problems, it decreases the stability and quality of the surrounding rocks. The direct method of measuring rock mass hydraulic conductivity consists of drilling the boreholes and observing the rate of fluid lost in the boreholes. Applying this method is still problematic due to the depth of underground spaces, and also the groundwater level covering them. Therefore, many researchers have tried to predict the water inflow indirectly. This paper attempts to predict the groundwater conditions in the Beheshtabad tunnel (in Iran) using the fuzzy inference system based on the datasets acquired from the preliminary exploration studies. 250 datasets for the Beheshtabad tunnel were used out of which, 200 datasets were used to develop the model and 50 were used to validate the results obtained. 90% accuracy was obtained through comparing the fuzzy estimation and actual groundwater conditions. The proposed model can be used with much less degree of complexity for prediction of the groundwater conditions as well as decreasing the overall costs of the exploration measurements, and due to these characteristics, it is applicable for most users.
R. Vahedi; B. Tokhmechi; M. Koneshloo
Abstract
We use a multi-resolution analysis based on a wavelet transform to upscale a 3D fractured reservoir. This paper describes a 3D, single-phase, and black-oil geological model (GM) that is used to simulate naturally-fractured reservoirs. The absolute permeability and porosity of GM is upscaled by all the ...
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We use a multi-resolution analysis based on a wavelet transform to upscale a 3D fractured reservoir. This paper describes a 3D, single-phase, and black-oil geological model (GM) that is used to simulate naturally-fractured reservoirs. The absolute permeability and porosity of GM is upscaled by all the possible combinations of Haar, Bior1.3, and Db4 wavelets in three levels of coarsening. The applied upscaling method creates a non-uniform computational grid, which preserves its resolved structure in the near-well zones as well as in the high-permeability sectors but the data are scaled up in the other regions. To demonstrate the accuracy and efficiency of the method, the values for the oil production rate, mean reservoir pressure, water cut, and total amount of water production are studied, and their mean error is estimated for the upscaled models. Finally, the optimized model is selected based on the computation time and accuracy value.
A. Siamaki; H. Bakhshandeh Amnieh
Abstract
A considerable amount of energy is released in the form of shock wave from explosive charge detonation. Shock wave energy is responsible for the creation of crushing and fracture zone around the blast hole. The rest of the shock wave energy is transferred to rock mass as ground vibration. Ground vibration ...
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A considerable amount of energy is released in the form of shock wave from explosive charge detonation. Shock wave energy is responsible for the creation of crushing and fracture zone around the blast hole. The rest of the shock wave energy is transferred to rock mass as ground vibration. Ground vibration is conveyed to the adjacent structures by body and surface waves. Geological structures like faults, fractures, and fillings play important roles in the wave attenuation. Studying the mechanism of ground wave propagation from blasts gives a better understanding about the stress wave transmission and its effect on the near structures. In this research work, the stress wave transmissions from discontinuities and fillings were evaluated using a field measurement and a Universal Distinct Element Code (UDEC). A single-hole blast was conducted in the Kangir dam, and the resulting vibrations were measured in many points before and after the faults. Numerical simulation shows the effects of geo-mechanical properties of fillings on the reflection and refraction rate of the stress wave. There are more energy reflections in the rock boundaries and soil fillings, and more energy is absorbed by soil fillings compared with rock fillings. Furthermore, there is a close correlation between the ground vibration records for the Kangir dam and the numerical results. The maximum relative error between the actual records and the simulated ones was found to be 18.5%, which shows the UDEC ability for the prediction of blast vibrations.
M. Mohammady Oskouei; S. Babakan
Abstract
This work aims to extract the mineralogical constituents of the Lahroud Hyperion scene situated in the NW of Iran. Like the other push-broom sensors, Hyperion images suffer from spectral distortions, namely the smile effect. The corresponding spectral curvature is defined as an across-track wavelength ...
