氟盐在液态氟化氢中的溶解分离研究

Dissolution-separation research of fluoride salts in liquid hydrogen fluoride

载体盐~7LiF的回收是熔盐堆核燃料后处理的重要环节。提出了一种利用氢氟酸溶解技术实现熔盐堆干法处理尾料中LiF分离回收的工艺。首先考察了氢氟酸浓度、溶解时间和溶解温度对LiF及ThF_4在氢氟酸中溶解的影响,得到LiF与ThF_4分离的最优溶解分离工艺条件,并对其溶解机制做了初步探讨。随后进行了混合氟盐中LiF的分离回收实验,结果表明LiF的收率在95%以上,产品LiF纯度在97%以上。

The recovery of -7LiF in carrier salt is the key process in molten-salt reactor spent fuel reprocessing.A kind of hydrofluoric acid solubility method was adopted to realize the LiF separation-recovery process with molten-salt reactor dry method reprocessing tails as crude material.First of all,the effects of concentration of hydrofluoric acid,dissolution time,and dissolution temperature on dissolution of LiF and ThF4 in hydrofluoric acid were investigated.The optimum dissolution separation conditions of LiF and ThF4 were obtained and a primarily discussion was made on the dissolution mechanism.After that,LiF in mixed fluoride salts separation-recovery research has been carried on.Results showed that the recovery of LiF was over95%,and LiF purity of the product was over 97%.