Mineral Processing
Kwang Sok Jong; Chang Il Kim; Kum Chon Jang; Song Chol Kim; Hyon Hui Jang
Abstract
In this study, the effects of various reagents-sodium carbonate and sodium hydroxide as pH regulators, calcium lignosulfonic acid as depressant, and combined sodium oleate and amide as collector on the flotation of apatite ore were investigated using flotation experiments, and adsorption mechanism of ...
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In this study, the effects of various reagents-sodium carbonate and sodium hydroxide as pH regulators, calcium lignosulfonic acid as depressant, and combined sodium oleate and amide as collector on the flotation of apatite ore were investigated using flotation experiments, and adsorption mechanism of collector on apatite surface were evaluated using quantum mechanical simulations. The flotation experiments showed that the addition of 4 kg/t sodium carbonate and 1.5 kg/t sodium hydroxide as pH regulators, 3 kg/t calcium lignosulfonic acid as depressant and 60 g/t combined sodium oleic acid and oleamide (acid number of collector; 105 mgKOH/g) as collector exhibited excellent collecting ability for apatite. From low-grade apatite ore with P2O5 7.05%, a concentrate with P2O5 31.42% was obtained with 81.08% recovery in rougher flotation. Compared with the simulation results for the interaction energy between apatite {001} surface and collectors, and the relative concentration of collector on apatite {001} surface, adsorption strength has following order; combined sodium oleic acid and oleamide > sodium oleic acid > oleamide. From the simulation results on the equilibrium configuration of the collector with the fluorapatite {001} surface in the liquid environment, it was revealed that the two atoms (N and H) of the oleamide can form a strong bidentate conformation, and O atom in the C-O group and that in -C=O group of oleic acid anion can bond with the Ca atom on the surface {001} to form monodentate conformation.
Mineral Processing
Mohammad Jahani Chegeni; Sajad Kolahi; Asghar Azizi
Abstract
Consumed energy is the most important issue and concern in industrial ball mills, and includes a major part of the costs of mineral processing plants. By using suitable liners and the optimal lifter count, the energy of the mill is properly transferred to the balls. In Part 1 of this research work, five ...
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Consumed energy is the most important issue and concern in industrial ball mills, and includes a major part of the costs of mineral processing plants. By using suitable liners and the optimal lifter count, the energy of the mill is properly transferred to the balls. In Part 1 of this research work, five types of liners, i.e. Lorain, Osborn, Rib, cuboid, and Hi-lo, are examined. These liners all have separate lifters with the same volume. Their difference is in the width, height, and type of lifter profile. First, all types of liners are simulated with four lifters using the Discrete Element Method (DEM). Then the lifter count is increased four by four to fill the entire wall of the mill with lifters. Based on this, Lorain liner from 4 to 24 lifters, Osborn liner from 4 to 120 lifters, Rib liner from 4 to 40 lifters, and cuboid and Hi-lo liners from 4 to 64 lifters are simulated. For the first time, the kinetic (KE) and potential (PE) energies as well as the sum of these two energies (TE) of all the balls are calculated, and compared in the entire duration of the simulation from 0–13s for all the liner types and lifter counts mentioned above. Finally, by using data related to KE, PE, and TE for each type of liner, the optimal lifter count is obtained. Accordingly, 16 to 20 lifters are recommended for the Lorain liner, 64 to 76 lifters for the Osborn liner, 24 to 32 lifters for the Rib liner, 44 lifters for the cuboid liner, and 36 to 44 lifters for the Hi-lo liner.
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.
Mineral Processing
Mostafa Maleki Moghaddam; Hosein Najmaddaini; Saeid Zare; Masoud Rezaei; Mohammad Ali Motamedineya; Gholamreza Biniaz
Abstract
Abstract
The 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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Abstract
The 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.
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.
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.
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.
Mineral Processing
Sahil Thakur; Ravi Kumar Sharma
Abstract
Slope stability is critical for infrastructure safety, particularly in seismically active regions. This work evaluates the stability of a slope along the Baroti-Reyur road in Himachal Pradesh, located in Zone 5, using a novel combination of Limit Equilibrium Methods (LEMs) and Finite Element Methods ...
