Abstract

The Chilean mining industry, after consolidating copper production through bioleaching in copper ore heaps, is now facing major challenges and changes in the exploitation of its copper reserves. The depletion of copper oxide ores, as well as a decrease in copper grade, have generated a significant amount of idle capacity in solvent extraction and electrowinning plants. The percentage of the total copper mined in Chile and produced as a concentrate is projected to increase to ~90% by 2027, with a very small increment in the total amount of copper per year. These changes, plus issues of efficiency and complexity, have contributed to a reduction in application of bioleaching in the Chilean mining industry. Several mining companies have transformed their bioleaching operations to chloride leaching, in search of more efficient technologies for leaching primary copper sulfides such as chalcopyrite, but with future environmental consequences that are still uncertain. These changes have impacted the R&D sector, where personnel have had to reorient their efforts to develop sustainable technologies in line with scarcity of water, complex mineralogy, and recent strict regulations. New products of bioleaching technology will include the revalorisation of tailings, technologies to stabilise dumps, as well as improvements in bioleaching of run-of-mine (ROM) ores and compatibility with new leaching technologies.