Leaching Chalcopyrite with High MnO₂ and Chloride Concentrations

• Main Authors: David Torres, Luís Ayala, Ricardo I. Jeldres, Eduardo Cerecedo-Sáenz, Eleazar Salinas-Rodríguez, Pedro Robles, Norman Toro
• Format: Article
• Language: English
• Published: MDPI AG 2020-01-01
• Series: Metals
• Subjects: dissolution; cufes₂; chloride media; manganese nodules
• Online Access: https://www.mdpi.com/2075-4701/10/1/107

Most copper minerals are found as sulfides, with chalcopyrite being the most abundant. However; this ore is refractory to conventional hydrometallurgical methods, so it has been historically exploited through froth flotation, followed by smelting operations. This implies that the processing involves polluting activities, either by the formation of tailings dams and the emission of large amounts of SO₂ into the atmosphere. Given the increasing environmental restrictions, it is necessary to consider new processing strategies, which are compatible with the environment, and, if feasible, combine the reuse of industrial waste. In the present research, the dissolution of pure chalcopyrite was studied considering the use of MnO₂ and wastewater with a high chloride content. Fine particles (−20 µm) generated an increase in extraction of copper from the mineral. Besides, it was discovered that working at high temperatures (80 °C); the large concentrations of MnO₂ become irrelevant. The biggest copper extractions of this work (71%) were achieved when operating at 80 °C; particle size of −47 + 38 µm, MnO₂/CuFeS₂ ratio of 5/1, and 1 mol/L of H₂SO₄.