Pub Date : 2025-11-17DOI: 10.1016/j.hydromet.2025.106609
Diego Teuber Gijon, Luciana Jandelli Gimenes, Marcela dos Passos Galluzzi Baltazar
Rare earth elements (REE) are a group of metals known for their recurrent use in ceramic materials, batteries, computer circuitry, and by their decreasing availability. A small group of countries control the concentrated mineral sources of REE and their production, while low-concentration sources are sparse and have low economic value. Global demand for these elements has reached an all-time high in the last five years, which foresees a necessary change in the way REE is obtained. Industrial and domestic residues have shown invaluable potential as secondary sources of REE. The exploration of these sources brings a direct approach to the principles of circular economy. Phosphogypsum (PG), a residue from the production of fertilizers, is an example of said sources with more than 250 million tons stored and considerable amount of REE (>0.5 wt.%). This short review will succinctly analyze current approaches to REE recovery from phosphogypsum while also evaluating its intrinsic value and place in a circular economy. The 12 principles of the hydrometallurgical circular economy will be used in this evaluation. Different ways to improve REE recovery have also been exposed, while implicating the challenges and new approaches utilizing combined processes, artificial intelligence and neural networks.
{"title":"The circularity of turning wastes into valuable resources: Rare earth elements recovery from phosphogypsum – A short review","authors":"Diego Teuber Gijon, Luciana Jandelli Gimenes, Marcela dos Passos Galluzzi Baltazar","doi":"10.1016/j.hydromet.2025.106609","DOIUrl":"10.1016/j.hydromet.2025.106609","url":null,"abstract":"<div><div>Rare earth elements (REE) are a group of metals known for their recurrent use in ceramic materials, batteries, computer circuitry, and by their decreasing availability. A small group of countries control the concentrated mineral sources of REE and their production, while low-concentration sources are sparse and have low economic value. Global demand for these elements has reached an all-time high in the last five years, which foresees a necessary change in the way REE is obtained. Industrial and domestic residues have shown invaluable potential as secondary sources of REE. The exploration of these sources brings a direct approach to the principles of circular economy. Phosphogypsum (PG), a residue from the production of fertilizers, is an example of said sources with more than 250 million tons stored and considerable amount of REE (>0.5 wt.%). This short review will succinctly analyze current approaches to REE recovery from phosphogypsum while also evaluating its intrinsic value and place in a circular economy. The 12 principles of the hydrometallurgical circular economy will be used in this evaluation. Different ways to improve REE recovery have also been exposed, while implicating the challenges and new approaches utilizing combined processes, artificial intelligence and neural networks.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106609"},"PeriodicalIF":4.8,"publicationDate":"2025-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145568950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-15DOI: 10.1016/j.hydromet.2025.106606
Quan Zheng , Kunning Tang , Ying Da Wang , Samuel J. Jackson , Thomas Poulet , Ryan Armstrong , Peyman Mostaghimi
This paper introduces a workflow for creating and analysing an engineered dual-porosity system, similar to those in copper heap leaching, by synthesising micro-porous chalcopyrite-glass beads. These beads are designed to match the size and shape of single-porosity glass beads. X-ray micro-CT imaging is utilised alongside mass balance measurements on comparative irrigation experiments in the dual and single-porosity systems to investigate the complex fluid dynamics governing the interaction between fluid flow in the micro-porous (intraparticle) and macroscopic (interparticle) domains. Results demonstrate that the dual porosity system, with 20% micro-porosity and 46% macro-porosity, retains over twice the liquid volume compared to the single porosity system, with the same macro-porosity and tortuosity. An increased macroscopic flow connectivity and liquid content is observed in the dual porosity system, due to lateral flow within the micro-pores that enhance surface area and connectivity at the bead contact points. A considerable amount of liquid is retained in the micro-pores through capillary forces, which impacts leaching performance in a large scale system. Overall, this imaging-based methodology and workflow provides a robust framework for designing and analysing engineered dual-porosity systems found in geosciences, chemical engineering, and hydrometallurgy, enabling improved prediction and optimisation of reactive transport and resource recovery processes in complex porous media.
