PERTH (miningweekly.com) – Despite lower iron-ore prices, mining giant Rio Tinto has maintained its momentum during the December quarter, boosting its production by 12% year-on-year to 79.1-million tonnes. This brought full year output to 295.4-million tonnes.

The Pilbara operations delivered 280.6-million tonnes of iron-ore during the full year, an increase of 12% on the previous calendar year, setting a new yearly record. The increase in the Pilbara production was driven by the early completion of the 290-million-tonne-a-year expansion project, which was completed in the first half of the year.

Infrastructure for the 360-million-tonne-a-year expansion was about 80% complete, Rio said on Tuesday, with all major rail line, marine and wharf works in place. The completion of this infrastructure remained on track for the end of the first half of 2015.

Some 40-million tonnes a year of brownfield expansions were under way to feed the expanded infrastructure capacity, and production from the Pilbara was expected to increase to 330-million tonnes a year in 2015.

Meanwhile, Rio reported that copper production for the quarter ended December had decreased by 23%, compared with the previous corresponding period, with the miner producing 128 300 t of copper.

Copper production was negatively affected by declining grades at the Escondida operation, in Chile, and the Kennecott Utah copper project, in the US.

The declining grades from the two mines were slightly offset by higher production from the Oyu Tolgoi mine, in Mongolia, which produced 16 900 t of copper during the quarter under review, a 53% increase on the previous corresponding period.

The increases in production at the Oyu Tolgoi mine were owing to higher copper and gold grades, as well as higher throughput.

Rio also reported that hard coking coal and semi-soft and thermal coal production had declined during the quarter, with hard coking coal production down 31% on the previous corresponding period, and semi-soft and thermal coal production down 16%.

Rio produced 1.65-million tonnes of hard coking coal during the quarter under review, and 5.5-million tonnes of semi-soft and thermal coal.

The miner noted that significant productivity gains across the Australian coal business had delivered yearly site production records at the Hail Creek operation, in Queensland, the Hunter Valley operations and Bengalla, also in New South Wales.

For the full year, hard coking coal production declined by 9% on the previous calendar year, to 7.4-million tonnes, while semi-soft and thermal coal production declined by 6%, to 25-million tonnes.

Meanwhile, aluminium production for the December quarter was down 1% to 842 000 t, while bauxite production dropped 6% to 10.7-million tonnes.