Hydrometallurgy最新文献

{"title":"Integrated acid leaching of spent battery cathode material (LCO, NMC111) and flotation tailings of pyrite and pyrrhotite","authors":"Anssi Karppinen,&nbsp;Henna Liljanko,&nbsp;Sipi Seisko,&nbsp;Mari Lundström","doi":"10.1016/j.hydromet.2025.106618","DOIUrl":"10.1016/j.hydromet.2025.106618","url":null,"abstract":"<div><div>Lithium-ion batteries require number of metals which have been listed as critical raw materials in European Union due to their supply risk and economic importance. Therefore, more emphasis needs to be put on (i) recycling of spent batteries, (ii) utilizing other secondary sources of battery metals and primary mining waste. In this research, leaching of battery metals from cathode materials—lithium cobalt oxide (LCO) and lithium nickel manganese cobalt oxide (NMC111)—was investigated with the aim to use waste fraction of primary mining, namely sulfide-rich flotation tailings, as reductant. Two types of tailings were investigated in the current study: pyrrhotite-pyrite tailings and pyrite tailings. These tailings contain reductive power necessary for leaching, as well as battery metals incorporated in the sulfide matrix. The investigated parameters were temperature (40–80 °C) and mass ratio of cathode material and tailings (0.5–2 g/g) whereas S/L-ratio (100 g/L), acid concentration ([H₂SO₄] = 1 M), and leaching time (180 min) were kept constant. The results showed that both pyrrhotite-pyrite as well as pyrite dominated tailings can act as an effective reductant for the leaching of metals from cathode materials. The extraction efficiency of battery metals correlate with dissolved iron concentration. When only pyrite tailings were used in the process, the reductive effect of S₂²⁻ could also be recognized as lower concentration of dissolved Fe²⁺ was required when compared to use of pyrrhotite tailings. At 80 °C, LCO and NMC could be completely dissolved within 60min while simultaneous extraction of battery metals from sulfide flotation tailings was up to 17 % of Ni, 15 % of Co, and 27 % of Cu.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"240 ","pages":"Article 106618"},"PeriodicalIF":4.8,"publicationDate":"2025-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145575458","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":"Studtite dissolution in the presence of organic complexants relevant to nuclear waste disposal","authors":"Zachary Murphy ,&nbsp;Rachel Cohen ,&nbsp;David Rai II ,&nbsp;Cassandra Munoz ,&nbsp;Caleb Johnson ,&nbsp;Edwin Davidson ,&nbsp;Swadeshmukul Santra ,&nbsp;Vasileios Anagnostopoulos","doi":"10.1016/j.hydromet.2025.106610","DOIUrl":"10.1016/j.hydromet.2025.106610","url":null,"abstract":"<div><div>Studtite (UO₂O₂∙4H₂O), a uranyl peroxide mineral, has been found in nuclear waste storage tanks alongside complexing agents such as EDTA, HEDTA, and NTA. The influence of these ligands on the fate and transport of uranium, a risk driving contaminant, is critical for understanding the consequences of nuclear waste leakages. This study investigated the stability of studtite in the presence of these ligands under varying pH conditions (3, 7, 9, and 11), ligand concentrations (0.15 mM, 1.5 mM, and 15 mM), and ionic strengths. Batch kinetic experiments were conducted with 1 mg of studtite in 50 mL suspensions (12.7 mg/L total U), and the uranium concentration in the aqueous phase was monitored over time. Results showed uranium release from studtite even in the absence of ligands at pH 3 and 11, while at pH 7 and 9 uranium was only released in the presence of ligands. The presence of EDTA and NTA increased aqueous uranium at pH 7 and 9 by forming soluble U-ligand complexes, as confirmed by NMR and speciation diagrams. HEDTA enhanced studtite dissolution at all tested pH values. Increased ionic strength reduced electrostatic repulsion between ligands and the mineral surface, further promoting dissolution. In simulated nuclear waste, uranium predominantly favored the aqueous phase regardless of ligand presence. These findings indicate that EDTA, HEDTA or NTA presence in waste can provide a pathway for studtite dissolution, increasing the amount of aqueous uranium in waste while also changing aqueous uranium speciation. This impacts the mobility of contaminated waste in the occurrence of waste leakage, complicating uranium fate and transport in the environment. These findings have implications for uranium fate and transport modeling and the development of nuclear waste treatment strategies.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"240 ","pages":"Article 106610"},"PeriodicalIF":4.8,"publicationDate":"2025-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145559854","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":"The circularity of turning wastes into valuable resources: Rare earth elements recovery from phosphogypsum – A short review","authors":"Diego Teuber Gijon,&nbsp;Luciana Jandelli Gimenes,&nbsp;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 (&gt;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}

{"title":"Utilising micro-CT to analyse fluid dynamics in dual-porosity packing systems","authors":"Quan Zheng ,&nbsp;Kunning Tang ,&nbsp;Ying Da Wang ,&nbsp;Samuel J. Jackson ,&nbsp;Thomas Poulet ,&nbsp;Ryan Armstrong ,&nbsp;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}

{"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 ,&nbsp;Kedhareswara Sairam Pasupuleti ,&nbsp;Hee-Nam Kang ,&nbsp;Tae-Hyuk Lee ,&nbsp;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_xCo_yMn_zO₂ 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 % (<em>v</em>/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.</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}

{"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 ,&nbsp;Retno Wijayanti ,&nbsp;Isyatun Rodliyah ,&nbsp;Kukuh Nur Hidayat ,&nbsp;Asep Bahtiar Purnama ,&nbsp;Denny Zahir Dayyan ,&nbsp;Siti Rochani ,&nbsp;Amelia Andriani ,&nbsp;Saboor Ahmad Torabi ,&nbsp;Sariman ,&nbsp;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}

{"title":"Copper leaching from water-quenched slag using an ethylenediamine-enhanced ammonia leaching system","authors":"Jianjun Sun ,&nbsp;Tianfu Zhang ,&nbsp;Peilun Shen ,&nbsp;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 &gt; EDA &gt; NH₃ and (NH₄)₂S₂O₈–EDA &gt; (NH₄)₂S₂O₈–NH₃ &gt; 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.</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}

{"title":"Tellurium metal recovery from copper smelter residues: A short-route via sulfide leaching and precipitation by sodium sulfite","authors":"Zuowei Liu ,&nbsp;Lili Jia ,&nbsp;Zhirui Tian ,&nbsp;Qinghua Tian ,&nbsp;Xueyi Guo ,&nbsp;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}

{"title":"New insights into zinc-to‑indium molar ratio, pH, and temperature effects on indium cementation rate and product quality","authors":"Thiago J. Santos ,&nbsp;Augusta Isaac ,&nbsp;Virginia S.T. Ciminelli ,&nbsp;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>_<em>Zn</em><em>/n</em>_<em>In</em>) 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>_<em>Zn</em><em>/n</em>_<em>In</em> 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 <em>n</em>_<em>Zn</em><em>/n</em>_<em>In</em> 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>_<em>Zn</em><em>/n</em>_<em>In</em> ratio. The refinement and quantitative chemical analysis revealed that increasing the <em>n</em>_<em>Zn</em><em>/n</em>_<em>In</em> 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.</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}

{"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,&nbsp;Yufeng Guo,&nbsp;Shuai Wang,&nbsp;Feng Chen,&nbsp;Yu Zheng,&nbsp;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 [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 M_xTi_3-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.</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}