Hydrometallurgy最新文献

{"title":"Recovery of transition metals (Ni, Co, and Mn) and Li from the sulfate leach solutions of spent ternary lithium-ion batteries by stepwise solvent extraction and precipitation","authors":"Kuifang Zhang ,&nbsp;Bohan Wei ,&nbsp;Bin Zeng ,&nbsp;Sen Qiu ,&nbsp;Xiaocong Zhong ,&nbsp;Ruixiang Wang","doi":"10.1016/j.hydromet.2025.106519","DOIUrl":"10.1016/j.hydromet.2025.106519","url":null,"abstract":"<div><div>Sulfate leachate from spent ternary lithium-ion batteries (LIBs) contain valuable metals, such as transition metals (Ni, Co, and Mn) and Li, and impurity metals, such as Al and Fe. Selectively separating them from solutions is necessary for their recovery. In this work, a stepwise solvent extraction and precipitation process is proposed for the selective separation and recovery of transition metals (Ni, Co, and Mn) and Li from sulfate-leaching solutions of spent ternary lithium-ion batteries. First, 100 % of the impurity metals (Al and Fe) were selectively removed from the solution through a single-stage extraction using 22.5 % (<em>v</em>/v) N1923 in sulfonated kerosene at an O/A ratio of 1:1 for 10 min. The losses of the transition metals (Ni, Co, and Mn) and Li were only 1.65 %. The Al and Fe in the loaded organic system was completely stripped using a 1 mol/L HNO₃ solution, followed by regeneration with sodium carbonate solution. Subsequently, the raffinate (pH = 4.46) was directly used for the co-extraction of Ni, Co, and Mn by Cyanex 272. A five-stage countercurrent extraction was performed with an organic system consisting of 1 mol/L Cyanex 272 (saponification degree: 50 %) in sulfonated kerosene, using an O/A ratio of 2.25:1. Nearly all of the Ni, Co, and Mn were extracted, while only 1.43 % Li was co-extracted. The extracted Ni, Co, and Mn in the loaded organic system were completely stripped through five-stage counter-current stripping using 1 mol/L H₂SO₄ with an O/A ratio of 5:1. During the stepwise solvent extraction process, stripped solutions of Ni, Co, Mn, and Li raffinates were sent to precipitate the pure ternary material precursors and Li₂CO₃. This study introduces a novel method for recycling spent ternary lithium-ion batteries.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106519"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144321257","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}

{"title":"Bioleaching and mechanism of ion-adsorption type rare earth ores and tailings using Acidithiobacillus ferrooxidans","authors":"Chunxiao Zhao ,&nbsp;Baojun Yang ,&nbsp;Shan Hu ,&nbsp;Jun Wang ,&nbsp;Yang Liu ,&nbsp;Guanzhou Qiu","doi":"10.1016/j.hydromet.2025.106495","DOIUrl":"10.1016/j.hydromet.2025.106495","url":null,"abstract":"<div><div>Traditionally, ammonium sulfate (NH₄)₂SO₄ has been utilised as the leaching agent in the extraction of ion-adsorption type rare earth (IATRE) ores. However, this method only extracts rare earth elements (REEs) from the ion-exchangeable phase, leaving behind a substantial amount of tailings that still contain REEs. Therefore, this study explored the bioleaching process of IATRE ores and tailings in the presence of <em>Acidithiobacillus ferrooxidans</em> (<em>A. ferrooxidans</em>) and the reaction mechanism. The results showed that in the two-step bioleaching system, where bacteria were cultured well prior to the addition of minerals for leaching, the extraction efficiencies for La (99.5 %), Ce (78.1 %), Nd (95.8 %), and Y (93.5 %) at a pyrite to IATRE ore mass ratio of 1.5:1 were 23.1 %, 58.3 %, 23.4 %, and 13.8 % higher, respectively, than those obtained using the current (NH₄)₂SO₄ leaching system. X-ray diffraction (XRD), scanning electron microscope coupled with energy-dispersive X-ray spectroscopy (SEM-EDS), and three-dimensional excitation-emission matrix (3DEEM) revealed the bioleaching mechanisms of the IATRE ore. These results demonstrated that the oxidative dissolution of pyrite by <em>A. ferrooxidans</em> promoted the production of acid and Fe²⁺. This facilitated proton exchange reactions between H⁺ and IATRE ores, the acid dissolution of IATRE ores, and the reduction of Ce⁴⁺ in the colloidal sediment phase. Additionally, bacterial surface groups and extracellular polymeric substances (EPS) produced by the bacteria formed complexes with rare earth ions, facilitating the release of REEs from IATRE ores. Furthermore, <em>A. ferrooxidans</em> successfully extracted REEs from IATRE tailings after leaching with (NH₄)₂SO₄. These findings provide valuable insights into the bioleaching of IATRE ores and present a novel approach for the adequate recovery of REEs from IATRE ores and tailings.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106495"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144288874","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}

