Researchers at the University of British Columbia and an international team have received $1.4 million to explore the use of plants to recover precious metals from mine tailings around the world.
Currently, metals obtained from ores contain platinum group metals (PGM) some of which are lost through various stages of processing. The research will investigate “phyto-mining,” which involves growing plants on mine waste materials to sponge up PGM into their cellular structure.
Initial studies show that plant cells used to phyto-mine PGM can be used for a variety of industrial applications – the one in most demand being catalytic converters for vehicle emissions control.
The PHYTOCAT project is supported by the G8 Research Councils Initiative on Multilateral Research Funding. The team is led by the University of York in the U.K. with additional support from Yale University and Massey University in New Zealand.
“We hope to increase recovery of these important metals and develop a new range of naturally derived catalysts,” says Mining Engineering Prof. John Meech, head of UBC’s Centre for Environmental Research in Minerals, Metals, and Materials.
For PGM phyto-mining, the researchers will investigate plants known as hyperaccumulators which include about 400 species from more than 40 plant families. Plants such as willow, corn and mustard have evolved a resistance to specific metals and can accumulate relatively large amounts of these metals, which once absorbed into the plants’ cellular structure form nano-scale clusters than can then be used directly as a catalyst.
Meech says, “With the numbers of vehicles ever increasing and with emission standards ever tightening, demand for these rare metals is rapidly increasing. So, as supplies become constrained, development of novel technologies to recover PGM is of global importance.”