USING AN INTERDIGITAL MICROMIXER FOR SEPARATION OF In3+ FROM ZINC HYDROMETALLURGICAL PROCESS WITH D2EHPA AS AN EXTRACTANT

Experiments were performed in an interdigital micromixer with 30 microchannels (40 mu m width of each channel) to separate In3+, Fe3+ and Zn2+ from sulfate solutions using Di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the extractant. The effects of pH, extractant concentration and flow rate on the extraction efficiency and flow rate on mass transfer coefficient of In3+, Fe3+ and Zn2+ were investigated. At a phase flow rate of 7.0 mL/min and initial solution pH of 0.423, the extraction efficiency of In3+, Fe3+ and Zn2+ was 99.29%, 3.43% and 2.54%, respectively and mass transfer coefficient of In3+, Fe3+ and Zn2+ was 144.307 s(-1),1.018 s(-1) and 0.750 s(-1). Then, the loaded organic phase was stripped in an interdigital micromixer. At a phase flow rate of 9.0 mL/min and HCl concentration of 160 g/L, stripping efficiency of In3+ was 98.92% and mass transfer coefficient of In3+ was 169.808 s(-1), while concentration of Fe3+ and Zn2+ was lower than 0.005 g/L with good separation of In3+ from Fe3+ and Zn2+.