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Slope stability is critical for infrastructure safety, particularly in seismically active regions. This work evaluates the stability of a slope along the Baroti-Reyur road in Himachal Pradesh, located in Zone 5, using a novel combination of Limit Equilibrium Methods (LEMs) and Finite Element Methods (FEMs). The analysis examines natural slope conditions and the impact of sustainable mitigation measures, including retaining structures and bioengineering techniques, under the static and dynamic conditions. The soil model incorporated a modulus of elasticity (E) of 90,000 kN/m², and a poisson's ratio (v) of 0.3 to reflect realistic slope-soil-structure interactions. Retaining structures such as gravity, cantilever, and gabion walls (4 m, 6 m, and 5 m high) were constructed using M30 RCC and Fe500 steel. Bioengineering measures featured deep-rooted grasses like Vetiver and Broom grass to improve soil cohesion (c), shrubs like Lantana camara for surface stability, and trees like Albizia lebbeck to reinforce deeper soil layers. These vegetation-based interventions enhanced slope resilience, while promoting ecological restoration. Theoretical LEM analysis revealed marginal stability, with static FOS values of 1.1 and pseudo-static FOS of 1.05. GEO5 pseudo-static analysis indicated critically low FOS value of 0.88 for dynamic saturated conditions, improving to 2.01 with retaining structures. FEM analysis using PLAXIS 2D provided more detailed insights, capturing complex soil-structure interactions with a static FOS of 1.028 and dynamic FOS of 0.994. By combining FEM with sustainable mitigation strategies, this work offers a framework for resilient slope stabilization, ensuring safety, while promoting environmental sustainability in seismically active regions.
Mineral Processing
Reza Zolfaghari; Mohammad Karamoozian
Abstract
In flotation, entrainment (ENT) affects the recovery of the concentrate, and the entrainment model is often supposed to be only a function of particle size in models. Some research shows that other variables may also significantly affect ENT. In this study, some flotation experiments executed using a ...
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In flotation, entrainment (ENT) affects the recovery of the concentrate, and the entrainment model is often supposed to be only a function of particle size in models. Some research shows that other variables may also significantly affect ENT. In this study, some flotation experiments executed using a mixture of pure quartz as the valuable mineral and a pure magnetite sample as the gangue mineral to investigate the effects of other variables, such as solid content, airflow rate, frother, and collector dosages, on ENT. The results showed ENT varied from 0.071 to 0.851 is different, while the entrainment recovery was between 0.006 to 0.23, which means that the difference is statistically significant. ENT affected by (1) collector dosage, (2) frother dosage, (3) solid content, (4) the interaction between airflow rate and solid content and, (5) the interaction between airflow rate and frother dosage. An empirical statistical model is presented based on operational parameters. As the present models for ENT incorporate just particle size, it is not enough to predict gangue recovery in industrial applications by keeping the operating conditions constant. This novel model can predict ENT based on different operational parameters. The developed model is presented based on the particle mass by changing the operation parameters.
Mineral Processing
Seyyed Mohsen Zamzami; Javad Vazifeh Mehrabani
Abstract
In this research, solid phase settling process from the liquid phase were optimized simultaneously on the different responses, using the response surface methodology (RSM). The effect of solid percentage, flocculant dosage, temperature, and pulp pH were evaluated on the responses of solid settling velocity, ...
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In this research, solid phase settling process from the liquid phase were optimized simultaneously on the different responses, using the response surface methodology (RSM). The effect of solid percentage, flocculant dosage, temperature, and pulp pH were evaluated on the responses of solid settling velocity, water turbidity, viscosity and density of settled pulp. The results showed that by increasing the flocculant dosage from 0.5 to 3.5 g/ton, settled pulp viscosity decreases from 49.05 cSt to 17.54 cSt. The higher values of pulp pH as well as low amount of solid percentage resulted in high water turbidity, which shows the lack of contact between flocs and suspended particles. The results indicated that the pulp solid percentage and the flocculants dosage are the most significant parameters on the responses. Optimum test conditions were obtained in industrial mode by using 5 g/t flocculant, solid percentage 23.96%, pH=7.5 temperature of the pulp 21.5°C in which condition, settling rate, pulp viscosity, pulp density and water turbidity were predicted to be 13.23 cm/min, 5.1 cSt, 1.61 g/cm3 and 15.7 NTU respectively. Repetition test in the model predicted optimum condition was carried out and verified the predicted optimized condition.
