World mine production of copper was 15.8 million metric tonnes (Mt) in
2009; world reserves are estimated to be 540Mt, 34 years at 2009 rate of
production. Twelve countries produced 86% of world production
(link).
Major sources of copper are found in disseminated form in magmatic
rocks near continental plate junctions - principally along the west of
the Americas and in central Asia
(link).
These are porphyry copper orebodies, of very low grade (typically 0.5%
Cu or less); these ores are sulphides - the copper bearing minerals are
mainly
chalcopyrites and
bornites. See geology
(link).
NB: world demand of refined copper in 2009 was 19Mt. The difference with
15.8Mt is recycling (15% of total) and variations of stocks. Mines and
smelters have excesss capacity due to past investments made in
anticipation of world growth (on this, more later).
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