{"title":"Utilising micro-CT to analyse fluid dynamics in dual-porosity packing systems","authors":"Quan Zheng , Kunning Tang , Ying Da Wang , Samuel J. Jackson , Thomas Poulet , Ryan Armstrong , Peyman Mostaghimi","doi":"10.1016/j.hydromet.2025.106606","DOIUrl":"10.1016/j.hydromet.2025.106606","url":null,"abstract":"<div><div>This paper introduces a workflow for creating and analysing an engineered dual-porosity system, similar to those in copper heap leaching, by synthesising micro-porous chalcopyrite-glass beads. These beads are designed to match the size and shape of single-porosity glass beads. X-ray micro-CT imaging is utilised alongside mass balance measurements on comparative irrigation experiments in the dual and single-porosity systems to investigate the complex fluid dynamics governing the interaction between fluid flow in the micro-porous (intraparticle) and macroscopic (interparticle) domains. Results demonstrate that the dual porosity system, with 20% micro-porosity and 46% macro-porosity, retains over twice the liquid volume compared to the single porosity system, with the same macro-porosity and tortuosity. An increased macroscopic flow connectivity and liquid content is observed in the dual porosity system, due to lateral flow within the micro-pores that enhance surface area and connectivity at the bead contact points. A considerable amount of liquid is retained in the micro-pores through capillary forces, which impacts leaching performance in a large scale system. Overall, this imaging-based methodology and workflow provides a robust framework for designing and analysing engineered dual-porosity systems found in geosciences, chemical engineering, and hydrometallurgy, enabling improved prediction and optimisation of reactive transport and resource recovery processes in complex porous media.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"240 ","pages":"Article 106606"},"PeriodicalIF":4.8,"publicationDate":"2025-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145578569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-14DOI: 10.1016/j.hydromet.2025.106604
Nityanand Singh , Kedhareswara Sairam Pasupuleti , Hee-Nam Kang , Tae-Hyuk Lee , Jin-Young Lee
The management of spent Nickel-Cobalt-Manganese (NCM) type lithium-ion batteries (LIBs) is critical to advancing sustainable development and aligning with circular economy principles. This study proposes an efficient hydrometallurgical process for the recovery of valuable metals from LiNixCoyMnzO2 black mass powder. The leaching process was optimized under specific conditions, namely a 1 M H2SO4 concentration, 15 % (v/v) H2O2, and a liquid-to-solid ratio of 100 g/L at 75 °C, with a mixing time of 120 min. These parameters facilitated the leaching of more than 95 % of Cu(II), Ni(II), Co(II), Mn(II), and Li(I). Subsequent metal recovery processes were conducted under carefully controlled conditions. Copper (Cu(II)) was extracted using 20 % (v/v) LIX 84-I at a pH of 2.7. Manganese (Mn(II)) was precipitated using KMnO4 at a pH of 2.0. Cobalt (Co(II)) was extracted with Ionquest 290 at pH 4.5, followed by stripping with 10 % (v/v) H2SO4 and crystallization to produce CoSO4.H2O crystals. Nickel (Ni(II)) was recovered as nickel sulfide at pH 3, while lithium (Li(I)) was concentrated through evaporation and subsequently precipitated with sodium carbonate (Na2CO3) at pH 12, under conditions of 85 °C and 35 min of stirring. The findings contribute to the development of more sustainable processes for the recycling of spent LIBs, emphasizing the importance of optimizing extraction and precipitation techniques to maximize resource recovery and minimize environmental impact.
{"title":"Enhancing selective extraction and recovery of critical metals from spent NCM black mass through a leaching procedure followed by precipitation and liquid-liquid extraction processes","authors":"Nityanand Singh , Kedhareswara Sairam Pasupuleti , Hee-Nam Kang , Tae-Hyuk Lee , Jin-Young Lee","doi":"10.1016/j.hydromet.2025.106604","DOIUrl":"10.1016/j.hydromet.2025.106604","url":null,"abstract":"<div><div>The management of spent Nickel-Cobalt-Manganese (NCM) type lithium-ion batteries (LIBs) is critical to advancing sustainable development and aligning with circular economy principles. This study proposes an efficient hydrometallurgical process for the recovery of valuable metals from LiNi<sub>x</sub>Co<sub>y</sub>Mn<sub>z</sub>O<sub>2</sub> black mass powder. The leaching process was optimized under specific conditions, namely a 1 M H<sub>2</sub>SO<sub>4</sub> concentration, 15 % (v/v) H<sub>2</sub>O<sub>2</sub>, and a liquid-to-solid ratio of 100 g/L at 75 °C, with a mixing time of 120 min. These parameters facilitated the leaching of more than 95 % of Cu(II), Ni(II), Co(II), Mn(II), and Li(I). Subsequent metal recovery processes were conducted under carefully controlled conditions. Copper (Cu(II)) was extracted using 20 % (<em>v</em>/v) LIX 84-I at a pH of 2.7. Manganese (Mn(II)) was precipitated using KMnO<sub>4</sub> at a pH of 2.0. Cobalt (Co(II)) was extracted with Ionquest 290 at pH 4.5, followed by stripping with 10 % (v/v) H<sub>2</sub>SO<sub>4</sub> and crystallization to produce CoSO<sub>4</sub>.H<sub>2</sub>O crystals. Nickel (Ni(II)) was recovered as nickel sulfide at pH 3, while lithium (Li(I)) was concentrated through evaporation and subsequently precipitated with sodium carbonate (Na<sub>2</sub>CO<sub>3</sub>) at pH 12, under conditions of 85 °C and 35 min of stirring. The findings contribute to the development of more sustainable processes for the recycling of spent LIBs, emphasizing the importance of optimizing extraction and precipitation techniques to maximize resource recovery and minimize environmental impact.