Abstract: A process for recovery of zinc values contained in thermally activated iron containing copper and zinc sulfides in which said activated sulfides have been subjected to an acid leach in aqueous sulfuric acid to produce a solution of ferrous sulfate and a solids residue containing copper and zinc values. The solids residue containing copper and zinc values is reacted with an acidic copper sulfate solution to precipitate copper values as a simple copper sulfide with concurrent dissolution of iron and zinc values to form a solution of ferrous sulfate containing said dissolved zinc values and said solution of ferrous sulfate is separated from the simple copper sulfides and reacted with H.sub.2 S for precipitation of zinc values therefrom as zinc sulfide. Any nickel and cobalt values present in said activated sulfides is dissolved in said solution of ferrous sulfate and reacted with the H.sub.2 S at elevated temperature for selective precipitaton.

Abstract: A hydrometallurgical process for treating iron containing metal sulfides for rendering iron and non-ferrous metal values active and amenable for selective extraction and separate recovery. Sulfur values can be controllably produced as elemental sulfur or as sulfuric acid to supply acid requirements of the process, while substantially obviating the discharge of sulfur-containing gases to the atmosphere. Ores and concentrates of the sulfides are thermally activated by sequentially heating and reducing said sulfides in a countercurrent flow of heating and reducing gases respectively in a reactor whereby the reaction products of the reducing gas and sulfides, together with liberated labile sulfur, are controllably combusted with oxygen to satisfy heat requirements of the thermal activation process and to convert sulfur values to SO.sub.2 gas. The activated sulfides are subjected to an acid leach in aqueous sulfuric acid for production of ferrous sulfate and evolution of H.sub.