Mineral Processing
Jiaye Li; Jing Zhao; Zebin Wang; Huan Liu; Qing Wen; Jinling Yin; Ze Li; Yang Lei; Guiling Wang
Abstract
Traditional graphite has safety and environmental issues, associated with fluorine purification. To address these issues, an energy-saving and efficient graphite purification process can be explored through the acid leaching method with composite additives. The acid leaching process was studied and optimized ...
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Traditional graphite has safety and environmental issues, associated with fluorine purification. To address these issues, an energy-saving and efficient graphite purification process can be explored through the acid leaching method with composite additives. The acid leaching process was studied and optimized in detail using the controlled variable method including the effects of the soaking time and temperature on the graphite purification process. Then the response surface method was used to simulate the orthogonal experiment of graphite purification to verify the correctness of the single-factor, experiment. The purity and micromorphology of the graphite samples at each stage were characterized and tested. The experimental results showed that the optimal liquid-to-solid ratio of the acid solution and graphite was 20:1, which could make the fixed carbon content reach 99.77%. On the basis of these optimal process conditions, the addition types were further explored. The experimental result showed that the best addition was ascorbic acid and EDTA, which could reduce the content of various impurities in the graphite raw material without destroying the microstructure of the graphite. Benefitting from the addition of compound additives in the two-step process, almost all the metal ions were leached from the graphite. After the acid and water leaching, the fixed carbon content of graphite could reach 99.96%. The process parameters proposed in this paper were scientifically verified by both the single-factor and multi-factor experiments, and innovative and effective additives were introduced in different steps to make the graphite purity break through 99.9%, which was difficult to reach by the traditional method.
Mineral Processing
Ahmed Mohammedelmubarak Ah Abbaker; Nevzat Aslan
Abstract
This work optimizes coarse particle flotation using microbubble-assisted flotation in a cationic environment created by dodecylamine (DDA). The flotation efficiency of coarse quartz particles (D50 = 495 μm) was investigated through an examination of the interactions between microbubbles (20-30 μm), ...
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This work optimizes coarse particle flotation using microbubble-assisted flotation in a cationic environment created by dodecylamine (DDA). The flotation efficiency of coarse quartz particles (D50 = 495 μm) was investigated through an examination of the interactions between microbubbles (20-30 μm), the cationic environment, and various operational parameters. A systematic approach utilizing factorial and Box-Behnken experimental designs was employed to evaluate the effects of the multiple variables. These variables included the dodecylamine (DDA) concentration, methyl isobutyl carbinol (MIBC) concentration, impeller speed, pulp density, the addition of fine particles, and the presence of microbubbles. The DDA concentration and the impeller speed significantly impacted the coarse particle recovery, while microbubbles increased recovery by 15% under non-optimized conditions; optimization revealed a more negligible difference. The optimized conditions achieved maximum recoveries of 99.47% and 97.88% with and without microbubbles, respectively, indicating the minimal effect when other parameters were optimized. This research work shows that a careful optimization of the flotation parameters can achieve high coarse particle recovery rates, with microbubbles playing a less significant role than anticipated. These findings suggest that optimizing the conventional parameters may be more crucial than the microbubble introduction for enhancing the flotation efficiency of larger particles. The work contributes to our understanding of coarse particle flotation, and provides insights for improving the mineral processing techniques for challenging the particle sizes.
Mineral Processing
Ashraf Alsafasfeh; Anum Razzaq; Abeer Sajid; Maryam Nazir; Muhammad Badar Hayat; Mirza Zaid
Abstract
Palygorskite (PAL), also known as attapulgite, is a clay mineral prized for its nanorod-like silicate structure and fibrous morphology. The traditional PAL purification methods often involve wet gravity separation techniques such as sedimentation and screening, which require significant water usage and ...
