{"title":"Leaching kinetics of molybdenite with layered structure and hydrophobic properties in the H2SO4-H2O2-H2O system at atmospheric pressure","authors":"Zhiyuan Chen , Zihui Jiang , Qiu Hu , Jiangtao Li","doi":"10.1016/j.hydromet.2025.106527","DOIUrl":null,"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 H<sub>2</sub>SO<sub>4</sub> and H<sub>2</sub>O<sub>2</sub> were determined as 0.063 and 0.959, respectively. Notably, variations in the H<sub>2</sub>O<sub>2</sub> concentration exerted a significant impact on the leaching effect, while changes in the concentration of H<sub>2</sub>SO<sub>4</sub> 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":4.8000,"publicationDate":"2025-07-03","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/S0304386X25000921","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
Abstract
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:
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.