Copper
A strong recovery in production across the Base Metals portfolio delivered a 27% increase in copper volumes from the September 2011 quarter. Escondida (Chile) average mill throughput per day steadily increased as operations recovered from the industrial action that affected production in the prior quarter. In addition, Olympic Dam (Australia) benefited from higher grades and improved smelter availability following the planned outage in the September 2011 quarter. The expansion of mining fleets at Antamina (Peru) and Pampa Norte (Chile) contributed to half yearly material mined records for both assets.
| | Dec ‘11 Half | Dec ‘11 Qtr | Dec H‘11 vs Dec H ‘10 | Dec Q ‘11 vs Dec Q ‘10 |
| Copper ('000 tonnes) | 500.6 | 280.3 | -16% | -7% |
| Lead (tonnes) | 122,651 | 66,992 | -9% | 3% |
| Zinc (tonnes) | 51,742 | 28,298 | -33% | -23% |
| Silver ('000 ounces) | 20,054 | 10,903 | -15% | -6% |
| Uranium oxide concentrate(tonnes) | 1,909 | 909 | -3% | -5% |
Consistent with prior guidance, Escondida production is forecast to be marginally lower in the 2012 financial year, with volumes weighted to the second half. Production is expected to improve beyond the 2012 financial year as mining activities progress towards higher grade ore with completion of the Escondida Ore Access project in the main pit.
At December 31st 2011, the Group had 219,718 tonnes of outstanding copper sales that were revalued at a weighted average price of USD 3.45 per pound. The final price of these sales will be determined over the remainder of the 2012 financial year. In addition, 239,156 tonnes of copper sales from the 2011 financial year were subject to a finalisation adjustment in the current period. The finalization adjustment and provisional pricing impact as at December 31st 2011 will decrease earnings before interest and tax by US$258 million for the period.
Lead/silver
Production at Cannington (Australia) decreased in the December 2011 half year reflecting lower average ore grades.
Zinc
Production at Antamina decreased in the December 2011 half year as mining continued to progress through a copper rich ore zone.
Uranium
Production was broadly in line with all comparable periods.
