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}
Pub Date : 2026-01-14DOI: 10.1016/j.mineng.2026.110062
Xin Wang, Lei Sun, Zhiyong Gao, Yang Cao, Wei Sun, Miaoxiang Ai, Qiqiang Lin, Yi Qiao
The Discrete Element Method (DEM) is widely applied to analyze the mechanical behavior and breakage characteristics of ores and rock-like materials. The accuracy of DEM simulations, however, depends critically on the proper calibration of model parameters. In this study, a systematic calibration framework for copper ore was developed by combining laboratory testing, numerical simulations, and a response surface methodology based on the angle of repose (AoR). The calibrated parameter set includes both the fundamental physical properties required for the DEM contact model and the key parameters used in constructing Bonded-Particle Models (BPM) and Particle Replacement Models (PRM). Validation through uniaxial compression and single-particle impact tests confirms that the calibrated parameters accurately captured the material’s strength and fragmentation behavior. The results indicated that the proposed calibration approach yields consistent parameters and is suitable for modeling copper ore comminution. This framework provides a practical reference for subsequent research and engineering applications in mineral processing.
{"title":"Systematic DEM parameter calibration for copper ore crushing","authors":"Xin Wang, Lei Sun, Zhiyong Gao, Yang Cao, Wei Sun, Miaoxiang Ai, Qiqiang Lin, Yi Qiao","doi":"10.1016/j.mineng.2026.110062","DOIUrl":"10.1016/j.mineng.2026.110062","url":null,"abstract":"<div><div>The Discrete Element Method (DEM) is widely applied to analyze the mechanical behavior and breakage characteristics of ores and rock-like materials. The accuracy of DEM simulations, however, depends critically on the proper calibration of model parameters. In this study, a systematic calibration framework for copper ore was developed by combining laboratory testing, numerical simulations, and a response surface methodology based on the angle of repose (AoR). The calibrated parameter set includes both the fundamental physical properties required for the DEM contact model and the key parameters used in constructing Bonded-Particle Models (BPM) and Particle Replacement Models (PRM). Validation through uniaxial compression and single-particle impact tests confirms that the calibrated parameters accurately captured the material’s strength and fragmentation behavior. The results indicated that the proposed calibration approach yields consistent parameters and is suitable for modeling copper ore comminution. This framework provides a practical reference for subsequent research and engineering applications in mineral processing.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"238 ","pages":"Article 110062"},"PeriodicalIF":5.0,"publicationDate":"2026-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145979335","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 : 2026-01-12DOI: 10.1016/j.mineng.2026.110063
Maoyuan Wang , Wenbo Li , Yuexin Han , Xiaolong Zhang , Shumin Zhang
The efficient separation of fine-grained bastnaesite–monazite intergrowths remains a persistent challenge in the beneficiation of mixed rare-earth ores. In this study, we integrate micro-flotation with surface spectroscopy (FT-IR/XPS) and density functional theory (DFT) calculations to elucidate reagent–mineral interactions and to develop a selective flotation regime. Phthalic acid (PA) is identified as an effective selective collector, exhibiting substantially stronger interaction with bastnaesite than with monazite. Under weakly acidic conditions (pH ≈ 6.0) with aluminum sulfate as a conditioning reagent, closed-circuit flotation yields a bastnaesite concentrate grading 67.42 % REO at 89.15 % REO recovery, corresponding to ∼90.01 % bastnaesite purity. These results establish practical operating parameters for selective bastnaesite flotation from monazite and provide mechanistically informed guidance for collector selection in complex rare-earth flotation systems.