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Palygorskite (PAL), also known as attapulgite, is a clay mineral prized for its nanorod-like silicate structure and fibrous morphology. The traditional PAL purification methods often involve wet gravity separation techniques such as sedimentation and screening, which require significant water usage and pose sustainability challenges, especially in the water-scarce regions. This work introduces a novel, environmentally sustainable dry beneficiation method for PAL. A large PAL sample with 41.7% content and 10% moisture was crushed, ground using a pin mill, and classified into three particle size fractions:-0.088 mm + 0.066 mm, -0.066mm +0.044 mm, and -0.044 mm. These fractions were treated with an air classifier. A Box-Behnken experimental design was employed to investigate the effects of particle size, shutter opening, and motor speed on the classification efficiency. The optimal parameters for grade were 400 rpm motor speed, shutter opening of 1 mm, and feed size of -0.066 mm + 0.044 mm. For the recovery, the optimal conditions were 1200 rpm motor speed, shutter opening of 2.5 mm, and feed size of -0.044 mm. The most favorable balance of grade (67.8%) and recovery (53.2%) was achieved with a motor speed of 1200 rpm, shutter opening of 4 mm, and feed size of -0.066 mm + 0.044 mm. The work concludes that air classification significantly enhances the PAL beneficiation process, with a 50% increase in grade, and recommends exploring the low shear grinding techniques for further improvement.
Mineral Processing
Sahil Kumar; Ravi Kumar 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 modelling 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.
Mineral Processing
Alireza Javadi
Abstract
The main and economic mineral of antimony is stibnite or antimony sulfide, and the research and processes in the world are based on it, and oxide minerals are not considered among the economic and important reserves of antimony due to the difficulty of processing and the lack of optimal efficiency of ...
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The main and economic mineral of antimony is stibnite or antimony sulfide, and the research and processes in the world are based on it, and oxide minerals are not considered among the economic and important reserves of antimony due to the difficulty of processing and the lack of optimal efficiency of the flotation method. On the other hand, taking into account that a large part of the antimony reserve of Sefidabeh is made up of low-grade oxidized ore; this research on the method of economic extraction and the possibility of recovering this type of reserve will be important due to the strategic nature of antimony metal. According to the experiments conducted in this research, the effective parameters for flotation include: pH, collector concentration, activator concentration, depressant concentration, activator type, and humic acid concentration. DX7 software was used for statistical modeling of experiments. Based on the above parameters, the design of the experiment was carried out using a partial factorial method and finally the number of 16 experiments was determined for the effect of the above factors on the grade and weight recovery of the sample. Antimony ore flotation with a grade of 4.32% was carried out in a two-stage method. In this method, in the first stage, flotation of antimony sulfur (stibnite, Sb2S3) was performed at a specific pH by adding the activator of copper sulfate or lead nitrate and the depressant together, potassium amyl xanthate collector and MIBC. In the second stage of flotation, the tailings of the first stage of flotation for antimony oxides were treated with a sodium oleate collector (with determined concentrations) at a specific pH by adding copper sulfate or lead nitrate activator, sodium oleate collector and humic acid and MIBC frother agent. The interaction between pH and activator concentration (BD) has a direct effect on the amount of concentrated antimony, with an increase in pH from 6 to 8 antimony when using an activator concentration of 300 g/t, and a decrease when using an activator concentration of 500 g/t. Flotation was done. In the best conditions, with two-stage flotation of antimony, 68.99% recovery and 13.32 grade were obtained.
Mineral Processing
Ahmad Abbasi Gharaei; Bahram Rezai; Hadi Hamidian Shormasti
Abstract
This paper examines the performance of Atmospheric Leaching (AL) and High-Pressure Acid Leaching (HPAL) on nickel laterite, classified as limonite. The study, conducted on a laboratory scale, involved temperatures of 35-95°C for AL and 220-250°C for HPAL. Nickel and cobalt contents were found ...
