Mining major Xstrata has reported a 16% drop in total copper production to 747,000 tonnes for 2012 financial year.
The decline in production was precipitated by a 66% decrease to 34,100 tonnes of copper produced at the Ernest Henry mine.
The Collahuasi mine in Chile also witnessed a drop of 38%, which the company attributes to lower grades and recoveries, adverse weather conditions, safety stoppages and an extended ball mill outage.
Increase in production at the Antamina project and Alumbrera mines – 34% and 16% respectively, mitigated some of the decline.
Coal production, meanwhile, registered a 7% increase to 90.4 million metric tonnes from the Australian thermal coal mines.
"Increased volumes predominantly resulted from the restart of mining at Blakefield South, commencement of mining at Ravensworth North, Ulan West and Ulan open cut, and the return to full production at Rolleston following flooding in 2011.
"The increase was partially off-set by end of mine life closures at Ravensworth West and Westside during 2012 and at Baal Bone in late 2011," said the company in a statement.