{"title":"From molecular adsorption to process design: selective flotation of bastnaesite and monazite with phthalic acid as collector","authors":"Maoyuan Wang , Wenbo Li , Yuexin Han , Xiaolong Zhang , Shumin Zhang","doi":"10.1016/j.mineng.2026.110063","DOIUrl":"10.1016/j.mineng.2026.110063","url":null,"abstract":"<div><div>The efficient separation of fine-grained bastnaesite–monazite intergrowths remains a persistent challenge in the beneficiation of mixed rare-earth ores. In this study, we integrate micro-flotation with surface spectroscopy (FT-IR/XPS) and density functional theory (DFT) calculations to elucidate reagent–mineral interactions and to develop a selective flotation regime. Phthalic acid (PA) is identified as an effective selective collector, exhibiting substantially stronger interaction with bastnaesite than with monazite. Under weakly acidic conditions (pH ≈ 6.0) with aluminum sulfate as a conditioning reagent, closed-circuit flotation yields a bastnaesite concentrate grading 67.42 % REO at 89.15 % REO recovery, corresponding to ∼90.01 % bastnaesite purity. These results establish practical operating parameters for selective bastnaesite flotation from monazite and provide mechanistically informed guidance for collector selection in complex rare-earth flotation systems.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"238 ","pages":"Article 110063"},"PeriodicalIF":5.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145957138","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 : 2026-01-12DOI: 10.1016/j.mineng.2026.110071
Sayed Janishar Anzoom, Ghislain Bournival, Seher Ata
In a fluidized-bed flotation system, hydrophobic particles are often buoyed in the pulp phase as bubble clusters. However, the impact of these clusters on the flotation process is not thoroughly understood due to a lack of characterization techniques to study their properties. A technique for studying the properties of clusters using micro-computed tomography (micro-CT) was established with single mineral particles (Anzoom et al., 2024). This study aims to extend this approach to real ores, such as copper ore, where the particles consist of different minerals, to gain a more comprehensive understanding of the properties of bubble clusters. The approach integrates micro-CT, X-ray, diffraction (XRD) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) to perform three-dimensional quantitative characterization of bubble clusters and visualize the internal structure and distribution of different mineral phases present in the particles. Two methods were used to generate clusters: one involving a hand-shaking experiment and another using a fluidised-bed flotation system. Results revealed that cluster characteristics vary depending on their formation method and the particle size distribution. Particle-particle aggregation was more pronounced in the cluster formed using the hand-shaking experiment. The hydrophobic chalcopyrite mineral phase was observed attaching to bubbles, while gangue minerals were engulfed within particles transported by the bubble clusters. While this study focuses on copper ore, which contains a high concentration of chalcopyrite, the method is applicable to studying bubble clusters with any mineral particles.
在流化床浮选系统中，疏水颗粒通常以气泡团簇的形式浮在矿浆相中。然而，由于缺乏表征技术来研究其性质，这些团簇对浮选过程的影响尚未完全了解。一种利用微计算机断层扫描（micro-CT）研究单个矿物颗粒簇性质的技术被建立起来（Anzoom et al., 2024）。本研究旨在将这种方法扩展到真实的矿石，如铜矿石，其中颗粒由不同的矿物组成，以获得对气泡团簇性质的更全面的了解。该方法将微ct、x射线、衍射（XRD）、扫描电子显微镜与能量色散x射线能谱（SEM-EDS）相结合，对气泡团簇进行三维定量表征，并可视化颗粒中不同矿物相的内部结构和分布。研究人员使用了两种方法来生成簇：一种是握手实验，另一种是流化床浮选系统。结果表明，聚类特征随其形成方式和粒径分布的不同而不同。在握手实验形成的团簇中，粒子-粒子聚集更为明显。观察到疏水黄铜矿矿物相附着在气泡上，而脉石矿物被气泡团运输的颗粒吞没。该方法适用于任何矿物颗粒的气泡团簇研究，但研究对象为铜矿石，其中黄铜矿含量较高。