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106604"},"PeriodicalIF":4.8,"publicationDate":"2025-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study focuses on the characterization and extraction of rare earth elements (REEs) from the IAT (ion adsorption type) deposit located in Keposang Toboali, South Bangka, Bangka Belitung Province, Indonesia. Comprehensive chemical and mineralogical analyses, including XRF, ICP-OES, and SEM-AMICS, revealed that the deposit is primarily composed of silicate minerals such as quartz, kaolinite, and sanidine. Rare earth elements, notably Ce (407 g/t), La (137 g/t), Nd (111 g/t), and Y (87.5 g/t), were identified, totaling 851.2 g/t of REEs. Element deportment analysis indicated that REEs are closely associated with kaolinite, making the isolation of kaolin is critical for REE extraction. Diagnostic leaching tests, performed with sulfuric acid (H₂SO₄), hydrochloric acid (HCl), and nitric acid (HNO₃), demonstrated that H₂SO₄ was the most efficient leaching agent, achieving REE recovery exceeding 90 %. Optimal recovery was achieved at 90 °C, with a leaching duration of 90 min and an acid dosage of 500 kg/ton. The study highlights the importance of temperature, acid concentration, and leaching duration in optimizing REE recovery from the mixed-IAT deposit. The findings provide insights into efficient REE extraction from ion-adsorption type (IAT) ores originated from Indonesia, with potential implications for resource recovery strategies in similar deposits.
{"title":"Extraction of rare earth elements from ion-adsorption clay deposit of Keposang Toboali, South Bangka, Indonesia: Mineralogical analysis and diagnostic leaching","authors":"Andina Septiarani , Retno Wijayanti , Isyatun Rodliyah , Kukuh Nur Hidayat , Asep Bahtiar Purnama , Denny Zahir Dayyan , Siti Rochani , Amelia Andriani , Saboor Ahmad Torabi , Sariman , Widi Astuti","doi":"10.1016/j.hydromet.2025.106607","DOIUrl":"10.1016/j.hydromet.2025.106607","url":null,"abstract":"<div><div>This study focuses on the characterization and extraction of rare earth elements (REEs) from the IAT (ion adsorption type) deposit located in Keposang Toboali, South Bangka, Bangka Belitung Province, Indonesia. Comprehensive chemical and mineralogical analyses, including XRF, ICP-OES, and SEM-AMICS, revealed that the deposit is primarily composed of silicate minerals such as quartz, kaolinite, and sanidine. Rare earth elements, notably Ce (407 g/t), La (137 g/t), Nd (111 g/t), and Y (87.5 g/t), were identified, totaling 851.2 g/t of REEs. Element deportment analysis indicated that REEs are closely associated with kaolinite, making the isolation of kaolin is critical for REE extraction. Diagnostic leaching tests, performed with sulfuric acid (H₂SO₄), hydrochloric acid (HCl), and nitric acid (HNO₃), demonstrated that H₂SO₄ was the most efficient leaching agent, achieving REE recovery exceeding 90 %. Optimal recovery was achieved at 90 °C, with a leaching duration of 90 min and an acid dosage of 500 kg/ton. The study highlights the importance of temperature, acid concentration, and leaching duration in optimizing REE recovery from the mixed-IAT deposit. The findings provide insights into efficient REE extraction from ion-adsorption type (IAT) ores originated from Indonesia, with potential implications for resource recovery strategies in similar deposits.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106607"},"PeriodicalIF":4.8,"publicationDate":"2025-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145516916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-11DOI: 10.1016/j.hydromet.2025.106608
Jianjun Sun , Tianfu Zhang , Peilun Shen , Dianwen Liu
Large quantities of copper-rich water-quenched slag (WQS) are generated during copper smelting. However, the efficient recovery of copper from WQS faces significant challenges, resulting in extensive stockpiling of WQS in slag yards for extended periods without prior copper recovery. This not only causes resource waste but also poses potential environmental pollution risks. To achieve efficient copper recovery from WQS, this study innovatively incorporates ethylenediamine (EDA) into the WQS ammonia leaching system—EDA acts as a bidentate ligand that not only exhibits strong coordination ability with copper ions but also forms stable and highly soluble complexes with them.
