Original Research Paper
Mineral Processing
Chol Ung Ryom; Kwang Hyok Pak; Il Chol Sin; Kwang Chol So
Abstract
Shaking table and flotation are often used in scheelite (CaWO4) beneficiation, and usually they are applied in sequence. In this paper, analysis of mineral movement have been investigated in shaking table in which pulp was conditioned with xanthate as a collector and fed, heavy scheelite was concentrated, ...
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Shaking table and flotation are often used in scheelite (CaWO4) beneficiation, and usually they are applied in sequence. In this paper, analysis of mineral movement have been investigated in shaking table in which pulp was conditioned with xanthate as a collector and fed, heavy scheelite was concentrated, while heavy pyrite removed directly on the deck by the action of collector. Artificially mixed mineral with 1% scheelite and 2% pyrite was used in CFD simulations and experiments. Through CFD simulations, it was found that pyrite particles, which were hydrophobic by collector, were attached to the water-air interface and subjected to upward buoyancy, which increased the density difference between scheelite and pyrite particles and enabled the separation of both minerals in the shaking table. The experiment results showed that the concentrate grade in conventional table concentration was 23.5% WO3, the separation efficiency was 77.89%, while the concentrate grade of scheelite in the table concentration of xanthate presence was 65.0% WO3 and the separation efficiency was 80.88%. The combination of flotation in table with collector addition not only eliminated the flotation to remove pyrite after table but also resulted in a lower rate of scheelite loss.
Original Research Paper
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.
Original Research Paper
Mineral Processing
Ayman M. Ibrahim; Han Wang; Nazar Mekawi; Jaber A. Yousif; Emadeldin Adam; Alfarouq Alnoor; Mohammed Kabashi; Dianwen Liu
Abstract
This work investigates the surface enrichment of malachite during sulfurization flotation to enhance copper recovery. The goal is to improve flotation efficiency by modifying malachite’s surface properties through sulfurization, using sodium sulfide as the sulfurizing agent. The effects of pre-treatment ...
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This work investigates the surface enrichment of malachite during sulfurization flotation to enhance copper recovery. The goal is to improve flotation efficiency by modifying malachite’s surface properties through sulfurization, using sodium sulfide as the sulfurizing agent. The effects of pre-treatment reagents on flotation recovery were evaluated, focusing on their impact on the surface chemistry of malachite. The findings indicated that malachite treated with ammonium sulfate ((NH₄)₂SO₄) exhibited superior flotation recovery compared to ammonium phosphate ((NH₄)₃PO₄), achieving an optimal recovery rate of 87.5%. FESEM-EDS and ToF-SIMS analyses revealed a significant increase in sulfur species on the surface, promoting the formation of copper sulfide (CuS) films and enhancing the mineral's reactivity during flotation. Theoretical solution chemistry calculations corroborated these findings, showing that ammonium salt treatments facilitate the formation of copper-ammonium complexes, stabilizing copper ions in solution and preventing their precipitation as copper hydroxides or carbonates. By maintaining copper in a stable reactive form, these complexes improve flotation efficiency. Both theoretical calculations and experimental observations confirm that stabilizing copper ions is crucial for enhancing flotation, ensuring copper remains available for interaction with flotation reagents and ultimately, improving copper recovery. The integration of theoretical and experimental approaches enhances the understanding of the sulfurization process and provides an optimized method for improving flotation performance and copper recovery.
Review Paper
Mineral Processing
Mona Mohamed Fawzy; Mahinaz Shawky; Ahmed Ismail; Mostafa Bayoumi; Hassan Shahin; Bahaa Emad; Ahmed Orabi; Gehan Ali; Ahmed Abdelmouty; Mohamed Diab
Abstract
In response to rising global demand for critical minerals and the need for environmentally responsible resource utilization, this study explores sustainable recovery methods from low-grade placer deposits in the Wadi Rahba area along the Southern Coast of the Red Sea of Egypt. The focus is on the beneficiation ...
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In response to rising global demand for critical minerals and the need for environmentally responsible resource utilization, this study explores sustainable recovery methods from low-grade placer deposits in the Wadi Rahba area along the Southern Coast of the Red Sea of Egypt. The focus is on the beneficiation of ilmenite and titanite as primary valuable minerals. Twenty-eight samples, including a composite technology sample, were analysed using XRD, SEM-EDX, and ED-XRF techniques. Results indicate that total heavy mineral (THM) content ranges from 4.5% to 17.7%, averaging approximately 10%, with 11% in the composite sample. Identified valuable minerals include titanite, ilmenite, leucoxene, zircon, magnetite, and rutile, alongside high concentrations of heavy silicate minerals such as epidote, pyroxene, and amphiboles. Estimated contents are 0.44 wt.% titanite, 0.15 wt.% ilmenite, and trace amounts of zircon (0.04 wt.%), spessartine (0.01wt.%), and magnetite (0.29 wt.%). To enhance recovery, a combination of gravity separation (Wilfley shaking table) and magnetic separation techniques (LIMS and HIMS) were applied. These methods effectively concentrated titanite and ilmenite, achieving recovery rates of 85.08% and 79%, respectively. The findings highlight the potential for economically viable extraction from low-grade sources using environmentally sustainable physical upgrading techniques.
