使用支撑液膜从Fe^3＋／Cu^2＋溶液中选择分离Fe^3＋的研究（I）液液萃取实验

支撑液膜在水溶液金属离子的分离中有着独特的优势。报道了从Fe^3 ／Cu^2 溶液中选择分离Fe^3 液／液萃取研究结果。水相为Fe^3 ／Cu^2 硫酸溶液，萃取相为正癸醇（n-de-canol），载体为二（2－乙基己基）磷酸（D2EHPA）。实验研究了溶液相中硫酸浓度以及有机相中载体D2EHPA浓度金属离子萃取速率的影响。研究发现水溶液的酸浓度对Fe^3 的萃取影响较明显，而对Cu^2 的萃取影响很小。在两相界面处Fe^3 与D2EHPA的反应速度比Cu^2 快很多。Fe^3 、Cu^2 与D2EHPA的络合物在有机相中的扩散速度都较慢，但是Fe^3 与D2EHPA的络合物的界面反应速度比络合物的扩散速度快。有机相中载体浓度对金属离子萃取速率的影响也很明显。液液萃取研究结果显示，在使用支撑液膜进行铁离子选择分离时，可以通过改变溶液相酸的浓度，有机相中载体浓度，或者通过缩短分离时间来提高选择率。

Facilitated separation of Fe~III from Fe~III/Cu~II solution with supported liquid membrane (I) Liquid-liquid extraction experiment

The extraction of Fe~III from an aqueous solutio n containing Fe~III and Cu~II is reported in this paper. The aqueous p hase was Fe~III and Cu~II in H_2SO_4 solution. The solvent was n-de canol containing D2EHPA which was employed to facilitate the extraction of Fe~ III from Cu~II. The effects of the acid concentration in the aqueous ph ase and the carrier concentration in the organic phase were studied. The liquid- liquid extraction experiments showed that the reaction of Fe~III and D2EHPA at the interface between the aqueous and the organic phase was much faster than that of Cu~II and D2EHPA. The diffusion velocity of the Fe~III comple x was much slower than its complexation rate with D2EHPA at the aqueous-o rganic interface. However the reaction of Cu~II with D2EHPA at the interfac e was much slower than the complex diffusion velocity. The pH of the aqueous sol ution and the D2EHPA concentration have a very important influence on the extrac tion ratios of the ions.