Environmental Life Cycle Assessment of Southern Yellow Pine ...

EXECUTIVE SUMMARY
Global mine reserves of zinc are approximately 250,000,000 tons, and world production from mining
in 2011 was 12,400,000 tons; 50 at this rate of consumption, primary zinc resources will be depleted in
approximately 20 years. However, the total world reserve also includes zinc that is currently in use,
which can be considered a secondary mineral supply. Including both primary and secondary zinc
resources, the USGS estimates that there are nearly 2 billion tons total of zinc resources in the world.
However, of the secondary zinc resources (those already in use), only 19% can be recovered, due to
this metal’s most common use in dissipative applications that cannot be recycled (e.g. zinc coatings,
and brass in brake linings). 51 Even at this low recovery rate, these data indicate that there is a volume
of retrievable reserves of secondary zinc that meets or exceeds the current reserves of primary zinc.
It is anticipated that as primary zinc reserves are depleted, the price of primary zinc will increase,
resulting in increased zinc recycling. Nevertheless, the depletion of primary zinc reserves is an
important impact, especially if only a small fraction of zinc in-­‐use can ever be recovered.
In the SPR scenario, consumption of zinc resources are a very small portion of the total primary zinc
production, with an annual average consumption of approximately 650 tons over the study time
horizon, less than 0.005% of the total world primary zinc production in 2012, according to the United
State Geological Survey. 52 While it is contributing to the depletion of a significant resource, the
depletion of zinc in the SPR scenario is not considered a major driver of zinc resource depletion
globally.
50 United States Geological Survey. Mineral Commodity Summaries 2012. US Department of the Interior.
51 Gordon, R.B., M. Bertram, T.E. Graedel. Metal stocks and sustainability. Proceedings of the National Academy of
Sciences. 2006 January 31; 103(5): 1209–1214.
52 USGS Minerals Information. Zinc: Statistics and Information. Mineral Commodity Summaries 2012.
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