Study on the floatation separation of gold with tetrabutyl ammonium bromide-potassium iodide-gold (III) ternary complex

In aqueous solution, gold (Ⅲ)) could form a water-insoluble ternary complex (AuI4-·TBAB+) with tetrabutyl ammonium bromide and potassium iodide. The ternary complex could float well on the surface of water phase, making the solution form a liquid-solid phase with a clear interface. When the concentrations of (NH4)2SO4, tetrabutyl ammonium bromide and KI in the solution were 0.1 g/mL,7.0×10-4 mol/L and 4.0×10-3 mol/L respectively, Au(Ⅲ) could be separated from Mg(Ⅱ), W(Ⅵ), Zr(Ⅳ), N(Ⅱ), Mo(Ⅵ), Rh(Ⅲ), U(Ⅵ), V(Ⅴ), Cr(Ⅲ), Mn(Ⅱ), Ga(Ⅲ), Al(Ⅲ), Fe(Ⅱ), Zn(Ⅱ), Co(Ⅱ), Ce(Ⅲ) and Sn(Ⅳ). This method has been applied to the separation and determination of Au(Ⅲ) in synthetic water sample, and the floatation rate of Au(Ⅲ) was up to 98.6 %, while the floatation rates of other metal ions were less than 2.9 %. This method had certain utility value in the separation and enrichment of micro gold.