Abstract：The separation behaviors and conditions of iridium from other metal ions were studied in potassium iodide tetrabutyl ammonium bromide water system. The results showed that Ir could form water insoluble ternary complex (［IrI6］［TBAB］2) with tetrabutyl ammonium bromide and potassium iodide in aqueous solution. This ternary complex floated on water phase, and the liquid solid two phase was formed with clear interface. When the concentrations of tetrabutyl ammonium bromide and potassium iodide were 8.0×10-4 mol/L and 6.0×10-3 mol/L, the flotation rate of Ir was up to 97.6 %. Meanwhile, Rh, W, V, Ce, Sn, Mo, U, Ga, Cr, Mn, Al, Fe, Zn, Co and Ni were not floated in this system, realizing the quantitative separation of Ir from these metal ions. Bi, Sb and Hg had high flotation rate in this system. Pb and Cu could react with KI to form water insoluble PbI2 and CuI, so Ir could not be separated from Pb, Cu, Bi, Sb and Hg. The synthetic water sample was separated by this method with satisfactory results.
