Cyanide tailings (CTs), which amount to hundreds of millions of tons and pose significant a danger to the environment's ecology, are regarded as hazardous waste. This study suggests an efficient and environmentally favorable method for the recovery of gold and silver from CTs. The influence of calcium chloride dosage, silicon dioxide dosage, pellet moisture content, roasting temperature, and roasting duration on chloridizing volatilization of Au and Ag was investigated. The simultaneous recovery of gold and silver from cyanide tailings via heating with chlorination was also investigated. It was found that the calcium chloride dosage and temperature increase the chloridizing volatilization rates, while the silicon dioxide dosage and particle moisture content decrease it. The inter-diffusion through the gangue layer served as the rate-limiting phase in the chloridizing volatilization kinetics, which was based on the shrinking core model. The apparent activation energies (Ea) of 24.01 kJ•mol-1 (Au) and 24.62 kJ•mol-1 (Ag) are in agreement with this result. The orders of reaction corresponding to various values of temperature, moisture content, silicon dioxide, and calcium chloride dosages were also computed. Semi-empirical equations can be used to describe the rate of reaction in diffusion-controlled processes.
{"title":"Kinetics of simultaneous recovering of Au and Ag from CTs by chloridizing volatilization methods","authors":"Weiwei Wang, Zhangkuang Peng, Qiang Li, Erdou Li, Shaochun Hou","doi":"10.37190/ppmp/172522","DOIUrl":"https://doi.org/10.37190/ppmp/172522","url":null,"abstract":"Cyanide tailings (CTs), which amount to hundreds of millions of tons and pose significant a danger to the environment's ecology, are regarded as hazardous waste. This study suggests an efficient and environmentally favorable method for the recovery of gold and silver from CTs. The influence of calcium chloride dosage, silicon dioxide dosage, pellet moisture content, roasting temperature, and roasting duration on chloridizing volatilization of Au and Ag was investigated. The simultaneous recovery of gold and silver from cyanide tailings via heating with chlorination was also investigated. It was found that the calcium chloride dosage and temperature increase the chloridizing volatilization rates, while the silicon dioxide dosage and particle moisture content decrease it. The inter-diffusion through the gangue layer served as the rate-limiting phase in the chloridizing volatilization kinetics, which was based on the shrinking core model. The apparent activation energies (Ea) of 24.01 kJ•mol-1 (Au) and 24.62 kJ•mol-1 (Ag) are in agreement with this result. The orders of reaction corresponding to various values of temperature, moisture content, silicon dioxide, and calcium chloride dosages were also computed. Semi-empirical equations can be used to describe the rate of reaction in diffusion-controlled processes.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135016090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Peiqiang Fan, Wenjie Zhang, Xiong Tong, Xian Xie, Ruiqi Xie, Qiang Song, Yunpeng Du, Yang Cao
The extraction of light rare earths (Pr and Nd) from chloride medium was investigated using a mixture of di(2-ethylhexyl) phosphoric acid (P204) and bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272) in sulfonated kerosene. The P204+Cyanex272 system exerted a synergistic effect on the separation of light rare earths, and the separation coefficient was higher than when P204 and Cyanex272 were used as extractants alone. The separation coefficient of Pr and Nd in the extraction system reached 1.75 when the pH of the aqueous phase material solution was approximately 2.5, and 1.5 mol/L hydrochloric acid as a stripping agent effectively eluted the rare earth ions in the loaded organic phase. Combining the slope method, infrared spectroscopy, and nuclear magnetic resonance spectroscopy, we explored the mechanism of the extracted Nd and Pr into the organic phase complex, and finally entered the organic phase with Re(HA2)2B. The P-O-H bond and P=O bond in the extractant P204 and Cyanex272 formed a coordination bond with Re3+. Therefore, this extraction method also provides a reference for a more environmentally friendly and efficient procedure for separation and purification of light rare earth elements Pr and Nd.
