Pub Date : 2026-01-20DOI: 10.1016/j.mineng.2026.110084
Liu Xingyu , Wang Yunfan , Jiang Bozhao , Huang Renjie , Song Zhenguo , Luo Ximei
To address the challenges of low bubble-particle collision efficiency, particle agglomeration, turbulent flow fields, and issues related to mineral surface oxidation layers and slime coatings inherent in traditional flotation columns, this study established a COMSOL Multiphysics-based numerical model incorporating coupled pressure acoustics, acoustic streaming, and fluid dynamics multiphysics. Copper-sulfur separation experiments were concurrently conducted using a laboratory-scale unilateral ultrasonic flotation column. Numerical simulations and experimental results revealed that an ultrasonic frequency of 20 kHz significantly enhanced both cavitation effects and localized acoustic streaming compared to 40 kHz. This improvement increased concentrate recovery from 51.51% to 65.14% while maintaining concentrate grade, consequently raising Beneficiation efficiency from 4.42% to 5.51%. Strategic placement of the ultrasonic vibrator plate near the feed inlet demonstrated superior efficacy, effectively stabilizing the flow field and optimizing the processing of incoming mineral particles relative to alternative positions. Furthermore, ultrasonic treatment promoted flow field homogenization. Collectively, these findings serve as a critical theoretical foundation and provide robust experimental support for optimizing frequency selection and vibrator plate positioning in ultrasonically enhanced flotation column technology.
{"title":"Effects of low-frequency ultrasound on enhancing the recovery of secondary copper resources via column flotation and corresponding numerical simulation","authors":"Liu Xingyu , Wang Yunfan , Jiang Bozhao , Huang Renjie , Song Zhenguo , Luo Ximei","doi":"10.1016/j.mineng.2026.110084","DOIUrl":"10.1016/j.mineng.2026.110084","url":null,"abstract":"<div><div>To address the challenges of low bubble-particle collision efficiency, particle agglomeration, turbulent flow fields, and issues related to mineral surface oxidation layers and slime coatings inherent in traditional flotation columns, this study established a COMSOL Multiphysics-based numerical model incorporating coupled pressure acoustics, acoustic streaming, and fluid dynamics multiphysics. Copper-sulfur separation experiments were concurrently conducted using a laboratory-scale unilateral ultrasonic flotation column. Numerical simulations and experimental results revealed that an ultrasonic frequency of 20 kHz significantly enhanced both cavitation effects and localized acoustic streaming compared to 40 kHz. This improvement increased concentrate recovery from 51.51% to 65.14% while maintaining concentrate grade, consequently raising Beneficiation efficiency from 4.42% to 5.51%. Strategic placement of the ultrasonic vibrator plate near the feed inlet demonstrated superior efficacy, effectively stabilizing the flow field and optimizing the processing of incoming mineral particles relative to alternative positions. Furthermore, ultrasonic treatment promoted flow field homogenization. Collectively, these findings serve as a critical theoretical foundation and provide robust experimental support for optimizing frequency selection and vibrator plate positioning in ultrasonically enhanced flotation column technology.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110084"},"PeriodicalIF":5.0,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146006463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.mineng.2026.110105
Yusen Yu , Wenbo Li , Yongsheng Sun , Yuexin Han , Yanjun Li
In the context of the escalating exhaustion of high-grade iron ore, the efficient development and utilization of refractory iron ore such as high-phosphorus oolitic hematite (HPOH) have significant strategic significance. After optimizing the technical parameters of flotation and leaching processes, this study conducted a comparative study of dephosphorization processes and analyzed the mineralogical characteristics of the samples using X-ray diffraction (XRD), scanning electron microscopy (SEM), and mineral liberation analyzer (MLA). The research results indicate that flotation process can effectively remove P-bearing minerals in the form of apatite but not phosphorus present in P-bearing iron minerals, under the high-temperature pretreatment temperature of 750 °C and selected conditions, flotation process can produce a concentrate with 62.26 % TFe grade, 0.33 % P content, and 54.02 % TFe recovery rate; In contrast, leaching process can effectively remove phosphorus present in P-bearing minerals, reduce the phosphorus content in concentrate, under the same pretreatment temperature and selected conditions, leaching concentrate with 63.10 % Fe grade, 0.27 % P content, and 67.81 % TFe recovery rate can be obtained through the leaching process, outperforming flotation. When the pretreatment temperature was raised to 1050 °C, under the optimal process conditions, leaching process achieved an iron concentrate with 62.16 % TFe grade, 0.13 % P content, and 88.04 % TFe recovery rate. The P content meets the industrial practical standards for iron concentrates used in the China’s steel metallurgy industry (P content shall not exceed 0.2 %). This study provides a reference for the efficient development and utilization of HPOH.
