A continuous counter-current extraction for the selective recovery of thorium (Th) and uranium (U) from the Yen Phu (Vietnam) rare earth concentrate leach solutions was systematically studied. The primary amine N1923 was used as an extractant which was prepared in the isoparaffin IP-2028 diluent. Thorium and uranium were selectively recovered in a hydrometallurgical circuit established by continuous mixer-settler extraction, scrubbing, and back-extraction at the laboratory scale. The desired purity of Th and U can be achieved by managing the volume ratio of organic to aqueous phase (O/A ratio) in the corresponding steps. Highly pure Th and U were recovered from the pregnant back-extraction liquor and the raffinate, respectively, which have satisfactory properties for further processing of the subsequent nuclear materials.

系统研究了从 Yen Phu（越南）稀土精矿浸出液中选择性回收钍 (Th) 和铀 (U) 的连续逆流萃取。伯胺 N1923 用作萃取剂，在异链烷烃 IP-2028 稀释剂中制备。钍和铀在实验室规模的连续混合沉降器萃取、洗涤和反萃取建立的湿法冶金回路中选择性回收。通过在相应步骤中管理有机相与水相的体积比（O/A 比），可以实现所需的 Th 和 U 纯度。从富集反萃液和萃余液中分别回收到高纯度的Th和U，对后续核材料的进一步加工具有满意的性能。