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This work aims to extract the mineralogical constituents of the Lahroud Hyperion scene situated in the NW of Iran. Like the other push-broom sensors, Hyperion images suffer from spectral distortions, namely the smile effect. The corresponding spectral curvature is defined as an across-track wavelength shift from the nominal central wavelength, and alters the pixel spectra. The common “column mean adjusted in MNF space” method was employed in this work to improve the processing accuracy by minimizing the smile effect before carrying out the atmospheric and topographical corrections. The mineral distributions were mapped by applying the standardized hyperspectral processing methodology developed by analytical imaging and geophysics (AIG). The spectral unmixing of the data resulted in the identification of five indicative minerals including natrolite, opal, analcime, kaolinite, and albite; and their spectra were employed for the generation of their distribution maps. Comparison of the results of the data processing with and without smile correction indicated a better classification performance after the smile correction. Quantitative validation of the final mineralogical map was performed using the 100 k geological map and reports of the region. Therefore, the coverage of the extracted minerals were investigated regarding the location of the lithological units in ArcGIS that implies a high coincidence. The mineral distributions in the final map show a high consistency with the geological map of the studied area, and thus it could be utilized successfully to reveal the mineralization trend in the region.
M. Nikkhah; Seyed S. Mousavi; Sh. Zare; O. Khademhosseini
Abstract
The joints between segmental rings can withstand a certain amount of bending moment as well as axial and shear forces. Generally, in the structural analysis of tunnel segmental lining, the joints can be modeled as elastic hinges or rotational springs, and their rigidity should be demonstrated in terms ...
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The joints between segmental rings can withstand a certain amount of bending moment as well as axial and shear forces. Generally, in the structural analysis of tunnel segmental lining, the joints can be modeled as elastic hinges or rotational springs, and their rigidity should be demonstrated in terms of the rigidity of the joints or their rotational stiffness. Therefore, the bending moment acting on the tunnel lining is reduced. Hence, the tunnel designers are free to choose a lining with a lower cost. In this research work, especially considering the joints, the structural analysis of the segmental lining with variation in the flexural stiffness of the joints ( ), soil resistance coefficient ( ), number of segmental lining joints, and joint arrangement of segmental lining were carried out by the Force-Method equations. The imposed bending moment and axial forces were computed based on the Beam-Spring method, which is widely used to analyze the internal forces of segmental lining, and compared them with the results of the Force-Method equations. Then the effects of joint arrangement patterns and joint rotational spring stiffness on the results of the Beam-Spring analysis were evaluated. Finally, the optimum characteristics of the reinforced concrete segmental lining design were evaluated using the interaction diagram of bending moments and axial forces. The results obtained showed that the presented pattern for the segmental lining at the Chamshir tunnel was imposed against the external pressures on the segmental lining with an acceptable safety factor.
H. Molayemat; F. Mohammad Torab
Abstract
Coalbed methane (CBM) plays an important role in coal mining safety and natural gas production. In this work, The CBM potential of B2 seam in Parvadeh IV coal deposit, in central Iran, was evaluated using a combination of local regression and geostatistical methods. As there were 30 sparse methane sampling ...
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Coalbed methane (CBM) plays an important role in coal mining safety and natural gas production. In this work, The CBM potential of B2 seam in Parvadeh IV coal deposit, in central Iran, was evaluated using a combination of local regression and geostatistical methods. As there were 30 sparse methane sampling points in the Parvadeh IV coal deposit, no valid variogram was achieved for the methane content. A multivariate adaptive regression splines (MARS) model was used to reproduce the methane content data based on seam depth, thickness, and ash content. The MARS model results were used in ordinary kriging to estimate the methane content in all mine blocks. A combination of MARS modeling and ordinary kriging in CBM studies is introduced, for the first time, in this paper. The results obtained show that high methane zones are located in the central and south western parts of the deposit. The in situ CBM potential varies from 6.0 to 16.1 m3/t, and it was estimated to be 1.39 billion m3 at the average depth of 267 m in an area of 86.55 km2. Although this volume is remarkable, little is known as how much of this resource is actually producible. Consequently, high methane-bearing zones are highly recommended for further studies as a source of natural gas for extraction and reducing the hazards and explosion risks of underground coal mining.
