ABSTRACT
Adsorption of anionic complexes of bismuth (Bi) with chloride, bromide, and nitrate on anion exchange resins is the basis of most methods so far reported for the isolation of Bi from natural and industrial materials. These techniques are of much higher selectivity than are procedures in which cation exchange resins or chelating polymers are used for the separations. While Bi is only negligibly adsorbed on strongly basic resins from very dilute sulfuric acid solutions and not at all adsorbed from 1 to 24 M hydrofluoric acid media, it is moderately retained from nitric acid solutions. Adsorption of Bi on anion exchange resins has been utilized rather frequently for separations used in connection with the determination of this element in geological materials. Bi is essentially not retained by strongly acidic cation exchange resins from dilute or concentrated solutions of HCl or HBr, because in these media stable anionic complexes are formed which prevent the adsorption on the cation exchangers.
