Physicochemical Problems of Mineral Processing, Nov 28, 2023
Ion flotation is one of the most promising and unique methods for reducing or removing toxic heav... more Ion flotation is one of the most promising and unique methods for reducing or removing toxic heavy metal ions, organic pollutants, or inorganic anions and cations from mining and metallurgical wastewater. It is a cost-effective and convenient method. In ion flotation, surface-active ions are removed from aqueous solutions by adding surfactants. Therefore, the main purpose of this review article was to summarize the application of various surfactants (nanoparticle surfactants, chemical synthetic surfactants, and biosurfactants) used in ion flotation. Then, the advantages, disadvantages, and prospects of surfactants were comprehensively discussed. Recent progress regarding nanoparticle surfactants in ion flotation and the mechanism of colligends binding with nanoparticles were evaluated.
This paper deals with the study of digestion and leaching process effectiveness in thorium minera... more This paper deals with the study of digestion and leaching process effectiveness in thorium minerals processing, and determining the optimum process conditions for acidic leaching of thoriumuranium ores in Zarigan region to dissolve thorium. To do this, some samples from Zarygan region were studied mineralogically in laboratory. The sample containing minerals such as Anorthite, Quartz, Sanidine, Vermiculite, Albite, Gypsum, Muscovite, Anatase and Magnetite were ground in specified dimensions and then mixed with concentrated sulfuric acid. Then the mixture was heated to a high temperature. After diluting the mixture with water, it was dissolved by means of agitation leaching. The effects of different parameters such as particle size, temperature and time of digestion, concentration of sulfuric acid, and acid to ore ratio, with the aim of determining their optimum value, were studied which resulted in the following optimum values for the above-mentioned parameters: particle size of 250 μm, temperature of 180 °C, time of 5h, concentration of sulfuric acid of 10.8 mol/lit, and acid to ore ratio of 3. Under these conditions, maximum recovery of thorium was 92%. Nitric acid (oxidant) concentration effect on the recovery of thorium in the optimum conditions was studied, and for the 2M of nitric acid concentration, thorium recovery of 97% was obtained.
Separation and Purification Technology, Jun 1, 2020
Abstract Amino functionalized graphene oxide was synthesized (AFGO) using a chemical method in or... more Abstract Amino functionalized graphene oxide was synthesized (AFGO) using a chemical method in order to apply in ion flotation process as a novel nanocollector for nickel ion removal with the aim of reducing collector consumption during the process. The synthesized AFGO was investigated using various analytical analysis. To create the negative charge onto the amino functionalized graphene oxide, 2,6-diaminopyridine was used to improve the properties of amino functionalized graphene oxide for removal of nickel ions with positive charge from synthetic wastewater using ion flotation. This study introduced a new collector for ion flotation to reduce the required collector concentration during the process which had simple synthesis, economical, high efficiency and stability in a wastewater. The nickel removal percentage of approximately 100% was achieved using the nanocollector.
Physicochemical Problems of Mineral Processing, Aug 31, 2022
In the development of tumbling mills' power models, the voidage of grinding media is assumed to b... more In the development of tumbling mills' power models, the voidage of grinding media is assumed to be static and equal to 40%. While the grinding media's voidage is dynamic; and hence is varied by changing the operating parameters. In this paper, to improve the Hogg and Fuerstenau model's accuracy in predicting the ball mills' power draw, the grinding media's static and dynamic voidage was studied for Bond's proposed ball size distributions (BSD) for the ball mills' first filling. To this end, by scaling down balls to one-tenth of actual size, developing a novel method to measure the dynamic voidage, and employing the three-level factorial method, a separate empirical model was developed for determining the dynamic voidage of each Bond's BSD with respect to mill's fractional filling and rotating speed. Moreover, using the multiple regression method, a general empirical model was derived to determine the dynamic voidage of each supposed BSD based on calculating the mean absolute deviation of balls diameter (MAD). Results indicated that grinding media's dynamic voidage increases with an increase in rotating speed and a decrease in fractional filling and balls diameter's MAD. The maximum and minimum static and dynamic voidage occurred for the seventh and first Bond's BSDs. By employing an industrial database and analyzing the mean absolute percentage error (MAPE) of predicted ball mills' power draw, it was found that the Hogg and Fuerstenau model's accuracy enhances by calculating the load's bulk density based on the grinding media's dynamic voidage.
