Abstract:

 The thermodynamics of the gallium extraction by two different kinds of microemulsions were studied. The microemulsion, which contained cationic surfactant or anionic surfactant, was composed of cetyltrimethylammonium bromide (CTAB)／n-butanol／n-heptane／HCl(solution) or sodium oleate (NaOL)／npentanol／n-heptane／HCl(solution). The variables such as the equilibrium time, the volume ratio between two phases, HCl′s molarity and the extractant concentration were tested, and the optimized conditions of extraction were fixed. The effects of different nature of the surfactants on the extraction were also discussed. The results showed that, in pretty short time, the extraction ratio by the microemulsion systems could achieve 98％. Microemulsion was proved to be an outstanding extraction medium.

Key words: microemulsion; cationic surfactant; anionic surfactant; gallium; extraction