A. Majdi; M. Yazdani
Abstract
The hydraulic jacking refers to the process of crack growth of the pre-existing joints in the rock mass under grout pressure above the minimum in-situ stress. Thus it is essential to understand the resistance behavior of the joints and maximum grout pressure. This paper describes a novel method for determining ...
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The hydraulic jacking refers to the process of crack growth of the pre-existing joints in the rock mass under grout pressure above the minimum in-situ stress. Thus it is essential to understand the resistance behavior of the joints and maximum grout pressure. This paper describes a novel method for determining the hydraulic jacking occurrence in anisotropic rock mass based on the principle of fracture mechanics. This method is established on three stage developments: developing an equation in order to calculate the equivalent stress intensity factor at the joint tip, determining the fracture toughness by employing the Brazilian disc test with a loading rate of 0.1 MPa/s on the rock cored samples, and assessing the stability of joints using the maximum tangential stress criterion. By comparing the joint stress intensity factor and fracture toughness in the direction of rock anisotropy, the joint stability is evaluated. Then the maximum allowable grout pressure is analytically formulated as a function of fracture toughness in order to avoid the unwanted deformations in the joints (i.e. jacking) during grouting. In order to validate the proposed method, the data obtained from the boreholes used to construct water curtain at the Sanandaj Azad Dam in phyllite rocks are analyzed. Finally, it is concluded that the growth and expansion of the joints due to the instability under grout pressure leads to an increased cement take and the occurrence of hydraulic jacking. In addition, the proposed equation for computing maximum allowable grout pressure provides an acceptable agreement with the existing empirical rules and the results of the field data.
Mohammadhosein Dehghani Firoozabadi; Mohammad Fatehi Marji; Abolfazl Abdollahipour; Alireza Yarahamdi Bafghi; Yousef Mirzaeian
Abstract
In this work, an effective methodology is introduced for simulation of the crack propagation in linear poroelastic media. The presence of pores and saturated cracks that can be accompanied by fluid flow makes the use of poroelastic media inevitable. In this work, involvement of the time parameter in ...
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In this work, an effective methodology is introduced for simulation of the crack propagation in linear poroelastic media. The presence of pores and saturated cracks that can be accompanied by fluid flow makes the use of poroelastic media inevitable. In this work, involvement of the time parameter in crack propagation is of particular importance. The order of doing the work is such that first, derives the fundamental solutions of a poroelastic higher order displacement discontinuity method (PHODDM). Then will be provided a numerical formulation and implementation for PHODDM in a code named linear element poroelastic DDM (LEP-DDM). Analytical solutions use different times to check the correctness and validity of the proposed solution and the newly developed code. The numerical results show a good agreement and coordination with the analytical results in time zero and 5000 seconds . The code is able to pursue crack-propagation in time and space. This topic is introduced and shown in an example.
Mineral Processing
Hossein Hamedani; Arash Sobouti; Mohammad Baqaeifar; Bahram Rezai; Fatemeh Sadat Hoseinian
Abstract
In this work, a representative sample was initially prepared from exploratory drilling cores, followed by identification and characterization studies based on XRD analysis; the sample consists primarily of quartz, kaolinite, muscovite-illite, calcite, potassium, feldspar, albite, dolomite, siderite, ...
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In this work, a representative sample was initially prepared from exploratory drilling cores, followed by identification and characterization studies based on XRD analysis; the sample consists primarily of quartz, kaolinite, muscovite-illite, calcite, potassium, feldspar, albite, dolomite, siderite, and chalcopyrite. Optical and scanning electron microscopy studies revealed that the sulfide minerals in the sample include chalcopyrite, chalcocite, and pyrite, with the most significant copper minerals primarily comprising chalcopyrite, chalcocite, and malachite. No free gold was observed, and gold mainly exists as a substitute within the structure of sulfide minerals. AAS analysis results indicated that the copper grade in the sample is 0.99%. To investigate the flotation of copper minerals, influential parameters such as pH, collector concentration, frother concentration, sodium sulfide concentration, and the effect of particle size were examined. The results demonstrated that under optimal conditions (pH = 11, collector concentration of 100 g/t Potassium Amyl Xanthate (PAX), 100 g/t Sodium Isopropyl Xanthate (SIPAX), 60 g/t frother methyl isobutyl carbinol (MIBC), 1000 g/t Na2S at a particle size of d80= 75μ), the total copper grade and recovery following two stages cleaner flotation were achieved at 21.2% and 60.2%, respectively.
