Solubility of lead and zinc compounds in ammoniacal ammonium sulphate solutions

Abstract The solubilities of lead sulphide, sulphate, chloride and oxide and zinc sulphide, sulphate and oxide in ammoniacal ammonium sulphate solutions have been determined. Solubility diagrams showing the effect of varying ammonia and ammonium sulphate concentrations are presented. The presence of high levels of zinc or copper is shown to reduce lead solubility to extremely low levels (0.1 (g/l Pb). Solutions containing lead were found to be unstable when removed from contact with the initial dissolving compound and a mechanism is postulated for the dissolution of lead compounds involving the production of a metastable intermediate complex.