磷酸三丁酯/甲基异丁基酮萃取锂的特性  

Characteristics of lithium extraction with tributyl phosphate/methyl-isobutyl ketone

作　　者：谭元忠[1] 秦炜[1] 

机构地区：[1]清华大学化学工程系化学工程联合国家重点实验室,北京100084

出　　处：《化学工程》2011年第10期26-28,33,共4页Chemical Engineering(China)

基　　金：科技部863项目(2008AA06Z111)

摘　　要：为从含有Li和Mg的水溶液中选择性地萃取Li,在FeCl3存在的条件下,以磷酸三丁酯(TBP)为萃取剂,以煤油为稀释剂,在萃取平衡时出现第3相的情况下研究了有机相中Li和Fe的浓度,结果表明萃合物主要集中在中间有机相。针对萃取过程中的分相问题,以TBP为萃取剂,比较了甲基异丁基酮(MIBK)、乙酸乙酯和煤油作为稀释剂对Li的分配系数以及Li,Mg分离因子的影响。结果表明:TBP/MIBK体系对Li有显著的萃取效果,对Li的选择性也优于其他体系。进一步比较了TBP/煤油、MIBK/煤油以及TBP/MIBK 3个体系对Li的分配系数,结果表明:在FeCl3存在的条件下,TBP和MIBK都具备萃取Li的能力,而二者的混合物组成了对Li的协同萃取体系。用TBP/MIBK萃取Li时,随着TBP体积分数的增大,Li的分配系数以及Li,Mg分离因子都会增大。The lithium distribution in the organic phases was studied when the third phase was formed in the extraction of lithium with tributyl phosphate（TBP） diluted by kerosene from the solutions containing lithium and magnesium in the presence of FeCl3.It indicates that lithium is mainly uploaded by the middle organic phase.To avoid the formation of the third phase,different diluents were compared when TBP was used as the extractant,and it shows that TBP diluted by methyl-isobutyl ketone（MIBK） presents a good extraction power for lithium with a high selectivity in the presence of FeCl3.Therefore TBP/MIBK can extract lithium from brine with a high ratio of lithium to magnesium effectively.The extractions of lithium with TBP/kerosene,MIBK/kerosene and TBP/MIBK were compared,and the results indicate that TBP and MIBK can both extract lithium.Further studies on the extraction of lithium with TBP/MIBK were carried out,and it reveals that TBP/MIBK form a synergistic extraction system of lithium.The values of distribution coefficient of lithium and lithium-to-magnesium separation factor both increase with the increase of the volume fraction of TBP in the organic phase.

关 键 词：锂 磷酸三丁酯 甲基异丁基酮 协同萃取 

分 类 号：TS396.5[轻工技术与工程]