乳酸在水溶液中对HEHEHP-La-HCl体系的络合助萃行为

Complexation of Lactic Acid to HEHEHP-La-HCl System in Aqueous Solution

摘要: 稀土是国家的战略资源，稀土元素的分离提纯是目前国内外关注的重点。本文提出一种新型的络合萃取分离技术，通过向水相中添加络合剂乳酸(HLac)，来改善现有萃取体系对稀土La的萃取性能。实验结果证明，HLac可以与La生成络合物，在水相和有机相接触过程中该络合物重新与萃取剂反应，生成稀土螯合物。在萃取过程中，HLac的络合作用可以缓冲萃取过程产生的H+对水相酸度的影响，最终提高非皂化萃取体系HEHEHP (2-乙基己基膦酸单2-乙基己基酯)对La的萃取性能。

Abstract: Rare earth is a national strategic resource, its separation and purification is the focus of attention at home and abroad. This paper presents a new type of chelating extraction separation technology, by adding complexing agent (HLac) into aqueous phase to improve the existing extraction of rare earth La. The experimental results shown that HLac can be combined with La, and in the process of aqueous phase and organic phase mixing together, it rereacted with the extractant to generate rare earth chelate. In the process of extraction, the complexation of HLac can buffer the influence of H+ in aqueous phase, and eventually improve the extraction performance of La in non-saponification HEHEHP (2-ethyl hexyl phosphonic acid single 2-ethyl hexyl ester) extracting system.