{"title":"Micro-CT imaging of bubble clusters: Extending single mineral observations to a real ore system","authors":"Sayed Janishar Anzoom, Ghislain Bournival, Seher Ata","doi":"10.1016/j.mineng.2026.110071","DOIUrl":"10.1016/j.mineng.2026.110071","url":null,"abstract":"<div><div>In a fluidized-bed flotation system, hydrophobic particles are often buoyed in the pulp phase as bubble clusters. However, the impact of these clusters on the flotation process is not thoroughly understood due to a lack of characterization techniques to study their properties. A technique for studying the properties of clusters using micro-computed tomography (micro-CT) was established with single mineral particles (<span><span>Anzoom et al., 2024</span></span>). This study aims to extend this approach to real ores, such as copper ore, where the particles consist of different minerals, to gain a more comprehensive understanding of the properties of bubble clusters. The approach integrates micro-CT, X-ray, diffraction (XRD) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) to perform three-dimensional quantitative characterization of bubble clusters and visualize the internal structure and distribution of different mineral phases present in the particles. Two methods were used to generate clusters: one involving a hand-shaking experiment and another using a fluidised-bed flotation system. Results revealed that cluster characteristics vary depending on their formation method and the particle size distribution. Particle-particle aggregation was more pronounced in the cluster formed using the hand-shaking experiment. The hydrophobic chalcopyrite mineral phase was observed attaching to bubbles, while gangue minerals were engulfed within particles transported by the bubble clusters. While this study focuses on copper ore, which contains a high concentration of chalcopyrite, the method is applicable to studying bubble clusters with any mineral particles.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"238 ","pages":"Article 110071"},"PeriodicalIF":5.0,"publicationDate":"2026-01-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145957137","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 : 2026-01-09DOI: 10.1016/j.mineng.2026.110070
Song Wang , Yanhong Fu , Yandaizi Zhou , Liang Dong , Tielin Wang , Dongsheng He
In gas–solid fluidized beds, distributor-governed bubble dynamics critically govern system efficiency and particle separation. However, traditional bubble identification methods based on thresholding and edge detection often struggle with accuracy due to their reliance on low-level image features. This study applies deep learning-based image semantic segmentation to quantitatively analyze bubble distribution and evolution in gas–solid fluidized beds equipped with conventional perforated distributors (CPD) or micro-orifice distributors (MOD). The deep learning method used in this study achieved 98.40% pixel accuracy and 83.92% Mean Intersection over Union (MIoU) in bubble image segmentation. Experimental results showed that MOD reduced average bubble diameter by 36–55% and lowered bed density standard deviation by 60.76% compared to CPD fluidized beds. Analysis of bubble coalescence mechanisms indicates that MOD suppresses coalescence rates through high-density micro-jetting flows, significantly improving bed density stability. Time-domain and frequency-domain analyses of bed pressure drop signals reveals that the MOD fluidized bed exhibits weaker periodic oscillations at the influence of small bubbles. The minimum standard deviation of bed density reached 0.031 g/cm3, compared to 0.079 g/cm3 for the CPD fluidized bed. A region-specific bubble growth model was developed by introducing parameter k corrections to traditional models, distinguishing between the near-distributor and upper bed regions, with prediction errors within 30%. These results provide a theoretical basis for the zonal optimization of gas–solid separation fluidized beds.