Original Research Paper
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.
Original Research Paper
Mineral Processing
Meysam Nikfarjam; Ardeshir Hezarkhani; Farhad Azizafshari; Hamidreza Golchin
Abstract
Geometallurgical modeling (GM) plays a crucial role in the mining industry, enabling a comprehensive understanding of the complex relationship between geological and metallurgical factors. This study focuses on evaluating metallurgical varibles at the Sungun Copper mine in Iran by measuring and predicting ...
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Geometallurgical modeling (GM) plays a crucial role in the mining industry, enabling a comprehensive understanding of the complex relationship between geological and metallurgical factors. This study focuses on evaluating metallurgical varibles at the Sungun Copper mine in Iran by measuring and predicting process properties, including semi-autogenous power index (SPI), recovery (Re), and concentration grade. To overcome the additivity limitations of geostatistical methods, we utilized machine learning algorithms for enhanced predictive modeling, aiming to improve decision-making and optimize mining operations in geometallurgy. The research incorporates crucial data inputs such as sample coordinates, grades, lithology, mineralization zones, and alteration to assess the accuracy and reliability of different machine learning regression methods. The Relative Standard Deviation (RSD) is highlighted as a significant metric for comparing the accuracy of predicted process properties. Evaluation metrics such as Root Mean Square Error (RMSE), Mean Absolute Error (MAE), and coefficient of determination (R2) further confirm the superiority of specific modeling methods in certain scenarios. The K-Nearest Neighbors (KNN) method exhibits superior accuracy, lower error metrics (RMSE and MAE), and a higher R2 for modeling the SPI test. For modeling Cu grade in concentrate, Support Vector Regression (SVR) proves to be effective and reliable, outperforming the Multilayer Perceptron (MLP) method. Despite MLP's high R2, its higher RSD suggests increased uncertainty and variability in the predictions. Therefore, SVR is considered more suitable for modeling Cu grade in concentrate. Findings optimize operations at Sungun Copper mine, improving decision-making, efficiency, and profitability.
Original Research Paper
Mineral Processing
Hosein Najmaddaini; Mostafa Maleki Moghaddam; Saeid Zare; Masoud Rezaei; Mohammad Ali Motamedineya; Gholamreza Biniaz
Abstract
AbstractThe structural characteristics of mill liners, such as lifter shape and mill speed, significantly influence the grinding process. At the Sarcheshmeh slag flotation plant, the 6×6 meters SAG mill was initially equipped with 48 rows of liners, designed in a Hi-Lo configuration for the first ...
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AbstractThe structural characteristics of mill liners, such as lifter shape and mill speed, significantly influence the grinding process. At the Sarcheshmeh slag flotation plant, the 6×6 meters SAG mill was initially equipped with 48 rows of liners, designed in a Hi-Lo configuration for the first half and a Lo-Lo configuration for the second. Throughout the mill shell liner's 1700-hour operational period, monitoring identified 30 failures. Investigations revealed that defects in the liner design and improper charge motion were the main causes. This study proposes modifications and standardization of the shell liner design, tailored to the specific circuit conditions, to enhance performance and reliability. The redesign included several key changes: 1) Reducing the number of rows: The number of liner rows was decreased from 48 to 32. 2) Adjusting lifter angle: The lifter angle was increased from 23 to 30o to optimize performance. 3) Eliminating Hi-Lo design liners: The Hi-Lo design liners were changed to Hi-Hi, and 4) Reducing liner variety: The variety of liners was streamlined from 5 types to 2. The installation of the proposed liners optimized the charge trajectory for grinding, resulting in higher liner's lifetime. It extended the liner life by 30% and eliminated liner failures, reducing them from 30 to zero. The wear rate for the proposed design was 0.05 mm/hour, while the original design had a wear rate of 0.11 mm/hour. This difference corresponds to a factor of 2.3 times improvement.
Original Research Paper
Mineral Processing
Fatemeh Kazemi; Ali akbar Abdollahzadeh
Abstract
This research work aims to explore the intricate mineralogy and texture of the tailing piles of iron ore processing plants to present a particle-based prediction for magnetite recovery. Three samples were taken from different points of tailings piles of an iron ore processing plant. Davis tube tests ...