The phenomenological theory of sedimentation-thickening processes predicts the settling behavior ... more The phenomenological theory of sedimentation-thickening processes predicts the settling behavior of a flocculated suspension in dependence of two functions, the batch flux density function and the effective solid stress. These functions were determined using batch settling tests. The governing equations for sedimentation were then solved numerically for these functions and the predictions were compared to the experimental results from pilot scale thickener tests. Firstly, the continuous tests were performed in the plexiglass pilot thickener at different feed flow rates and discharge rates and the solid volume fraction of discharge, the bed height and the time were recorded for each condition. These tests were also simulated and it was observed that there is a good agreement between the results of continuous tests and the results of dynamic simulation. Secondly, the discontinuous tests were performed in the plexiglass pilot thickener at different feed flow rates with a discharge rate of zero. The bed formation rate was determined for each condition. These tests were also simulated and it was observed that there is a good agreement between the results of discontinuous tests and the results of simulation.
Selective ion flotation of neodymium ions from aluminum, iron, and calcium ions using sodium dode... more Selective ion flotation of neodymium ions from aluminum, iron, and calcium ions using sodium dodecyl sulfate (SDS) as a surfactant and di-(2-ethylhexyl) phosphoric acid (D2EHPA) as an extractant was performed to selectively recover neodymium ions from solutions in a binary system of ions. The results indicated that the D2EHPA caused an increase in the neodymium ion recovery in the presence of all competing ions. Using D2EHPA, the calcium ion removal decreased and the removal of iron and aluminum ions increased. The Gibbs free energy of neodymium-D2EHPA complex formation was more than that of other ions, which led to an increase in the selective recovery of neodymium ions. The aluminum ions had a greater effect on decreasing the neodymium recovery than iron or calcium ions. Similar Gibbs free energy and complex structures of the neodymium and aluminum ions with D2EHPA led to the less selective separation of neodymium from aluminum.
In this study, the effects of chemical conditions on the recovery of Zn(II) and water during the ... more In this study, the effects of chemical conditions on the recovery of Zn(II) and water during the ion flotation process were evaluated using a central composite design (CCD) of response surface methodology. The optimum effective parameters including pH, collector and frother concentration were determined. The results showed that the pH and collector concentration were effective factors for the efficiency of Zn(II) flotation. The effects of collector and frother concentration on the characterization of sublate and the complexation of sodium dodecyl sulphate with Zn(II) were studied using scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The results show that foam fractionation occurred at a pH of 1.5, 3 and 5.5 and ion flotation at a pH of 8.
Surface roughness of quartz particles was determined by measuring the specific surface area of pa... more Surface roughness of quartz particles was determined by measuring the specific surface area of particles. The wettability characteristics of particles were determined by measuring the flotation rate using a laboratory flotation cell. Experimental results show that the rod mill product has higher roughness than the ball mill product. For the particles with larger surface roughness, the flotation kinetics constant is also higher. Finally, empirical relationships between surface roughness (r) and the flotation kinetics constant (k) of quartz particles as k=A+Br+Cr 0.5 lnr+D/lnr+E/r and k=A+Br are presented, in which A, B, C, D and E are constants related to experimental conditions and mineralogical properties of mineral.
