[Omim][BF4]/OP-4+OP-7/苯甲醇/煤油/P204/HCl微乳液体系萃取分离轻稀土

Extraction and Separation of Light Rare Earth by[Omim][BF4]/OP-4+OP-7/Benzyl Alcohol/Kerosene/P204/HCl Microemulsion System

针对稀土元素因性质相近而难以分离单一高纯产品问题,研究了(OP-4+OP-7)/苯甲醇/煤油/P204/盐酸体系中加入[Omim][BF4]制备离子液体微乳液体系,并考察离子液体质量分数、水乳体积比、料液中稀土浓度、料液pH、振荡时间等对轻稀土元素(La^3+、Ce^3+、Pr^3+、Nd^3+)萃取分离的影响。结果表明:向传统微乳液体系中加入少量[Omim][BF4],可明显强化稀土的萃取分离效果;在[Omim][BF4]质量分数3.71%、水乳体积比3/1、料液中稀土浓度4.0 mmol/L、料液pH=3、振荡时间8 min条件下,La^3+、Ce^3+、Pr^3+、Nd^3+最大萃取率分别为97.5%、92.5%、95%、84.81%,La^3+/Ce^3+和Pr^3+/Nd^3+分离系数分别达4.3和4.5,分离效果较好。

To solve the problem of difficultly separating a single high-purity product due to special chemical properties of rare earth elements,the[Omim][BF4]was added to(OP-4+OP-7)/benzyl alcohol/kerosene/P204/hydrochloric acid system to prepare ionic liquid microemulsion,and the effects of different ionic liquid mass fractions,water-to-emulsion volume ratios,feed liquid concentrations,feed liquid pH,shaking time and other factors on the extraction rates and separation coefficients of light rare earth elements(La^3+,Ce^3+,Pr^3+,Nd^3+)were investigated.The results show that the addition of a small amount of[Omim][BF4]to the traditional microemulsion system obviously strengthens the extraction and separation of rare earths.Under the conditions of[Omim][BF4]mass fraction of 3.71%,water-to-emulsion volume ratio of 3/1,feed liquid concentration of 4.0 mmol/L,pH of 3 and shaking time of 8 min,the maximum extraction rates of La^3+,Ce^3+,Pr^3+,Nd^3+are 97.5%,92.5%,95%and 84.81%,respectively.The separation coefficients of La^3+/Ce^3+and Pr^3+/Nd^3+are 4.3 and 4.5,respectively.