Hydrometallurgy最新文献

{"title":"The role of oxidants in the intensive cyanidation of gold. 1. Gold dissolution","authors":"M. Nicol ,&nbsp;W.P. Staunton ,&nbsp;T. McGrath","doi":"10.1016/j.hydromet.2024.106363","DOIUrl":"10.1016/j.hydromet.2024.106363","url":null,"abstract":"<div><p>In the intensive cyanidation of gravity gold concentrates, sodium m-nitrobenzene sulfonate (NBS) is often used to supplement dissolved oxygen as the oxidant in the process. This paper presents the results of a largely electrochemical study of the behaviour of NBS during cyanidation. The results have confirmed that NBS acts as an oxidant in the cyanidation of gold and that the mixed potential model can be applied to describe the mechanism of its action.</p><p>The mixed potential is a good initial indicator of the rate of gold dissolution and, as expected, the anodic dissolution of pure gold in cyanide solutions is characterized by passivation at potentials above about −0.35 <em>V</em>.</p><p>The reduction of oxygen under the conditions of the present study occurs in two 2-electron steps with peroxide as an intermediate. Dissolution of gold occurs at potentials in the diffusion-controlled region for the first step. The cathodic reduction of NBS occurs in the same potential region as the reduction of oxygen. The reaction is first order in the concentration of NBS and is largely independent of the pH. The stoichiometry of the reaction involves six moles of gold per mole of NBS confirming that the amine is the final product of reduction of NBS.</p><p>Rates of gold dissolution in various solutions have been measured using a calibrated linear polarisation method. The rate increases approximately linearly with increasing NBS concentration and is independent of pH. The rate in 0.5 g/L NBS is approximately the same as in oxygenated solutions.</p><p>A relatively simple titration has been adapted for use in determining NBS concentrations.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106363"},"PeriodicalIF":4.8,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0304386X24001038/pdfft?md5=b4066a634b80387e78295882e22d3033&pid=1-s2.0-S0304386X24001038-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141638017","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recovery of Pt, Pd, and Rh from spent automotive catalysts through combined chloride leaching and ion exchange: A review","authors":"Mostafa Hosseinzadeh,&nbsp;Jochen Petersen","doi":"10.1016/j.hydromet.2024.106360","DOIUrl":"10.1016/j.hydromet.2024.106360","url":null,"abstract":"<div><p>Three platinum group metals (PGMs), platinum (Pt), palladium (Pd), and rhodium (Rh), are key components in automotive catalytic convertors, playing a pivotal role in controlling harmful emissions. The recycling and recovery of Pt, Pd, and Rh from spent automotive catalysts (SACs) have gained increasing attention as essential measures to mitigate resource depletion, supply risks, and environmental impacts. Due to the growing demand for automobiles and increasingly stricter environmental regulations, a substantial amount of spent automotive catalysts is generated annually, leading to increased interest in their efficient recycling and recovery of the PGMs they contain. Hydrometallurgical processes, particularly chloride leaching and ion exchange, have emerged as promising methods for efficient PGM extraction and separation from these discarded catalysts.</p><p>This review includes a critical examination of recent advances and innovations in both chloride leaching and ion exchange methods, highlighting their effectiveness in terms of Pt, Pd, and Rh recyclability and recovery efficiency from spent catalysts. The study offers valuable insights into the efficacy of their recycling from SACs through various processes. The importance of investigating the solution chemistry of PGMs in chloride media is highlighted and the leaching of SACs has been explored using various chloride media, including AlCl₃, NaCl, CaCl₂, MgCl, and NH₄Cl, alongside a range of inorganic and organic leaching agents such as HCl, H₂SO₄, HNO₃, acetic acid, citric acid, and oxidizing agents like H₂O₂, NaClO, NaClO₃, Fe³⁺, Cl₂, and Cu²⁺. This work is critically reviewed, examining the influence of key parameters investigated on the leaching efficiency of PGMs, such as HCl, Cl⁻, and oxidizing concentrations, temperature, solid-to-liquid ratio (S/L), particle size, and leaching time. Furthermore, it evaluates the effectiveness of pretreatment techniques such as calcination, salt roasting, and pre-reduction methods involving high temperatures, hydrogen gas flow, formic acid, hydrazine hydrate, and Zn-vapor treatments. The review then turns to the efficacy of the ion exchange method, utilizing a diverse range of anion exchange resins for the selective adsorption of PGMs as well as various elution reagents for the selective desorption of PGMs from loaded resins, aiming to recover them selectively from chloride leach solutions. Therefore, this study seeks to contribute to the development of strategies for recycling and reusing PGMs from SACs, with a view to reducing the industry's dependence on primary raw materials and promoting principles of the circular economy.