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 pollution.

“The coal refuse contains a variety of metal elements and could become an important source of critical metal supply,” Dai Shifeng, a member of the Chinese Academy of Sciences and professor at China University of Mining and Technology-Beijing, said in an interview with China Energy News in late April.

While the United States, Australia and Russia are also researching metal extraction from coal, China has some advantages and can already extract multiple metals – including germanium, aluminium, lithium and gallium – from coal gangue and fly ash, according to the report.

“China’s coal production lines already have integrated facilities for washing, chemical processing and power generation, providing a strong industrial foundation for resource recovery,” the report said.

“Thanks to the development of the new energy industry, demand for critical metals is rising fast, so extracting them from coal holds strong promise and China’s experience with germanium provides a solid foundation for recovering other metals.”

However, Dai cautioned that successful metal extraction required close tracking of coal quality and composition. “Some power plants blend coal from different sources before combustion. As a result, the metal content in fly ash from the same plant is constantly changing, making extraction difficult,” he added.