Computer Simulation Study on Uranium and Thorium Separation（1B Extractor） in Thorex Process

A computer program was developed to simulate the separation of thorium from uranium (1B) in the Thorex process based on the mathematical distribution model and the theory of cascade extraction in the system of Th(NO₃)₄-UO₂(NO₃)₂-HNO₃-H₂O/30%TBP-dodecane. The program can be employed for simulating the steady-state behavior of thorium, uranium and nitric acid in 1B extractor. The reliability of the program was verified by the reported data. The separation process was analyzed, and the parameters of the process were optimized through changing the flow ratio and the concentration of stripping stream (1BX) as well as changing the flow ratio of the supplementary extractant (1BS). The results show that the separation of thorium from uranium is remarkably affected by the flow ratio of 1BX, slightly by the flow ratio of 1BS and the nitric acid concentration of 1BX. The best combination of parameters of the thorium-uranium separation with different concentrations of feed stream (1BF) can be obtained by this program.