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106360"},"PeriodicalIF":4.8,"publicationDate":"2024-07-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0304386X24001002/pdfft?md5=40de6c004bb02d98fcaba694a8e8dd60&pid=1-s2.0-S0304386X24001002-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141630425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Design of a continuous ion exchange process in battery metals recycling: From single column experiments towards a simulated moving bed configuration","authors":"Tobias Wesselborg ,&nbsp;Siiri Asumalahti ,&nbsp;Sami Virolainen ,&nbsp;Tuomo Sainio","doi":"10.1016/j.hydromet.2024.106361","DOIUrl":"10.1016/j.hydromet.2024.106361","url":null,"abstract":"<div><p>In hydrometallurgical recovery of LIB metals, ion exchange (IX) has hitherto played only a minor role. Separation experiments were conducted in single laboratory-scale IX columns with the aim of laying the foundation for a continuously operated multicolumn IX process similar to a simulated moving bed (SMB) configuration. In this study, the initial process developed earlier was improved by reducing the number of process steps and external streams. The desorption step with oxalate solution was examined in single-column batch experiments to ensure complete desorption of iron in the proposed continuous multicolumn IX process. Additionally, the volume flowrates were adjusted to achieve acceptable switch times of 25 min in an SMB configuration. It was found that the bead size of the resin is a critical factor in IX recovery of battery metals. The raffinate purity for the case of processing 2.5 BV lithium-ion battery waste leachate (LIBWL) improved from 97.2 % to 99.8 % when the resin bead size was reduced from 0.55 ± 0.05 mm to 0.4 ± 0.04 mm and a narrower bead size distribution. The LIBWL feed concentration was varied to mimic the dilution of fresh feed in an SMB set-up. The percentage recovery of Co and Ni decreased from 93.7 % and 96.6 % to 80.8 % and 89.4 %, respectively, when the LIBWL was diluted. This was a result of the decrease in concentration of impurity metals in the feed. Less impurity metals were sorbed and consequently, more ion exchange sites were available for the sorption of the target metals, which enhanced the retention of Co and Ni. The results were used to develop an IX column operation strategy and to suggest an initial SMB design. The multicolumn configuration presented in this work offers great potential for continuous production of high-purity Li, Ni and Co-containing raffinate (&gt; 99.5 %).</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106361"},"PeriodicalIF":4.8,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0304386X24001014/pdfft?md5=c7b5a37071e50f17419103cef06821e2&pid=1-s2.0-S0304386X24001014-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141638917","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of processes in Cu-ore heap leaching using Cu isotopes and leachate chemistry at Tschudi mine, northern Namibia","authors":"Ondra Sracek ,&nbsp;Vojtěch Ettler ,&nbsp;Martin Mihaljevič ,&nbsp;Bohdan Kříbek ,&nbsp;Ben Mapani ,&nbsp;Vít Penížek ,&nbsp;Tereza Zádorová ,&nbsp;Aleš Vaněk","doi":"10.1016/j.hydromet.2024.106356","DOIUrl":"https://doi.org/10.1016/j.hydromet.2024.106356","url":null,"abstract":"<div><p>Copper isotopic fractionation (in δ⁶⁵Cu) and leachate characterization were studied in the context of heap leaching at the Tschudi copper mine in northern Namibia. The leached solution is of Mg-SO₄ type with high Al and Fe concentrations. The source of Mg and Al in the leachate can be from the alteration of micas such as Mg-bearing muscovite confirmed by X-ray diffraction and scanning electron microscopy; however, the source of Mg cannot be determined with certainty. The principal secondary minerals identified in the leached ore are gypsum and jarosite. The value of pH in leachate is ∼1.21 and the concentration of dissolved Cu, occurring mostly as CuSO₄⁰ and Cu²⁺, is about 2 g/L. In comparison with unleached ore (avg. δ⁶⁵Cu −1.47 ‰), leached ore exhibits lighter isotopic values (avg. δ⁶⁵Cu −6.01 ‰) with apparent isotopic fractionation Δ⁶⁵Cu_{leached ore-unleached ore} of about −4.54 ‰. In contrast, there is isotopic enrichment of leachate in heavier ⁶⁵Cu isotope (leachate δ⁶⁵Cu 0.34 ‰) with apparent isotopic fractionation Δ⁶⁵Cu_{leachate-unleached ore} value of +1.81 ‰. These results are in good agreement with Cu isotopic fractionation and depletion in heavier ⁶⁵Cu isotope reported for dissolution experiments in laboratory and groundwater linked to the porphyry copper ore deposits around the world. The leaching of heaps can be considered an analogy of upper part of gossans, but here the supergene enrichment zone is missing due to extremely low pH and oxidizing conditions.