Leaching by ferric sulphate of raw and concentrated copper-zinc complex sulphide ores

A composite mixture of three typical Cu/Zn complex ores, namely black-, yellow- and altered-ore, from Cayeli deposit in Turkey, was used for leaching experiments under atmospheric pressure in ferric sulphate solutions, In order to study the reaction kinetics of the copper and zinc dissolution in the temperature range from 50 to 80-degrees-C; also in the presence of a solvent for elemental sulphur, such as CCl4. Owing to the fact that quite low copper extraction yields were obtained and to the clearly evident necessity of using pressure leaching in autoclave at higher temperatures, a tentative process of the ore enrichment by selective or bulk-flotation was then examined. Leaching tests in an autoclave at temperatures ranging from 100 to 230-degrees-C were carried out on the bulk-concentrate produced. Good extraction yields for both metals were achieved at 140-degrees-C after a few hours leaching by ferric sulphate.