在气固流化床中，分布器控制的气泡动力学对系统效率和颗粒分离起着关键的控制作用。然而，传统的基于阈值和边缘检测的气泡识别方法由于依赖于低层次的图像特征，往往难以准确识别。本研究采用基于深度学习的图像语义分割方法，定量分析了传统穿孔分布器（CPD）和微孔分布器（MOD）气固流化床中气泡的分布和演化。本研究使用的深度学习方法在气泡图像分割中，像素精度达到98.40%,MIoU （Mean Intersection over Union）达到83.92%。实验结果表明，与CPD流化床相比，MOD可使平均气泡直径减小36-55%，使床层密度标准差降低60.76%。气泡聚结机理分析表明，MOD通过高密度微喷流抑制了气泡聚结速率，显著提高了床层密度稳定性。对床层压降信号的时域和频域分析表明，在小气泡影响下，MOD流化床表现出较弱的周期振荡。床层密度的最小标准偏差达到0.031 g/cm3，而CPD流化床的最小标准偏差为0.079 g/cm3。通过对传统模型引入参数k校正，建立了区域性气泡生长模型，区分了近分布区和上层区，预测误差在30%以内。研究结果为气固分离流化床分区优化提供了理论依据。
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An efficient, low-impact technology is needed to recover rare earth elements (REEs) from the environment. We previously showed that phosphorylated yeast (P-yeast) effectively adsorbs REEs in acidic solutions. This study evaluates P-yeast for REE recovery from Tsukahara hot spring water, which has high mineral ion concentrations. This hot spring water contains higher levels of base metals and REEs than others. By adjusting the pH, we achieved nearly 100 % removal of Al and Fe, leaving 43 %–67 % of REEs in the supernatant. Remarkably, P-yeast adsorbed almost all REEs, with an Mg adsorption ratio of about 8.6 %, while removing Mg effectively. REEs were desorbed using 1.0 M HCl, achieving a 31 % recovery ratio after three desorption cycles for all seven REEs. Overall, P-yeast is an effective method for REE recovery, showcasing the potential of biosorbents.
从环境中回收稀土元素需要一种高效、低影响的技术。我们之前发现磷酸化酵母（p -酵母）在酸性溶液中有效吸附稀土。本研究评价了p -酵母菌对高矿质离子含量的土原温泉水中稀土元素的回收效果。这里的温泉比其他温泉含有更多的基本金属和稀土元素。通过调整pH，我们实现了几乎100%的Al和Fe的去除，在上清中留下43% - 67%的ree。p -酵母菌对稀土元素几乎全部吸附，对Mg的吸附率约为8.6%，对Mg的去除效果较好。用1.0 M HCl解吸7种稀土元素，经过3个解吸循环，7种稀土元素的回收率均达到31%。综上所述，p -酵母是一种有效的稀土回收方法，显示了生物吸附剂的潜力。
{"title":"Recovery of rare earth elements using phosphorylated yeast: A practical application from mineral ion-rich Tsukahara hot spring water","authors":"Maya Kihara, Moena Amano, Yoshihiro Ojima, Koichi Igarashi, Masayuki Azuma","doi":"10.1016/j.mineng.2026.110061","DOIUrl":"10.1016/j.mineng.2026.110061","url":null,"abstract":"<div><div>An efficient, low-impact technology is needed to recover rare earth elements (REEs) from the environment. We previously showed that phosphorylated yeast (P-yeast) effectively adsorbs REEs in acidic solutions. This study evaluates P-yeast for REE recovery from Tsukahara hot spring water, which has high mineral ion concentrations. This hot spring water contains higher levels of base metals and REEs than others. By adjusting the pH, we achieved nearly 100 % removal of Al and Fe, leaving 43 %–67 % of REEs in the supernatant. Remarkably, P-yeast adsorbed almost all REEs, with an Mg adsorption ratio of about 8.6 %, while removing Mg effectively. REEs were desorbed using 1.0 M HCl, achieving a 31 % recovery ratio after three desorption cycles for all seven REEs. Overall, P-yeast is an effective method for REE recovery, showcasing the potential of biosorbents.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"238 ","pages":"Article 110061"},"PeriodicalIF":5.0,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940748","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 : 2026-01-09DOI: 10.1016/j.mineng.2025.110050
Shiqi Zhang , Hongying Yang , Linlin Tong , Zhenan Jin , Pengcheng Ma