{"title":"Separation and purification of light rare earth elements from chloride media using P204 and Cyanex272 in sulfonated kerosene under non-saponification conditions","authors":"Peiqiang Fan, Wenjie Zhang, Xiong Tong, Xian Xie, Ruiqi Xie, Qiang Song, Yunpeng Du, Yang Cao","doi":"10.37190/ppmp/172444","DOIUrl":"https://doi.org/10.37190/ppmp/172444","url":null,"abstract":"The extraction of light rare earths (Pr and Nd) from chloride medium was investigated using a mixture of di(2-ethylhexyl) phosphoric acid (P204) and bis(2,4,4-trimethylpentyl) phosphinic acid (Cyanex272) in sulfonated kerosene. The P204+Cyanex272 system exerted a synergistic effect on the separation of light rare earths, and the separation coefficient was higher than when P204 and Cyanex272 were used as extractants alone. The separation coefficient of Pr and Nd in the extraction system reached 1.75 when the pH of the aqueous phase material solution was approximately 2.5, and 1.5 mol/L hydrochloric acid as a stripping agent effectively eluted the rare earth ions in the loaded organic phase. Combining the slope method, infrared spectroscopy, and nuclear magnetic resonance spectroscopy, we explored the mechanism of the extracted Nd and Pr into the organic phase complex, and finally entered the organic phase with Re(HA<sub>2</sub>)<sub>2</sub>B. The P-O-H bond and P=O bond in the extractant P204 and Cyanex272 formed a coordination bond with Re<sup>3+</sup>. Therefore, this extraction method also provides a reference for a more environmentally friendly and efficient procedure for separation and purification of light rare earth elements Pr and Nd.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"352 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135154030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) was first introduced as a depressant during separating chalcopyrite from molybdenite (Cu-Mo). The selective effects of HACC on the separation of Cu-Mo were conducted by single-mineral flotation tests. The findings revealed that HACC helps separate Cu and Mo efficiently at pH 6 with 8 mg/L of HACC, resulting in 76.22% and 5.38% of Mo and Cu recovery, respectively. The adsorption mechanism of HACC was investigated via Zeta potential, adsorption density, contact angle, FT-IR and XPS analysis. The contact angle and adsorption density measurements offer indisputable proof that HACC can adsorb on the surface of chalcopyrite. Furthermore, FT-IR and XPS measurements confirm that N atoms in quaternary ammonium groups of HACC interact with Cu sites on the surface of chalcopyrite. The findings also suggest that HACC adsorbs on the surface without significantly impacting molybdenite. All these results confirm that HACC can be an effective chalcopyrite depressant.
{"title":"Insights into the depression effect and adsorption mechanism of HACC on chalcopyrite surface in Cu-Mo flotation separation","authors":"Mingyang Li, Pengpeng Zhang, Xiangpeng Gao, Lingyun Huang","doi":"10.37190/ppmp/172481","DOIUrl":"https://doi.org/10.37190/ppmp/172481","url":null,"abstract":"In this study, hydroxypropyltrimethyl ammonium chloride chitosan (HACC) was first introduced as a depressant during separating chalcopyrite from molybdenite (Cu-Mo). The selective effects of HACC on the separation of Cu-Mo were conducted by single-mineral flotation tests. The findings revealed that HACC helps separate Cu and Mo efficiently at pH 6 with 8 mg/L of HACC, resulting in 76.22% and 5.38% of Mo and Cu recovery, respectively. The adsorption mechanism of HACC was investigated via Zeta potential, adsorption density, contact angle, FT-IR and XPS analysis. The contact angle and adsorption density measurements offer indisputable proof that HACC can adsorb on the surface of chalcopyrite. Furthermore, FT-IR and XPS measurements confirm that N atoms in quaternary ammonium groups of HACC interact with Cu sites on the surface of chalcopyrite. The findings also suggest that HACC adsorbs on the surface without significantly impacting molybdenite. All these results confirm that HACC can be an effective chalcopyrite depressant.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"222 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135153697","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ramón Arellano-Piña, Elvia Angélica Sanchez-Ramirez, Roberto Pérez-Garibay, Victor Hugo Gutiérrez-Pérez