{"title":"Comparison of dephosphorization processes for high-phosphorus oolitic hematite based on MLA mineralogical characteristic analysis","authors":"Yusen Yu , Wenbo Li , Yongsheng Sun , Yuexin Han , Yanjun Li","doi":"10.1016/j.mineng.2026.110105","DOIUrl":"10.1016/j.mineng.2026.110105","url":null,"abstract":"<div><div>In the context of the escalating exhaustion of high-grade iron ore, the efficient development and utilization of refractory iron ore such as high-phosphorus oolitic hematite (HPOH) have significant strategic significance. After optimizing the technical parameters of flotation and leaching processes, this study conducted a comparative study of dephosphorization processes and analyzed the mineralogical characteristics of the samples using X-ray diffraction (XRD), scanning electron microscopy (SEM), and mineral liberation analyzer (MLA). The research results indicate that flotation process can effectively remove P-bearing minerals in the form of apatite but not phosphorus present in P-bearing iron minerals, under the high-temperature pretreatment temperature of 750 °C and selected conditions, flotation process can produce a concentrate with 62.26 % TFe grade, 0.33 % P content, and 54.02 % TFe recovery rate; In contrast, leaching process can effectively remove phosphorus present in P-bearing minerals, reduce the phosphorus content in concentrate, under the same pretreatment temperature and selected conditions, leaching concentrate with 63.10 % Fe grade, 0.27 % P content, and 67.81 % TFe recovery rate can be obtained through the leaching process, outperforming flotation. When the pretreatment temperature was raised to 1050 °C, under the optimal process conditions, leaching process achieved an iron concentrate with 62.16 % TFe grade, 0.13 % P content, and 88.04 % TFe recovery rate. The P content meets the industrial practical standards for iron concentrates used in the China’s steel metallurgy industry (P content shall not exceed 0.2 %). This study provides a reference for the efficient development and utilization of HPOH.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110105"},"PeriodicalIF":5.0,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.mineng.2026.110073
Qianlong Li , Mamadou Fall
This study investigates the rheological properties of cemented paste backfill (CPB) incorporating high-volume slag and fly ash (FA) as sustainable substitutes for Portland cement type I (PCI). The research aims to enhance CPB flowability while maximizing the reuse of industrial byproducts. Rheological tests were conducted on CPB samples composed of silica tailings with varying PCI/slag/FA ratios to assess their effects on yield stress and viscosity. Using a central composite design and response surface methodology, mathematical models were developed to quantify and predict the relationships between rheological parameters and binder composition. Microstructural and monitoring analyses revealed that slag and FA influence CPB flowability through particle size, shape, and hydration characteristics. Results indicate that replacing up to 80 % of PCI with slag and FA reduces yield stress and viscosity by 4.2 %–21.7 % and 0.7 %–5.0 %, respectively, improving flowability for mine filling applications. However, excessive slag and FA contents (90 %) increase fine particle interactions, elevating yield stress and viscosity. Time-dependent rheological changes were observed, with yield stress and viscosity increasing by 40 %–66.7 % and 3.9 %–7.1 % during two hours of curing, driven by hydration product formation. The optimal binder ratio (10.15 % PCI, 20.3 % slag, and 79.7 % FA) achieves a desirable balance of low yield stress (137.4 Pa) and viscosity (2.91 Pa·s) with over 90 % industrial waste reutilization. This study provides a robust framework for optimizing CPB formulations, addressing key challenges in sustainable mining practices, and guiding the large-scale reuse of industrial wastes.