The bio-oxidation of refractory gold concentrates with high arsenic and sulfur contents is inefficient, due to its slow reaction kinetics and the arsenic toxicity. To address this limitation, present study proposed a novel strategy involving ferric (Fe3+) pre-oxidation synergistically combined with the simultaneous addition of hydrolyzed rice husk (HRH) and urea. Chemical and interfacial analyses revealed that ferric oxidation removed 13.4 ± 1.4 % of arsenic (As) from the concentrate and disrupted the physicochemical structures of mineral surfaces (pyrite and arsenopyrite), thereby creating favorable conditions for subsequent microbial growth, adsorption, and mineral dissolution. Bio-oxidation analysis demonstrated that urea supplementation significantly stimulated the growth of iron-oxidizing microorganisms, predominantly Leptospirillum spp., while HRH addition promoted the proliferation of the mixotrophic Sulfobacillus spp. and enhanced its adsorption capacity by improving mineral surface hydrophilicity. The combined effect of HRH and urea effectively optimized the microbial community structure, increasing species diversity and evenness, which in turn enhanced Fe3+/Fe2+ cycling and the metabolism of the sulfur passivation layer. This effectively enhanced the reaction kinetics of the sulfide minerals. Consequently, this synergistic strategy improved the bio-oxidation efficiencies of Fe and S by 1.17-fold and 1.42-fold, respectively, compared with conventional bio-oxidation, and elevated the cyanide leaching levels of Au and Ag to 97.3 ± 0.5 % and 93.6 ± 0.8 % (31.0 % and 30.7 % improvements). This research provides a novel technical approach and theoretical foundation for the efficient and environmentally friendly processing of complex refractory gold ores.
{"title":"Synergistic strategy for enhanced bio-oxidation of refractory gold concentrate with high arsenic and sulfur: ferric oxidation with mixed organic nutrients supplementation","authors":"Shiqi Zhang , Hongying Yang , Linlin Tong , Zhenan Jin , Pengcheng Ma","doi":"10.1016/j.mineng.2025.110050","DOIUrl":"10.1016/j.mineng.2025.110050","url":null,"abstract":"<div><div>The bio-oxidation of refractory gold concentrates with high arsenic and sulfur contents is inefficient, due to its slow reaction kinetics and the arsenic toxicity. To address this limitation, present study proposed a novel strategy involving ferric (Fe<sup>3+</sup>) pre-oxidation synergistically combined with the simultaneous addition of hydrolyzed rice husk (HRH) and urea. Chemical and interfacial analyses revealed that ferric oxidation removed 13.4 ± 1.4 % of arsenic (As) from the concentrate and disrupted the physicochemical structures of mineral surfaces (pyrite and arsenopyrite), thereby creating favorable conditions for subsequent microbial growth, adsorption, and mineral dissolution. Bio-oxidation analysis demonstrated that urea supplementation significantly stimulated the growth of iron-oxidizing microorganisms, predominantly <em>Leptospirillum</em> spp., while HRH addition promoted the proliferation of the mixotrophic <em>Sulfobacillus</em> spp. and enhanced its adsorption capacity by improving mineral surface hydrophilicity. The combined effect of HRH and urea effectively optimized the microbial community structure, increasing species diversity and evenness, which in turn enhanced Fe<sup>3+</sup>/Fe<sup>2+</sup> cycling and the metabolism of the sulfur passivation layer. This effectively enhanced the reaction kinetics of the sulfide minerals. Consequently, this synergistic strategy improved the bio-oxidation efficiencies of Fe and S by 1.17-fold and 1.42-fold, respectively, compared with conventional bio-oxidation, and elevated the cyanide leaching levels of Au and Ag to 97.3 ± 0.5 % and 93.6 ± 0.8 % (31.0 % and 30.7 % improvements). This research provides a novel technical approach and theoretical foundation for the efficient and environmentally friendly processing of complex refractory gold ores.</div></div>","PeriodicalId":18594,"journal":{"name":"Minerals Engineering","volume":"238 ","pages":"Article 110050"},"PeriodicalIF":5.0,"publicationDate":"2026-01-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145940751","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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