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This research work aims to explore the intricate mineralogy and texture of the tailing piles of iron ore processing plants to present a particle-based prediction for magnetite recovery. Three samples were taken from different points of tailings piles of an iron ore processing plant. Davis tube tests were performed on each sample under various operating conditions. Process mineralogy studies were conducted to determine the mineralogy modal of the feed and product of each test. An Artificial Neural Network (ANN) model was used to make a model that related the grade and recovery of magnetite in the product to the mineralogy modal of the tailing piles. The magnetite grade and association index of feed, the magnetic intensity, and the water flow rate were the inputs to this network. The grade and magnetite recovery correlation coefficients were 0.954 and 0.86, respectively. The grade of magnetite in the feed emerged as a limiting factor on the grade and recovery of magnetite in concentrate. An increase of one unit in magnetite grade in the feed resulted in a 1.68 decrease in the recovery. The association index changes with the coefficients of -0.173 cause the changes in predicted magnetite recovery in the concentrate.
Original Research Paper
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.
Original Research Paper
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.
Original Research Paper
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.
Original Research Paper
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.
Original Research Paper
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.
Original Research Paper
Environment
Shima Rahimi; Mehdi Irannajad
Abstract
In this study, Red Mud (RM) as a byproduct in alumina production process from bauxite was used as an adsorbent for sulfate contaminant adsorption from acid mine drainage (AMD). AMD discharge led to the acidification of water which has detrimental effects on aquatic life and human health. Analytical methods, ...
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In this study, Red Mud (RM) as a byproduct in alumina production process from bauxite was used as an adsorbent for sulfate contaminant adsorption from acid mine drainage (AMD). AMD discharge led to the acidification of water which has detrimental effects on aquatic life and human health. Analytical methods, laboratory studies and molecular simulations were conducted to investigate sulfate adsorption on RM. Thermodynamic calculations were performed after optimizing of existing metal oxide in RM structure with the Material Studio software using the dmol3 and DFT method. The adsorption energy results by Adsorption locator module determined -819.09, -561.7, -268.8, -105.4, and -314.7 kcal/mol for Fe2O3, Al2O3, CaCO3, TiO2 and SiO2, respectively. The most active compounds in RM structure (iron and aluminum oxides) account for 22.5% and 13.3% in the red mud structure, respectively. In addition, seawater washing was employed as RM modification methods, and it could decrease high rates of pH and improve the sorption capacity of raw RM. The effect of this modification was investigated by simulation of solvent in adsorption environment of sulfate on RM and the dielectric constant selection. For water as the primary solvent with a dielectric constant of 78.54, adsorption energy for RM was calculated to be -35.68 kcal/mol and it was increased to -56.69 kcal/mol for the seawater medium with a dielectric constant of 86. Therefore, RM can be considered as a potential sulfate adsorbent because of cost-effectiveness and alkaline pH that can lead to the neutralization of AMD.
Case Study
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.
Original Research Paper
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.
Original Research Paper
Mineral Processing
Mohammad Karimi; Mohammad Karamoozian
Abstract
This research investigates the process of cerium extraction from tailings that have been separated from iron using a magnetic drum separator, through both acid leaching and solvent extraction methods. Initially, the mineralogical characteristics of the samples were analysed using microscopic studies. ...
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This research investigates the process of cerium extraction from tailings that have been separated from iron using a magnetic drum separator, through both acid leaching and solvent extraction methods. Initially, the mineralogical characteristics of the samples were analysed using microscopic studies. The main minerals identified were feldspar, garnet, calcite, gypsum, amphibole, and secondary minerals such as chlorite, quartz, and apatite. The metallic minerals were included pyrite, chalcopyrite, magnetite, and hematite. The sample was taken from the tailing’s damps, then it was crushed to a particle size of less than 800 microns. The sample was then placed in a stirred tank along with water, fed into a spiral separator, and subsequently into a shaking table. The analysis results showed that the cerium grade increased from 320 ppm in the feed to 1364 ppm. In the leaching experiments, the influence of various parameters including temperature, acid concentration, type of acid, leaching time, and particle size on cerium leaching recovery rate was evaluated. The results indicated that temperature and acid concentration had the greatest impact on the leaching rate of cerium. In this stage, 95% of cerium was dissolved. Optimization tests for leaching conditions showed that the best conditions for cerium leaching were using hydrochloric acid at a 1:3 concentration with water (concentration of hydrochloric acid became 9 Molar), at a temperature of 90°C and a leaching time of 4 hours. In the subsequent phase, an optimization experiment was conducted with the same parameters. Under these conditions, 96.5% of cerium was dissolved. Then, the solvent extraction process was examined using organic solvents, di(2-ethylhexyl) phosphoric acid and tributyl phosphate. The results showed that the highest cerium extraction rate (81%) was achieved when di(2-ethylhexyl) phosphoric acid was used, considering parameters such as pH 3, organic-to-aqueous phase ratio of 1:1, 20-minute extraction time, 25°C temperature, and stirring speed of 300 rpm. Finally, the results of this research contribute to the optimization of the cerium extraction process and provide suggestions for improving the efficiency of this process.
