University discovery to boost green technologies
FIERCE competition over raw materials for new green technologies could become a thing of the past thanks to a discovery by Leeds University.
Researchers from the Faculty of Engineering have discovered how to recover significant quantities of rare-earth oxides, present in titanium dioxide minerals.
The rare-earth oxides, which are used for the manufacture of wind turbines, energy-efficient lighting and hybrid and electric cars, are extracted or reclaimed simply and cheaply from the waste materials of another industrial process.
Leeds University claims that the new process if taken to industrial scale could eventually shift the balance of power in global supply breaking China’s near monopoly on these scarce but crucial resources.
China currently holds 95% of the world’s reserves of rare earth metals in a multi-billion dollar global market, which is seeing demand grow steadily.
Professor Animesh Jha, who led the research, said: “These materials are also widely used in the engines of cars and electronics, defence and nuclear industries.
“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.”
The Leeds breakthrough came as Professor 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% purity.
Not only does the technology eliminate hazardous wastes, cut costs and carbon dioxide emissions, the team also discovered they can extract significant quantities of rare earth metal oxides as co-products of the refining process.
“Our recovery rate varies between 60 and 80% although through better process engineering we will be able to recover more in the future,” added Prof Jha.
Despite their name the 15 rare earth metals occur more commonly within the Earth’s crust than precious metals such as gold and platinum.
But their oxides are rarely found in sufficient concentrations to allow for commercial mining and purification.
They are found however relatively frequently alongside titanium dioxide – a versatile mineral used in everything from cosmetics and medicines to electronics and the aerospace industries.
The research has been funded by the Engineering and Physical Sciences Research Council (EPSRC) and US firm Cristal Global.