This study employed process mineralogy, single-factor experiments, response surface methodology (RSM), and thermodynamic analyses to characterize WQS mineralogical properties, identify factors influencing copper leaching efficiency, determine the significance order of the effects of individual factors and interactions between different factors on copper leaching efficiency, and clarify the mechanism of EDA-enhanced leaching. The results demonstrated that EDA addition enhanced copper leaching efficiency from 90.5 % to 93.2 %. The RSM analysis indicated that the significance order of the effects of individual factors and interactions between different factors on copper leaching efficiency is (NH₄)₂S₂O₈ > EDA > NH₃ and (NH₄)₂S₂O₈–EDA > (NH₄)₂S₂O₈–NH₃ > NH₃–EDA, respectively. The leaching mechanism analysis revealed that the core reason for EDA-enhanced copper leaching is as follows: the [Cu(EDA)2]2+ complexes formed by EDA and copper ions exhibit significantly higher stability than the [Cu(NH3)4]2+ complexes. This stability difference facilitates the dissolution of copper from the solid phase into the leaching solution, thereby improving copper leaching efficiency. This study provides an alternative method for large-scale utilization of WQS.
{"title":"Copper leaching from water-quenched slag using an ethylenediamine-enhanced ammonia leaching system","authors":"Jianjun Sun , Tianfu Zhang , Peilun Shen , Dianwen Liu","doi":"10.1016/j.hydromet.2025.106608","DOIUrl":"10.1016/j.hydromet.2025.106608","url":null,"abstract":"<div><div>Large quantities of copper-rich water-quenched slag (WQS) are generated during copper smelting. However, the efficient recovery of copper from WQS faces significant challenges, resulting in extensive stockpiling of WQS in slag yards for extended periods without prior copper recovery. This not only causes resource waste but also poses potential environmental pollution risks. To achieve efficient copper recovery from WQS, this study innovatively incorporates ethylenediamine (EDA) into the WQS ammonia leaching system—EDA acts as a bidentate ligand that not only exhibits strong coordination ability with copper ions but also forms stable and highly soluble complexes with them.</div><div>This study employed process mineralogy, single-factor experiments, response surface methodology (RSM), and thermodynamic analyses to characterize WQS mineralogical properties, identify factors influencing copper leaching efficiency, determine the significance order of the effects of individual factors and interactions between different factors on copper leaching efficiency, and clarify the mechanism of EDA-enhanced leaching. The results demonstrated that EDA addition enhanced copper leaching efficiency from 90.5 % to 93.2 %. The RSM analysis indicated that the significance order of the effects of individual factors and interactions between different factors on copper leaching efficiency is (NH₄)₂S₂O₈ > EDA > NH₃ and (NH₄)₂S₂O₈–EDA > (NH₄)₂S₂O₈–NH₃ > NH₃–EDA, respectively. The leaching mechanism analysis revealed that the core reason for EDA-enhanced copper leaching is as follows: the [Cu(EDA)<sub>2</sub>]<sup>2+</sup> complexes formed by EDA and copper ions exhibit significantly higher stability than the [Cu(NH<sub>3</sub>)<sub>4</sub>]<sup>2+</sup> complexes. This stability difference facilitates the dissolution of copper from the solid phase into the leaching solution, thereby improving copper leaching efficiency. This study provides an alternative method for large-scale utilization of WQS.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106608"},"PeriodicalIF":4.8,"publicationDate":"2025-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145498874","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conventional methods for processing copper anode slime are often hampered by lengthy workflows and low tellurium recovery efficiencies. To overcome these limitations, this study introduces a novel two-stage process combining sulfide leaching and potential-controlled precipitation for tellurium recovery from copper telluride residue. Thermodynamic analysis and experimental characterization were used to elucidate the underlying reaction mechanisms, and key process parameters were systematically optimized. During sulfide leaching, tellurium from copper telluride is displaced by sulfide ions and dissolved into solution predominantly as ditelluride anions, achieving a tellurium leaching efficiency of 96.9 %. In the subsequent potential-controlled precipitation stage, the dissolved ditelluride ions were oxidized by sulfite to elemental tellurium, precipitating with 99.1 % efficiency. After washing, the final tellurium powder exhibited a purity exceeding 99.0 %. The proposed process significantly simplifies the workflow, achieves high tellurium recovery, and enhances environmental performance by operating under alkaline conditions that prevent toxic gas emissions and reduce equipment corrosion. This work demonstrates a promising and sustainable alternative for industrial tellurium recovery from copper telluride residue.
