{"title":"在酸性条件下使用硫脲从锌湿法冶金过程中产生的金刚石残渣中选择性提取银:动力学分析和浸出优化","authors":"","doi":"10.1016/j.hydromet.2024.106396","DOIUrl":null,"url":null,"abstract":"<div><p>In this work, an industrial hazardous jarosite residue produced in the zinc hydrometallurgical process containing silver was used to evaluate the feasibility of using thiourea (Tu) for silver leaching under acidic conditions in the presence of oxalate (C<sub>2</sub>O<sub>4</sub><sup>2−</sup> ion denoted as Ox<sup>2−</sup>). The shrinking core kinetic model (SCKM) was applied to evaluate the effect of variables on the reaction rate. The chemical reaction of H<sub>3</sub>O<sup>+</sup> with the jarosite surface was the controlling stage. The results of batch experiments revealed that silver extraction is influenced by various factors in the descending order: pH > T (temperature) > [Tu] (thiourea concentration) > [Ox<sup>2−</sup>] (oxalate concentration). The extraction efficiency of Ag was 98 % at high levels of both T and [H<sub>2</sub>SO<sub>4</sub>], although a higher [Tu] was required. High Tu consumption was associated with the stability of Tu due to the presence of Fe<sup>3+</sup> and Cu<sup>2+</sup> ions leached along with Ag<sup>+</sup>, which affect the redox potential catalyzing Tu oxidation. Temperature is the most effective variable with a reaction rate constant of k<sub>exp</sub> = 1.1 min<sup>−1</sup> at 60 °C, but it causes a decrease in silver extraction to 92.5 %. The kinetic parameters were obtained using the SCKM; furthermore, the experimental results were statistically validated through a surface response experimental design.</p></div>","PeriodicalId":13193,"journal":{"name":"Hydrometallurgy","volume":null,"pages":null},"PeriodicalIF":4.8000,"publicationDate":"2024-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Selective extraction of silver from jarosite residues produced in the zinc hydrometallurgical process using thiourea under acidic conditions: Kinetic analysis and leaching optimization\",\"authors\":\"\",\"doi\":\"10.1016/j.hydromet.2024.106396\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>In this work, an industrial hazardous jarosite residue produced in the zinc hydrometallurgical process containing silver was used to evaluate the feasibility of using thiourea (Tu) for silver leaching under acidic conditions in the presence of oxalate (C<sub>2</sub>O<sub>4</sub><sup>2−</sup> ion denoted as Ox<sup>2−</sup>). The shrinking core kinetic model (SCKM) was applied to evaluate the effect of variables on the reaction rate. The chemical reaction of H<sub>3</sub>O<sup>+</sup> with the jarosite surface was the controlling stage. The results of batch experiments revealed that silver extraction is influenced by various factors in the descending order: pH > T (temperature) > [Tu] (thiourea concentration) > [Ox<sup>2−</sup>] (oxalate concentration). The extraction efficiency of Ag was 98 % at high levels of both T and [H<sub>2</sub>SO<sub>4</sub>], although a higher [Tu] was required. High Tu consumption was associated with the stability of Tu due to the presence of Fe<sup>3+</sup> and Cu<sup>2+</sup> ions leached along with Ag<sup>+</sup>, which affect the redox potential catalyzing Tu oxidation. Temperature is the most effective variable with a reaction rate constant of k<sub>exp</sub> = 1.1 min<sup>−1</sup> at 60 °C, but it causes a decrease in silver extraction to 92.5 %. The kinetic parameters were obtained using the SCKM; furthermore, the experimental results were statistically validated through a surface response experimental design.</p></div>\",\"PeriodicalId\":13193,\"journal\":{\"name\":\"Hydrometallurgy\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.8000,\"publicationDate\":\"2024-09-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Hydrometallurgy\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0304386X24001361\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"METALLURGY & METALLURGICAL ENGINEERING\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Hydrometallurgy","FirstCategoryId":"88","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0304386X24001361","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"METALLURGY & METALLURGICAL ENGINEERING","Score":null,"Total":0}
引用次数: 0
摘要
本研究利用锌湿法冶金过程中产生的一种含银的工业有害金刚石残渣,评估了在草酸盐(C2O42- 离子,以 Ox2-表示)存在的酸性条件下使用硫脲(Tu)进行银浸出的可行性。应用收缩核心动力学模型(SCKM)评估了变量对反应速率的影响。H3O+ 与金刚石表面的化学反应是控制阶段。批次实验结果表明,银的萃取受多种因素的影响,影响程度从大到小依次为:pH;T(温度);[Tu](硫脲浓度);[Ox2-](草酸盐浓度)。在 T 和[H2SO4]都较高的情况下,虽然需要较高的[Tu],但银的萃取效率为 98%。高 Tu 消耗量与 Tu 的稳定性有关,这是因为与 Ag+ 一起沥滤的还有 Fe3+ 和 Cu2+ 离子,它们会影响催化 Tu 氧化的氧化还原电位。温度是最有效的变量,60 °C 时的反应速率常数为 kexp = 1.1 min-1,但温度会导致银提取率下降至 92.5%。使用 SCKM 得出了动力学参数;此外,还通过表面响应实验设计对实验结果进行了统计验证。
Selective extraction of silver from jarosite residues produced in the zinc hydrometallurgical process using thiourea under acidic conditions: Kinetic analysis and leaching optimization
In this work, an industrial hazardous jarosite residue produced in the zinc hydrometallurgical process containing silver was used to evaluate the feasibility of using thiourea (Tu) for silver leaching under acidic conditions in the presence of oxalate (C2O42− ion denoted as Ox2−). The shrinking core kinetic model (SCKM) was applied to evaluate the effect of variables on the reaction rate. The chemical reaction of H3O+ with the jarosite surface was the controlling stage. The results of batch experiments revealed that silver extraction is influenced by various factors in the descending order: pH > T (temperature) > [Tu] (thiourea concentration) > [Ox2−] (oxalate concentration). The extraction efficiency of Ag was 98 % at high levels of both T and [H2SO4], although a higher [Tu] was required. High Tu consumption was associated with the stability of Tu due to the presence of Fe3+ and Cu2+ ions leached along with Ag+, which affect the redox potential catalyzing Tu oxidation. Temperature is the most effective variable with a reaction rate constant of kexp = 1.1 min−1 at 60 °C, but it causes a decrease in silver extraction to 92.5 %. The kinetic parameters were obtained using the SCKM; furthermore, the experimental results were statistically validated through a surface response experimental design.
期刊介绍:
Hydrometallurgy aims to compile studies on novel processes, process design, chemistry, modelling, control, economics and interfaces between unit operations, and to provide a forum for discussions on case histories and operational difficulties.
Topics covered include: leaching of metal values by chemical reagents or bacterial action at ambient or elevated pressures and temperatures; separation of solids from leach liquors; removal of impurities and recovery of metal values by precipitation, ion exchange, solvent extraction, gaseous reduction, cementation, electro-winning and electro-refining; pre-treatment of ores by roasting or chemical treatments such as halogenation or reduction; recycling of reagents and treatment of effluents.