Treatment of copper concentrates containing chalcopyrite and non-ferrous sulphides by the BRISA process

The technical viability of the BRISA process for copper concentrates consisting of mixtures of either chalcopyrite and secondary copper sulphides (chalcocite and covellite) or chalcopyrite and sphalerite was studied. The ferric leaching of six concentrates (different in origin, granulometric, chemical and mineralogical composition) was tested in this work. In order to speed up the process, ferric leaching was carried out in two stages. In the first one, metallic sulphides associated with chalcopyrite were leached and, in the second one, the unattacked chalcopyrite was leached with Ag+ as a catalyst. Applying this sequence of leaching stages, copper extractions higher than 96% were achieved within 20 h for all the studied concentrates.