Mineral Processing
Mehrshad Asghari; Mohammad Noaparast; Mohammad Jahani Chegeni
Abstract
Because roller screens are connected to the pelletizing discs on one side and the green iron ore induration furnaces on the other side in pelletizing plants, they play a crucial role in the plant's productivity and steel production process. Consequently, an optimal performance and structural design are ...
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Because roller screens are connected to the pelletizing discs on one side and the green iron ore induration furnaces on the other side in pelletizing plants, they play a crucial role in the plant's productivity and steel production process. Consequently, an optimal performance and structural design are essential in this context. A significant issue with roller screens during the classification of green pellets is the deformation of the rolls caused by the force exerted by the pellets during operation. This deformation disrupts the uniformity of the gap between the rolls, thereby reducing the efficiency of the screen, and the overall performance of the circuit, as well. Despite the importance of this issue, no studies have been conducted to investigate the force exerted by the pellets during classification on the screen or the subsequent mechanical behavior of the rolls. Therefore, this study employs the discrete element method–finite element method (DEM-FEM) coupling simulation technique to examine, for the first time, the mechanical behavior of rolls and to optimize their structural design. The results indicated that decreasing the roll diameter from 80 mm to 30 mm led to 1088 times increase in the average total deformation of the rolls. Furthermore, increasing the thickness of the polyurethane liner from 3 mm to 14 mm caused the average total deformation to rise by 54 times.
Mineral Processing
Arefeh Zahab Nazoori; Bahram Rezai; Aliakbar Abdolahzadeh
Abstract
Assessing frother performance through various indices is crucial to understanding how their molecular structure affects functionality, as well as evaluating their effectiveness in floating both fine and coarse particles. This study investigates for the first time the frothing behavior and froth stability ...
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Assessing frother performance through various indices is crucial to understanding how their molecular structure affects functionality, as well as evaluating their effectiveness in floating both fine and coarse particles. This study investigates for the first time the frothing behavior and froth stability of Polyethylene Glycol 300 (PEG300), Dipropylene Glycol (DPG), and Tetraethylene Glycol (TEG) and compares them with conventional frothers such as Dow Froth-250 (DF-250). To evaluate frother performance, air flow rate and frother concentration were selected as the main operational variables influencing froth formation and stability index. Initially, the frothing behavior of the reagents was predicted using the HLB-MW diagram, and then the frothing power of the desired frothers was examined using the dynamic frothability and dynamic froth stability indices. The results revealed that PEG300 exhibited the highest dynamic frothing index (13000 s.dm3/mol) and high froth stability, which is suitable for the flotation of coarse particles. In contrast, DPG showed the lowest frothing power and froth stability, with a dynamic frothing index of 2500 s.dm3/mol. TEG, with an intermediate frothing index of 5000 s.dm3/mol, demonstrated moderate performance in both froth production and stability. DF-250, with an exceptionally high frothing index, outperformed all the other agents, providing both superior froth generation and stability. Froth stability was assessed using dynamic froth stability indices and dynamic frothing capability, providing meaningful insights into frother performance. The results also showed that both air flow rate and frother concentration had a significant impact on frothing index and stability, with higher concentrations generally enhancing froth stability, particularly for PEG300 and DF-250.
Mineral Processing
Dorna Pirouzan; Reza Parvareh; Ziaeddin Pourkarimi; Mehdi Rahimi; Javad Moosavi; Hossein Habibi
Abstract
In our country, a massive volume of slag is generated annually from steel production facilities, amounting to about 20 percent of the total steel produced. This slag is an important and valuable source for extracting vanadium, with 67 percent of the world's vanadium production sourced from slag. Iran ...