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106356"},"PeriodicalIF":4.8,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0304386X24000963/pdfft?md5=11018e4a539a5742cc9696c72c81f229&pid=1-s2.0-S0304386X24000963-main.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Variations in pore structures and permeabilities of ion adsorption rare earth ores during simulated in-situ leaching: Effect of newly formed clay particles and their swelling","authors":"Lian Zhang ,&nbsp;BaoPing Wen ,&nbsp;Lingkang Chen ,&nbsp;Haixia Chen ,&nbsp;Kaixing Wu","doi":"10.1016/j.hydromet.2024.106357","DOIUrl":"https://doi.org/10.1016/j.hydromet.2024.106357","url":null,"abstract":"<div><p>In-situ leaching is essential for mining rare earth elements (REEs) from ion-adsorption rare earth (RE) ores. The efficiency of RE mining is dependent on the permeabilities of ion-adsorption RE ores, and the permeabilities are controlled by their pore structures. However, the current understanding of the pore structures and permeabilities of the RE ores during leaching is limited, particularly their dynamic variations, the controlling roles of different pore structure parameters on the permeability, the roles of the influencing factors and the mechanisms causing the variations. To investigate the above-mentioned issues, we conducted an experimental study of simulated in-situ leaching on undisturbed ion-adsorption RE ore samples under different conditions via constant waterhead permeability tests. The leaching conditions included leaching time, concentration and waterhead of the (NH₄)₂SO₄ solution. Three-dimensional (3-D) pore structures of the RE ores before, during, and after leaching were constructed via X-ray computed tomography, and their pore structure parameters were measured using 3-D image computation. It was observed that the dynamic variations in both the pore structure parameters and permeability coefficients of the RE ores occurred in three distinct stages: rapid reduction, less rapid reduction, and little reduction. The experimental results also revealed that the permeability coefficients of the RE ores were primarily dependent on the average coordination number among the seven pore structure parameters examined, and that the pore throats larger than 30 μm in diameter served as the most effective seepage channels within the RE ores. The waterhead of the leaching solution had a stronger influence on the variations in pore structures and permeabilities compared to that of the concentration. Analysis of the particle/aggregate size distribution and mineralogical compositions of the RE ores before and after leaching indicated that the decreases in the pore structure parameters and permeabilities were largely attributed to clogging of the pore throats and pores by migrated and newly formed clays, as well as swelling of the latter. The newly formed clays were the products of the decomposition of K-feldspar and mica resulting from chemical reactions with the leaching solution. The clays from the two sources occurred in disaggregated and aggregated forms. The results of this study provide an important reference for the mining of RE ores via leaching.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106357"},"PeriodicalIF":4.8,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141582665","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":"Gold recovery from roasted refractory gold concentrate through cyclic extraction using MnO2-assisted thiocyanate leaching and cementation with zinc powder","authors":"Weiyao Li,&nbsp;Bo Liu,&nbsp;Jiajia Wu,&nbsp;Wei Liu,&nbsp;Fen Jiao,&nbsp;Wenqing Qin","doi":"10.1016/j.hydromet.2024.106359","DOIUrl":"https://doi.org/10.1016/j.hydromet.2024.106359","url":null,"abstract":"<div><p>Cyanidation has long served as the industrial standard in the gold industry, necessitating heightened attention to cyanide management owing to its inherent toxicity. This study developed a novel MnO₂-assisted thiocyanate leaching system as an alternative to cyanide. The sample was generated from a refractory gold concentrate processed by roasting, containing 54.4 g/t gold with iron oxide and quartz as the major mineral phases. Within the framework of the novel system, gold recovery was investigated in terms of gold association, recovery behavior, thermodynamics, and optimization using