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This paper examines the performance of Atmospheric Leaching (AL) and High-Pressure Acid Leaching (HPAL) on nickel laterite, classified as limonite. The study, conducted on a laboratory scale, involved temperatures of 35-95°C for AL and 220-250°C for HPAL. Nickel and cobalt contents were found to be 0.7% and 0.04%, respectively. AL achieved an 89% yield of Al with a pH of 0.2 and a 14-hour leaching time, while nickel and iron recoveries reached 92% and 87% after 20 hours, with an acid consumption of 1.2 kg H2SO4 per 100 kg laterite (dry) at pH 0.2. Leaching experiments at 220-250°C for 2 hours showed similar nickel recovery rates, indicating no improvement beyond 240°C. Hematite, a stable compound associated with nickel, hindered its release during HPAL due to its resistance to leaching. Nickel yields remained around 90% in both AL and HPAL tests. Iron behavior differed significantly between the two methods, with HPAL dissolving iron initially but transforming it into hematite in situ, leading to lower net acid consumption compared to AL. The leaching mechanism for iron oxides followed empirical power law kinetics of order 1.5 with activation energies of 36.23 and 25.09 kJ/mol for Ni and Fe, respectively.
Mineral Processing
Reza Khodadadi Bordboland; Asghar Azizi; Mohammad Reza Khani
Abstract
The global growth of aluminum demand with the modernization of our society has led to the interest in developing alternative methods to produce aluminum from non-bauxite and low-grade resources such as shale bauxites. For such reserves, the conventional Bayer process is challenging and is not efficient ...
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The global growth of aluminum demand with the modernization of our society has led to the interest in developing alternative methods to produce aluminum from non-bauxite and low-grade resources such as shale bauxites. For such reserves, the conventional Bayer process is challenging and is not efficient to extract aluminum, and the sintering process is known to be effective. Thus, this study aimed to scrutinize the technical feasibility of alumina extraction from an Iranian low-grade (shale) bauxite ore containing 36.22% Al2O3, 22.11% SiO2, 20.42% Fe2O3, 3.33% TiO2, and 3.13% CaO. In this regard, the sintering process with lime-soda followed by alkaline leaching was adopted to extract alumina, and response surface modeling was employed to assess the important parameters such as the sintering temperature, Na2O(caustic) concentration, CaO/SiO2 molar ratio, and Na2O/Al2O3 molar ratio. The findings indicated that the extraction rate improved by increasing the sintering temperature and CaO/SiO2 ratio and decreasing the Na2O(caustic) dose and Na2O/Al2O3 ratio. It was also found that the Na2O(caustic) concentration, sintering temperature, and interactive effect of Na2O(caustic) concentration with Na2O/Al2O3 ratio had the greatest influence on the extraction efficiency. The process optimization was conducted applying the desirability function approach, and more than 71% of Al2O3 was extracted at 1150 °C sintering temperature, 2.1 CaO/SiO2 molar ratio, 0.9 Na2O/Al2O3 molar ratio and 30 g/L Na2O(caustic) dose. Ultimately, it was concluded that a lime-soda sintering process at 1150 °C followed by one-step alkaline leaching with Na2O(caustic) at 90 °C could be metallurgically efficient for treating the low-grade (shale) bauxites.
Mineral Processing
Rahul Shakya; Manendra Singh
Abstract
Due to the critical nature of seismic risk in metro tunnels, the seismic response of underground tunnels is a highly delicate topic. The seismic response of a sub-surface structure depends more on the properties of the surrounding ground and the induced earth deformation during an earthquake than on ...
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Due to the critical nature of seismic risk in metro tunnels, the seismic response of underground tunnels is a highly delicate topic. The seismic response of a sub-surface structure depends more on the properties of the surrounding ground and the induced earth deformation during an earthquake than on the structure's inertial properties. This paper examines the seismic response of a typical section of the underground tunnel of Delhi Metro Rail Corporation (DMRC) between Rajiv Square and Patel Square in New Delhi's Connaught Place. Three-dimensional elasto-plastic analysis of Delhi metro underground tunnels under the seismic loading has been performed by finite element method using the Plaxis 3D software. Additionally, the influence of various boundary conditions on the dynamic response of metro tunnels has been examined. A comparison of the three-dimensional analysis with the two-dimensional plane-strain analysis has also been made. Horizontal displacements were experienced maximum compared to the longitudinal and vertical displacements in the soil-tunnel system. In dynamic analysis, the absorbent boundary is much more effective in controlling the displacements and the induced acceleration than the elementary boundary or the free-field boundary.
