Th(NO_3)_4-UO_2(NO_3)_2-HNO_3-H_2O/30%TBP-正十二烷萃取体系主要组分分配比模型

利用文献报道的Th(NO3)4-UO2(NO3)2-HNO3-H2O/30%TBP-正十二烷体系各组分的分配比实验数据对现有的分配比模型进行分析和比对,提出了一个计算该体系各组分分配比的新模型。利用34组实验数据对新模型进行了验证,符合情况良好。计算结果表明,本文提出的模型明显优于原模型,可作为Th(NO3)4-UO2(NO3)2-HNO3-H2O/30%TBP-正十二烷萃取体系中Th(Ⅳ)、U(Ⅵ)和HNO3萃取行为计算机模拟的基础。模型建立的条件为:温度,25℃;U(Ⅵ)浓度,0~100g/L;Th(Ⅳ)浓度,0~232g/L;硝酸浓度,0~4.5mol/L。

Distribution Coefficient Model of Main Component inTh(NO3)4-UO2(NO3)2-HNO3-H2O/30%TBP-dodecane Extraction System

Based on distribution coefficient data of thorium (Th), uranium (U) and nitric acid in the tributyl phosphate (TBP) extraction system, and by comparing and analyzing the presented distribution coefficient models in the literature, a new mathematical distribution coefficient model with relative computer program for simulating the extraction behavior of Th(Ⅳ), U(Ⅵ) and HNO₃ in the TBP extraction system. The reliability of the new model with computer program was verified by 34 sets of distribution coefficient data. The calculated results agree well with the experimental data. The results by comparing the actual distribution coefficient data with the computing results indicate that the calculated results by using this new model are more reliable and accurate than those of SEPHIS model reported previously. The model presented in this work can be a foundation for simulating the extraction behavior of thorium, uranium and nitric acid in the extraction system of Th(NO₃)₄-UO₂(NO₃)₂-HNO₃-H₂O/30%TBP-dodecane with uranium concentrations from 0 g/L to 100 g/L, thorium from 0 g/L to 232 g/L, and HNO₃ from 0 g/L to 4.5 mol/L at 25 ℃.