含不同价态的多组份体系萃取平衡算法研究

基于萃取平衡计算的计算机模拟是研究稀土分离工艺的重要手段,在实践中获得了成功应用。在实际稀土萃取分离过程中,除三价稀土离子外还存在着不同价态的其他离子,如Na+,Ca2+,Mg2+,Eu2+,Fe3+,Al3+,Ce4+,Th4+等。研究不同价态离子共存条件下的萃取平衡计算方法,对于研究实际萃取分离体系中非稀土元素及变价稀土元素的行为具有重要意义。本文从酸性萃取剂体系中n价阳离子的萃取平衡关系出发,推导出萃取平衡计算的多元方程组,并将其简化为一元方程后给出了抛物线逼近的数值求解方法。通过对数据实例的计算表明,算法收敛快速稳定,适用于含不同价态多组份体系的萃取平衡计算。

Extraction Equilibrium Algorithm for Multi-Component System with Different-Valance Ions

Based on the calculation of extraction equilibrium,the computer simulation plays an important role in the research and industrial application of rare earth(RE) separation process.In the RE separation process,RE usually exists in triple valance state,while some metal ions exist in different valance state,such as Na+,Ca2+,Mg2+,Eu2+,Fe3+,Al3+,Ce4+,Th4+,etc.Therefore,study on the extraction equilibrium algorithm dealing with multi-component and multi-valance system is valuable for revealing the behavior of non-RE3+ ions in the extraction process.Starting with the extraction equilibrium and mass balance of mental ions in extraction process,the balance equation was conducted and parabolic approaching algorithm was introduced to solve the equilibrium parameters.Through testing computation of specific sample data,the present algorithm was shown to be with good performance of convergence and accuracy,therefore it was appropriate for solving extraction equilibrium of the multi-component extraction system with different valance.