Towards “Critical Geometallurgy” of post-subduction mineral resources.

Critical metals such as tellurium (Te), bismuth (Bi), antimony (Sb), and platinum group metals (PGMs) are essential for the green technologies that will underpin the global transition to net zero. However, despite forecast increased demand, the current market value of many critical metals is too low to make their extraction economically viable as the sole product of a mine. Fortunately, Te, Bi, Sb and PGMs are often associated with more abundant metals such as copper (Cu) and gold (Au), and therefore have the potential to be extracted as by-products during processing of the ore. Efficient recovery of these critical metals as by-products can secure future supplies, while at the same time minimising environmental impact through enhanced extraction efficiency. However, we currently have a poor understanding of where within deposits these critical metal by-products are hosted – mineralogically, spatially, and physically – and what controls this distribution and their concentrations, impeding the design of processing techniques to recover these vital resources.
The properties of critical metals which determine how they will behave during mineral processing are controlled by the geological processes that concentrate, transport, and deposit these metals in mineral deposits. However, for many deposit types these processes are still unknown. We will investigate the processes controlling critical metal distribution in the Cu and Au deposits of Newmont Lake in British Columbia, Canada, in collaboration with researchers from the University of British Columbia (UBC) and Enduro Metals Corporation, the company which owns the deposits. Newmont Lake deposits contain potential Te, Bi and PGM by-products. Metals in the Newmont Lake deposits were carried by hot, salty water which exsolved from magma. Unlike most deposits of this type which form above subduction zones, where oceanic and continental plates collide, the deposits in British Columbia formed after subduction ceased and...