Abstract: Process for removing chlorine from an acidic zinc or cadmium sulphate solon, comprising adding thereto acid of Caro or an ammonium or alkali metal salt thereof.

Abstract: The invention relates to a process for recovering silver and possibly gold contained in a silver and possibly gold bearing solid starting material, in which said metals are present in low proportions, a part thereof being in the form of free sulphides, possibly in mixture with elemental sulphur, in which said starting material is treated with an aqueous solution of thiourea, so as to solubilize the silver and the gold in the form of complexes with the thiourea, and the obtained solution is subjected to a cementation with a metal so as to obtain a cement containing more than about 90% of silver.

Abstract: Process for removing impurities selected from the group consisting of manese, cobalt, nickel and thallium from an acidic zinc or cadmium solution comprising adding thereto acid of Caro or an ammonium or alkali metal salt thereof.