Mineral Processing
Mohammadreza Shahbazi; Hadi Abdollahi; Sied Ziaeddin Shafaei; Ziaeddin Pourkarimi; Sajjad Jannesar Malakooti; Ehsan Ebrahimi
Abstract
Tabas coal possesses favorable plastometric properties that make it suitable for use in metallurgical industries as coking coal. However, its high sulfur content, which stands at approximately 2%, poses a significant environmental pollution risk. Additionally, reducing ash content to below 10% is a critical ...
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Tabas coal possesses favorable plastometric properties that make it suitable for use in metallurgical industries as coking coal. However, its high sulfur content, which stands at approximately 2%, poses a significant environmental pollution risk. Additionally, reducing ash content to below 10% is a critical objective of this study to prevent a decline in coal's thermal efficiency in the metallurgical industries. This research work investigates the removal of sulfur and ash from Tabas coal samples using the biological methods including bioflotation and bioleaching. Initially, a combination of mesophilic bacteria including Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans, and Leptosprillium ferrooxidans were employed in the bioflotation method to detain pyrite sulfur in the Tabas coal samples. The highest reduction percentages of pyrite sulfur and ash were equal to 62% and 54.18%, respectively. In the next stage, bioleaching experiments were conducted, the effect of the test time, percentage of bacteria by volume, percentage of coal solids, and absence of bacteria on the amount of sulfur and ash removal was investigated. The test time emerged as the most critical factor. The best sulfur removal was achieved using bioleaching, with a maximum removal of 72.43%, observed for the PE coal sample. Bioflotation also achieved significant sulfur removal, with a maximum removal of 61% observed for the same sample. On the other hand, the best ash removal was achieved using bioflotation, with a maximum removal of 68.98% observed for the PE coal sample, and a maximum removal of 69.34% observed for the B4B2 coal sample using bioleaching. Finally, this research work conducted a comparison of biological methods to determine the amount of sulfur and ash reduction achieved. The results showed that both bioleaching and bioflotation were effective for coal desulfurization and ash removal, with bioleaching performing slightly better for sulfur removal and bioflotation performing slightly better for ash removal.
Mineral Processing
Ali Nikouei Mahani; Mohammad Karamoozian; Mohammad Jahani Chegeni; Mohammad Mahmoodi Meymand
Abstract
Generally, mineral processing plants generate a large quantity of waste in the form of fine particles. The flotation speed of mineral microbubbles by coarse bubbles is dramatically higher than that of individual particles. The advantage of microbubbles is due to the increase of binding efficiency of ...
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Generally, mineral processing plants generate a large quantity of waste in the form of fine particles. The flotation speed of mineral microbubbles by coarse bubbles is dramatically higher than that of individual particles. The advantage of microbubbles is due to the increase of binding efficiency of conventional bubbles with fine particles coated with microbubbles. Here, the focus is on reducing chemicals consumption and improving recovery. After preparing a representative sample, XRF, XRD, and mineralogical analyses were performed. Then 50 experiments were selected by experimental design using the response surface method (RSM), and in the form of central Composite design (CCD) by (design expert) DX 13 software. The interactions of collector consumption, frother agent, pH, particle size, and solid percentage were investigated, and 25 experiments using typical flotation and without nano-microbubbles and others with nano-microbubbles were conducted. The laboratory standard limit of the collector used in the pilot plant of the Sarcheshmeh Copper copper complex is 40 g/t (25 g/t of C7240 plus 15 g/t of Z11). Here, by consuming 20 g/t of collector in the absence of nanomicrobubbles, a recovery of 79.96% and in the presence of nanomicrobubbles, a recovery of 80.07% was obtained, that is a 50% reduction in collector consumption and a 0.11% increase in recovery was observed. Also the laboratory standard limit of frother used in the pilot plant of Sarcheshemeh Copper Complex is 30 g/t (15 g/t of MIBC plus 15 g/t of A65). Here, by using 10 g/t of frother in the absence of nanomicrobubbles, a recovery of 78.12%, and in the presence of nanomicrobubbles, a recovery of 82.05% was obtained. In other words, a decrease of 66.6% in the consumption of frother and an increase of 1.93% in recovery was observed.
