Hydrometallurgy最新文献

{"title":"Electrochemically assisted leaching of rare earth carbonates in non-aqueous green solvents: Solvent design, characterization, and process optimization","authors":"Salih Cihangir","doi":"10.1016/j.hydromet.2025.106599","DOIUrl":"10.1016/j.hydromet.2025.106599","url":null,"abstract":"<div><div>This study presents a systematic approach to the design, characterization, and application of non-aqueous green solvents (NAGSs) for the leaching of rare earth carbonate hydrates (RECHs). Four NAGSs based on choline chloride, ethylene glycol, and various carboxylic acids were synthesized and evaluated for their physicochemical and electrochemical properties. Among the evaluated formulations, the choline chloride–ethylene glycol–Na₂EDTA·2H₂O mixture (N1) and the chloride–levulinic acid mixture (N2) were found were found suitable for both traditional and electrochemically assisted leaching due to their optimal viscosity, conductivity, and electrochemical stability. Electrochemical assistance significantly enhanced leaching efficiency, with improvements ranging from 22 % to over 300 % for certain elements compared to conventional methods. Mechanistic investigations revealed that the application of an oxidative potential facilitates the protonation and dissolution of RECHs, likely through the generation of localized acidic environments and the formation of intermediate species. The FTIR analysis confirmed the dissolution of carbonate phases and the formation of rare earth–ligand complexes, particularly in the N1 system, where new bands associated with carboxylate and amine coordination were observed. Importantly, the proposed electrochemically assisted method can be applied to different primary or secondary sources in both aqueous and non-aqueous solutions. The results demonstrate the advantages of combining non-aqueous green solvents with electrochemical assistance as an environmentally benign alternative to conventional acid-based leaching, especially for challenging carbonate forms of rare earth elements. This work provides important guidelines for the development of sustainable hydrometallurgical processes, with future directions including solvent recyclability, selective recovery, and environmental assessment.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106599"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145360215","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":"2026-01-01","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":"Field-effect separation of rare earth elements in gelatin-supported media","authors":"Benjamin Schroeder ,&nbsp;Michael Free ,&nbsp;Prashant K. Sarswat","doi":"10.1016/j.hydromet.2025.106585","DOIUrl":"10.1016/j.hydromet.2025.106585","url":null,"abstract":"<div><div>The unique optical, electronic, and magnetic properties of the Rare Earth Elements (La-Lu + Sc, Y) have led to a significant increase in their demand by a wide variety of industries. This, coupled with the significant difficulty associated with their extraction, separation, and purification, has resulted in a strong interest in replacing the traditional solvent extraction with a new approach. In response, a new technology called “Field-Effect Separation” (FES) has been developed, which utilizes differences in the magnetic susceptibilities of ions in a strong field to separate them from one another. While it has been demonstrated that this approach can work, it is necessary to more fully understand and optimize the separation of elements. The approach taken to study this was to suspend a solution of REE ions in a firm gelatin, separating them using a strong magnet, freezing the sample to preserve separation, and taking fine slices to analyze the concentration of ions at different spatial positions relative to the magnet as well as different times relative to the beginning of the magnetic field exposure. The results show a significant concentration effect for the magnetically susceptible REEs near the magnet's surface, while the non-susceptible ions seem relatively unconcentrated by the magnetic field. Additionally, among the susceptible REEs, at certain, short separation timescales, a significant stratification of REEs was observed. This suggests that the REEs can be separated from one another using FES assuming a correct time and length scale can be selected for the system.