Original Research Paper
Mineral Processing
Behzad Nemati akhgar
Abstract
Researchers in various engineering fields are increasingly interested in evaluating the influence of the microstructural properties of minerals, such as hematite, on their reactivity. Hematite behaviour and microstructural changes during mechanical activation (MA) were investigated using the shape parameter. ...
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Researchers in various engineering fields are increasingly interested in evaluating the influence of the microstructural properties of minerals, such as hematite, on their reactivity. Hematite behaviour and microstructural changes during mechanical activation (MA) were investigated using the shape parameter. The laser diffraction analysis indicates the occurrence of agglomeration in the mechanically activated hematite after 60 min of MA. Based on the microstructural studies, the hematite crystallinity reduced to below 16% after 240 min of MA. Microstrain and crystallite size continuously changed during MA, leading to an increase in hematite leaching efficiency by sulfuric acid. The results revealed that the microstrain variation rate is higher than other microstructural parameters. The obtained shape parameter increased from about 0.31 in the initial hematite to 0.88 and 0.66 in the hematite mechanically activated for 60 and 240 min, respectively. The shape parameter study demonstrated that most mechanical energy is stored in the hematite lattice as microstrain after 240 minutes of MA. Considering the lower impact of microstrain on promoting hematite reactivity, shorter MA times could be preferred over prolonged MA, which would reduce costs and increase capacity.
Original Research Paper
Environment
Hosein Esmaeili; Mohammad Ali Afshar Kazemi; Reza Radfar; Nazanin Pilevari
Abstract
This study introduces a Hybrid Markov–Bayesian Framework for predicting and managing accident risks in high-risk industries, with a specific focus on the mining sector. The framework integrates Markov models to analyze dynamic risk transitions and Bayesian networks to infer causal relationships ...
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This study introduces a Hybrid Markov–Bayesian Framework for predicting and managing accident risks in high-risk industries, with a specific focus on the mining sector. The framework integrates Markov models to analyze dynamic risk transitions and Bayesian networks to infer causal relationships among key human and environmental factors. Drawing from a comprehensive dataset of mining operations, the framework evaluates variables such as age, experience, task type, and injury characteristics to predict and control accident risks. The results highlight the model's high performance, achieving an accuracy of 87%, precision of 85%, and an F1-score of 0.84. This innovative approach enables real-time safety interventions and proactive risk management strategies. The findings underscore the framework's potential to improve workplace safety and serve as a scalable tool for accident prevention in other high-risk industries. Future research will focus on enhancing the framework’s adaptability and incorporating additional contextual variables for broader applicability.
Original Research Paper
Environment
Amirmahmood Razavian; Alireza Arab Amiri; Abolghasem Kamkar Rouhani; Meysam Davoodabadi Farahani
Abstract
Mining activities cause environmental pollution. Satellite remote sensing is considered an effective strategy for monitoring pollution, as other direct methods of testing soil pollution levels are often costly and face accessibility challenges in certain areas. Unlike optical sensors, radar systems can ...
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Mining activities cause environmental pollution. Satellite remote sensing is considered an effective strategy for monitoring pollution, as other direct methods of testing soil pollution levels are often costly and face accessibility challenges in certain areas. Unlike optical sensors, radar systems can capture data in all weather conditions and operate around the clock. However, radar systems do not display details and borders of zones and lack multispectral data collection capability. Consequently, combining various characteristics of optical images and radar data offers a comprehensive approach to monitoring pollution. Given these pros and cons, a combination of optical and radar images from the Sentinel satellite was employed in this study to identify surface and physical pollution areas caused by mining activities. The proposed method is a combination of Curvelet Transform, Simple Linear Iterative Clustering, Principle Components Analysis, and integration of radar and optical results using a statistical based clustering scheme, which allows the detection of contaminated zones. This research benefits from several innovative strategies, such as the separate processing and integration of optical and radar images, the simultaneous application of the curvelet transform and principle component analysis, and the utilization of two distinct clustering methods. Finally, the results obtained from radar and optical images of the Damghan region in Semnan province, Iran, on a 1 to 100.000 scale showed the proposed methodology can segment the contaminated zone caused by the eastern Alborz coal preparation plant through soil pollution modelling.