Ore concentrators seek the stability of processes by feeding blends of rocks with average hardness and ore content. Therefore, large amounts of samples must be characterized in a short time. The Bond Work Index (Wi) is a common technique for the estimation of hardness and energy requirement for comminution using ball mills. However, this technique is time-consuming (close to 5 hours) and liable to experimental errors. This work contributes to obtaining new models for rapid Bond Work Index estimation using non-standard dimensions mills. This was done by proposing grinding tests using four types of ores and four mills of different dimensions, including the standard Bond ball mill (BBM). For all tests it was kept constant: (a) critical speed (91%), and (b) mill charge by volume (10.5%), varying the amount of fresh feed according to its density. The results showed that using the non-standard mills (between 20 and 35 cm in diameter), the Bond´s model constants (α=0.23; β= 0.82, and γ = 44.5), are unable to predict the Work Index properly. Therefore, these constants must be recalculated using linear models based on mill diameter. With the models proposed for α, β, and γ, the Bond Work Index (kWh/t) can be rapidly estimated (less than 2 hours) and show a high accuracy for mills of non-standard dimensions (R2= 0.96).
{"title":"Bond´s work index estimation using non-standard ball mills","authors":"Ramón Arellano-Piña, Elvia Angélica Sanchez-Ramirez, Roberto Pérez-Garibay, Victor Hugo Gutiérrez-Pérez","doi":"10.37190/ppmp/172458","DOIUrl":"https://doi.org/10.37190/ppmp/172458","url":null,"abstract":"Ore concentrators seek the stability of processes by feeding blends of rocks with average hardness and ore content. Therefore, large amounts of samples must be characterized in a short time. The Bond Work Index (Wi) is a common technique for the estimation of hardness and energy requirement for comminution using ball mills. However, this technique is time-consuming (close to 5 hours) and liable to experimental errors. This work contributes to obtaining new models for rapid Bond Work Index estimation using non-standard dimensions mills. This was done by proposing grinding tests using four types of ores and four mills of different dimensions, including the standard Bond ball mill (BBM). For all tests it was kept constant: (a) critical speed (91%), and (b) mill charge by volume (10.5%), varying the amount of fresh feed according to its density. The results showed that using the non-standard mills (between 20 and 35 cm in diameter), the Bond´s model constants (α=0.23; β= 0.82, and γ = 44.5), are unable to predict the Work Index properly. Therefore, these constants must be recalculated using linear models based on mill diameter. With the models proposed for α, β, and γ, the Bond Work Index (kWh/t) can be rapidly estimated (less than 2 hours) and show a high accuracy for mills of non-standard dimensions (R<sup>2</sup>= 0.96).","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135153365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ahmed Mohammedelmubarak Ahmed Abbaker, Nevzat Aslan
Since the grinding and chemical reagents required for flotation are expensive, coarse particle flotation reduces grinding costs and makes the subsequent process more accessible and cheaper. Recent studies suggest that the flotation of coarse particles using microbubbles has some advantages. However, a thorough analysis of the effectiveness of various flotation parameters and the impact of their interactions on the recovery of coarse particles in the presence and absence of microbubbles has yet to be fully understood. In the current study, the two-level factorial and Box-Behnken experimental designs were performed to characterize, assess, and optimize the implications of seven numerical (sodium oleate, collector; calcium oxide, activator; MIBC, frother; impeller speed; froth depth; pulp concentration; fine particles) and one categorical (microbubbles) independent parameters on the coarse quartz particles. Characterization revealed that froth depth did not significantly affect the flotation recovery of coarse particles in the mechanical laboratory cell. The effects of the variables in the presence of microbubbles revealed that sodium oleate and impeller speed significantly impacted recovery, followed by calcium oxide and fine particles, both of which had a medium influence, and MIBC and pulp concentration, which had a minimal impact. The recovery of coarse particles increased by 92.714% when microbubbles were used, compared to the estimated maximum recovery under ideal conditions of 62.258% without them. From this, it can be concluded that a high coarse particle flotation recovery is possible by optimizing the hydrodynamic conditions and the chemical environment using microbubbles.
