SEPARATION AND CONCENTRATION OF INDIUM (III) BY AN EMULSION LIQUID MEMBRANE CONTAINING DIISOSTEARYLPHOSPHORIC ACID AS A MOBILE CARRIER

Permeation of indium through an emulsion liquid membrane (ELM) contain ing diisostearylphosphoric acid (DISPA) as a carrier was carried out. First, the influences of the emulsifier (Span 80) concentration, the r eaction temperature and the stirring speed during the permeation of in dium on the membrane stability were studied. Indium ions were quantita tively extracted with the ELM under the optimum conditions from the vi ewpoint of membrane stability. Furthermore, the permeation mechanism o f indium through the ELM was examined under various operational condit ions. The permeation process of indium was controlled by the interfaci al reaction between In(OH)(2+) and DISPA adsorbed at the interface and by the external aqueous diffusion of indium. (C) 1998 Elsevier Scienc e B.V.