Byproduct-to-Host\nRatios for Assessing the Accessibility\nof Mineral Resources

Mineral resources are essential for reaching net-zero\nambitions\nby 2050. There is a rising diversity of metals in electricity generation\nand storage technologies, as well as for mobility technologies. However,\nlittle is known about the future supply of minor elements historically\nmined in low volumes such as indium, tellurium, germanium, or tantalum.\nThose minor elements are found in lower concentrations in the ores\nof major elements and therefore rarely form economic deposits on their\nown. Such elements are often produced as byproducts of a host (or\n“target commodity”, which underpins the bulk of a mine’s\nprofitability) in ore, e.g., in porphyry ore, tellurium is a byproduct\nwhere copper is the host. As a result, the primary supply of those\nminor elements depends on the supply of the major elements. Such dependency\nhas not been accounted for in scenarios of the mineral supply. To\naddress this gap, we developed a methodology to harmonize scattered\ndata of mineral resource estimates and to calculate the mass ratio\nbetween the byproduct and the host in ores and concentrates, called\nthe byproduct-to-host (BtH) ratio. We collected crude ore tonnage\nand element grades, among other key data, from the state-of-the-art\nliterature and publicly available mining company reports. Our data\nset covers 3422 deposits across 141 countries providing 22 275\nBtH ratios. The future supply of minor elements can be derived by\nmultiplying the primary production of host elements by the developed\nBtH ratios, noting the limitations of data representativity. The open-access\nnature of this work facilitates the enrichment and update of this\ndata set in the coming years.