钍、铀和钚在盐环境中的迁移行为研究

MIGRATION STUDIES OF THORIUM,URANIUM AND PLUTONIUM IN SALT ENVIRONMENT

采用柱迁移实验研究了钍、铀和钚在盐柱上的迁移行为。实验结果表明，体系中水溶液的ｐＨ值对钍、铀的回收率影响很大。ｐＨ≥３时，约８５％Ｔｈ^（４＋）被阻滞在盐柱上。铀通过ＮａＣｌ柱时，其化学回收率与ｐＨ值的关系曲线呈“马鞍型”；ｐＨ≤２或ｐＨ≥８时，化学回收率＞８４％；ｐＨ≈６时，化学回收率仅为９％。进料液或淋洗液中的配位剂影响铀、钚在盐柱上的迁移。阻滞在盐往上的大部分铀分布在距离进料口下端２ｃｍ之内。以ＮａＣｌ为填充材料，淋洗液ｐＨ＝１２时，钚几乎１００％阻滞在盐柱上。铀和钚易与ＤＢＰ、ＴＢＰ形成大分子配合物而被盐柱阻滞。

The migration behaviour of Th,U and Pu in passing through column filled with NaCl or natural rock salt(Va 3γ)is investigated.The experimental results show that the recovery of Th and U depends strongly upon the pH value.When pH≥3,85% of thorium is retarded on the NaCl colurnn,When pH≤2 or pH≥8,the recovery of U(that passing through NaCl column)is>84%;when pH=6,the recovery of U is the lowest(9%).The influence of organic complexant on the migration behviour of U and Pu is carried out using the column filled with NaCl or Na3γ.Most of the uranium retarded in the column filled with Na3γis located in the bottom zone.