吡啶类离子液体体系对模拟盐湖老卤中锂的萃取研究  

Study on extraction of lithium from simulated old brine of salt lake by pyridine ionic liquid system

作　　者：卢娜娜 秦亚茹 马淑清 王琪慧 刘兵 石成龙 LU Nana;QIN Yaru;MA Shuqing;WANG Qihui;LIU Bing;SHI Chenglong(School of Chemistry and Chemical Engineering,Qinghai Minzu University,Xining 810007,China;Key Laboratory of Resource Chemistry and Eco-environmental Protection in Tibetan Plateau,State Ethnic Affairs Commission,Xining 810007,China;Qinghai Institute of Salt Lakes,Chinese Academy of Sciences,Xining 810008,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]中国科学院青海盐湖研究所,青海西宁810008

出　　处：《无机盐工业》2023年第7期45-50,共6页Inorganic Chemicals Industry

基　　金：青海省自然科学基金项目(2020-ZJ-953Q);青海民族大学校级规划项目(2022GH12);青海民族大学高层次人才项目(2019XJG04);青海民族大学研究生创新基金项目(12M2021014);天津大学-青海民族大学自主创新基金项目(2022TQ05)。

摘　　要：采用磷酸三丁酯(TBP)为萃取剂、N-丁基吡啶六氟磷酸盐([BPy][PF_(6)])为协萃剂、二氯乙烷(C_(2)H_(4)Cl_(2))为稀释剂,构建了[BPy][PF_(6)]-TBP-C_(2)H_(4)Cl_(2)萃取体系,并用于盐湖卤水中分离锂离子。通过单因素实验考察了水相酸度、离子液体浓度、TBP浓度等因素对锂萃取率的影响。结果表明该萃取体系的最优条件为:离子液体浓度为0.3 mol/L;TBP的体积分数为60%;相比(有机相与水相的体积比)为2.5/1。在最优条件下得到Li^(+)的单级萃取率为91.65%、Mg^(2+)的单级萃取率为5.86%,该萃取体系对Li^(+)有较好的选择性。热力学研究表明,该离子液体体系对锂离子的萃取反应是自发的放热反应。该研究为离子液体体系提取分离溶液中锂离子提供了一定的基础和参考依据。The[BPy][PF_(6)]-TBP-C_(2)H_(4)Cl_(2) extraction system was constructed by using tributyl phosphate(TBP)as extractant,N-butylpyridine hexafluorophosphate([BPy][PF_(6)])as coextractant,and dichloroethane(C_(2)H_(4)Cl_(2))as diluent to separate lithium ions in salt lake brine.The effects of water phase acidity,ionic liquid concentration,TBP concentration,and other factors on the lithium extraction efficiency were investigated by single factor experiments.The results showed that the optimal conditions of the extraction system were as follows:the concentration of ionic liquid was 0.3 mol/L,the volume fraction of TBP was 60%,and the ratio of O/A was 2.5/1.Under these conditions,single-stage extraction efficiency of 91.65% for Li+and 5.86% for Mg^(2+) were obtained,and this extraction system showed good selectivity for Li^(+).The thermodynamic study showed that the extraction reaction of lithium ions by the ionic liquid system was a spontaneous exothermic reaction.This experimental study provided a certain basis and reference for the extraction and separation of lithium ions in the ionic liquid system.

关 键 词：锂 盐湖卤水 离子液体 萃取 

分 类 号：TQ131.11[化学工程—无机化工]