{"title":"Pulsed electrolysis: An efficient approach to enhancing purity from 4N to 6N copper","authors":"Qing-hua Tian,&nbsp;Liang-hong Duan,&nbsp;Zhi-peng Xu","doi":"10.1016/j.hydromet.2025.106513","DOIUrl":"10.1016/j.hydromet.2025.106513","url":null,"abstract":"<div><div>The conventional direct-current (DC) electrorefining process is widely used for the purification of blister copper to achieve high-purity grades. However, this process typically requires extended operational cycles and exhibits limitations in removing trace impurities such as silver and tin. To address these challenges, a pulsed electro-refining method is proposed that achieves enhanced impurity removal efficiency and shorter purification time. The experimental results showed that higher impurities removal efficiency and better appearance of high-purity copper deposits could be reached in the pulse electrolysis process. The total impurities concentration of copper products could be reduced to 0.74 mg/kg after 24 h by pulse electro-refining, which could only reach 1.24 mg/kg by DC electrolysis. Moreover, the silver and tin concentrations decreased by 95 % and 85 %, respectively. In addition, the effects of several crucial conditions during the pulsed electrolysis process were investigated, including pulse current density, pulse frequency, pulse duty ratio, and pulse electrolysis duration. The results indicated that the concentrations of all impurities apart from silicon were reduced and the purity of copper deposits reached 6 N under the experimental conditions of pulse current density of 400 A/m², pulse frequency of 500 Hz, and pulse duty ratio of 50 % after 36 h. In summarily, the pulsed electrolysis process demonstrates excellent efficacy in producing high-purity copper.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106513"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144290928","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}

{"title":"Vanadium(II) reductive upgrading of copper sulfide concentrates via Iron leaching to facilitate stagewise oxidative copper leaching at room temperature","authors":"Charles Kim ,&nbsp;Brian Donovan ,&nbsp;Jeffrey P. Fitts ,&nbsp;Raymond S. Farinato ,&nbsp;D.R. Nagaraj ,&nbsp;Scott Banta ,&nbsp;Alan C. West","doi":"10.1016/j.hydromet.2025.106509","DOIUrl":"10.1016/j.hydromet.2025.106509","url":null,"abstract":"<div><div>Over this coming decade, copper demand in the United States is projected to increase significantly because of the energy transition to carbon-free sources. Compared to traditional hydrometallurgical processes involving oxidation, reductive leaching of copper mineral concentrates has been shown to yield significant advantages. For example, reductive leaching of chalcopyrite can be performed at ambient temperatures without intensive grinding. This could achieve high yields, reduced processing costs, all while minimizing environmental impacts.</div><div>This work explores vanadium reductive leaching of other copper mineral concentrates by measuring leaching kinetics and yields. Over 90 % of the copper was successfully extracted from copper concentrates obtained from three active mines, each with different mineral compositions, after reacting in VSO₄, H₂SO₄ solution at room temperature for 60 min. It was shown that the addition of FeSO₄ enhanced the leaching yields of copper from chalcocite (Cu₂S), from 55.1 % to 100 % in concentrates having moderate iron concentrations and from 62.7 % to 82.2 % in low-iron concentrates. The copper recovery in low-iron concentrates could be increased to 99 % after leaching a second time, suggesting a staged operation may be favored. Results show that similar yields may be achieved when leaching occurs in a continuous flow reactor with residence times between 10 and 20 min. For example, 85.2 % - 100 % of iron was leached from Source 2 concentrates, and 87.7 % - 95.3 % of iron was leached from Source 3 concentrates in continuous flow leaching. The processing rate using the continuous flow reactor was 87 g/L h⁻¹, a rate competitive with existing processing methods.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106509"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144196148","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}