{"title":"The effect of microbubbles on coarse particle anionic flotation: analysis and optimization","authors":"Ahmed Mohammedelmubarak Ahmed Abbaker, Nevzat Aslan","doi":"10.37190/ppmp/172298","DOIUrl":"https://doi.org/10.37190/ppmp/172298","url":null,"abstract":"Since the grinding and chemical reagents required for flotation are expensive, coarse particle flotation reduces grinding costs and makes the subsequent process more accessible and cheaper. Recent studies suggest that the flotation of coarse particles using microbubbles has some advantages. However, a thorough analysis of the effectiveness of various flotation parameters and the impact of their interactions on the recovery of coarse particles in the presence and absence of microbubbles has yet to be fully understood. In the current study, the two-level factorial and Box-Behnken experimental designs were performed to characterize, assess, and optimize the implications of seven numerical (sodium oleate, collector; calcium oxide, activator; MIBC, frother; impeller speed; froth depth; pulp concentration; fine particles) and one categorical (microbubbles) independent parameters on the coarse quartz particles. Characterization revealed that froth depth did not significantly affect the flotation recovery of coarse particles in the mechanical laboratory cell. The effects of the variables in the presence of microbubbles revealed that sodium oleate and impeller speed significantly impacted recovery, followed by calcium oxide and fine particles, both of which had a medium influence, and MIBC and pulp concentration, which had a minimal impact. The recovery of coarse particles increased by 92.714% when microbubbles were used, compared to the estimated maximum recovery under ideal conditions of 62.258% without them. From this, it can be concluded that a high coarse particle flotation recovery is possible by optimizing the hydrodynamic conditions and the chemical environment using microbubbles.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135489856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Grinding is commonly responsible for the liberation of valuable minerals from host rocks but can entail high costs in terms of energy and medium consumption, but a tower mill is a unique power-saving grinding machine over traditional mills. In a tower mill, many operating parameters affect the grinding performance, such as the amount of slurry with a known solid concentration, screw mixer speed, medium filling rate, material-ball ratio, and medium properties. Thus, 25 groups of grinding tests were conducted to establish the relationship between the grinding power consumption and operating parameters. The prediction model was established based on the backpropagation “BP” neural network, further optimized by the genetic algorithm GA to ensure the accuracy of the model, and verified. The test results show that the relative error of the predicted and actual values of the backpropagation “BP” neural network prediction model within 3% was reduced to within 2% by conducting the generic algorithm backpropagation “GA-BP” neural network. The optimum grinding power consumption of 41.069 kWh/t was obtained at the predicted operating parameters of 66.49% grinding concentration, 301.86 r/min screw speed, 20.47% medium filling rate, 96.61% medium ratio, and 0.1394 material-ball ratio. The verifying laboratory test at the optimum conditions, produced a grinding power consumption of 41.85 kWh/t with a relative error of 1.87%, showing the feasibility of using the genetic algorithm and BP neural network to optimize the grinding power consumption of the tower mill.