Physicochemical Problems of Mineral Processing, Aug 28, 2020
The present study deals with nickel ions removal from dilute aqueous solution by ion flotation wi... more The present study deals with nickel ions removal from dilute aqueous solution by ion flotation with emphasizing the process efficiency. The effect of collector structure on ion flotation efficiency and water recovery was evaluated using anionic collectors of sodium dodecyl sulfate (SDS) and functionalized graphene oxide by 2,6-diaminopyridine (AFGO). The results showed that process efficiency enhanced with the increase in pH and reached to complete removal at pH of 9 and 9.7 for SDS and AFGO, respectively. The AFGO showed the multifunctional bindings for complex formations with nickel ions. A coordinate bond may be formed between nickel ions and AFGO at the pH of 9 which increased nickel ion removal. The water recovery as a critical parameter that contributes to removal efficiency was significantly affected by the collector structure. The AFGO doesn't have a frothing property and so decreases the water recovery during the process. The AFGO had significantly lower water recovery than SDS (almost threefold).
Geometallurgy has become an important tool to predict the processing behaviour of ores, and to de... more Geometallurgy has become an important tool to predict the processing behaviour of ores, and to decrease the production risks associated with the variable nature of economic mineral deposits. Understanding the ore variability and subsequently the response of the ore to processing are considered to be the most important functions of an accurate geometallurgical study. In this paper geometallurgical indices for grinding properties of a copper ore are investigated. Geometallurgical index (GI) is described as any geological feature which makes a footprint on the processing performance of the ores. A comprehensive study at Sarcheshmeh porphyry copper mine was undertaken. This included the process responses of the ore such as grade, recovery and plant throughput as possible geometallurgical indices. In this paper the effects of rock breakage variability on the plant throughput and energy consumption are presented. Ninety samples were collected based on geological features including lithology, hydrothermal alteration, and geological structures. The samples were characterized using X-ray diffraction, X-ray fluorescence, electron and optical microscopy. A small scale simulated test method for Bond ball mill work index (BWI) was used to perform the comminution examinations. The results showed that BWI values vary from 5.67 kWh/t to 20.21 kWh/t. Examination of the possible correlations between BWI and the geological features showed that the key geological feature related to comminution variability is lithology. In addition, the hydrothermal alteration would be an effective parameter in the period that the plant is fed with a single lithology.
Physicochemical Problems of Mineral Processing, Nov 28, 2023
Ion flotation is one of the most promising and unique methods for reducing or removing toxic heav... more Ion flotation is one of the most promising and unique methods for reducing or removing toxic heavy metal ions, organic pollutants, or inorganic anions and cations from mining and metallurgical wastewater. It is a cost-effective and convenient method. In ion flotation, surface-active ions are removed from aqueous solutions by adding surfactants. Therefore, the main purpose of this review article was to summarize the application of various surfactants (nanoparticle surfactants, chemical synthetic surfactants, and biosurfactants) used in ion flotation. Then, the advantages, disadvantages, and prospects of surfactants were comprehensively discussed. Recent progress regarding nanoparticle surfactants in ion flotation and the mechanism of colligends binding with nanoparticles were evaluated.
This paper deals with the study of digestion and leaching process effectiveness in thorium minera... more This paper deals with the study of digestion and leaching process effectiveness in thorium minerals processing, and determining the optimum process conditions for acidic leaching of thoriumuranium ores in Zarigan region to dissolve thorium. To do this, some samples from Zarygan region were studied mineralogically in laboratory. The sample containing minerals such as Anorthite, Quartz, Sanidine, Vermiculite, Albite, Gypsum, Muscovite, Anatase and Magnetite were ground in specified dimensions and then mixed with concentrated sulfuric acid. Then the mixture was heated to a high temperature. After diluting the mixture with water, it was dissolved by means of agitation leaching. The effects of different parameters such as particle size, temperature and time of digestion, concentration of sulfuric acid, and acid to ore ratio, with the aim of determining their optimum value, were studied which resulted in the following optimum values for the above-mentioned parameters: particle size of 250 μm, temperature of 180 °C, time of 5h, concentration of sulfuric acid of 10.8 mol/lit, and acid to ore ratio of 3. Under these conditions, maximum recovery of thorium was 92%. Nitric acid (oxidant) concentration effect on the recovery of thorium in the optimum conditions was studied, and for the 2M of nitric acid concentration, thorium recovery of 97% was obtained.
