Why China is looking to coal waste as a source of critical metals

China is turning coal waste into a source of critical metals including lithium, gallium and germanium, leveraging its advantages in extraction technology and industrial infrastructure. Coal mining and burning produce large amounts of waste, including coal gangue, the rock embedded in coal seams, and fly ash, the fine particulate ash captured after burning. Traditionally both are used only as low-value cement additives, while their stockpiling consumes land and causes environmental...