{"title":"Prediction and optimization of tower mill grinding power consumption based on GA-BP neural network","authors":"Ziyang Wang, Ying Hou, Ahmed Sobhy","doi":"10.37190/ppmp/172096","DOIUrl":"https://doi.org/10.37190/ppmp/172096","url":null,"abstract":"Grinding is commonly responsible for the liberation of valuable minerals from host rocks but can entail high costs in terms of energy and medium consumption, but a tower mill is a unique power-saving grinding machine over traditional mills. In a tower mill, many operating parameters affect the grinding performance, such as the amount of slurry with a known solid concentration, screw mixer speed, medium filling rate, material-ball ratio, and medium properties. Thus, 25 groups of grinding tests were conducted to establish the relationship between the grinding power consumption and operating parameters. The prediction model was established based on the backpropagation “BP” neural network, further optimized by the genetic algorithm GA to ensure the accuracy of the model, and verified. The test results show that the relative error of the predicted and actual values of the backpropagation “BP” neural network prediction model within 3% was reduced to within 2% by conducting the generic algorithm backpropagation “GA-BP” neural network. The optimum grinding power consumption of 41.069 kWh/t was obtained at the predicted operating parameters of 66.49% grinding concentration, 301.86 r/min screw speed, 20.47% medium filling rate, 96.61% medium ratio, and 0.1394 material-ball ratio. The verifying laboratory test at the optimum conditions, produced a grinding power consumption of 41.85 kWh/t with a relative error of 1.87%, showing the feasibility of using the genetic algorithm and BP neural network to optimize the grinding power consumption of the tower mill.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135939077","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The representative of natural layered clays, bentonite, was modified according to two routes and tested as a new catalyst for selective catalytic reduction of nitrogen oxides with ammonia (NH3-SCR). The natural acid-activated clay was ion-exchanged with Na+ or remained in H-form and pillared with metal oxides. In order to limit the number of synthesis steps, iron as an active phase was introduced simultaneously with Al2O3 during the intercalation procedure. Additionally, the samples were doped with 0.5 wt% of copper to promote low-temperature activity. It was found that the performed modifications resulted in disorganization of the ordered layered arrangement of bentonite. Nevertheless, acid activation and pillaring improved structural and textural parameters. The results of catalytic tests indicated that the samples containing Fe2O3 pillars promoted with Cu exhibited the highest NO conversion of 85% at 250 °C (H-Bent-AlFe-Cu) and 75% at 300 °C (Na-Bent-AlFe-Cu). What is important, activity of the protonated samples in the high-temperature region was noticeably affected by the side reaction of ammonia oxidation, correlated with the production of NO and resulting in N2O emission during the process comparing to Na-Bentonite catalysts.
{"title":"Physicochemical properties and NH<sub>3</sub>-SCR catalytic performance of intercalated layered aluminosilicates","authors":"Agnieszka Szymaszek-Wawryca, Urbano Díaz, Bogdan Samojeden, Monika Motak","doi":"10.37190/ppmp/171381","DOIUrl":"https://doi.org/10.37190/ppmp/171381","url":null,"abstract":"The representative of natural layered clays, bentonite, was modified according to two routes and tested as a new catalyst for selective catalytic reduction of nitrogen oxides with ammonia (NH<sub>3</sub>-SCR). The natural acid-activated clay was ion-exchanged with Na<sup>+</sup> or remained in H-form and pillared with metal oxides. In order to limit the number of synthesis steps, iron as an active phase was introduced simultaneously with Al<sub>2</sub>O<sub>3</sub> during the intercalation procedure. Additionally, the samples were doped with 0.5 wt% of copper to promote low-temperature activity. It was found that the performed modifications resulted in disorganization of the ordered layered arrangement of bentonite. Nevertheless, acid activation and pillaring improved structural and textural parameters. The results of catalytic tests indicated that the samples containing Fe<sub>2</sub>O<sub>3</sub> pillars promoted with Cu exhibited the highest NO conversion of 85% at 250 °C (H-Bent-AlFe-Cu) and 75% at 300 °C (Na-Bent-AlFe-Cu). What is important, activity of the protonated samples in the high-temperature region was noticeably affected by the side reaction of ammonia oxidation, correlated with the production of NO and resulting in N<sub>2</sub>O emission during the process comparing to Na-Bentonite catalysts.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135717092","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lizardite slime coating is one of significant factors in the deterioration of the floatability of sulphide minerals. In this study, a nanoparticle cationic polystyrene-co-poly(n-butylacrylate)(PS-PBNH) collector was introduced to eliminate the negative impact of lizardite slimes in pyrite flotation. Microflotation results demonstrated that lizardite slims did not affect the recovery of pyrite in the presence of PS-PBNH. Good flotation separation of pyrite from lizardite was achieved when the nanoparticle PS-PBNH collector was used. The results from adsorption study indicated that PS-PBNH exhibited a significant adsorption on the pyrite surface in the presence of lizardite slimes. Sedimentation tests showed that hetero-aggregation occurred between lizardite slimes and pyrite, whereas the introduction of PS-PBNH collector resulted in a heterogeneous dispersion between them. Zeta potential measurements suggested that PS-PBNH collector interacted with pyrite surface, and the PS-PBNH adsorption changed the surface charge of pyrite from negative to be positive. As a result, the interaction of pyrite with lizardite shifted from electrostatic attraction to electrostatic repulsion, as supported by the DLVO calculations. These results indicated PS-PBNH can be used as a potential collector for pyrite flotation in pyrite/lizardite slimes system without the need for a depressant.
