A resource is the identified concentration of a mineral in the Earth’s crust, in such form and amount that economic extraction is potentially feasible. The reserve base is that part of a resource, that meets certain minimum criteria, related to current mining and production practices. Reserves refer to the portion of the reserve base, which has been measured, and which is, or may become in the close future, available for production.
Information provided by the United States Geological Survey indicates that lead reserves amounted to 90 million tonnes and the reserve base was 170 million tonnes, with total resources at around 2 billion tonnes.
In 2021, global lead mine production was 4.6 million tonnes.
Zinc is an abundant component of the earth’s crust. It is estimated that the amount of zinc in the first mile of the crust, under dry land, is over 200 trillion tonnes and, in the Oceans and seabed the amount is put at 15 billion tonnes. Zinc ores and deposits are widely spread throughout the world, and extracted in more than 50 countries. Information provided by the United States Geological Survey indicates that zinc reserves amounted to 250 million tonnes and the reserve base was nearly half a billion tonnes, with total resources at around 1.9 billion tonnes.
In 2021, global zinc mine production was 12.8 million tonnes.