Separation and Purification Technology, Jun 1, 2020
Abstract Amino functionalized graphene oxide was synthesized (AFGO) using a chemical method in or... more Abstract Amino functionalized graphene oxide was synthesized (AFGO) using a chemical method in order to apply in ion flotation process as a novel nanocollector for nickel ion removal with the aim of reducing collector consumption during the process. The synthesized AFGO was investigated using various analytical analysis. To create the negative charge onto the amino functionalized graphene oxide, 2,6-diaminopyridine was used to improve the properties of amino functionalized graphene oxide for removal of nickel ions with positive charge from synthetic wastewater using ion flotation. This study introduced a new collector for ion flotation to reduce the required collector concentration during the process which had simple synthesis, economical, high efficiency and stability in a wastewater. The nickel removal percentage of approximately 100% was achieved using the nanocollector.
Physicochemical Problems of Mineral Processing, Aug 31, 2022
In the development of tumbling mills' power models, the voidage of grinding media is assumed to b... more In the development of tumbling mills' power models, the voidage of grinding media is assumed to be static and equal to 40%. While the grinding media's voidage is dynamic; and hence is varied by changing the operating parameters. In this paper, to improve the Hogg and Fuerstenau model's accuracy in predicting the ball mills' power draw, the grinding media's static and dynamic voidage was studied for Bond's proposed ball size distributions (BSD) for the ball mills' first filling. To this end, by scaling down balls to one-tenth of actual size, developing a novel method to measure the dynamic voidage, and employing the three-level factorial method, a separate empirical model was developed for determining the dynamic voidage of each Bond's BSD with respect to mill's fractional filling and rotating speed. Moreover, using the multiple regression method, a general empirical model was derived to determine the dynamic voidage of each supposed BSD based on calculating the mean absolute deviation of balls diameter (MAD). Results indicated that grinding media's dynamic voidage increases with an increase in rotating speed and a decrease in fractional filling and balls diameter's MAD. The maximum and minimum static and dynamic voidage occurred for the seventh and first Bond's BSDs. By employing an industrial database and analyzing the mean absolute percentage error (MAPE) of predicted ball mills' power draw, it was found that the Hogg and Fuerstenau model's accuracy enhances by calculating the load's bulk density based on the grinding media's dynamic voidage.
The phenomenological theory of sedimentation-thickening processes predicts the settling behavior ... more The phenomenological theory of sedimentation-thickening processes predicts the settling behavior of a flocculated suspension in dependence of two functions, the batch flux density function and the effective solid stress. These functions were determined using batch settling tests. The governing equations for sedimentation were then solved numerically for these functions and the predictions were compared to the experimental results from pilot scale thickener tests. Firstly, the continuous tests were performed in the plexiglass pilot thickener at different feed flow rates and discharge rates and the solid volume fraction of discharge, the bed height and the time were recorded for each condition. These tests were also simulated and it was observed that there is a good agreement between the results of continuous tests and the results of dynamic simulation. Secondly, the discontinuous tests were performed in the plexiglass pilot thickener at different feed flow rates with a discharge rate of zero. The bed formation rate was determined for each condition. These tests were also simulated and it was observed that there is a good agreement between the results of discontinuous tests and the results of simulation.
Selective ion flotation of neodymium ions from aluminum, iron, and calcium ions using sodium dode... more Selective ion flotation of neodymium ions from aluminum, iron, and calcium ions using sodium dodecyl sulfate (SDS) as a surfactant and di-(2-ethylhexyl) phosphoric acid (D2EHPA) as an extractant was performed to selectively recover neodymium ions from solutions in a binary system of ions. The results indicated that the D2EHPA caused an increase in the neodymium ion recovery in the presence of all competing ions. Using D2EHPA, the calcium ion removal decreased and the removal of iron and aluminum ions increased. The Gibbs free energy of neodymium-D2EHPA complex formation was more than that of other ions, which led to an increase in the selective recovery of neodymium ions. The aluminum ions had a greater effect on decreasing the neodymium recovery than iron or calcium ions. Similar Gibbs free energy and complex structures of the neodymium and aluminum ions with D2EHPA led to the less selective separation of neodymium from aluminum.