{"title":"A nanoparticle cationic polystyrene-co-poly(n-butylacrylate) collector to eliminate the negative effect of lizardite slimes in pyrite flotation","authors":"Guanghua Ai, Cheng Liu, G. Zhu, Siyuan Yang","doi":"10.37190/ppmp/170899","DOIUrl":"https://doi.org/10.37190/ppmp/170899","url":null,"abstract":"Lizardite slime coating is one of significant factors in the deterioration of the floatability of sulphide minerals. In this study, a nanoparticle cationic polystyrene-co-poly(n-butylacrylate)(PS-PBNH) collector was introduced to eliminate the negative impact of lizardite slimes in pyrite flotation. Microflotation results demonstrated that lizardite slims did not affect the recovery of pyrite in the presence of PS-PBNH. Good flotation separation of pyrite from lizardite was achieved when the nanoparticle PS-PBNH collector was used. The results from adsorption study indicated that PS-PBNH exhibited a significant adsorption on the pyrite surface in the presence of lizardite slimes. Sedimentation tests showed that hetero-aggregation occurred between lizardite slimes and pyrite, whereas the introduction of PS-PBNH collector resulted in a heterogeneous dispersion between them. Zeta potential measurements suggested that PS-PBNH collector interacted with pyrite surface, and the PS-PBNH adsorption changed the surface charge of pyrite from negative to be positive. As a result, the interaction of pyrite with lizardite shifted from electrostatic attraction to electrostatic repulsion, as supported by the DLVO calculations. These results indicated PS-PBNH can be used as a potential collector for pyrite flotation in pyrite/lizardite slimes system without the need for a depressant.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45592362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article aims to investigate in detail to what extent surfactants affect the determination of cadmium by anodic stripping voltammetry. In recent years, the production and use of surfactants have been steadily increasing, so that their concentration in environmental water samples is rising. At the same time, it is known that organic compounds, such as surfactants, often hinder the voltammetric determination of trace elements by stripping. Non-ionic (Triton X-100, Brij 35, Tween 20, Tween 60, Tween 80), cationic (CTAB, CTAC, DTAB, HPC) and anionic (DSS, SDS) compounds were selected to investigate the effect of surfactants on the voltammetric signal of cadmium. At the same time, the extent to which the addition of Amberlite resins to the analysed solution eliminates the interfering effect of surfactants was tested. Three types of Amberlite resins XAD-2, XAD-7 and XAD-16 were selected for the study and the ratio of resin weight to solution volume was determined. Finally, the determination of cadmium in surfactant-enriched environmental samples was carried out. The recoveries obtained between 95.5 and 107%, with RSD between 3.4 and 6.2%, confirm the validity and correctness of the proposed procedure All measurements were carried out by anodic stripping voltammetry using a CNTs/SGC electrode modified with a bismuth film as the working electrode.