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In our country, a massive volume of slag is generated annually from steel production facilities, amounting to about 20 percent of the total steel produced. This slag is an important and valuable source for extracting vanadium, with 67 percent of the world's vanadium production sourced from slag. Iran ranks among the top five countries that possess this vital metal; however, vanadium extraction from slag has not been carried out to date. Moreover, due to the unstable quality of the slag, its utilization in other industries has not been feasible. To prevent the environmentally harmful effects of accumulating slag and the inability to utilize it in various industries, it is essential to implement an economic solution for recovering the components present in steel-making slag. In the present project, after sampling from the stored slag deposits at Mobarakeh Steel Company, comprehensive laboratory and pilot-scale studies were conducted on the representative samples. Through processes involving roasting with sodium carbonate, acid leaching with 2 M sulfuric acid, iron cementation, solvent extraction using DEHPA, stripping, and scrubbing, we successfully extracted pentoxide vanadium with high purity suitable for producing ferrovanadium.
Mineral Processing
Raheleh Hazrati; Shahram Rostami; Sadegh Marahem
Abstract
The components of low-grade bauxite were 28.4% silica, 34.9% alumina, 16.1% iron oxide as ferric oxide and 11.26% loss on ignition. Due to the high silica content of this type of bauxite, it couldn’t be processed by Bayer method. Therefore, a sintering method with limestone and sodium carbonate ...
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The components of low-grade bauxite were 28.4% silica, 34.9% alumina, 16.1% iron oxide as ferric oxide and 11.26% loss on ignition. Due to the high silica content of this type of bauxite, it couldn’t be processed by Bayer method. Therefore, a sintering method with limestone and sodium carbonate was used for selective extraction of alumina. Experimental design was performed by surface response method (RSM) using central composite design. Selected parameters were temperature, soaking time, mole ratio of sodium oxide to alumina, mole ratio of calcium oxide to silica. The maximum amount of extraction of alumina from low-grade Jajarm bauxite by sintering method was 74.2%, which was obtained in the optimal values of the parameters as follows: A temperature of 1157°C, a soaking time of 35 minutes, a mole ratio of alkaline oxide (K2O + Na2O) of 1.25 and a mole ratio of calcium oxide to silica of 1.99. In 31 run experiments, the mixture of materials powder was transferred to an alumina crucible and heated in a muffle furnace at temperatures and soaking times determined by the experimental design. The sintered material was pulverized. The resulting powder was leached by 150 mL of a boiling alkaline solution (20 g/L NaOH + 20g/L Na2CO3) for 30 minutes at a stirring speed of 300rpm. Extracted aluminum from the leaching stage was analyzed by atomic absorption spectrometry.
Exploration
Satyajeet Parida; Abhishek Kumar Tripathi; Tarek Salem Abdennaji; Yewuhalashet Fissha
Abstract
Coal quality is predominantly determined by its Gross Calorific Value (GCV), which directly influences its economic valuation. Traditional empirical formulas for GCV estimation, though effective, become inefficient and laborious when handling large datasets. To address this, machine learning (ML) techniques ...
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Coal quality is predominantly determined by its Gross Calorific Value (GCV), which directly influences its economic valuation. Traditional empirical formulas for GCV estimation, though effective, become inefficient and laborious when handling large datasets. To address this, machine learning (ML) techniques offer a robust alternative for accurate and rapid predictions. This study employs seven coal quality parameters. Total Moisture (TM), Ash (ASH), Volatile Matter (VM), Hydrogen (H), Carbon (C), Nitrogen (N), and Sulphur (S), as independent variables to develop predictive models for GCV. Four conventional regression techniques, namely Support Vector Regression (SVR), K-Nearest Neighbors (KNN), Random Forest (RF), and Decision Tree (DT), along with two robust regression models Random Sample Consensus (RANSAC) and Huber Regressor (HR) are explored. The dataset comprises coal samples from five Asia-Pacific countries: China, Indonesia, Korea, the Philippines, and Thailand. Comparative performance analysis reveals that the robust regression models significantly outperform the conventional ML techniques. The RANSAC and Huber Regressor models achieve superior prediction accuracy with R² values of 0.9941 and 0.9952, respectively. These findings highlight the potential of robust regression approaches for reliable GCV estimation, facilitating efficient coal quality assessment in large-scale applications.