{"title":"Flow ability of cemented paste backfill with high-volume industrial wastes","authors":"Qianlong Li , Mamadou Fall","doi":"10.1016/j.mineng.2026.110073","DOIUrl":"10.1016/j.mineng.2026.110073","url":null,"abstract":"<div><div>This study investigates the rheological properties of cemented paste backfill (CPB) incorporating high-volume slag and fly ash (FA) as sustainable substitutes for Portland cement type I (PCI). The research aims to enhance CPB flowability while maximizing the reuse of industrial byproducts. Rheological tests were conducted on CPB samples composed of silica tailings with varying PCI/slag/FA ratios to assess their effects on yield stress and viscosity. Using a central composite design and response surface methodology, mathematical models were developed to quantify and predict the relationships between rheological parameters and binder composition. Microstructural and monitoring analyses revealed that slag and FA influence CPB flowability through particle size, shape, and hydration characteristics. Results indicate that replacing up to 80 % of PCI with slag and FA reduces yield stress and viscosity by 4.2 %–21.7 % and 0.7 %–5.0 %, respectively, improving flowability for mine filling applications. However, excessive slag and FA contents (90 %) increase fine particle interactions, elevating yield stress and viscosity. Time-dependent rheological changes were observed, with yield stress and viscosity increasing by 40 %–66.7 % and 3.9 %–7.1 % during two hours of curing, driven by hydration product formation. The optimal binder ratio (10.15 % PCI, 20.3 % slag, and 79.7 % FA) achieves a desirable balance of low yield stress (137.4 Pa) and viscosity (2.91 Pa·s) with over 90 % industrial waste reutilization. This study provides a robust framework for optimizing CPB formulations, addressing key challenges in sustainable mining practices, and guiding the large-scale reuse of industrial wastes.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110073"},"PeriodicalIF":5.0,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-20DOI: 10.1016/j.mineng.2026.110102
Yanling Jin , Haiyun Xie , Liuyang Dong , Peilun Shen , Chao Lv , Taiguo Jiang , Dianwen Liu
Copper and lead are essential non-ferrous metals widely used in construction, energy, transportation, electronics, and defense industries. Galena (PbS) and chalcopyrite (CuFeS2), the primary carrier minerals of copper-lead sulfide ores, commonly coexist in complex polymetallic deposits and are often intergrown at fine scales. Their similar surface physicochemical properties and the presence of surface oxidation products lead to poor flotation selectivity, resulting in mutual contamination of concentrates and low resource utilization efficiency. Flotation remains the most effective method for copper-lead separation, in which selective depression plays a decisive role. However, conventional inorganic depressants, such as chromates and cyanides, are increasingly restricted due to their high toxicity and environmental risks. In this review, the geological occurrence, crystal structures, and surface physicochemical characteristics of galena and chalcopyrite are systematically summarized. The interfacial mechanisms governing the flotation separation of galena and chalcopyrite are critically reviewed, with particular attention to the adsorption behavior, selectivity differences, and structure–activity relationships of collectors and depressants. The molecular structures, action modes, and structure–activity relationships of traditional and novel flotation reagents are classified and compared. Emphasis is placed on recent advances in green organic depressants, including small-molecule compounds, natural polymers, and synthetic polymers, as well as their selective regulation mechanisms in copper-lead flotation systems. In addition, the synergistic effects between collectors and depressants and their implications for improving selectivity are discussed. This review highlights that the rational design of environmentally friendly reagent systems and the integration of collector–depressant synergy are key to achieving efficient and sustainable flotation separation of complex copper-lead sulfide ores. The insights summarized herein aim to provide theoretical guidance and practical references for the development of green flotation reagents and the optimization of copper-lead separation processes.
