冠醚/离子液体体系对锂离子萃取动力学的研究  

Extraction Kinetics of Lithium Ions from High Concentration Aqueous Solutions Using Crown Ether and Ionic Liquids

作　　者：朱文波 贾永忠[1,2] 邵斐 张全有[1,2] 姚颖 景燕[1,2] ZHU Wen-bo;JIA Yong-zhong;SHAO Fei;ZHANG Quan-you;YAO Ying;JING Yan(Key Laboratory of Comprehensive and Highly Efficient Utilization of Salt Lake Resources,Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining,810008,China;Qinghai Engineering and Technology Research Center of Comprehensive Utilization of Salt Lake Resources,Xining,810008,China;University of Chinese Academy of Sciences,Beijing,100049 China)

机构地区：[1]中国科学院青海盐湖研究所,中国科学院盐湖资源综合高效利用重点实验室,青海西宁810008 [2]青海盐湖资源综合利用工程技术研究中心,青海西宁810008 [3]中国科学院大学,北京100049

出　　处：《盐湖研究》2020年第2期31-43,共13页Journal of Salt Lake Research

基　　金：the support of National Natural Science Foundation of China (U1407117);the Key Research and Development Program of Qinghai Province (2019-GX-169)

摘　　要：本文通过恒界面池法研究了以4’—乙酰基苯并—15—冠—5作为萃取剂和1—丁基—3—甲基咪唑双[(三氟甲基)磺酰基]酰亚胺作为协萃剂的萃取体系从高浓度水溶液中提取锂的动力学。研究了搅拌速度、平衡时间、温度、界面面积和传质阻力区对锂离子传质速率的影响。结果表明,界面膜的厚度在1600 rpm^2000 rpm转速范围内是逐渐变薄的,并且在1800 rmp^2000 rmp转速范围内是没有变化的,说明锂离子传质速率1800 rmp^2000 rmp转速范围内是不变的;在锂离子的萃取平衡时间为40 min;萃取过程的传质阻力主要来自有机相;该萃取过程是混合控制的动力学过程;在两相界面上发生的萃取反应。通过研究锂离子、冠醚离子液体的浓度,锂离子的动力学方程可表达为:νLi,0=10-3.843±0.001·[Li+]^0.9071·[[BMIm]+]^0.8328·[AcB15C5]^0.8555。通过两相界面处形成锂离子最终配合物的传质速率步骤推导出锂的提取机理,这与实验结果一致。In this works,the extraction kinetics of lithium from high concentration aqueous solutions using 4’-acetylbenzo-15-crown-5 and 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide with constant interfacial area cell are reported.The effects of stirring speed,equilibration time,temperature,interfacial area and the mass transfer resistance zone are studied.The results indicate that the thickness of interface film does not change from 1600 rpm to 2000 rpm,the extraction equilibrium time of lithium ions is 40 minutes,the mass-transfer resistance of the extraction process is mainly from organic phase and this extraction process is a mixing-controlled kinetics process that occurs at interfacial area.The extraction kinetic equation ofνLi,0=10-3.843±0.001·[Li+]^0.9071·[[BMIm]+]^0.8328·[AcB15C5]^0.8555 is obtained by researching the concentration of lithium ions,crown ether,ionic liquids.The extraction mechanism of lithium is deduced by determining the mass-transfer rate step of forming the final complex of lithium ions at the interface,which is consistent with the experimental results.

关 键 词：萃取动力学 锂离子 冠醚 离子液体 界面反应 

分 类 号：O642.4[理学—物理化学]