{"title":"Tellurium metal recovery from copper smelter residues: A short-route via sulfide leaching and precipitation by sodium sulfite","authors":"Zuowei Liu , Lili Jia , Zhirui Tian , Qinghua Tian , Xueyi Guo , Zhipeng Xu","doi":"10.1016/j.hydromet.2025.106605","DOIUrl":"10.1016/j.hydromet.2025.106605","url":null,"abstract":"<div><div>Conventional methods for processing copper anode slime are often hampered by lengthy workflows and low tellurium recovery efficiencies. To overcome these limitations, this study introduces a novel two-stage process combining sulfide leaching and potential-controlled precipitation for tellurium recovery from copper telluride residue. Thermodynamic analysis and experimental characterization were used to elucidate the underlying reaction mechanisms, and key process parameters were systematically optimized. During sulfide leaching, tellurium from copper telluride is displaced by sulfide ions and dissolved into solution predominantly as ditelluride anions, achieving a tellurium leaching efficiency of 96.9 %. In the subsequent potential-controlled precipitation stage, the dissolved ditelluride ions were oxidized by sulfite to elemental tellurium, precipitating with 99.1 % efficiency. After washing, the final tellurium powder exhibited a purity exceeding 99.0 %. The proposed process significantly simplifies the workflow, achieves high tellurium recovery, and enhances environmental performance by operating under alkaline conditions that prevent toxic gas emissions and reduce equipment corrosion. This work demonstrates a promising and sustainable alternative for industrial tellurium recovery from copper telluride residue.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106605"},"PeriodicalIF":4.8,"publicationDate":"2025-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145473107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-11-03DOI: 10.1016/j.hydromet.2025.106603
Thiago J. Santos , Augusta Isaac , Virginia S.T. Ciminelli , Daniel Majuste
This study examines the effect of zinc-to‑indium molar ratio (nZn/nIn) on the behavior of indium cementation from sulfate solutions. It also investigates the correlation between this variable and the solution's acidity, temperature, and indium concentration. Zinc powder was chosen as the reducing agent because it is readily available in high-purity grades at a relatively low cost, exhibits a low hydrogen overpotential, and has faster kinetics than metal plates. The cementation tests revealed that increasing the nZn/nIn ratio in concentrated (10 g L−1) and dilute (1 g L−1) indium solutions enhances metal recovery regardless of temperature and initial pH. However, the nZn/nIn ratio was found to have a significant impact on the pH changes of the electrolyte due to hydrogen evolution. Depending on the indium concentration in the solution, increases in pH above 2–3 may result in indium precipitation. Analysis of individual cemented particles using scanning microscopy revealed that the morphology, thickness, and coherence of the indium layer formed on zinc is highly irregular. Analysis of agglomerates formed during the cementation process using three-dimensional X-rays microscopy revealed the formation of an almost continuous indium layer surrounding the zinc metal. The formation of these agglomerates and the observed decrease in their porosity as a function of time likely explains the decrease of the indium cementation rates due to the decreased availability of zinc surface areas for indium deposition and the decreased accessibility of the solution through the agglomerate's complex pore matrix. X-ray diffraction patterns and Rietveld refinement showed that only metallic zinc and indium were detected in the products regardless of nZn/nIn ratio. The refinement and quantitative chemical analysis revealed that increasing the nZn/nIn ratio results in a gradual decrease in the indium content and an increase in the zinc content. A better understanding of the rate and effectiveness of indium cementation in the H2SO4-Zn system can help design and improve technologies for high indium recovery from secondary sources.
