Advances in high-temperature heap leaching of refractory copper sulphide ores

Heap leaching has gained renewed attention for processing not only copper and gold ores, but also uranium and nickel laterites as part of integrated leaching processes. This study highlights the complexities introduced by each application, focusing particularly on the heap leaching of copper ores. Initially restricted to copper oxide ores, heap leaching has expanded to include secondary copper sulphides that necessitate generating an oxidative environment through forced aeration and bacterial activity. In this context, chalcopyrite ore treatment has emerged as a significant research area, specifically addressing challenges associated with lower grade and refractory ores. The methodology employed involved enhancing leach kinetics via elevated temperatures and the effective management of irrigation and aeration rates. Critical factors for efficient processing include the concentration of pyrite, as it plays a vital role in promoting leach rates through bacterial oxidation. The results indicate that high leach temperatures (>50°C) are essential for meaningful extraction rates and underscore the need for adaptive design in heap leaching operations to accommodate the unique characteristics of refractory ores. This innovation in heap leaching technology promises to extend the viability of processing lower grade copper sulphide deposits.