Dissolution of pure chalcopyrite with manganese nodules and waste water

Chalcopyrite is the most abundant copper ore and, consequently, the most utilised to produce metallic copper. The main route of treatment is through pyrometallurgical processes, but these emit significant quantities of SO2 into the atmosphere (e.g. 182,000 t/year among all Chilean smelters), producing mighty concern in the community. In this context, hydrometallurgy is presented as an alternative that may be more environmentally friendly; however, the difficulties of processing sulphide minerals prevent achieving sustainable efficiencies for the industry. In this research, a pure chalcopyrite mineral is leached at 25 °C with the addition of manganese nodules as an oxidizing agent, and wastewater with a high concentration of chloride that both enhances the dissolution and avoid the passivation of the chalcopyrite. The high concentrations of MnO2 (4/1 and 5/1) allows that the potential values can be between 580 and 650 mV, which favors the dissolution of CuFeS2. The XRD showed the formation of non-polluting species and, besides, they do not cause obstacles to the copper dissolution. High concentrations of chloride enable increasing copper solutions from CuFeS2, attaining favorable outcomes when working with wastewater instead of seawater.