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106585"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145270451","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 gallium from acid leachates of zinc smelting slag by tartaric acid coordinated complexation and anion-exchange","authors":"Mingwei Qi ,&nbsp;Minyu Zhu ,&nbsp;Hao Chen ,&nbsp;Yun Liu ,&nbsp;Zhiqiang Lin ,&nbsp;Zezuo Jiang ,&nbsp;Jing Wu ,&nbsp;Chunlin He","doi":"10.1016/j.hydromet.2025.106581","DOIUrl":"10.1016/j.hydromet.2025.106581","url":null,"abstract":"<div><div>The rapid advancement of strategic technologies, including semiconductor manufacturing, 5G infrastructure, renewable energy systems, and aerospace engineering, has driven a surge in global demand for gallium (Ga). To address this need, secondary resources such as zinc smelting slag have emerged as a critical source for gallium recovery. This study proposes a novel strategy for gallium recovery by leveraging the ligand complexation capability of tartaric acid to convert Ga(OH)₃ into negatively charged complexes([GaO₂(OH)C₄H₂O₄]₂⁴⁻), followed by selective adsorption using a polystyrene-based anion-exchange resin (D201 × 7). The results demonstrated that the maximum adsorption capacity was 138 mg/g at pH 4, <em>T</em> = 328 K, <em>t</em> = 45 min and 1:1 M ratio of tartaric acid with Ga. The adsorption process conformed to the pseudo-second-order kinetic and Langmuir isotherm models. The primary mechanism for the adsorption of Ga(III) involved complexation with tartaric acid to form an anionic species and undergo ion exchange via the Cl⁻ functional groups on the D201 × 7 resin. The column experiment demonstrated highly selective adsorption efficiency of Ga(III) in the presence of various interfering metal ions. This study provides a feasible alternative for the separation of Ga(III) from industrial zinc slag processing in sulfuric acid systems and has broad application prospects.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106581"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145236566","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":"Specific chelating extraction of gallium(III) with H-N and H-CCl2 hydrogen atoms of dichlorinated secondary amide","authors":"Gehui Pang ,&nbsp;Shintaro Morisada ,&nbsp;Hidetaka Kawakita ,&nbsp;Keisuke Ohto","doi":"10.1016/j.hydromet.2025.106596","DOIUrl":"10.1016/j.hydromet.2025.106596","url":null,"abstract":"<div><div>Three secondary amides with different numbers of chlorine atom(s)—<em>N</em>-(2-ethylhexyl)monochloroacetamide (<strong>MCAA</strong>), <em>N</em>-(2-ethylhexyl)dichloroacetamide (<strong>DCAA</strong>), and <em>N</em>-(2-ethylhexyl)-2,2,2-trichloroacetamide (<strong>TCAA</strong>)—were synthesised for Ga(III) extraction. These three amides exhibited a preference for extracting Ga(III) compared to other metals at higher HCl concentrations, with the stoichiometries of Ga(III) extraction using the three reagents investigated <em>via</em> slope analysis. Spectroscopic studies were performed to elucidate the extraction mechanism of GaCl₄⁻. The hydronium ion extraction with (<strong>O</strong>)=C oxygen atoms of amides did not occur in lower HCl concentration media ([HCl] &lt; 8.46 mol dm⁻³), indicating that (<strong>H</strong>)-N hydrogen atom displayed a distinctive interaction with GaCl₄⁻. The <strong>DCAA</strong> exhibited the highest Ga(III) extraction efficiency among the three secondary amides. The proton nuclear magnetic resonance spectroscopic analysis and density functional theory calculations indicated that the <em>δ</em>⁺ value of the hydrogen atom in (<strong>H</strong>)-C-Cl₂ of <strong>DCAA</strong> was enhanced to assist GaCl₄⁻ extraction with the (<strong>H</strong>)-N hydrogen atom. Stable intermolecular hydrogen bonding between (<strong>H</strong>)-N hydrogen and the partially negatively charged (<strong>O</strong>)=C oxygen atoms of <strong>MCAA</strong> inhibited GaCl₄⁻ extraction. The complete stripping of Ga(III) from the Ga-loaded <strong>MCAA</strong> and <strong>TCAA</strong> was achieved using water, while chelation extraction with <strong>DCAA</strong> suppressed the efficiency of Ga(III) stripping with water.