{"title":"Hydrometallurgical process of spent lithium-ion battery recycling Part. 2 Recovery of valuable metals from the cathode active material leachates: Review and cost analysis","authors":"Junghyun Lim ,&nbsp;Yunjai Jang ,&nbsp;Junbeum Lee ,&nbsp;Chaehyeon Lee ,&nbsp;Omayma Jbari ,&nbsp;Kyungjung Kwon ,&nbsp;Eunhyea Chung","doi":"10.1016/j.hydromet.2025.106516","DOIUrl":"10.1016/j.hydromet.2025.106516","url":null,"abstract":"<div><div>The rapid increase in lithium-ion batteries (LIBs) usage, particularly in portable electronics and electric vehicles, has led to considerable environmental challenges due to waste generation, creating a need for recovery of metals from waste. This review examines methods for recovering valuable metals—Co, Ni, Mn, and Li—from the leachates of end-of-life spent LIBs using hydrometallurgical unit processes, summarizing current research and technological advancements. Recovery techniques such as precipitation, solvent extraction, electrodeposition, ion exchange (and adsorption), and other approaches were evaluated in terms of efficiency, cost-effectiveness, and environmental impact. Moreover, a cost analysis comparing hydrometallurgical methods—precipitation, solvent extraction, electrochemical extraction—was conducted. This review highlights the technological gaps in current recovery methods and stresses the need for further research to improve metal recoveries and minimize the environmental impacts of hydrometallurgical processes. Integrating experimental findings, the review offers a comprehensive overview of recovery pathways and provides insights into the future of sustainable LIBs recycling and cost analysis.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106516"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144313460","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}

{"title":"Integration of H2S gas cleaning and bioleaching for zinc recovery from electric arc furnace dust","authors":"Päivi Kinnunen ,&nbsp;Hanna Miettinen ,&nbsp;Christian Frilund ,&nbsp;Pekka Simell","doi":"10.1016/j.hydromet.2025.106505","DOIUrl":"10.1016/j.hydromet.2025.106505","url":null,"abstract":"<div><div>Electric arc furnace (EAF) dust is a by-product of the stainless-steel industry that contains significant amounts of zinc and iron as well as lead and is classified as hazardous waste. Recovering metals from the EAF dust would increase the zinc supply from waste and decrease the amount of hazardous waste. Cleaning of industrial gases using EAF dust is a potential low-cost alternative to non-regenerable primary ZnO adsorbents. The challenge is to develop further treatment methods for sulfide materials to recover their metal values and manage sulfur, by comparing the leaching of EAF before and after sulfidation with H₂S. This study shows the feasibility of integrating H₂S removal by adsorption at elevated temperatures using EAF dust with zinc recovery from the sulfide material of EAF after sulfidation (S-EAF) using bioleaching. In this process, sulfur- and iron-oxidizing microorganisms oxidize the sulfide mineral and leach zinc into the solution. Hydrometallurgical EAF dust recycling technologies require significant quantities of acid. A part of the acid used for leaching can be produced from the sulfide material itself, significantly reducing the need for external sulfuric acid. Integrating gas cleaning with bioleaching enables the utilisation of both the metal and captured sulfur content. The integrated sulfur capture-bioleaching concept has potential for adaptation to other oxidized waste materials beyond EAF dust.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106505"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144123459","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}