In this study, the effects of chemical conditions on the recovery of Zn(II) and water during the ... more In this study, the effects of chemical conditions on the recovery of Zn(II) and water during the ion flotation process were evaluated using a central composite design (CCD) of response surface methodology. The optimum effective parameters including pH, collector and frother concentration were determined. The results showed that the pH and collector concentration were effective factors for the efficiency of Zn(II) flotation. The effects of collector and frother concentration on the characterization of sublate and the complexation of sodium dodecyl sulphate with Zn(II) were studied using scanning electron microscopy coupled with energy dispersive X-ray (SEM/EDX) spectroscopy and Fourier transform infrared (FTIR) spectroscopy. The results show that foam fractionation occurred at a pH of 1.5, 3 and 5.5 and ion flotation at a pH of 8.
Surface roughness of quartz particles was determined by measuring the specific surface area of pa... more Surface roughness of quartz particles was determined by measuring the specific surface area of particles. The wettability characteristics of particles were determined by measuring the flotation rate using a laboratory flotation cell. Experimental results show that the rod mill product has higher roughness than the ball mill product. For the particles with larger surface roughness, the flotation kinetics constant is also higher. Finally, empirical relationships between surface roughness (r) and the flotation kinetics constant (k) of quartz particles as k=A+Br+Cr 0.5 lnr+D/lnr+E/r and k=A+Br are presented, in which A, B, C, D and E are constants related to experimental conditions and mineralogical properties of mineral.
Physicochemical Problems of Mineral Processing, Aug 28, 2020
The present study deals with nickel ions removal from dilute aqueous solution by ion flotation wi... more The present study deals with nickel ions removal from dilute aqueous solution by ion flotation with emphasizing the process efficiency. The effect of collector structure on ion flotation efficiency and water recovery was evaluated using anionic collectors of sodium dodecyl sulfate (SDS) and functionalized graphene oxide by 2,6-diaminopyridine (AFGO). The results showed that process efficiency enhanced with the increase in pH and reached to complete removal at pH of 9 and 9.7 for SDS and AFGO, respectively. The AFGO showed the multifunctional bindings for complex formations with nickel ions. A coordinate bond may be formed between nickel ions and AFGO at the pH of 9 which increased nickel ion removal. The water recovery as a critical parameter that contributes to removal efficiency was significantly affected by the collector structure. The AFGO doesn't have a frothing property and so decreases the water recovery during the process. The AFGO had significantly lower water recovery than SDS (almost threefold).
Geometallurgy has become an important tool to predict the processing behaviour of ores, and to de... more Geometallurgy has become an important tool to predict the processing behaviour of ores, and to decrease the production risks associated with the variable nature of economic mineral deposits. Understanding the ore variability and subsequently the response of the ore to processing are considered to be the most important functions of an accurate geometallurgical study. In this paper geometallurgical indices for grinding properties of a copper ore are investigated. Geometallurgical index (GI) is described as any geological feature which makes a footprint on the processing performance of the ores. A comprehensive study at Sarcheshmeh porphyry copper mine was undertaken. This included the process responses of the ore such as grade, recovery and plant throughput as possible geometallurgical indices. In this paper the effects of rock breakage variability on the plant throughput and energy consumption are presented. Ninety samples were collected based on geological features including lithology, hydrothermal alteration, and geological structures. The samples were characterized using X-ray diffraction, X-ray fluorescence, electron and optical microscopy. A small scale simulated test method for Bond ball mill work index (BWI) was used to perform the comminution examinations. The results showed that BWI values vary from 5.67 kWh/t to 20.21 kWh/t. Examination of the possible correlations between BWI and the geological features showed that the key geological feature related to comminution variability is lithology. In addition, the hydrothermal alteration would be an effective parameter in the period that the plant is fed with a single lithology.
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