Coal fly ash could yield up to 45,000 tonnes of rare earth metals a year, according to a research from Australia's Monash University in Melbourne.
Scientists have developed a cleaner, more efficient method for extracting rare earth elements (REE) from coal fly ash, mine tailings and e-waste, offering a potential alternative to traditional mining of these essential minerals.
Fly ash, the fine powder produced by burning brown coal, has long been considered an environmental problem, with millions of tonnes sitting in dumps and landfills across Australia. Monash's technology aims to turn it into a resource.
Australia has rare earth metal deposits and several mining projects under development, but new mines can take up to 15 years to develop, require significant capital investment, and come with environmental and social concerns. Monash’s “urban mining” approach can extract all 17 REEs with more than 90% efficiency. This includes high-value magnetic REEs such as neodymium and dysprosium, used in permanent magnets for electric motors and wind turbines. In addition, fly ash from the brown coal of south-eastern Victoria is generally free of radioactive elements such as thorium or uranium, making mining safer and less regulated.
Monash says coal fly ash alone could yield up to 45,000 tonnes of rare earth metals per year, more than double Australia’s 2021 output and nearly 30% of current global production. That would be enough to produce magnets for around 15 million electric cars.
Victoria produces more than a million tonnes of fly ash a year, with even larger quantities stored around the country. Recycling these stockpiles would avoid the environmental impacts of new developments while creating value from the material we already have, the scientists say.
The university has moved from lab experiments to a 30-litre system and is developing a 100-litre semi-continuous plant, with plans for a demonstration plant at Monash. The technology has already won industry awards, and the research team is working with government and industry partners to commercialise the process.
Hélène Tarin, Editor-in-Chief of the Asian Bureau, Rough&Polished
