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(英文)

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

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Fe3+/Cu2 +溶液中选择分离Fe3+液 /液萃取研究结果 .水相为Fe3+/Cu2 +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浓度对金属离子萃取速率的影响 .研究发现水溶液的酸浓度对Fe3+的萃取影响较明显 ,而对Cu2 +的萃取影响很小 .在两相界面处Fe3+与D2EHPA的反应速度比Cu2 +快很多 .Fe3+、Cu2 +与D2EHPA的络合物在有机相中的扩散速度都较慢 ,但是Fe3+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 .

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.