{"title":"Leaching kinetics of molybdenite with layered structure and hydrophobic properties in the H2SO4-H2O2-H2O system at atmospheric pressure","authors":"Zhiyuan Chen ,&nbsp;Zihui Jiang ,&nbsp;Qiu Hu ,&nbsp;Jiangtao Li","doi":"10.1016/j.hydromet.2025.106527","DOIUrl":"10.1016/j.hydromet.2025.106527","url":null,"abstract":"<div><div>Previous studies on the leaching kinetics of molybdenite were primarily based on processing data using a contraction core model with spherical mineral particles. However, molybdenite particles exhibit a thin plate and layered structure. In this study, a model of circular particles was employed to derive the kinetic equation. The apparent activation energies of the molybdenite leaching reaction, both without mechanical activation and with mechanical activation treatment, were calculated as 55.3 kJ/mol and 49.5 kJ/mol, respectively. The layered structure of molybdenite renders its mineral particles challenging to grind during the ball milling process. Nonetheless, this process enhanced the active point of the mineral to a certain extent, thereby facilitating the leaching reaction. The rate-limiting step of the leaching reaction was identified as the chemical reaction step. Specifically, the reaction order of H₂SO₄ and H₂O₂ were determined as 0.063 and 0.959, respectively. Notably, variations in the H₂O₂ concentration exerted a significant impact on the leaching effect, while changes in the concentration of H₂SO₄ exhibited a relatively smaller effect. Additionally, molybdenite exhibited strong hydrophobic properties. The addition of surfactants improved the reaction environment and enhanced the leaching effect. The expression for leaching kinetics was defined as follows:<span><span><span><math><mn>1</mn><mo>−</mo><msqrt><mrow><mn>1</mn><mo>−</mo><mi>α</mi></mrow></msqrt><mo>=</mo><msub><mi>k</mi><mi>r</mi></msub><mi>t</mi><mo>=</mo><mn>7.73</mn><mo>×</mo><msup><mn>10</mn><mn>3</mn></msup><msubsup><mi>r</mi><mn>0</mn><mrow><mo>−</mo><mn>1</mn></mrow></msubsup><msubsup><mi>C</mi><mrow><mi>H</mi><mn>2</mn><mi>SO</mi><mn>4</mn></mrow><mn>0.063</mn></msubsup><msubsup><mi>C</mi><mrow><mi>H</mi><mn>2</mn><mi>O</mi><mn>2</mn></mrow><mn>0.959</mn></msubsup><msup><mi>e</mi><mrow><mo>−</mo><mfrac><mn>59706</mn><mi>RT</mi></mfrac></mrow></msup><mi>t</mi></math></span></span></span></div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106527"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144572672","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}

{"title":"Arsenic precipitation and bioscorodite crystallization from acidic metallurgical wastewater under different bioreactor schemes: In-silico performance analysis","authors":"Evelyn Gaxiola-Muñiz ,&nbsp;Ricardo Aguilar-López ,&nbsp;Sergio A. Medina-Moreno ,&nbsp;Edgar N. Tec-Caamal","doi":"10.1016/j.hydromet.2025.106531","DOIUrl":"10.1016/j.hydromet.2025.106531","url":null,"abstract":"<div><div>Arsenic removal from water is still a challenge to overcome, and the biologically induced formation of scorodite offers an effective approach for treating arsenic-containing effluents from the metallurgical industry. This paper presents a model-based analysis of the dynamics of the overall bioscorodite process under different bioreactor schemes. For this purpose, a modified model was experimentally validated obtaining 0.87 &lt; R² &lt; 0.99 for all variables with <em>p</em>-values &lt;0.001. The validated model was able to adequately predict the dynamics of each variable, which were verified by experimental observations. Subsequently, batch, fed-batch, combined batch/continuous, single-stage, and multi-stage continuous bioreactors were investigated through simulations, testing operational variables that influence the arsenic removal capacity, such as inoculum, ion concentration, dilution rate, and seeding. A comparative basis was then established to identify the bioreactor setups that enhance the arsenic immobilization as a bioscorodite. Single-stage and cascade bioreactors had high arsenic precipitation rates (up to 3.2 g L⁻¹ d⁻¹) and crystal sizes around ∼150 μm. Results showed that three reactors connected in series were able to precipitate 87 % arsenic with a high fed concentration (6.2 g L⁻¹), while a higher number of serial reactors may increase conversion but affect negatively the practicality and feasibility of the system. Combined batch/continuous scheme was useful to obtain large crystal sizes, up to 225 μm. These findings underscore the effectiveness of a model-based design for bioscorodite crystallization process, providing a promising and scalable solution for arsenic removal from industrial effluents.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106531"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144571024","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}