本研究考察了锌铟摩尔比(nZn/nIn)对硫酸盐溶液中铟胶结行为的影响。它还研究了这个变量与溶液的酸度、温度和铟浓度之间的相关性。选择锌粉作为还原剂是因为它很容易以相对较低的成本获得高纯度的等级,表现出较低的氢过电位,并且具有比金属板更快的动力学。胶结试验表明,在浓(10 g L−1)和稀(1 g L−1)铟溶液中,提高nZn/nIn比,无论温度和初始pH值如何,都能提高金属的回收率。然而,由于析氢,nZn/nIn比对电解质pH值的变化有显著影响。根据溶液中铟的浓度,pH值高于2-3可能导致铟析出。使用扫描显微镜对单个胶结颗粒进行分析,发现锌上形成的铟层的形态、厚度和相干性是高度不规则的。利用三维x射线显微镜对胶结过程中形成的团块进行分析,发现锌金属周围形成了几乎连续的铟层。这些团块的形成和观察到的孔隙率随时间的降低可能解释了铟胶结率的降低,这是由于锌表面沉积铟的可用性降低,溶液通过团块的复杂孔隙基质的可及性降低。x射线衍射图和Rietveld细化表明,无论nZn/nIn比如何,产物中只检测到金属锌和铟。细化和定量化学分析表明,增大nZn/nIn比,铟含量逐渐降低,锌含量逐渐升高。更好地了解H2SO4-Zn体系中铟胶结的速率和有效性,有助于设计和改进从二次源中高回收率铟的技术。
{"title":"New insights into zinc-to‑indium molar ratio, pH, and temperature effects on indium cementation rate and product quality","authors":"Thiago J. Santos , Augusta Isaac , Virginia S.T. Ciminelli , Daniel Majuste","doi":"10.1016/j.hydromet.2025.106603","DOIUrl":"10.1016/j.hydromet.2025.106603","url":null,"abstract":"<div><div>This study examines the effect of zinc-to‑indium molar ratio (<em>n</em><sub><em>Zn</em></sub><em>/n</em><sub><em>In</em></sub>) on the behavior of indium cementation from sulfate solutions. It also investigates the correlation between this variable and the solution's acidity, temperature, and indium concentration. Zinc powder was chosen as the reducing agent because it is readily available in high-purity grades at a relatively low cost, exhibits a low hydrogen overpotential, and has faster kinetics than metal plates. The cementation tests revealed that increasing the <em>n</em><sub><em>Zn</em></sub><em>/n</em><sub><em>In</em></sub> ratio in concentrated (10 g L<sup>−1</sup>) and dilute (1 g L<sup>−1</sup>) indium solutions enhances metal recovery regardless of temperature and initial pH. However, the <em>n</em><sub><em>Zn</em></sub><em>/n</em><sub><em>In</em></sub> ratio was found to have a significant impact on the pH changes of the electrolyte due to hydrogen evolution. Depending on the indium concentration in the solution, increases in pH above 2–3 may result in indium precipitation. Analysis of individual cemented particles using scanning microscopy revealed that the morphology, thickness, and coherence of the indium layer formed on zinc is highly irregular. Analysis of agglomerates formed during the cementation process using three-dimensional X-rays microscopy revealed the formation of an almost continuous indium layer surrounding the zinc metal. The formation of these agglomerates and the observed decrease in their porosity as a function of time likely explains the decrease of the indium cementation rates due to the decreased availability of zinc surface areas for indium deposition and the decreased accessibility of the solution through the agglomerate's complex pore matrix. X-ray diffraction patterns and Rietveld refinement showed that only metallic zinc and indium were detected in the products regardless of <em>n</em><sub><em>Zn</em></sub><em>/n</em><sub><em>In</em></sub> ratio. The refinement and quantitative chemical analysis revealed that increasing the <em>n</em><sub><em>Zn</em></sub><em>/n</em><sub><em>In</em></sub> ratio results in a gradual decrease in the indium content and an increase in the zinc content. A better understanding of the rate and effectiveness of indium cementation in the H<sub>2</sub>SO<sub>4</sub>-Zn system can help design and improve technologies for high indium recovery from secondary sources.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106603"},"PeriodicalIF":4.8,"publicationDate":"2025-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145435022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fluoride leaching is a promising and clean route for extracting titanium from Ti-bearing furnace slag (TBFS). This study systematically investigated the phase-controlled selective separation of Ti, with particular focus on the effect of the [NH4+]/[F−] molar ratio on Ti dissolution and impurity behavior. The results reveal two main controlling factors. First, the acidity (H+ concentration) governs the overall dissolution efficiency of TBFS, and higher acidity promotes complete slag decomposition. Second, the [NH4+]/[F−] molar ratio (0–0.5) controls the phase transformation of the products. Titanium selectively dissolves as stable TiF62− complexes, while Ca, Al, and Mg precipitate as distinct fluoride phases (MgAlF5·1.5H2O, MgF2, AlF3, and CaMg2Al2F12). The presence of NH4+ promotes the formation of additional coordination compounds (NH4MgAlF6 and (NH4)3AlF6), further enhancing phase separation of impurities. Reactivity analysis indicates that FeTi2O5 is the most readily leached phase within the MxTi3-xO5 system. Under optimized [NH4+]/[F−] conditions, the Ti-rich leachate can be directly converted to TiO2 precursors ((NH4)3TiOF5 and (NH4)2TiOF4) through controlled ammonia hydrolysis. These findings provide mechanistic insights into selective Ti recovery from TBFS and demonstrate the potential of fluoride leaching for clean titanium resource utilization.
