Rare earths race: plan to turn ash into critical metals

Australia could double its rare earth metals stocks without digging a new mine under a plan to turn coal waste into critical minerals.

Instead of waiting for new rare earth mines to become operational in 10 to 15 years, Monash University researchers say ash emitted from coal-fired power stations could be used to extract the metals in a cheaper and more environmentally friendly way.

"We don't have to dig up new mines. We can use something that's already processed and just sitting in landfill," Monash engineering researcher Bennet Thomas said.

Rare earths are a group of 17 metals found in natural resources that are critical to producing defence systems, smartphones and tablets, electric cars and wind turbine motors.

The industry is dominated by China and the United States, but Australia is home to the largest rare earths processing facility outside of the Asian superpower.

Australia's strict environment laws have hampered its ability to process rare earth materials onshore since many are found in proximity of radioactive metals, forcing miners to ship it overseas.

"The current techniques of producing rare earths is concentrated, politicised and monopolised by a few rare earth-producing countries in the world," Dr Thomas told AAP.

"That is a national risk."

The process, first conceptualised by Monash professor Sankar Bhattacharya in 2015, involves using environmentally benign acids to break down the ash to bring out the metals in a liquid form before it is isolated and purified into specific elements.

"We needed this technology yesterday, but what we have figured out in the last five years is we don't have to look too far ahead," Dr Thomas said.

While there is no timeline as to when the project will be rolled out on a commercial scale, the researchers say they have designed a plant that can operate up to 1000 litres and are now seeking investment from private and government backers.

They estimate up to 45,000 tonnes of rare earth metals could be recovered annually from coal ash alone - more than twice what Australia produced in 2021.

But as governments accelerate their transition away from coal mining in favour of renewables, Dr Thomas said the team had been able to diversify the process to include other materials including mine tailings and electronic waste.

"We are in a global race ... Everybody is looking for these metals. Everybody is trying to beat us in this game," he said.