Mineral Processing
Chaimae LOUDARI; Moha Cherkaoui; Imad El Harraki; Rachid Bennani; Mohamed El Adnani; EL Hassan Abdelwahed; Intissar Benzakour; François Bourzeix; Karim Baina
Abstract
Energy efficiency and product quality control are critical concerns in grinding mill operations, particularly within the innovative context of Mine 4.0. This study introduces a novel Genetic Algorithm (GA)-based optimization framework specifically developed to address these challenges. Given the mining ...
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Energy efficiency and product quality control are critical concerns in grinding mill operations, particularly within the innovative context of Mine 4.0. This study introduces a novel Genetic Algorithm (GA)-based optimization framework specifically developed to address these challenges. Given the mining industry’s significant energy consumption, especially in grinding processes, the proposed approach optimizes key parameters such as feed composition, water flow rates, and power consumption levels, while maintaining sieve refusal near the target threshold of 20%. Using real operational data from a Moroccan plant, the GA achieved a Mean Absolute Error (MAE) of 0.47, outperforming Simulated Annealing (SA) and Particle Swarm Optimization (PSO), which yielded MAEs of 1.14 and 0.74, respectively. The GA also demonstrated superior convergence stability and robustness, as evidenced by lower variability in predicted power consumption. These results validate the effectiveness of the GA framework in navigating nonlinear, high-dimensional parameter spaces and improving energy efficiency while ensuring product quality consistency. Ultimately, this research confirms the potential of metaheuristic optimization in enhancing grinding mill efficiency and supports the broader shift towards intelligent and sustainable mining operations under the Mine 4.0 paradigm.
Rock Mechanics
Sonu Saran; Prudhvi Raju Gadepaka; Ashok Jaiswal
Abstract
The stability of underground coal galleries is critically influenced by time-dependent deformation behavior of surrounding rock masses, particularly in deep mining environments where long-term stress redistribution can lead to delayed failure. In continuous miner-based mining systems, determining an ...
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The stability of underground coal galleries is critically influenced by time-dependent deformation behavior of surrounding rock masses, particularly in deep mining environments where long-term stress redistribution can lead to delayed failure. In continuous miner-based mining systems, determining an appropriate cut-out distance is essential to ensure productivity and safety, especially for weak rock mass. This study proposes a novel numerical–statistical framework for the optimal design of cut-out distance (COD) in room-and-pillar coal mining using continuous miners. A time-dependent viscoelastic-viscoplastic constitutive model was implemented in FLAC3D to simulate roof deformation across varying geo-mining conditions, including gallery widths (5 & 6 m), depths (100 to 400 m), and COD values (4 to 12 m). The Coal Roof Index (CRI), a composite geotechnical classification parameter, was incorporated to evaluate roof integrity. Results from the numerical simulations were used to develop two empirical models, COD₁ for depths ≤ 200 m and COD₂ for depths > 200 m, via multivariate nonlinear regression. The models demonstrated high predictive accuracy, with R² values of 0.95 and 0.90, respectively. The results reveal a strong correlation between the cut-out distance and various influencing parameters, i.e., width, depth, and CRI classification. Statistical validation through t-tests and ANOVA confirms the significance and reliability of the proposed model. Both proposed models have been validated by two field cases of the Indian coal mine. Critical CRI thresholds were quantified for safe CODs, offering actionable insights for field implementation. The proposed design approach provides a robust framework for improving the safety and sustainability of underground coal mine development, particularly under weak roof conditions.
