Separation of Cadmium( Ⅱ ) with Replacement-Flotation

A separation process involving the removal of Ag+ and Pd2+ by displacement with Fe and flotation separation of Cd2+from other metal ions by (NH4)2SO4-KI-bu-RhB was studied. The results showed that Ag+and Pd2+ can be replaced by Fe in the presence of certain amount of Fe2+. It also showed that with 1.0 g of (NH4)2SO4, 2.0 mL of 0.1 mol/L KI and 2.5 mL of 1.0×10-3 mol/L bu-RhB, Cd2+was quantitatively floated, while Zn2+, Ni2+, Mn2+, Co2+, Al3+, Fe2+, Cu2+ were not floated. Cd2+ was separated from other metal ions in synthetic water samples with flotation rate of 98.3％～100.6％.This process was used in separation and determination of Cd2+ in National Standard ore samples with satisfactory results.