{"title":"A review of research progress in the flotation separation of galena and chalcopyrite with a focus on green reagents","authors":"Yanling Jin , Haiyun Xie , Liuyang Dong , Peilun Shen , Chao Lv , Taiguo Jiang , Dianwen Liu","doi":"10.1016/j.mineng.2026.110102","DOIUrl":"10.1016/j.mineng.2026.110102","url":null,"abstract":"<div><div>Copper and lead are essential non-ferrous metals widely used in construction, energy, transportation, electronics, and defense industries. Galena (PbS) and chalcopyrite (CuFeS<sub>2</sub>), the primary carrier minerals of copper-lead sulfide ores, commonly coexist in complex polymetallic deposits and are often intergrown at fine scales. Their similar surface physicochemical properties and the presence of surface oxidation products lead to poor flotation selectivity, resulting in mutual contamination of concentrates and low resource utilization efficiency. Flotation remains the most effective method for copper-lead separation, in which selective depression plays a decisive role. However, conventional inorganic depressants, such as chromates and cyanides, are increasingly restricted due to their high toxicity and environmental risks. In this review, the geological occurrence, crystal structures, and surface physicochemical characteristics of galena and chalcopyrite are systematically summarized. The interfacial mechanisms governing the flotation separation of galena and chalcopyrite are critically reviewed, with particular attention to the adsorption behavior, selectivity differences, and structure–activity relationships of collectors and depressants. The molecular structures, action modes, and structure–activity relationships of traditional and novel flotation reagents are classified and compared. Emphasis is placed on recent advances in green organic depressants, including small-molecule compounds, natural polymers, and synthetic polymers, as well as their selective regulation mechanisms in copper-lead flotation systems. In addition, the synergistic effects between collectors and depressants and their implications for improving selectivity are discussed. This review highlights that the rational design of environmentally friendly reagent systems and the integration of collector–depressant synergy are key to achieving efficient and sustainable flotation separation of complex copper-lead sulfide ores. The insights summarized herein aim to provide theoretical guidance and practical references for the development of green flotation reagents and the optimization of copper-lead separation processes.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110102"},"PeriodicalIF":5.0,"publicationDate":"2026-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146014878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-19DOI: 10.1016/j.mineng.2026.110076
Jonathan Rincon , Nils Jansson , Yousef Ghorbani , Iris McElroy , Helen Thomas , Dominique Brising , Nils-Johan Bolin , Christina Wanhainen
The grinding and flotation performance of Zn-Pb-Cu-Ag ores is highly sensitive to ore mineralogy, host rock composition, and textural variability, factors that are often overlooked in favour of bulk grade values. This study examines the Rävliden North Zn-Cu-Pb-Ag volcanogenic massive sulphide deposit (VMS) deposit in northern Sweden. Two main ore types are identified: massive sphalerite- and galena-rich ore and chalcopyrite-rich vein-dominated ore that coupled with host rock type led to further 6 sub-types. Mineralogical and textural characterisation of flotation feed and products, using Quantitative Evaluation of Minerals by Scanning Electron Microscopy (QEMSCAN®) and element to mineral conversion (EMC) based on multi-element chemical assays, reveals that fine-grained, sphalerite-dominated ore is more amenable to grinding and exhibit better liberation, enhancing flotation efficiency. In contrast, chalcopyrite-rich ore perform better in Cu-Pb flotation but is harder to grind due to its silicate-rich gangue (e.g., quartz). Minerals such as micas, amphiboles, and carbonates affect ore hardness, and ore mineralogy (sphalerite, galena, chalcopyrite and Ag mineralogy) directly affects flotation efficiency. Blending of poor grade and hard to grind (problematic) ores with better grade and softer to grind (fairly good to good) ore is recommended to improve concentrate quality. Precious, critical, and deleterious elements are mostly recovered in the chalcopyrite-galena flotation circuit in amalgams (Ag, Hg), dyscrasite (Ag, Sb), hessite (Ag), sulphosalts (Ag, Sb, Bi), native Bi, and tellurobismuthite (Bi). These minerals are fine-grained (< 20 µm) and poorly liberated, leading to recovery in both target and non-target flotation concentrates. Nevertheless, established metallurgical methods enable their efficient extraction maximising ore value. This study highlights the importance of process mineralogy for improved beneficiation in concentration circuits, and the understanding of by-products during processing of complex polymetallic ores.