{"title":"Phase-controlled selective separation of titanium from titanium-bearing furnace slag via fluoride leaching: Critical role of [NH4+]/[F−] molar ratio","authors":"Jinlai Zhang, Yufeng Guo, Shuai Wang, Feng Chen, Yu Zheng, Lingzhi Yang","doi":"10.1016/j.hydromet.2025.106602","DOIUrl":"10.1016/j.hydromet.2025.106602","url":null,"abstract":"<div><div>Fluoride leaching is a promising and clean route for extracting titanium from Ti-bearing furnace slag (TBFS). This study systematically investigated the phase-controlled selective separation of Ti, with particular focus on the effect of the [NH<sub>4</sub><sup>+</sup>]/[F<sup>−</sup>] molar ratio on Ti dissolution and impurity behavior. The results reveal two main controlling factors. First, the acidity (H<sup>+</sup> concentration) governs the overall dissolution efficiency of TBFS, and higher acidity promotes complete slag decomposition. Second, the [NH<sub>4</sub><sup>+</sup>]/[F<sup>−</sup>] molar ratio (0–0.5) controls the phase transformation of the products. Titanium selectively dissolves as stable TiF<sub>6</sub><sup>2−</sup> complexes, while Ca, Al, and Mg precipitate as distinct fluoride phases (MgAlF<sub>5</sub>·1.5H<sub>2</sub>O, MgF<sub>2</sub>, AlF<sub>3</sub>, and CaMg<sub>2</sub>Al<sub>2</sub>F<sub>12</sub>). The presence of NH<sub>4</sub><sup>+</sup> promotes the formation of additional coordination compounds (NH<sub>4</sub>MgAlF<sub>6</sub> and (NH<sub>4</sub>)<sub>3</sub>AlF<sub>6</sub>), further enhancing phase separation of impurities. Reactivity analysis indicates that FeTi<sub>2</sub>O<sub>5</sub> is the most readily leached phase within the M<sub>x</sub>Ti<sub>3-x</sub>O<sub>5</sub> system. Under optimized [NH<sub>4</sub><sup>+</sup>]/[F<sup>−</sup>] conditions, the Ti-rich leachate can be directly converted to TiO<sub>2</sub> precursors ((NH<sub>4</sub>)<sub>3</sub>TiOF<sub>5</sub> and (NH<sub>4</sub>)<sub>2</sub>TiOF<sub>4</sub>) through controlled ammonia hydrolysis. These findings provide mechanistic insights into selective Ti recovery from TBFS and demonstrate the potential of fluoride leaching for clean titanium resource utilization.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106602"},"PeriodicalIF":4.8,"publicationDate":"2025-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145382856","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-21DOI: 10.1016/j.hydromet.2025.106601
Puloma Chakrabarty , Geanna Hovey , Minju Cha , Anya Dickinson-Cove , Gaurav Sant , Erika La Plante , David Jassby
To meet the growing demand for critical metals in low carbon technologies, efficient extraction of nickel (Ni) from ultramafic rocks is essential. We present a sonication-based aqueous hydrometallurgical method that enhances Ni extraction under sub-boiling temperatures (∼20–80 °C) and ambient pressure. Batch dissolution experiments were conducted at 30 °C using sulfuric (H₂SO₄) and hydrochloric acid (HCl) with concentrations, between 0.1 and 2 M, solid-to-liquid ratios between 1:500 to 1:5, and sonication frequencies from 0 to 80 kHz over 1–24 h. Dissolution rates of Mg (lizardite) and Ni (pentlandite) were dependent on the acid concentration and stoichiometry. H2SO4 required fewer moles than HCl for dissolution of an equivalent Ni concentration. Sonication significantly increased reaction kinetics, increasing Ni recovery from 15 to 20 % (without sonication) to 65–70 % under optimal conditions (s: l 1:10, 1 M H₂SO₄, 37–40 kHz, 8 h). This process demonstrates a low-energy, acid-efficient dissolution method reduces processing times and minimizes environmental impact. By integrating acoustic stimulation into conventional leaching methods, this method paves way for scalable CO2-negative technologies for Ni extraction that lead to more sustainable hydrometallurgical processing.
