COLLOIDAL PRECIPITATION FLOTATION OF BISMUTH

A method is described for complete separation of bismuth(III) from aqu eous solutions as colloidal sulphide precipitate using sodium sulphide as a precipitant and oleic acid as a surfactant. Hydrogen ion concent ration appears to be an important factor affecting the floatation proc ess. At pH 1.0 bismuth(III) was completely floated. The floatation of bismuth(III) was successful in the presence of some foreign ions. It w as found that, the order of the additive additive reagents and the tem perature markedly affect the floatability. Moreover, ionic strength ha s no appreciable effect on the floatation efficiency. A suggested mech anism for the floatation process has been proposed.