cyclic extraction protocols. The most suitable leaching conditions were determined as 1.20 mol/L NaSCN, 4.00 mmol/L MnO₂, pH at 1.00, liquid-to-solid ratio of 4 mL/g, and leaching duration of 24 h, resulting in a maximum gold extraction of 94.8%. Subsequent zinc precipitation facilitated a gold recovery of 99.4% from the leachate. Furthermore, the implementation of a cyclic extraction scheme, coupled with reagent addition to offset consumption, yielded a significant thiocyanate dosage reduction by 75% while maintaining gold recovery. This acidic leaching system yields satisfactory gold recovery with minimized reagent consumption, particularly suited for refractory gold ore that has undergone acidic pretreatment.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106359"},"PeriodicalIF":4.8,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539660","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":"Study on pre-oxidation of silver concentrate and leaching behaviour of Zn, Cu and In during oxygen-pressure leaching","authors":"Liu Qiang,&nbsp;Li Cun-xiong ,&nbsp;Gu Zhi-hui,&nbsp;Li Chang-wen,&nbsp;Wang Qi-liang","doi":"10.1016/j.hydromet.2024.106358","DOIUrl":"https://doi.org/10.1016/j.hydromet.2024.106358","url":null,"abstract":"<div><p>Given the limitations of current processing methods and the potential of high recovery of silver as a flotation concentrate, this study proposes a pre-oxidation followed by oxygen pressure sulphuric acid leaching route for zinc, copper and indium and thoroughly examines the alteration in micro-morphology of the silver concentrate of 1.22% Pb, 3010 g/t Ag and 649 g/t In. Under the optimal conditions of a sulphuric acid pre-oxidation temperature of 60 °C, and an acid-to-ore mass ratio of 0.6, over 15 h, the P<img>O and -OH polar groups of flotation reagents on the surface of silver concentrate particles are effectively neutralized through sulphuric acid oxidation. This action prevents the formation of a hydration film and mineral inclusions, thereby facilitating the efficient leaching of valuable elements. With a set reaction temperature of 155 °C, an initial acidity of 160 g/L, a reaction time of 180 min, an oxygen partial pressure of 0.8 MPa and a liquid-to-solid ratio of 7 mL/g, the leaching efficiency of Zn, Cu and In in the silver concentrate reach 94.8%, 98.4% and 91.1%, respectively while the lead and silver grades in the leach residue increase to 2.88% and 7754 g/t, respectively.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106358"},"PeriodicalIF":4.8,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141583083","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":"Cesium extraction from an alkali-free solution using a 4-tert-butyl-2-(α-methylbenzyl) phenol–di-(2-ethylhexyl) phosphoric acid synergistic system: A conceptual process flowsheet for separating cesium salt from salt-lake brine","authors":"Xinyu Cheng ,&nbsp;Dong Shi ,&nbsp;Yuze Zhang ,&nbsp;Xiaowu Peng ,&nbsp;Shaolei Xie ,&nbsp;Lijuan Li ,&nbsp;Yong Niu ,&nbsp;Yuxuan Wang ,&nbsp;Fugen Song","doi":"10.1016/j.hydromet.2024.106353","DOIUrl":"https://doi.org/10.1016/j.hydromet.2024.106353","url":null,"abstract":"<div><p>Cesium is an important strategic resource, and solvent extraction is the most frequently used technology for its extraction from various minerals and brines. However, this common method faces operational and cost problems owing to large alkali consumption. A synergistic extraction system consisting of 4-<em>tert</em>-butyl-2-(α-methylbenzyl) phenol (t-BAMBP) and di-(2-ethylhexyl) phosphoric acid (D2EHPA) was designed and used to extract Cs⁺ from an alkali-free solution. The effects of variables such as: (i) pH, (ii) concentration of t-BAMBP and D2EHPA, (iii) temperature, (iv) Cs⁺ concentration, and (v) coexisting cations, on the Cs⁺ extraction performance of the synergistic system were investigated. The most suitable organic phase composition was 1.0 mol/L t-BAMBP and 0.1 mol/L D2EHPA in kerosene, and the synergistic coefficient was up to 57 at 25 °C and an organic/aqueous phase volume ratio of 1/1. The extraction sequence of cations using the t-BAMBP–D2EHPA synergistic system followed the descending order Cs⁺ &gt; Rb⁺ &gt; Ca²⁺ &gt; K⁺ &gt; Li⁺ &gt; Mg²⁺ &gt; Na⁺. The chemical formula of the extracted species was determined as [CsA(HA)(ROH)₂] using the slope method. The Cs⁺ extraction process is an exothermic reaction with an enthalpy (<em>ΔH</em>^<em>o</em>) of −55.3 kJ mol⁻¹, confirmed by the thermodynamic study. After three-stage countercurrent extraction, the extraction efficiency of Cs⁺ was 92.6%, demonstrating excellent selectivity from coexisting cations. The t-BAMBP–D2EHPA synergistic system showed outstanding economic and environmental advantages and a good application prospect to develop a conceptual process flowsheet for extraction with this system and stripping with HCl to separate cesium salt from salt-lake brine.