Stop throwing away critical minerals, USA told

Colorado School of Mines researchers argue for improved critical mineral recovery.

Analysis published this month in Science reveals that all the critical minerals required by the US for energy, defence and technology applications are already being mined at existing facilities, within the country.

However, large amounts of them are currently being discarded as tailings from other mineral streams, argues Elizabeth Holley, Associate Professor of Mining Engineering at Colorado School of Mines and lead author of the paper.

Holley calls for ‘more research, development and policy to make the recovery of these critical minerals economically feasible.’

As part of their research work, Holley and her team has built a database of annual production from federally permitted metal mines in the US. They used a statistical resampling technique to pair the data with the geochemical concentrations of critical minerals in ores, recently compiled by the US Geological Survey, Geoscience Australia and the Geologic Survey of Canada.

This provided an estimate of the quantities of critical minerals being mined and processed every year at the metal mines without being recovered. Holley suggests that even 1% recovery improvement could dramatically reduce or remove the need to import that mineral.

The published analysis looks at 70 elements with roles in electronics, medical devices, satellites, renewable energy and defence. Results indicate that unrecovered by-products could meet American demand for all but two – platinum and palladium.

Aside from economic and geopolitical benefits, reducing tailings piles would reduce the environmental impact of mine waste and open more opportunities for reuse in construction and other industries, says Holley.

‘Now that we know which sites are low-hanging fruit, we need to conduct detailed analyses of the minerals in which these chemical elements reside and then test the technologies suitable for recovery of those elements from those specific minerals,' Holley says.

'We also need policies that incentivise mine operators to incorporate additional processing infrastructure. Although these elements are needed, their market value may not be sufficient to motivate operators to invest in new equipment and processes without the right policies in place.’