环烷酸萃取体系中稀土和铝分配比及分离系数的研究

本文通过对在不同萃取剂皂化值、料液酸度和铝浓度条件下,稀土和铝在环烷酸体系中的分配比和分离系数的研究,发现料液含有中、高浓度铝时,由于pH值较高造成羧酸的溶解损失增大以及铝离子易水解发生乳化的问题,使得铝和稀土的分离系数βAl/RE随着料液pH值的升高急剧减小。经分析比较得出环烷酸萃取体系分离稀土和铝的优化工艺参数为:皂化值0.35M、铝浓度为12.5mmol/L、pH值为0.10条件下,分配比DAl=0.18,DRE=0.059,分离系数βAl/RE=3.06。

RESEARCH ON THE DISTRIBUTION RATIO AND SEPARATION COEFFICIENT OF RARE EARTH AND ALUMINIUM IN NAPHTHENIC ACID SYSTEM

The distribution ratio and separation coefficient of aluminium and rare earth in the naphthenic acid system are researched in the conditions of different extractant saponification value,different acidity and aluminium concentration in this article.The results show that in the condition of mid or high concentration of aluminium,the separation coefficient of aluminium and rare earth βAl/RE decrease dramatically with the increasing pH because of the increasing loss by solution of carboxylic acid and the emulsion problem caused by the hydrolyzed aluminum ion.By analysis and comparison,DAl=0.18,DRE=0.059 and βAl/RE=3.06 can be gained in the condition of 0.35M extractant saponification value,MAl=150mmol/L and pH=0.10,which is the optimizing process parameter in extracting aluminium and rare earth by the naphthenic acid system.