从稀土分解液中连续去除铁、铝

Continuous Removing of Iron and Aluminum From Rare Earth Solution

研究了南方离子型稀土分解液在萃取槽内用环烷酸连续去除铁、铝杂质，考察了分解液初始pH、杂质初始质量浓度、有机相皂化度和萃取级数对杂质去除效果的影响。结果表明：控制分解液初始pH为1～2、Al^3＋初始质量浓度≤2g／L、有机相皂化度0．10mol／L及萃取级数20级，可获得Fe^3＋质量浓度〈30mg／L、Al^3＋质量浓度〈300mg／L的合格料液，所得料液可进入分离工序进一步分离单一稀土；负载有机相经盐酸反萃取后回收其中的少量稀土，确保稀土收率。该工艺简单、连续、除杂率高，已成功实现产业化。

The removal of iron and aluminum from a rare-earth leaching solution using naphthenic acid as extractant by continuous purification in extraction tanks. The effects of initial pH of rare earth solution,initial concentration of impurities,saponification value of organic phase and extraction series on removal rate of impurities were examined. The results show that the optimal conditions is the initial pH of 1-2,initial Al^3＋ concentration of less than 2 g/L, saponification value of organic phase of 0.10 mol/L,and extraction series of 20. Under the conditions, the solution containing Fe^3＋ less than 30 mg/L and Al^3＋ less than 300 mg/L can be obtained and can be used in next step to separate rare earth. A small amount of rare earth in the loading organic phase is stripped using hydrochloric acid,the yield of rare earth can ensure. The process is simple, continuous, and high removal rate of impurity, has successfully realized industrialization.