{"title":"Investigation and elimination of surfactant-induced interferences in anodic stripping voltammetry for the determination of trace amounts of cadmium","authors":"M. Grabarczyk, C. Wardak, Agnieszka Wawruch","doi":"10.37190/ppmp/170717","DOIUrl":"https://doi.org/10.37190/ppmp/170717","url":null,"abstract":"This article aims to investigate in detail to what extent surfactants affect the determination of cadmium by anodic stripping voltammetry. In recent years, the production and use of surfactants have been steadily increasing, so that their concentration in environmental water samples is rising. At the same time, it is known that organic compounds, such as surfactants, often hinder the voltammetric determination of trace elements by stripping. Non-ionic (Triton X-100, Brij 35, Tween 20, Tween 60, Tween 80), cationic (CTAB, CTAC, DTAB, HPC) and anionic (DSS, SDS) compounds were selected to investigate the effect of surfactants on the voltammetric signal of cadmium. At the same time, the extent to which the addition of Amberlite resins to the analysed solution eliminates the interfering effect of surfactants was tested. Three types of Amberlite resins XAD-2, XAD-7 and XAD-16 were selected for the study and the ratio of resin weight to solution volume was determined. Finally, the determination of cadmium in surfactant-enriched environmental samples was carried out. The recoveries obtained between 95.5 and 107%, with RSD between 3.4 and 6.2%, confirm the validity and correctness of the proposed procedure All measurements were carried out by anodic stripping voltammetry using a CNTs/SGC electrode modified with a bismuth film as the working electrode.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41495118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chunfu Liu, Wei-Tong Wang, Han Wang, Chenyu Zhu, Bao Ren
To investigate the adsorption mechanism of quaternary ammonium salt on the α-quartz (001) sur-face, the adsorption models of hydrophobic modifiers 1231, 1431, 1631 and 1831 were constructed and simulated using the density functional theory (DFT). Results indicate that the adsorption energy of quaternary ammonium salt increases with the increase of carbon chain length, and the adsorption energy reaches the maximum at 18 carbon atoms; however, the adsorption capacity of 1631 is weak owing to the carbon chain deflection. Based on the Mulliken bond population analysis, reagent 1831 has the strongest interaction with α-quartz (001) surface compared with 1231, 1431 and 1631; and during the adsorption process, charge transfer and electrostatic attraction occur between the reagent and α-quartz (001) surface with similar degrees of charge transfer observed. This study emphasizes that electrostatic attraction plays a key role in the adsorption process, while the week hydrogen bonding plays a secondary role.
{"title":"Adsorption of quaternary ammonium salt hydrophobic modifiers on the α-quartz (001) surface: a density functional theory study","authors":"Chunfu Liu, Wei-Tong Wang, Han Wang, Chenyu Zhu, Bao Ren","doi":"10.37190/ppmp/170260","DOIUrl":"https://doi.org/10.37190/ppmp/170260","url":null,"abstract":"To investigate the adsorption mechanism of quaternary ammonium salt on the α-quartz (001) sur-face, the adsorption models of hydrophobic modifiers 1231, 1431, 1631 and 1831 were constructed and simulated using the density functional theory (DFT). Results indicate that the adsorption energy of quaternary ammonium salt increases with the increase of carbon chain length, and the adsorption energy reaches the maximum at 18 carbon atoms; however, the adsorption capacity of 1631 is weak owing to the carbon chain deflection. Based on the Mulliken bond population analysis, reagent 1831 has the strongest interaction with α-quartz (001) surface compared with 1231, 1431 and 1631; and during the adsorption process, charge transfer and electrostatic attraction occur between the reagent and α-quartz (001) surface with similar degrees of charge transfer observed. This study emphasizes that electrostatic attraction plays a key role in the adsorption process, while the week hydrogen bonding plays a secondary role.","PeriodicalId":49137,"journal":{"name":"Physicochemical Problems of Mineral Processing","volume":" ","pages":""},"PeriodicalIF":1.5,"publicationDate":"2023-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44817330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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