{"title":"The role of ore and host rock mineralogy in the beneficiation of a VMS deposit: Insights from Rävliden North, northern Sweden","authors":"Jonathan Rincon , Nils Jansson , Yousef Ghorbani , Iris McElroy , Helen Thomas , Dominique Brising , Nils-Johan Bolin , Christina Wanhainen","doi":"10.1016/j.mineng.2026.110076","DOIUrl":"10.1016/j.mineng.2026.110076","url":null,"abstract":"<div><div>The grinding and flotation performance of Zn-Pb-Cu-Ag ores is highly sensitive to ore mineralogy, host rock composition, and textural variability, factors that are often overlooked in favour of bulk grade values. This study examines the Rävliden North Zn-Cu-Pb-Ag volcanogenic massive sulphide deposit (VMS) deposit in northern Sweden. Two main ore types are identified: massive sphalerite- and galena-rich ore and chalcopyrite-rich vein-dominated ore that coupled with host rock type led to further 6 sub-types. Mineralogical and textural characterisation of flotation feed and products, using Quantitative Evaluation of Minerals by Scanning Electron Microscopy (QEMSCAN®) and element to mineral conversion (EMC) based on multi-element chemical assays, reveals that fine-grained, sphalerite-dominated ore is more amenable to grinding and exhibit better liberation, enhancing flotation efficiency. In contrast, chalcopyrite-rich ore perform better in Cu-Pb flotation but is harder to grind due to its silicate-rich gangue (e.g., quartz). Minerals such as micas, amphiboles, and carbonates affect ore hardness, and ore mineralogy (sphalerite, galena, chalcopyrite and Ag mineralogy) directly affects flotation efficiency. Blending of poor grade and hard to grind (problematic) ores with better grade and softer to grind (fairly good to good) ore is recommended to improve concentrate quality. Precious, critical, and deleterious elements are mostly recovered in the chalcopyrite-galena flotation circuit in amalgams (Ag, Hg), dyscrasite (Ag, Sb), hessite (Ag), sulphosalts (Ag, Sb, Bi), native Bi, and tellurobismuthite (Bi). These minerals are fine-grained (< 20 µm) and poorly liberated, leading to recovery in both target and non-target flotation concentrates. Nevertheless, established metallurgical methods enable their efficient extraction maximising ore value. This study highlights the importance of process mineralogy for improved beneficiation in concentration circuits, and the understanding of by-products during processing of complex polymetallic ores.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110076"},"PeriodicalIF":5.0,"publicationDate":"2026-01-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146000593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-17DOI: 10.1016/j.mineng.2026.110083
Ruofeng Wang , Shuai Yuan , Jiangang Ku , Qinglong Fan , Yanjun Li
This study systematically investigates the hydrogen-based mineral phase transformation behavior of iron-bearing manganese ore, with particular emphasis on the reduction characteristics of hematite and pyrolusite. One-factor reduction experiments reveal that increasing roasting temperature and reduction time significantly enhance the reduction efficiency of both iron and manganese oxides. Hematite exhibits a temperature-dependent reduction pathway from Fe2O3 to Fe or via FeO at elevated temperatures, whereas pyrolusite undergoes stepwise reduction from MnO2 to MnO. In mixed ore systems, magnetite or ferrous oxide formed during the hematite reduction process promotes the reduction of high-valence manganese oxides, resulting in a higher Mn2+ distribution rate than that obtained in individual pyrolusite reduction. These results demonstrate that the reduction behavior of iron-bearing manganese ore cannot be interpreted as a simple superposition of single-mineral systems.
{"title":"Mechanistic insights into the hydrogen-based phase transformation processes of iron-bearing manganese ores","authors":"Ruofeng Wang , Shuai Yuan , Jiangang Ku , Qinglong Fan , Yanjun Li","doi":"10.1016/j.mineng.2026.110083","DOIUrl":"10.1016/j.mineng.2026.110083","url":null,"abstract":"<div><div>This study systematically investigates the hydrogen-based mineral phase transformation behavior of iron-bearing manganese ore, with particular emphasis on the reduction characteristics of hematite and pyrolusite. One-factor reduction experiments reveal that increasing roasting temperature and reduction time significantly enhance the reduction efficiency of both iron and manganese oxides. Hematite exhibits a temperature-dependent reduction pathway from Fe<sub>2</sub>O<sub>3</sub> to Fe or via FeO at elevated temperatures, whereas pyrolusite undergoes stepwise reduction from MnO<sub>2</sub> to MnO. In mixed ore systems, magnetite or ferrous oxide formed during the hematite reduction process promotes the reduction of high-valence manganese oxides, resulting in a higher Mn<sup>2+</sup> distribution rate than that obtained in individual pyrolusite reduction. These results demonstrate that the reduction behavior of iron-bearing manganese ore cannot be interpreted as a simple superposition of single-mineral systems.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110083"},"PeriodicalIF":5.0,"publicationDate":"2026-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145995456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.mineng.2026.110086
Johan Lindqvist , Khalid Atta , J. Derik le Roux , Andreas Johansson
A control-oriented Gaussian process regression (GPR) model of froth flotation is developed and compared to a previously developed parametric model. The model aims to predict the behaviour of froth flotation, taking into consideration which state variables are available from measurements: air recovery, top of froth bubble size, and pulp level. The framework encodes prior knowledge of a published flotation model. Each state is modelled using a separate GP, with a custom covariance function whose form is given by the flotation model. These kernels capture the interaction between the relevant state variables and manipulated variables. The model aims to balance the complexity required to explain such a complex process with the uncertainty of its instrumentation. To evaluate the ability of the GPR model to capture the process dynamics, the GP model is assessed using an industrial data set, demonstrating its capacity to improve the performance of state prediction. The purpose of the GPR model is to enable supervisory and advanced model-based control.
