Thorex流程钍铀分离工艺单元计算机模拟研究

在Th(NO₃)₄-UO₂(NO₃)₂-HNO₃-H₂O/30%TBP-正十二烷分配比模型的基础上，使用串级萃取理论编写了Thorex流程钍铀分离工艺单元(1B)的计算机模拟程序，该程序可对钍、铀、硝酸的萃取行为进行模拟计算。通过文献数据对该程序的可靠性进行了验证，结果表明，该程序的计算值与文献值符合良好。在此基础上利用该模拟程序对钍铀分离单元的工艺参数进行了计算分析，结果表明：工艺运行状况受工艺参数的综合影响，其中反萃液(1BX)硝酸浓度是影响因素之一，铀产品(1BU)中钍含量随酸度的增大而增大，而钍产品(1BT)中铀含量则随酸度的增大而降低，酸度过大或过小均不能实现二者的良好分离；1BX流比对分离效果的影响与酸度相反，随着1BX流比的增大，1BU中钍含量显著降低，而1BT中铀含量增大；补萃剂(1BS)流比对分离效果的影响与1BX流比的影响趋势相反，因此在工艺寻优中可利用本程序选择分离效果最好的条件组合。此外，还可利用本程序进行其他工艺要求的钍铀分离工艺参数寻优计算等。

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‐H2 O/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 pro‐gram 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 con‐centration of stripping stream (1BX) as well as changing the flow ratio of the supple‐mentary extractant (1BS) .The results show that the separation of thorium from urani‐um is remarkably affected by the flow ratio of 1BX ,slightly by the flow ratio of 1BS and the nitric acid concentration of 1BX .T he best combination of parameters of the thorium‐uranium separation with different concentrations of feed stream (1BF) can be obtained by this program .