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"239 ","pages":"Article 106596"},"PeriodicalIF":4.8,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322432","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":"2026-01-01","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":"Aluminium recovery from coal fly ash for the production of high purity alumina","authors":"Cameron J. Johnston ,&nbsp;Rachel A. Pepper ,&nbsp;Wayde N. Martens ,&nbsp;Sara J. Couperthwaite","doi":"10.1016/j.hydromet.2025.106573","DOIUrl":"10.1016/j.hydromet.2025.106573","url":null,"abstract":"<div><div>The vast scale of coal combustion worldwide has led to large amounts of fly ash (waste product) being produced. One method of dealing with this waste is using it as a feedstock for new processes, such as producing high purity alumina (HPA: &gt;99.99 % Al₂O₃). The research presented demonstrates a method of recovering aluminium from coal fly ash for the synthesis of high purity alumina. The method involves: (1) a caustic fusion method that converts mullite into soluble sodalite phase, (2) a pH adjustment to concentrate aluminium, (3) a purification stage using hydrochloric acid crystallisation, and (4) calcination at 1250 °C to convert aluminium chloride hexahydrate crystals to α-Al₂O₃. This method produced HPA with an alumina purity of 99.99 %.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"238 ","pages":"Article 106573"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145026480","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":"High-pressure acid leaching of laterite ores: Effect of acid and solid content on Ni and Co yield under non-isothermal and isothermal conditions","authors":"Okechukwu Vincent Dickson ,&nbsp;Thomas Deleau ,&nbsp;Fabienne Espitalier ,&nbsp;Christophe Coquelet ,&nbsp;Julien Lombart ,&nbsp;Philippe Accart","doi":"10.1016/j.hydromet.2025.106576","DOIUrl":"10.1016/j.hydromet.2025.106576","url":null,"abstract":"<div><div>The increasing demand for nickel (Ni) in electric vehicle batteries necessitates efficient extraction methods from laterite ores. High-Pressure Acid Leaching (HPAL) is a prominent hydrometallurgical technique known for its rapid kinetics and high (&gt;90 %) metal dissolution. This study examines the influence of acid-to-ore (A/O) ratios (0.25, 0.35, and 0.45) and slurry solid contents (22, 26, and 30 wt.%) on Ni yield and selectivity under both non-isothermal (100 °C, 1.2 bar; 150 °C, 4.7 bar; 200 °C, 18.9 bar; 265 °C, 50.5 bar) and isothermal (265 °C) conditions.</div><div>Under non-isothermal conditions, Ni leaching efficiency improved with temperature, achieving a maximum yield of 94.67 ± 0.02 wt.% at 265 °C, compared to 50.86 ± 0.02 wt.% at 200 °C, using an A/O ratio of 0.45 and 26 wt.% solids over 60 min. Isothermal experiments at 265 °C revealed that higher A/O ratios enhanced Ni yield, reaching 94.45 ± 0.01 wt.% at 60 min with 26 wt.% solids and an A/O of 0.45. However, this increased yield was accompanied by higher dissolution of Fe (1.07 ± 0.12 wt.%) and Al (38.84 ± 0.07 wt.%), reducing selectivity to 0.73 ± 0.01. Conversely, an A/O ratio of 0.25 at 26 wt.% solids achieved a higher selectivity of 3.83 ± 0.05 but with a lower Ni yield of 79.14 ± 0.03 wt.%. Lower slurry solid content further improved Ni leaching; at 22 wt.% solids and an A/O of 0.45, Ni yield reached 95.87 ± 0.01 wt.% with a selectivity of 0.89 ± 0.02 at 60 min.</div><div>Scanning Electron Microscopy (SEM) and X-ray Diffraction (XRD) analyses of leached residues indicated that high temperatures facilitate the transformation of primary minerals like goethite and gibbsite into hematite and hydronium alunite. This transformation is more pronounced at higher A/O ratios, affecting the mineralogical composition of the post-leach solid residue.