Abstract: Process for receovering copper values (and zinc, if present) from copper bearing materials, optionally in admixture with iron. The feed material is leached with a mixture of nitric and sulphuric acids, after which the dissolved copper is cemented from solution by contact with iron. The solution, containing dissolved iron (and zinc, if present in the feed material) salts is reacted with ZnO to precipitate iron as ferric oxide, which is separated, leaving zinc sulfate in solution. Solid zinc sulfate is recovered from the solution by evaporation, and then calcined to produce SO.sub.2, which is recovered and recycled as H.sub.2 SO.sub.4, and ZnO, which is reused in the process, any excess being recovered as a product.