{"title":"Separation of thorium using new solvent extractant derived from recycling discarded plastic bottles","authors":"Ahmed Orabi ,&nbsp;Hend Salem ,&nbsp;Nagwa Falila ,&nbsp;Doaa Ismaiel ,&nbsp;Magd Badr","doi":"10.1016/j.hydromet.2025.106533","DOIUrl":"10.1016/j.hydromet.2025.106533","url":null,"abstract":"<div><div>Due to the non-biodegradable nature of plastic bottle waste, this work offers a method to recycle this waste by converting it into a valuable and efficient extractor for thorium separation from spent ore. A new promising extractant (Rec-UPEST) was successfully synthesized based on the glycolysis of plastic bottle waste by utilizing a mixture of glycerol and diethylene glycol, followed by esterification using the natural fatty acid of linolenic acid. Several characterizations, such as FTIR spectrometry, ¹H NMR analysis, and MS analysis, were performed to ensure its felicitous preparation. The produced material (Rec-UPEST) dissolved in CHCl₃ could extract Th(IV) efficiently with the maximum loading capacity of 1.08 g L⁻¹ at 15 min, organic to aqueous ratio = 1:1, <em>T</em> = 298 K, and pH = 2. Infrared data confirmed that the extraction was achieved by the bonding of the extractant to the thorium through glycol and ester oxygen atoms. The slope analysis technique inferred that Rec-UPEST has been able to extract Th as a complex with a 2:1 (Rec-UPEST: Th) molar ratio. In two stages, as shown by the resulting McCabe-Thiele diagrams, Th can be successfully extracted and stripped. Thermodynamic calculations showed that Rec-UPEST /Th extraction is an exothermic process. The stripping process of Th (99.8 %) was achieved using 2 mol L⁻¹ HNO₃. To compile all of the recovery steps of Th from the waste residue of the mineralized microgranite dike used in this research, a proposed flow diagram was created.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106533"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144621881","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}

{"title":"Recovery process of rare earths, Al, U, and Th from ionic rare earth purification residue using sequential alkaline leaching, acid leaching solvent extraction and stripping","authors":"Qiaofa Lan ,&nbsp;Xiaolin Zhang ,&nbsp;Fei Niu ,&nbsp;Donghui Liu ,&nbsp;Youming Yang","doi":"10.1016/j.hydromet.2025.106524","DOIUrl":"10.1016/j.hydromet.2025.106524","url":null,"abstract":"<div><div>Ionic rare earth purification residue (PR) originates from refining of ionic rare earth ores and is predominantly composed of rare earth elements (REEs), aluminum (Al), and silicon (Si). This is a recyclable secondary resource. It provides substantial challenges due to its classification as low-level radioactive waste (LLW). Recognizing the distinctive properties of PR, this paper describes a highly efficient process for the recovery and enrichment of Al, REEs, uranium (U), and thorium (Th) through a multistep process encompassing alkali digestion, hydrochloric acid leaching, sole extractant enrichment and separation. At a controlled temperature of 70 °C, the Al digestion efficiency reached 88.9 %. The alkali digestion residue underwent hydrochloric acid leaching, yielding leaching efficiencies of 99.9 %, 99.4 %, and 99.0 % for REEs, U(VI), and Th(IV), respectively. Notably, the amount of insoluble residue was reduced by 90 %, and it was transformed from LLW into general solid waste residue. Additionally, the utilization of 2-ethylhexyl phosphonic acid mono 2-ethylhexyl ester (HEHEHP) as the sole extractant provided 100 % extraction efficiencies for U(VI) and Th(IV). After stepwise stripping processes, the purities of both U(VI) and Th(IV) exceeded 90 %. The REEs were precipitated as RE₂(C₂O₄)₃ and subsequently calcined to produce rare earth oxides with a recovery of 90.1 % and a purity of 97.4 %. This comprehensive scheme addressed the persistent challenges associated with long-term storage and radiological environmental risk.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"236 ","pages":"Article 106524"},"PeriodicalIF":4.8,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144518263","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}