China currently enjoys a near-monopoly on the rare-earth oxides needed to make wind turbines, electric cars and other green technologies, but that could change, thanks to a discovery by British researchers.

While the 15 rare-earth metals really aren’t so rare — they’re more common in the Earth’s crust than gold or platinum — their oxides are rarely found in concentrations great enough to support commercial mining and purification. In fact, China currently holds 95 per cent of the world’s reserves of rare earth metals in a multibillion-dollar global market in which demand is growing steadily.

Researchers at the University of Leeds, though, have now found a way to cheaply and easily recover significant quantities of rare-earth oxides from industrial waste.

“These materials are also widely used in the engines of cars and electronics, defence and nuclear industries,” said Animesh Jha, who led the research at the university’s Faculty of Engineering. “In fact, they cut across so many leading-edge technologies, the additional demand for device-related applications is set to outstrip supply.”

Not only does the new process eliminate hazardous waste, but it reduces the possibility that rare-earth oxide shortages could lower production of green technologies.

“There is a serious risk that technologies that can make a major environmental impact could be held back through lack of the necessary raw materials — but hopefully our new process, which is itself much ‘greener’ than current techniques, could make this less likely,” Jha said.

While hard to find in mineable quantities in nature, rare-earth metal oxides are found relatively frequently alongside titanium dioxide, a versatile mineral used in everything from cosmetics and medicines to electronics and the aerospace industries.

The Leeds breakthrough came as Jha and his team were fine-tuning a patented industrial process they have developed to extract higher yields of titanium dioxide and refine it to over 99 per cent purity. They discovered the technology eliminates hazardous wastes, cuts costs and carbon dioxide emissions … and makes it easier to extract significant quantities of rare-earth metal oxides as co-products of the refining process.

“Our recovery rate varies between 60 and 80 per cent, although through better process engineering we will be able to recover more in the future,” Jha said. “But already, the recovery of oxides of neodymium, cerium and lanthanum from the waste products — which are most commonly found with titanium dioxide minerals — is an impressive environmental double benefit.”

Tags: metals