| A study on the extraction of In(III) and Ga(III) from sulfuric acid solutions with liquid membrane in the D₂EHPA-Kerosene-Span 80-H₂SO₄, system has been performed and a kinetic model has been proposed. Also the separation of In(III) and Ga(III) from mixed sulfuric acid solutions has been performed. The extraction percentage of In(III) and Ga(III) increased with stirring speeds up to 300r.p. m. and with the decrease of V_(ia)/V_o and V_w/V_e ratios. In the case of Ga(III) the extraction percentage increased as the surfactant concentration decreased. In the model we considered the chemical reaction at the interface between external aqueous phase and emulsion phase, the diffusion through the emulsion phase, breakage and swelling of the emulsion. Results calculated by this model were found to be in good agreement with the experimental data. In mixed solutions, the extraction percentage of In(III) and Ga(III) also increased with the pH of the external aqueous phase. The experimental conditions for optimum separation between In(III) and Ga(III) are as follows:5vol.% D₂EHPA, 3vol.% Span 80, pH=3, 300rpm, V_w/V_e=10 and extraction time=15minutes. |
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