{"title":"Gaussian process modelling of an industrial flotation bank","authors":"Johan Lindqvist , Khalid Atta , J. Derik le Roux , Andreas Johansson","doi":"10.1016/j.mineng.2026.110086","DOIUrl":"10.1016/j.mineng.2026.110086","url":null,"abstract":"<div><div>A control-oriented Gaussian process regression (GPR) model of froth flotation is developed and compared to a previously developed parametric model. The model aims to predict the behaviour of froth flotation, taking into consideration which state variables are available from measurements: air recovery, top of froth bubble size, and pulp level. The framework encodes prior knowledge of a published flotation model. Each state is modelled using a separate GP, with a custom covariance function whose form is given by the flotation model. These kernels capture the interaction between the relevant state variables and manipulated variables. The model aims to balance the complexity required to explain such a complex process with the uncertainty of its instrumentation. To evaluate the ability of the GPR model to capture the process dynamics, the GP model is assessed using an industrial data set, demonstrating its capacity to improve the performance of state prediction. The purpose of the GPR model is to enable supervisory and advanced model-based control.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110086"},"PeriodicalIF":5.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-16DOI: 10.1016/j.mineng.2026.110082
S. Al-Thyabat , H. Al-Zoubi , B. Albiss
Phosphorite is a non-renewable source of elemental phosphorus, an indispensable constituent of phosphate-based fertilizers. For low grade phosphorite ores, froth flotation is the most widely used upgrading technique. However, flotation collectors’ low performance and deteriorating selectivity in the presence of fine phosphorite increased interest in new types of nanoparticles −based collectors.
Carboxyl-functionalized polystyrene nanoparticles (FPSNPs) were synthesized by emulsion polymerization and evaluated as a replacement for the traditional sodium oleate (NaOL) collector. Nanoparticles characterization, adsorption isotherms, and flotation performance were evaluated by SEM, dynamic light scattering (DLS), FT-IR, and Uv–vis spectroscopy. Four adsorption isothermal models were used to compare the adsorption of FPSNPs and NaOL collector on phosphorite particle surface.
It was found that FPSNPs were positively charged with average size of 29 nm. Both FPSNPs and NaOL were physically adsorbed on phosphorite surface as a multilayer by either electrostatic interaction or precipitation. However, the maximum adsorption density of FPSNPs was higher than NaOL, indicating thicker layer of FPSNPs collector. This may be due to stronger interaction (i.e. more selectivity) between FPSNPs and Ca+2 sites on both of phosphorite surface and those dissolved in the flotation pulp. On the other hand, flotation results showed that silica removal by FPSNPs was about 80 % compared with 58 % with NaOL., while the concentrate grade was 32.7 % P2O5 when 2010 g/tonne of FPSNPs collector was used. These findings contribute to our understanding of the mechanisms of nanoparticles −based collectors which facilitate the development of more efficient and environmentally friendly phosphorite collectors.
