China is exploring the recovery of critical minerals from coal waste, with researchers highlighting fly ash and coal gangue as potential sources of strategic metals including germanium, gallium, lithium and aluminum.
According to a new report, China’s extensive coal mining and power generation infrastructure could be leveraged to recover valuable metals from by-products that have traditionally been treated as industrial waste.
“The coal refuse contains a variety of metal elements and could become an important source of critical metal supply,” said Dai Shifeng, a member of the Chinese Academy of Sciences and professor at the China University of Mining and Technology-Beijing.
Coal gangue refers to the rock separated from coal during mining, while fly ash is the fine mineral residue left after coal combustion. Although typically disposed of or used in construction materials such as cement, both materials can contain economically valuable concentrations of critical minerals and rare earth elements.
Researchers argue that China’s integrated coal industry provides a strong foundation for resource recovery. Existing coal washing, chemical processing and power generation facilities could potentially be adapted to extract strategic metals from waste streams, reducing the need for additional mining.
The approach could support China’s growing demand for critical minerals used in semiconductors, batteries, electric vehicles, renewable energy technologies and defence applications, while also improving resource efficiency and reducing industrial waste.
However, the report notes that commercial recovery remains technically challenging. Metal concentrations vary significantly depending on the geological characteristics of individual coal deposits, and fly ash from different coal sources is often blended during power generation, resulting in inconsistent feedstock quality that can affect the economic viability of extraction.
Researchers nevertheless believe rising demand for critical minerals will continue to improve the prospects for recovering metals from coal waste, building on China’s existing experience in extracting germanium from coal-related resources.