Mineral Processing
Zehra Khan; Abhishek Sharma
Abstract
Due to rapid growth in infrastructure sector, the construction of high-rise buildings is becoming very popular among all the countries. Engineers face significant issues with high rise buildings, particularly in terms of structural and foundation aspects. Many old design approaches can't be used with ...
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Due to rapid growth in infrastructure sector, the construction of high-rise buildings is becoming very popular among all the countries. Engineers face significant issues with high rise buildings, particularly in terms of structural and foundation aspects. Many old design approaches can't be used with certainty since they involve extrapolation far beyond the domains of existing experience, hence structural and geotechnical engineers are being compelled to use more advanced analysis and design methodologies. The current study is an attempt to predict the bearing capacity and settlement behavior of piled-raft footing when embedded into cohesionless deposit. The numerical analysis has been carried out to examine the effect of numerous key parameters of pile and raft such as pile length (10, 15, 20 m), pile diameter (0.3, 0.4, 0.5 m), pile number (16, 20, 24), pile spacing (2D, 3D, 4D) (where “D” is diameter of the pile), raft thickness (0.4, 0.5, 0.6 m), and angle of internal friction of soil (25°, 30°, 35°) on load-settlement behavior of the piled- raft foundation using ABAQUS software. A constant spacing between the piles, i.e. 3D was used throughout the analysis. The results of numerical investigation revealed an improvement in bearing capacity and a reduction in settlement value on increasing length, diameter and number of piles and also with increasing angle of internal friction. The current study not only increases the bearing capacity of the foundation but provides a cost-effective foundation technique to engineers.
Mineral Processing
Satya Sai Srikant; Raghupatruni Bhima Rao
Abstract
The present paper deals with the development of process flowsheet for recovery of high-grade graphite from rougher graphite concentrate for use in industrial applications. In the present investigation, since the coarser graphite flakes have a higher demand, an attempt is made at every stage of comminution, ...
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The present paper deals with the development of process flowsheet for recovery of high-grade graphite from rougher graphite concentrate for use in industrial applications. In the present investigation, since the coarser graphite flakes have a higher demand, an attempt is made at every stage of comminution, and flash flotation experiments have been carried out, and the end product obtained by stage comminution followed by flotation has been further subjected to alkali pressure leaching followed by grinding and flotation to recover industrial grade graphite concentrate. During this stage grinding, an additive, a depressant that is being used for depression of silica during flotation, has been used as grinding aid. The data indicates that at any given time of grind, the effect of grinding aid is significantly better as far as the separation efficiency of graphite. Hence, it is concluded that excessive size reduction of graphite is minimised while using a grinding aid. Based on these observations, further studies have been planned for flash flotation using a comminution circuit with grinding aids. The results of the present study reveals that number of cleaning of rougher concentrate alone will not fetch more than 75% of fixed carbon (FC) with less than 8% yield and 41% recovery. The effect of four stage cleanings continued with starvation dosage in grinding circuit followed by flash flotation indicate that the end product achieved contains 97.8% FC with 11.6% yield and 78% recovery and the overall values loss in tailings contain 3.6% FC. The end product achieved by alkali digestion method from a flotation product [97.8% FC] contains 99.2% FC with overall 10.4% yield and 71% recovery. The process adopted in the present investigation is friendly environment and process flowsheet is an innovative. The end product obtained from this process is useful for various industrial applications.