{"title":"Sonication-enhanced aqueous dissolution of nickel from ultramafic rocks under ambient conditions","authors":"Puloma Chakrabarty , Geanna Hovey , Minju Cha , Anya Dickinson-Cove , Gaurav Sant , Erika La Plante , David Jassby","doi":"10.1016/j.hydromet.2025.106601","DOIUrl":"10.1016/j.hydromet.2025.106601","url":null,"abstract":"<div><div>To meet the growing demand for critical metals in low carbon technologies, efficient extraction of nickel (Ni) from ultramafic rocks is essential. We present a sonication-based aqueous hydrometallurgical method that enhances Ni extraction under sub-boiling temperatures (∼20–80 °C) and ambient pressure. Batch dissolution experiments were conducted at 30 °C using sulfuric (H₂SO₄) and hydrochloric acid (HCl) with concentrations, between 0.1 and 2 M, solid-to-liquid ratios between 1:500 to 1:5, and sonication frequencies from 0 to 80 kHz over 1–24 h. Dissolution rates of Mg (lizardite) and Ni (pentlandite) were dependent on the acid concentration and stoichiometry. H<sub>2</sub>SO<sub>4</sub> required fewer moles than HCl for dissolution of an equivalent Ni concentration. Sonication significantly increased reaction kinetics, increasing Ni recovery from 15 to 20 % (without sonication) to 65–70 % under optimal conditions (s: l 1:10, 1 M H₂SO₄, 37–40 kHz, 8 h). This process demonstrates a low-energy, acid-efficient dissolution method reduces processing times and minimizes environmental impact. By integrating acoustic stimulation into conventional leaching methods, this method paves way for scalable CO<sub>2</sub>-negative technologies for Ni extraction that lead to more sustainable hydrometallurgical processing.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106601"},"PeriodicalIF":4.8,"publicationDate":"2025-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360218","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-10-19DOI: 10.1016/j.hydromet.2025.106600
Xuting Si, Shuai Wei, Yilin Yang, Yulu Li, Youcai Lu
The increasing demand for lithium resources has promoted significant advancements in lithium extraction and recovery technologies. This study introduces a series of novel aminophosphonic acid extractants with varying branched-chain structures, designed to enhance lithium recovery from spent battery leachates with high sodium interference. These bifunctional extractants, incorporating both phosphonic acid and amino groups, demonstrated notable efficiency and selectivity. Under optimal conditions, a single-stage extraction achieved a lithium extraction efficiency of 70 %, with a lithium‑sodium separation factor of 139. A four-stage countercurrent extraction process further elevated the lithium recovery to 99 %. The extraction mechanism was elucidated through Fourier-transform infrared (FT-IR) spectroscopy and 31P nuclear magnetic resonance (NMR) spectroscopy, complemented by density functional theory (DFT) calculations. This research not only provides a feasible method for lithium extraction from high Na/Li ratio leachates but also offers useful insights for industrial applications, highlighting the potential of bifunctional extractants in sustainable lithium recovery.
{"title":"Novel bifunctional aminophosphonic acid extractants for efficient lithium recovery from spent battery leachates with high sodium interference","authors":"Xuting Si, Shuai Wei, Yilin Yang, Yulu Li, Youcai Lu","doi":"10.1016/j.hydromet.2025.106600","DOIUrl":"10.1016/j.hydromet.2025.106600","url":null,"abstract":"<div><div>The increasing demand for lithium resources has promoted significant advancements in lithium extraction and recovery technologies. This study introduces a series of novel aminophosphonic acid extractants with varying branched-chain structures, designed to enhance lithium recovery from spent battery leachates with high sodium interference. These bifunctional extractants, incorporating both phosphonic acid and amino groups, demonstrated notable efficiency and selectivity. Under optimal conditions, a single-stage extraction achieved a lithium extraction efficiency of 70 %, with a lithium‑sodium separation factor of 139. A four-stage countercurrent extraction process further elevated the lithium recovery to 99 %. The extraction mechanism was elucidated through Fourier-transform infrared (FT-IR) spectroscopy and <sup>31</sup>P nuclear magnetic resonance (NMR) spectroscopy, complemented by density functional theory (DFT) calculations. This research not only provides a feasible method for lithium extraction from high Na/Li ratio leachates but also offers useful insights for industrial applications, highlighting the potential of bifunctional extractants in sustainable lithium recovery.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106600"},"PeriodicalIF":4.8,"publicationDate":"2025-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}