ARE WE FACING A ZINC CRUNCH? AN OVERVIEW OF GLOBAL PB-ZN RESOURCES, MINERAL DEPOSIT TYPES, AND IMPLICATIONS FOR FUTURE EXPLORATION AND PRODUCTION

The mining, extraction and processing of metals is fundamental to modern life, meaning that the discovery of mineral deposits is fundamental to sustaining current levels of production and enabling the mining industry to meet increasing levels of demand for metals. This is the case for lead and zinc, where a recent lack of discovery of significant greenfields Pb-Zn deposits has led to a perceived potential zinc crunch, where excess demand combines with insufficient supply to drive Zn prices up.

Here, we comprehensively address the sustainability of the global growth of Zn and Pb production by presenting the results of a comprehensive analysis of current Pb- and Zn-containing mineral resources. Globally, there is at least 184 Mt of contained Pb and 548 Mt of contained Zn present within 801 individual mineral deposits and mine waste projects in 70 countries, at an average grade of 0.38% Pb and 1.14% Zn. These resources are dominated by sediment-hosted Pb-Zn deposits, which contain resources equal to that within known VMS, skarn, porphyry, and epithermal deposits combined. These reported Pb-Zn resources can meet global demand for both Pb and Zn until 2050, although this is a minimum estimate, as our data indicate that Pb-Zn deposits frequently cumulatively produce well beyond their reported resources over time.

However, the fact that current resources of other metals such as Cu, Ni and Co can sustain current and increased production for 90-100+ years suggests a relative dearth of known Pb and Zn resources. The lower amounts of known Pb and Zn resources relative to other base metals are most probably due to a lack of exploration expenditure, rather than a global depletion of Pb and Zn resources; it is not that we cannot find them, it is that we haven’t been looking. In addition Pb and Zn production increases have been coincident with an increase in estimated Pb and Zn reserves and resources over time (although more slowly than other base metals), with this trend expected to continue and most likely accelerate if exploration expenditure continues to increase. Overall, our data suggests that a Zn crunch is a significant way off, with the future supply of Pb and Zn likely to be governed by prevailing exploration, economic, social and environmental factors more than sheer resource constraints.