Mineral Processing
Chol Ung Ryom; Kwang Hyok Pak; Il Chol Sin; Kwang Chol So; Un Chol Han
Abstract
Scheelite ore with heavy and magnetic minerals can be generally concentrated using shaking table centered gravity-magnetic processing. When magnetic field is formed by fixing magnetic bars on which permanent magnets are arranged at a constant interval, above the table desk, heavy scheelite particles ...
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Scheelite ore with heavy and magnetic minerals can be generally concentrated using shaking table centered gravity-magnetic processing. When magnetic field is formed by fixing magnetic bars on which permanent magnets are arranged at a constant interval, above the table desk, heavy scheelite particles can be concentrated by gravity, whereas heavy magnetic mineral particles can be floated off like light mineral particles by upward magnetic force. In this paper, concentration of scheelite and removal of pyrrhotite floated by magnetic force was simulated using CFD for the sample containing 1% scheelite and 2% pyrrhotite, and compared with the experiment. As a result, WO3 grade and separation efficiency of concentrate were 65.3% and 80.1%, respectively, in the new table equipped with magnetic bars, whereas 28.4% and 76.5%, respectively, in conventional table. The magnetic field formed by fixing magnetic bars above table could be significant in simplifying the sequential tabling-magnetic separation process and reducing the loss of scheelite.
Mineral Processing
Nooshin Navi; Mohammad Karamoozian; Mohammad Reza Khani
Abstract
Red mud is an important solid tailing with strong alkalinity that is obtained during the extraction of alumina in the Bayer process. The global reserve of red mud is more than 4 billion tons, and its disposal as tailing has always been a serious environmental problem. This tailing is considered as a ...
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Red mud is an important solid tailing with strong alkalinity that is obtained during the extraction of alumina in the Bayer process. The global reserve of red mud is more than 4 billion tons, and its disposal as tailing has always been a serious environmental problem. This tailing is considered as a potential source, due to its high content of valuable metal compounds including iron. In this research work, the extraction of iron in red mud is investigated by the method of reduction roasting. The main influencing factors are also investigated. These methods include reduction in muffle and tube furnace, and temperature, reduction agent, and additive type are as important factors. Reduction roasting of the samples in a tube furnace, with Argon gas and vacuum, a mixture of red mud, graphite, and sodium carbonate at 700–1000 °C results in the formation of Fe3O4. Magnetic measurements indicate that saturation magnetization increases from 0.239 to 38.205 emu/g due to the formation of Fe3O4. Applying the magnetic field intensity of about 1000 Gauss results in the iron recovery of 89.9%.
Mineral Processing
Pedram Ashtari; Saeid Karimi; Seyyede Atefeh Hosseini
Abstract
In this research work, the reductive leaching of pyrolusite in a sulfuric acid medium with the aid of orange peel as a reductant was investigated. The important parameters affecting the leaching process include temperature in the range of 25 to 95 °C, the weight ratio of reducing agent to pyrolusite ...
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In this research work, the reductive leaching of pyrolusite in a sulfuric acid medium with the aid of orange peel as a reductant was investigated. The important parameters affecting the leaching process include temperature in the range of 25 to 95 °C, the weight ratio of reducing agent to pyrolusite (R/P) in the range of 0 to 2 (w/w), and the concentration of sulfuric acid in the range of 0.05 to 0.25 M. According to the results, the parameters of temperature and the R/P are more significant in the reductive leaching process. With increasing temperature from 25 to 95 °C, Mn recovery increases from 0.5% to 52.5%. Also Mn recovery with a two-step increase in 0-0.1 and 0.1-1.5 of the R/P indicates a jump of 28.5% and 19.0%, respectively. Sulfuric acid concentration shows its effect by supplying sulfate and hydrogen ions in the leaching process. The successful use of orange peel as a reductant was confirmed by achieving a manganese dissolution efficiency of 98.1% under optimum conditions (temperature of 90 °C, sulfuric acid concentration of 0.1 M, and R/P ratio of 1.5 (w/w)). Kinetic investigations showed that the shrinking core model could not be used to determine the leaching mechanism of pyrolusite in the presence of fruit peel reductant. Avrami's kinetic model with very high fitting accuracy was used to determine the kinetic model of pyrolusite leaching.