Exploitation
Ali Nemati vardni; Masoud Monjezi; Hasel Amini Khoshalan; Jafar Hamidi Khademi; Mojtaba Rezakhah
Abstract
Drilling is one of the most important operations in open-pit mining, and the penetration rate of drill bits is a key performance measure. This paper presents research on the penetration rate of drill bits based on mining rock mass rating, thrust pressure (weight on bit), rotational pressure, and Schmidt ...
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Drilling is one of the most important operations in open-pit mining, and the penetration rate of drill bits is a key performance measure. This paper presents research on the penetration rate of drill bits based on mining rock mass rating, thrust pressure (weight on bit), rotational pressure, and Schmidt hammer rebound hardness. To achieve this, a dataset comprising the drilling operations of 85 blastholes from the Sungun copper mine in Iran was prepared and analyzed using statistical and intelligent methods. Multivariate regression analysis and artificial neural networks developed in Python, utilizing optimization algorithms such as gradient descent, stochastic gradient descent, and adaptive moment estimation, were applied to predict the penetration rate of drill bits in this study. The coefficient of determination (R²), mean absolute error (MAE), and root mean square error (RMSE) served as performance indicators to evaluate the methods employed. Among these, the adaptive moment estimation (Adam)-based model exhibited superior performance compared to alternative models, achieving values of R² = 0.96, MAE = 4.55, and RMSE = 4.30. Furthermore, the sensitivity analysis revealed that mining rock mass rating is the most influential factor on the rate of penetration, while thrust pressure has the least impact.
Mineral Processing
Hossna Darabi; Faraz Soltani
Abstract
The main characteristic of mechanical flotation cells is to have an impeller, which is responsible for creating particle suspension, gas dispersion, and producing turbulence necessary to create effective bubble-particle interactions. For this purpose, in this paper, the conditions for complete gas dispersion ...
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The main characteristic of mechanical flotation cells is to have an impeller, which is responsible for creating particle suspension, gas dispersion, and producing turbulence necessary to create effective bubble-particle interactions. For this purpose, in this paper, the conditions for complete gas dispersion in a Denver laboratory flotation cell have been investigated. Then, the critical impeller speed has been investigated for quartz particles with different size fractions. The effect of complete dispersion of introduced gas and critical impeller speed on the flotation rate constant (k) of particles was investigated. The results showed that k was the minimum value at an impeller speed of 700 rpm in the superficial gas velocity of 0.041- 0.125 cm/s for all size fractions. The impeller speed of 700 rpm was sufficient to keep -106µm quartz particles suspended, but at all superficial gas velocities, the minimum impeller speed required for complete gas dispersion was 850 rpm. Therefore, it can be stated that the reason for the low k value at a stirring speed of 700 rpm is the incomplete distribution of bubbles and particles (+106µm), resulting in a reduced probability of air bubbles colliding with solid particles. By increasing the impeller speed to values greater than 700 rpm, the k value increased, which is due to the complete distribution of particles and air bubbles in the flotation cell (increased probability of bubble-particle collision). Therefore, it is necessary to provide suitable operating conditions for the complete dispersion of air bubbles and also to keep solid particles suspended.
Environment
Aditi Nag
Abstract
India's mining heritage sites (MHSs) represent underdeveloped tourist avenues for culture conservation and community upliftment. This study undertakes a dual-site comparison depending on a mixed-methods approach combining perception surveys of visitors, satellite image analysis, and statistical techniques ...
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India's mining heritage sites (MHSs) represent underdeveloped tourist avenues for culture conservation and community upliftment. This study undertakes a dual-site comparison depending on a mixed-methods approach combining perception surveys of visitors, satellite image analysis, and statistical techniques involving t-tests, chi-square analysis, and hierarchical clustering, for Dhori Mines (Jharkhand) and Barr Conglomerate (Rajasthan). Results starkly reveal contrasts: while Barr confirms ecological recovery and community integration, Dhori suffers due to infrastructure and interpretive constraints. Other strategies include AI-powered heritage interpretation and visitor segmentation to improve site competitiveness. It emerges from the findings that data-oriented landscape and tourism planning coupled with local participation can sustain and promote post-mining landscapes effectively.