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106353"},"PeriodicalIF":4.8,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141539662","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":"Production of α-Ti(HPO4)2·H2O, TiP2O7 and (TiO)2P2O7 from ilmenite by KOH roasting, H3PO4 leaching and calcination","authors":"Ushan S. Kulathunga ,&nbsp;Kusal D. Mendis ,&nbsp;Ashen I. Mapa ,&nbsp;Champa D. Jayaweera ,&nbsp;Masaru Shimomura ,&nbsp;Lalinda Palliyaguru ,&nbsp;Pradeep M. Jayaweera","doi":"10.1016/j.hydromet.2024.106354","DOIUrl":"https://doi.org/10.1016/j.hydromet.2024.106354","url":null,"abstract":"<div><p>Alpha titanium bis(hydrogenphosphate) monohydrate, α-Ti(HPO₄)₂·H₂O, (α-TiP) is a precursor material utilized to obtain a broad range of important compounds having a great deal of applications ranging from ion-exchange chromatography, chemical catalysis to energy storage materials. The novel synthetic procedure developed in this study shows a higher conversion of titanium in ilmenite to α-TiP with a good purity. For the synthesis of TiPs, the direct use of natural ilmenite ore with commonly available chemicals such as KOH, H₃PO₄, HCl, and H₂C₂O₄ highlights the significance of the present investigation. A mixture of ilmenite and KOH with a molar ratio of 1:4 was roasted at 800<span><math><msup><mrow></mrow><mo>°</mo></msup><mi>C</mi></math></span> for 4 h to concentrate all the titanium to potassium titanate and iron to iron oxide. A reaction between potassium titanate and iron oxide with 85% (<em>w</em>/w) H₃PO₄ acid results in a leachate rich in iron in the form of soluble iron phosphates and a white precipitate identified as α-TiP. Calcination of α-TiP at 800<span><math><msup><mrow></mrow><mo>°</mo></msup><mi>C</mi></math></span> produces titanium pyrophosphate, TiP₂O₇. Residual iron that co-precipitated with α-TiP was further removed by multiple washing steps with complexing acids; H₃PO₄ or concentrated HCl. Washing with oxalic acid (H₂C₂O₄) produces a precipitate upon calcination identified as titanyl pyrophosphate, (TiO)₂P₂O₇. Flowcharts were developed and the chemical identities and the purity of the prepared α-Ti(HPO₄)₂·H₂O and (TiO)₂P₂O₇ were tested with X-ray diffraction, X-ray fluorescence, thermogravimetric, and Raman spectroscopic techniques.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106354"},"PeriodicalIF":4.8,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141486524","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":"A hydrometallurgical process flowsheet for recovering MoO3 from Molybdenite","authors":"Hossein Shalchian ,&nbsp;Ionela Birloaga ,&nbsp;Motahareh Bagheri Moghaddam ,&nbsp;Hadi Nasiri ,&nbsp;Francesco Vegliò","doi":"10.1016/j.hydromet.2024.106355","DOIUrl":"https://doi.org/10.1016/j.hydromet.2024.106355","url":null,"abstract":"<div><p>In this study, a comprehensive hydrometallurgical processing of molybdenite (MoS₂) concentrate was investigated. This investigation involved a novel approach combining mechanical activation, leaching, and polyelectrolyte extraction methods. The integrated method effectively addressed the challenge of low leaching rate of molybdenite, resulting in the successful production of high-purity molybdenum trioxide. Milled molybdenite samples were analyzed by different methods of X-ray diffraction, atomic force and electron microscopy, and BET. The increasing trend of the specific surface area during milling was determined by a model fitting which was useful for optimization of milling time. Several leaching reagents were studied to achieve high molybdenum dissolution. The most promising results were achieved through a two-hour process, yielding an impressive leaching efficiency of 80% and a resulting Mo concentration of 6700 mg/L. Molybdenum recovery was efficiently carried out through polyelectrolyte extraction, as confirmed by ICP and CHNS analyses, demonstrating selective precipitation of molybdenum from the solution. The subsequent calcination of the precipitated molybdenum(VI) compound resulted in the production of high-purity molybdenum trioxide. Furthermore, a conceptual hydrometallurgical treatment process for molybdenite concentrate was proposed, aiming to recover molybdenum, sulfuric acid, and copper. This proposed process presents a promising avenue for further exploration in pilot plant studies within the molybdenum industry.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":"228 ","pages":"Article 106355"},"PeriodicalIF":4.8,"publicationDate":"2024-06-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141438352","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}