氧化镧中~(227)Ac的去除

采用2-乙基己基磷酸单-2-乙基己基酯(P507)作为萃取剂,磺化煤油为稀释剂,研究了盐酸体系中La~(3+)和Ac~(3+)的萃取分离性能。研究了酸度、萃取剂皂化度、La~(3+)浓度和盐析剂浓度等条件对萃取分离性能的影响。当萃取剂皂化度为30%、母液酸度pH=2.45、La~(3+)质量浓度约32g/L、盐析剂浓度c(KNO_3)=3mol/L时,该萃取体系对镧锕具有较好的分离效果,分离因子SFLa/Ac可达67.6。采用优化的实验条件,经过扩大实验证明,氧化镧产品中的放射性得到有效去除,氧化镧中~(227)Ac去除率约89.97%,得到了纯化氧化镧产品。

Removal of 227Ac From Lanthanum Oxide

The extraction performance of La³⁺ and Ac³⁺ in hydrochloric acid medium was studied by using 2-ethylhexyl phosphate mono-2-ethylhexyl ester (P₅₀₇) as extractant and sulfonated kerosene as diluent. The effects of acidity, saponification of extractant, La³⁺ concentration and concentration of salting-out agent on extraction were studied. When experimental conditions are as follows: the saponification degree of P₅₀₇ : 30%, the acidity of the feed solution: pH=2.45, the La³⁺ mass concentration: 32 g/L, and KNO₃ concentration of the salting-out agent: 3 mol/L, the extraction and separation properties of La³⁺ and Ac³⁺ are better. The separation factor (SF_La/Ac) between La³⁺and Ac³⁺ can reach 67.6. The results of a pilot experiment with the optimized experimental conditions show that the radioactivity in lanthanum oxide is effectively removed. The removal ratio of ²²⁷Ac in lanthanum oxide is approximately 89.97%, and the purified product of lanthanum oxide is obtained.