Beijing is betting that coal ash and mining waste could help secure future supplies of critical minerals.
A new report explains that China should consider turning coal waste (like fly ash) into a valuable resource for critical metals like germanium, aluminum, lithium, and gallium. By combining its large supply of coal (and waste) and industrial prowess, this could prove a game-changer for the nation.
The idea is that coal isn’t just a great fuel source, but it also contains tiny trace amounts of valuable metals. For a nation like China, which mines and burns vast amounts of the stuff, not using this resource is like leaving money on the table.
“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, explained.
What is proposed is not just to use fly ash (the waste left after burning coal), but also something called gangue. This is the rocky “junk” often mixed in with coal when mined.
Coal is found in seams or layers that are often intermixed with other non-coal layers. These are often filtered out and simply dumped as waste. As for fly ash, once the carbon is burned away, the residual ash contains tiny mineral particles that are often captured in smokestacks.
Historically, this ash is dumped in piles, mixed in cement, or simply thrown away as industrial rubbish. But, chemically speaking, this ash often contains surprisingly high concentrations of rare earth metals, aluminum compounds, etc.
Such metals are critical for certain advanced industries like semiconductors, batteries, optics, motors, and military applications. China is already a leading supplier of many traditional mining and supply products, so any new way to “make money for old rope” could be a valuable potential income stream.
What’s more, China already has the industrial base to use waste materials like fly ash and gangue as a viable resource for metals. Its gigantic coal infrastructure, coal-to-chemical plants, and processing facilities could readily be adapted to handle the load.
“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 explains.
In short, China already has the knowledge and capacity to do this. The coal waste is also already concentrated where it needs to be for processing, i.e., concentrated in industrial areas.
Money for old rope
Such a move would not only help feed China’s exploding EV, battery, and electronics industries but also help it meet its plans to reduce dependence on imports. It would also help them reduce waste, maximize the “bang for its buck” when it comes to mining and using coal, and help vertically integrate supply chains.
Sounds like a no-brainer, but there is a catch. Not all coal is the same, and different mines have differing geological situations with highly variable mineral traces in produced coal.
At power plants, different coal sources can get mixed, and the resulting fly ash can vary widely in composition. This means, in reality, that one batch of fly ash could be full of something like gallium, say, while the next has next to none.
That would make extraction unpredictable and potentially not economically viable if it is expensive to extract.
“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,” the report added.
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Christopher graduated from Cardiff University in 2004 with a Masters Degree in Geology. Since then, he has worked exclusively within the Built Environment, Occupational Health and Safety and Environmental Consultancy industries. He is a qualified and accredited Energy Consultant, Green Deal Assessor and Practitioner member of IEMA. Chris’s main interests range from Science and Engineering, Military and Ancient History to Politics and Philosophy.























