The current state and future directions of percolation leaching in the Chinese mining industry: Challenges and opportunities

China is one of the most rapidly growing economies in the world and this growth is underpinned by growing demand for natural resources to meet base and precious metals and energy requirements. Even though China is currently the largest producer of several mined commodities, such as gold and the rare earth elements, meeting the future demands for metal consumption will require China to either develop new mining projects or increase material imports. In terms of nuclear energy requirements the country still depends on uranium imports. To meet this growth in Chinese demand, there has been a strong interest in technologies suited for mining and processing of low grade ore bodies. Percolation leaching methods have been very effective in extracting metals from low grade ores, which could not otherwise be economically extracted. Percolation leaching techniques, such as heap leaching, dump leaching, bio-leaching and in-situ leaching have been extensively employed in the Chinese mining industry in recent decades, primarily to extract gold, copper, rare earth elements and uranium. This paper discusses the application of various percolation leaching techniques in the Chinese mining industry and offers a scientific and extensive literature overview on technological developments in commercial percolation leaching operations in China. It also presents the current challenges of percolation leaching and recent technological and research developments and regulatory frameworks pertaining to the application of percolation leaching in China. The future directions of percolation leaching in the Chinese mining industry will also be presented to extract the low grade natural resources both economically and in an environmentally sustainable manner.