Rio Tinto's Pilbara iron ore shipments in the third quarter increased 5% year over year to 86.1 million tonnes, while Pilbara iron ore production increased 6% to 87.3 Mt, reflecting a recovery from the operational and weather challenges earlier in the year.
Copper mined in the period fell 1% on a yearly basis to 157,800 tonnes but was 15% higher than the second quarter due to higher grades at the Kennecott mine in Utah and improved throughput at the Escondida mine in Chile, according to an Oct. 16 operational update.
Rio Tinto's majority-owned Turquoise Hill Resources Ltd. reported a 27.8% year-over-year decrease in copper production to 28,446 tonnes and a 66.8% year-over-year decrease in gold production to 25,607 ounces from the Oyu Tolgoi mine in Mongolia. Performance suffered due to a plant shutdown being brought forward, with higher-than-planned feed from harder ore.
Meanwhile, refined copper output from Kennecott slumped 26% to 40,300 tonnes, while Escondida refined copper totaled 16,800 tonnes, a 1% increase from 2018
Bauxite output was up 9% to 13.8 million tonnes due to increased production across all sites, but aluminum output declined 3% to 789,000 tonnes, reflecting reduced production at the ISAL smelter in Iceland and the Kitimat smelter in British Columbia.
While maintaining guidance for all other commodities, Rio Tinto lowered its 2019 forecast for bauxite to about 54 Mt from the previous range of 56 Mt to 59 Mt, citing harsh weather conditions in the first quarter, downtime to address commissioning items on new mines, and lower production from the Pacific refineries. Alumina production is expected at about 7.7 Mt, compared to previous guidance of 8.1 Mt to 8.4 Mt, due to maintenance at its Pacific refineries. Aluminum production is also seen coming in at the lower end of full-year guidance of 3.2 Mt to 3.4 Mt.
Diamond production at the company's Diavik mine in Canada's Northwest Territories slipped 7% to 994,000 carats on lower ore availability. Output from the Argyle mine in Western Australia also fell 7% to 3.6 million carats due to lower recovered grade, partially offset by stronger mining and processing rates.
Iron ore pellets and concentrate output from Rio Tinto's majority-owned Iron Ore Co. of Canada Inc.'s IOC operations in Labrador rose 3% to 3.0 million tonnes as operations normalized following flooding in June.
Earlier in October, Rio Tinto was reported to have no plans of stopping mining at the Oyu Tolgoi open pit despite declining grades, delays and cost blowouts on the underground expansion of the Mongolian project.