{"title":"Carboxyl-functionalized polystyrene nanoparticles as flotation collectors for siliceous phosphorite","authors":"S. Al-Thyabat , H. Al-Zoubi , B. Albiss","doi":"10.1016/j.mineng.2026.110082","DOIUrl":"10.1016/j.mineng.2026.110082","url":null,"abstract":"<div><div>Phosphorite is a non-renewable source of elemental phosphorus, an indispensable constituent of phosphate-based fertilizers. For low grade phosphorite ores, froth flotation is the most widely used upgrading technique. However, flotation collectors’ low performance and deteriorating selectivity in the presence of fine phosphorite increased interest in new types of nanoparticles −based collectors.</div><div>Carboxyl-functionalized polystyrene nanoparticles (FPSNPs) were synthesized by emulsion polymerization and evaluated as a replacement for the traditional sodium oleate (NaOL) collector. Nanoparticles characterization, adsorption isotherms, and flotation performance were evaluated by SEM, dynamic light scattering (DLS), FT-IR, and Uv–vis spectroscopy. Four adsorption isothermal models were used to compare the adsorption of FPSNPs and NaOL collector on phosphorite particle surface.</div><div>It was found that FPSNPs were positively charged with average size of 29 nm. Both FPSNPs and NaOL were physically adsorbed on phosphorite surface as a multilayer by either electrostatic interaction or precipitation. However, the maximum adsorption density of FPSNPs was higher than NaOL, indicating thicker layer of FPSNPs collector. This may be due to stronger interaction (i.e. more selectivity) between FPSNPs and Ca<sup>+2</sup> sites on both of phosphorite surface and those dissolved in the flotation pulp. On the other hand, flotation results showed that silica removal by FPSNPs was about 80 % compared with 58 % with NaOL., while the concentrate grade was 32.7 % P<sub>2</sub>O<sub>5</sub> when 2010 g/tonne of FPSNPs collector was used. These findings contribute to our understanding of the mechanisms of nanoparticles −based collectors which facilitate the development of more efficient and environmentally friendly phosphorite collectors.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110082"},"PeriodicalIF":5.0,"publicationDate":"2026-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145981985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2026-01-15DOI: 10.1016/j.mineng.2026.110074
Qiya Bian , Sha Deng , Wei Yang , Tao Long , Sirui Chen , Chuntao Yan , Yuran Wang , Qubing Li
The critical role of cobalt in renewable energy and advanced industries makes developing efficient recovery technologies from secondary resources an imperative. This study systematically investigates the bioleaching of Co-bearing sulfide tailings by Acidithiobacillus ferrooxidans under variable parameters, including pulp density, temperature, initial pH, and bacterial inoculum concentration. Under the condition of 8 % pulp density, 35 °C, an initial pH of 2.0, and an inoculum concentration of 2.5 × 107 cells/mL, 44.53 % of cobalt extraction was obtained. Mineral morphology and phase evolution analyses, consistent with the kinetic fitting results based on the shrinking-core model, revealed that during the bacterial lag phase (0–5 days), pyrrhotite dissolved preferentially, and cobalt leaching was controlled by surface chemical reactions. Extensive pyrite dissolution occurred in the log-stationary phase (5–27 days), but jarosite precipitates formed a passivation layer that hindered cobalt release. Consequently, cobalt leaching shifted to diffusion control through the product layer. Meanwhile, H+ released during bacterial oxidation and jarosite formation drove extensive vermiculite dissolution. Elevated temperatures accelerated the oxidation of elemental sulfur and increased the solution acidity. This enhanced the breakdown of lepidocrocite and suppressed jarosite generation, thereby favoring cobalt leaching mechanisms, although the leaching efficiency decreased at 45 °C. These findings advance theoretical frameworks and provide fundamental principles for processing Co-bearing sulfide tailings/concentrates.
