铁基离子液体体系从溶液中萃取锂的动力学研究  

Kinetic study of lithium extraction from solution with iron⁃based ionic liquid system

作　　者：马淑清 李昌文 石成龙 秦亚茹 MA Shuqing;LI Changwen;SHI Chenglong;QIN Yaru(School of Chemistry and Chemical Engineering,Qinghai Minzu University,Xining 810007,China;Key Laboratory ofResource Chemistry and Eco-environmental Protection in Tibetan Plateau,State Ethnic Affairs Commission,Xining 810007,China;College of Chemistry and Chemical Engineering,Xiamen University,Xiamen 361005,China)

机构地区：[1]青海民族大学化学化工学院,青海西宁810007 [2]青藏高原资源化学与生态环境保护国家民委重点实验室,青海西宁810007 [3]厦门大学化学化学化工学院,福建厦门361005

出　　处：《无机盐工业》2024年第9期60-66,共7页Inorganic Chemicals Industry

基　　金：青海民族大学校级规划项目(2022GH12);天津大学-青海民族大学自主创新基金项目(2022TQ05);青海民族大学理工类科学研究项目面上A类(2024XJMA02)。

摘　　要：以磷酸三丁酯(TBP)为萃取剂,1,2-二氯乙烷(C_(2)H_(4)Cl_(2))为稀释剂,铁基离子液体1-丁基-3-甲基咪唑四氯合铁([C_(4)mim][FeCl_(4)])为共萃取剂,构建了TBP-[C_(4)mim][FeCl_(4)]-C_(2)H_(4)Cl_(2)萃取体系。采用恒界面池法研究了TBP-[C_(4)mim][FeCl_(4)]-C_(2)H_(4)Cl_(2)体系从溶液中萃取锂的动力学过程。通过单因素实验考察了离子液体体积分数、水相锂的浓度、界面面积、搅拌速度、温度等因素对萃取速率的影响。结果表明,增大搅拌速度、界面面积、温度均能加快萃取速率。TBP-[C_(4)mim][FeCl_(4)]-C_(2)H_(4)Cl_(2)体系对Li^(+)的萃取反应主要发生在相界面处。表观活化能Ea=10.68 kJ/mol,锂的萃取过程受扩散控制。通过线性拟合得到TBP-[C_(4)mim][FeCl_(4)]-C_(2)H_(4)Cl_(2)体系的动力学方程为R2(Li)=1.221×10^(-2)c(Li^(+))^(1.347)φ(FeCl_(4)^(-))^(0.474)φ(TBP)^(1.877)。Li^(+)浓度、FeCl_(4)^(-)体积分数和TBP体积分数的反应级数分别接近于1、0.5和2,这3个因素对反应速率的影响由大到小顺序为TBP体积分数、Li^(+)浓度、FeCl_(4)^(-)体积分数。该研究为深入了解离子液体体系萃取提锂过程中的传质机制、反应的控制模式等提供了一定的指导和参考。In this paper,tributyl phosphate(TBP)was used as an extractant,1,2-dichloroethane(C_(2)H_(4)Cl_(2))was used as a diluent,and the iron⁃based ionic liquid 1-butyl-3-methylimidazole iron tetrachloride([C_(4)mim][FeCl_(4)])was used as a co⁃extractant to construct TBP-[C_(4)mim][FeCl_(4)]-C_(2)H_(4)Cl_(2)extraction system.The kinetic process of lithium extraction from solu⁃tion by TBP-[C_(4)mim][FeCl_(4)]-C_(2)H_(4)Cl_(2)system was studied by constant interface cell method.The effects of volume fraction of ionic liquid,concentration of lithium in aqueous phase,interface area,stirring rate and temperature on the extraction rate were investigated by single factor experiment.The results showed that the extraction reaction rate could be increased by in⁃creasing stirring rate,interface area and temperature.The extraction reaction of Li^(+)by TBP-[C_(4)mim][FeCl_(4)]-C_(2)H_(4)Cl_(2)sys⁃tem mainly occurred at the phase interface.The apparent activation energy was Ea=10.68 kJ/mol and the extraction process of lithium was controlled by diffusion.The kinetic equation of the extraction system was obtained by linear fitting:R_(2)(Li)=1.221×10^(-2) c(Li^(+))^(1.347)φ(FeCl_(4)^(-))^(0.474)φ(TBP)^(1.877).The reaction order of Li^(+)concentration,FeCl_(4)^(-)concentration and TBP con⁃centration was close to 1,0.5 and 2,respectively.The effect of these three factors on the reaction rate was in the descending order:TBP,Li^(+),FeCl_(4)^(-).This study provided some guidance and reference for in⁃depth understanding of the mass transfer mechanism and reaction control mode in the process of lithium extraction by ionic liquid system.

关 键 词：铁基离子液体 动力学 恒界面池 萃取提锂 

分 类 号：TQ131.11[化学工程—无机化工]