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"238 ","pages":"Article 106576"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145105653","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 nickel, copper and zinc sulfate solutions from electroplating sludge leachate using a novel synergistic solvent system of DMPY and Versatic 10","authors":"Haokai Peng ,&nbsp;Zuoying Cao ,&nbsp;Shengxi Wu ,&nbsp;Qinggang Li ,&nbsp;Mingyu Wang ,&nbsp;Xinsheng Wu ,&nbsp;Wenjuan Guan ,&nbsp;Guiqing Zhang","doi":"10.1016/j.hydromet.2025.106567","DOIUrl":"10.1016/j.hydromet.2025.106567","url":null,"abstract":"<div><div>As the demand for Ni continues to rise, the recovery of Ni from electroplating sludge leachate has become an effective approach to alleviate supply constraints. However, the presence of impurities such as Cu, Zn, and Ca in the leachate complicates the Ni recovery process. To address these challenges, a novel pyridine group extractant, 2-((dodecylthio) methyl) pyridine (DMPY), was designed, synthesized, and evaluated for its synergistic performance with Versatic 10 (C₁₀H₂₀O₂) in selectively extracting Ni. Under optimal conditions, Ni was selectively recovered from electroplating sludge leachate including Cu, Zn, and Ca through three steps of the extraction processes. Mechanistic studies revealed that both DMPY and Versatic 10 anion coordinated with Ni²⁺, providing charge balance, forming the complex [Ni²⁺(DMPY)₂(C₁₀H₁₉O₂⁻)₂]. This synergistic solvent system significantly improved Ni extraction efficiency while minimizing reagent consumption. In conclusion, The DMPY-Versatic 10 system offers a sustainable and environmentally friendly solution, enhancing the hydrometallurgical treatment of polymetallic electroplating sludge and contributing to resource recovery and environmental protection.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"238 ","pages":"Article 106567"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145019906","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":"Palladium adsorption from alkaline glycine-cyanide solutions using activated carbon","authors":"C. Rubina Acuña,&nbsp;E.A. Oraby,&nbsp;G.A. Bezuidenhout,&nbsp;C.C. Beh,&nbsp;J.J. Eksteen","doi":"10.1016/j.hydromet.2025.106575","DOIUrl":"10.1016/j.hydromet.2025.106575","url":null,"abstract":"<div><div>There is an increasing demand for the use of Platinum Group Metals (PGMs) in various industries such as fuel cells, auto catalysts, electrical and electronics, e-waste and medical, which has significantly increased their market value (250 % increased value for palladium). Currently, technologies for separating and purifying metals, such as solvent extraction (SX) and ion exchange (IX), are generally applied with cyanide and acidic chloride systems to recover PGMs. In recent years, applications of amino acids, particularly glycine, have been developed and patented, as an alternative lixiviant for gold and copper leaching. Recent research on e-waste has shown an effective dissolution/leaching of Pd from glycine and glycine-cyanide solutions. The alkaline amino acid leaching represents an opportunity for a more selective and environmentally friendly approach, compared to the current applications using cyanide and chlorine systems.</div><div>The objective of this research is to investigate the feasibility of palladium (Pd) adsorption, using activated carbon, from synthetic leach solutions containing alkaline glycine–cyanide. 24-h tests were performed to assess the impact over Pd adsorption from various operational parameters including Pd initial concentration, pH, glycine and cyanide concentrations, carbon dosage, and temperature. Results showed that Pd can be efficiently recovered from glycine–cyanide solutions using activated carbon under different operational conditions, with the highest recoveries achieved at 20 g/L carbon dosage and pH 9.5 (98.2 %), and 95.5 % at 5000 mg/L glycine. The results have shown that the most significant parameters impacting adsorption efficiency (kinetics) are carbon dosage, temperature and pH. The experimental data from various initial concentrations of Pd were best fitted to the Langmuir model (R² &gt; 0.9), with the maximum uptake capacity (Q_m) at different initial Pd concentrations ranging between 0.5 mg/g and 2.2 mg/g. In addition, the results of the kinetic modelling were best described by a pseudo-second-order model (R² &gt; 0.99), for all parameters studied.</div></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"238 ","pages":"Article 106575"},"PeriodicalIF":4.8,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145118633","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}