{"title":"Bioleaching of Co-bearing sulfide tailings by Acidithiobacillus ferrooxidans: Influencing factors, mechanism and kinetics","authors":"Qiya Bian , Sha Deng , Wei Yang , Tao Long , Sirui Chen , Chuntao Yan , Yuran Wang , Qubing Li","doi":"10.1016/j.mineng.2026.110074","DOIUrl":"10.1016/j.mineng.2026.110074","url":null,"abstract":"<div><div>The critical role of cobalt in renewable energy and advanced industries makes developing efficient recovery technologies from secondary resources an imperative. This study systematically investigates the bioleaching of Co-bearing sulfide tailings by <em>Acidithiobacillus ferrooxidans</em> under variable parameters, including pulp density, temperature, initial pH, and bacterial inoculum concentration. Under the condition of 8 % pulp density, 35 °C, an initial pH of 2.0, and an inoculum concentration of 2.5 × 10<sup>7</sup> cells/mL, 44.53 % of cobalt extraction was obtained. Mineral morphology and phase evolution analyses, consistent with the kinetic fitting results based on the shrinking-core model, revealed that during the bacterial lag phase (0–5 days), pyrrhotite dissolved preferentially, and cobalt leaching was controlled by surface chemical reactions. Extensive pyrite dissolution occurred in the log-stationary phase (5–27 days), but jarosite precipitates formed a passivation layer that hindered cobalt release. Consequently, cobalt leaching shifted to diffusion control through the product layer. Meanwhile, H<sup>+</sup> released during bacterial oxidation and jarosite formation drove extensive vermiculite dissolution. Elevated temperatures accelerated the oxidation of elemental sulfur and increased the solution acidity. This enhanced the breakdown of lepidocrocite and suppressed jarosite generation, thereby favoring cobalt leaching mechanisms, although the leaching efficiency decreased at 45 °C. These findings advance theoretical frameworks and provide fundamental principles for processing Co-bearing sulfide tailings/concentrates.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"239 ","pages":"Article 110074"},"PeriodicalIF":5.0,"publicationDate":"2026-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145969258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Under a dispersed system of cetylpyridinium bromide, selective flocculation mechanism of sodium oleate (NaOL) in flotation separation of cassiterite and calcite were investigated by micro-flotation experiments, turbidity measurements, particle size distribution analysis, contact angle measurements, zeta potentials measurements, infrared spectrum analysis and extended Derjaguin-Landau-Verwey-Overbeek (DLVO) calculation in this study. Compared with conventional flocculants, micro-flotation results demonstrated that addition of NaOL significantly enhanced the flotation separation between cassiterite and calcite. Results of turbidity tests and particle size distribution showed that NaOL effectively reduced the suspension turbidity and increased the particle size of minerals. Moreover, the addition of NaOL increased contact angle of cassiterite, improving the hydrophobicity of cassiterite. Zeta potentials measurements proved that the surfaces of cassiterite and calcite had positive surface charges after interaction with NaOL at pH values below 10.45. Infrared spectrum analysis demonstrated that NaOL acted on the surface of cassiterite and calcite in the form of chemisorption. Extended DLVO theory proved that the addition of NaOL reduced the electrostatic repulsion between cassiterite particles and enhanced hydrophobic attraction, leading to the mutual aggregation between cassiterite particles. The selective flocculation of NaOL facilitated the efficient separation of fine-grained cassiterite and calcite.
{"title":"Selective flocculation mechanism of sodium oleate in flotation separation of cassiterite and calcite with cetylpyridinium bromide as a dispersant","authors":"Jinfang Lv , Chunli Zhang , Jinwen Li , Haiyu Qian","doi":"10.1016/j.mineng.2026.110079","DOIUrl":"10.1016/j.mineng.2026.110079","url":null,"abstract":"<div><div>Under a dispersed system of cetylpyridinium bromide, selective flocculation mechanism of sodium oleate (NaOL) in flotation separation of cassiterite and calcite were investigated by micro-flotation experiments, turbidity measurements, particle size distribution analysis, contact angle measurements, zeta potentials measurements, infrared spectrum analysis and extended Derjaguin-Landau-Verwey-Overbeek (DLVO) calculation in this study. Compared with conventional flocculants, micro-flotation results demonstrated that addition of NaOL significantly enhanced the flotation separation between cassiterite and calcite. Results of turbidity tests and particle size distribution showed that NaOL effectively reduced the suspension turbidity and increased the particle size of minerals. Moreover, the addition of NaOL increased contact angle of cassiterite, improving the hydrophobicity of cassiterite. Zeta potentials measurements proved that the surfaces of cassiterite and calcite had positive surface charges after interaction with NaOL at pH values below 10.45. Infrared spectrum analysis demonstrated that NaOL acted on the surface of cassiterite and calcite in the form of chemisorption. Extended DLVO theory proved that the addition of NaOL reduced the electrostatic repulsion between cassiterite particles and enhanced hydrophobic attraction, leading to the mutual aggregation between cassiterite particles. The selective flocculation of NaOL facilitated the efficient separation of fine-grained cassiterite and calcite.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"238 ","pages":"Article 110079"},"PeriodicalIF":5.0,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145962552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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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