离子液体/金属盐萃取体系用于高镁卤水提锂的研究  

Study on extraction lithium from brine with high magnesium using ionic liquid/metal salt extraction system

作　　者：周万嵇 黎四霞 ZHOU Wanji;LI Sixia(School of Chemical Engineering,Qinghai University,Xining 810016,China;School of Chemistry and Chemical Engineering,Qinghai Normal University,Xining 810016,China)

机构地区：[1]青海大学化工学院,青海西宁810016 [2]青海师范大学化学化工学院,青海西宁810016

出　　处：《无机盐工业》2024年第9期54-59,共6页Inorganic Chemicals Industry

基　　金：青海大学部省合建盐湖化工大型系列研究设施资助项目(2023-DXSSZZ-02);青海省“昆仑英才‧高端创新创业人才”项目。

摘　　要：通过研究不同金属盐共萃剂、不同萃取体系对锂镁萃取率及离子液体阳离子损失率的影响,确定出最佳的萃取体系为1-辛基-3-甲基咪唑六氟磷酸盐([C_(8)mim]PF_(6))/六氟磷酸钠(NaPF_(6))/磷酸三丁酯(TBP)。考察了[C_(8)mim]PF_(6)浓度、NaPF_(6)浓度、相比对[C_(8)mim]PF_(6)/NaPF_(6)/TBP萃取体系锂镁萃取率及离子液体阳离子损失率的影响,确定最佳的[C_(8)mim]PF_(6)浓度为0.2 mol/L,NaPF_(6)浓度为0.2 mol/L,两者相比(体积比)为2.5;在最佳萃取条件下,锂的单级萃取率为80.5%,镁的单级萃取率为6.5%,离子液体阳离子损失率为2.6%。最佳反萃盐酸浓度为1.0 mol/L,反萃相比(体积比)为2.5;在最佳反萃条件下,锂和镁的反萃率分别为95.2%和99.0%。[C_(8)mim]PF_(6)/NaPF_(6)/TBP萃取体系能够实现锂的高效萃取,并且能够降低离子液体中阳离子的损失率,其可为用于高镁锂比卤水提锂的新型离子液体/金属盐萃取体系开发提供借鉴。The optimal extraction system was determined to be 1-octyl-3-methylimidazole hexafluorophosphate([C_(8)mim]PF_(6))/sodium hexafluorophosphate(NaPF_(6))/tributyl phosphate(TBP)by studying the effects of different metal salt co-extraction reagent,and different extraction systems on the extraction efficiency of lithium and magnesium,and the cation loss rate of ionic liquid.The effects of[C_(8)mim]PF_(6) concentration,NaPF_(6) concentration and phase ratio on the extraction effi⁃ciency of lithium and magnesium,and the cation loss rate of ionic liquid in[C_(8)mim]PF_(6)/NaPF_(6)/TBP/extraction system were investigated,it was concluded that[C_(8)mim]PF_(6) concentration was 0.2 mol/L,NaPF_(6) concentration was 0.2 mol/L,and phase ratio was 2.5.Under the optimum extraction conditions,the single stage extraction efficiency of lithium was 80.5%,the single stage extraction efficiency of magnesium was 6.5%,and the cation loss rate of ionic liquid was 2.6%.The optimum concentration of hydrochloric acid for stripping was 1 mol/L,and the stripping phase ratio was 2.5.Under the optimum strip⁃ping conditions,the stripping efficiency of lithium and magnesium was 95.2%and 99.0%,respectively.[C_(8)mim]PF_(6)/NaPF_(6)/TBP extraction system could efficiently extract lithium,and reduce the cation loss rate of ionic liquid.It could be used as a reference for the development of a new ionic liquid/metal salt extraction system for extracting lithium from brine with high magnesium lithium ratio.

关 键 词：萃取 高镁锂比 磷酸三丁酯 离子液体 提锂 

分 类 号：TQ132.2[化学工程—无机化工]