Abstract: The extraction features of maleic acid by trioctylamine (TOA) were investigated further to study the extraction mechanism.Based on the first part (Ⅰ) of this paper,we proposed an assumption of four kinds of dissolution existing during extraction of maleic acid with TOA,i.e.physical dissolution of maleic in diluent,hydrogen bond action of TOA on maleic acid,ion pair association of maleic acid with TOA,and physical dissolution of maleic acid in complex.A model containing these four kinds of dissolution was set up using Mass Action Law.The results showed that the calculated concentration of maleic acid in organic phase approached the experimental data.The overall distribution coefficient of physical dissolution of solvent was not always equal to the sum of the diluent and complex,where the experimental distribution coefficient was larger than the sum value for MIBK system,smaller than the sum value for chloroform system and equivalent to the sum value for n -octanol system.

摘要： 为进一步研究三辛胺 (TOA)萃取马来酸的机理 ,深入分析溶质在萃取平衡中的行为 ,在本文 (Ⅰ )报研究的基础上提出萃取平衡存在 4种溶解过程 ,即稀释剂的物理溶解、萃取剂TOA对溶质的氢键作用、萃取剂TOA对溶质的离子对成盐作用、萃合物对溶质的物理溶解 ,在此基础上提出了考虑 4种溶解过程的萃取平衡模型 ,根据实验结果拟合了模型参数 ,模型拟合精度是满意的 .结果表明 ,氯仿为稀释剂时 ,体系对马来酸的物理溶解与其简单的加和性比较具有负偏差 ;MIBK体系为正偏差 ;而正辛醇体系基本符合简单加合性