Rio Tintowitnessed higher production across most of its portfolio in the second quarter,with the most notable increase coming from its bauxite operations.
Bauxite production climbed 13% year over year to 12.1million tonnes, with output from all mines increasing over the second quarterof 2015.
According to the July 19 results, second-quarter iron oreproduction rose 8% to 80.9 million tonnes and shipments shifted up 6% to 82.2million tonnes compared to a year earlier.
The higher output was largely due to minimal weather impactsas well as operational improvements and the ramp up of expanded and new minesacross the Pilbara operations in Western Australia.
Rio Tinto said its iron ore sales achieved a run-rate closeto 330 million tonnes per annum, which puts it on track to meet its annualguidance.
Delaysin the company's AutoHaul system means production from the Pilbara is expectedto be between 330 million tonnes and 340 million tonnes in 2017, instead of thepreviously forecast 350 million tonnes.
Meanwhile, quarterly aluminum output grew 11% year over yearto 911,000 tonnes and alumina production jumped 6% to 2.0 million tonnes.
While mined copper production was up 5% at 141,000 tonnes,refined copper output from the Kennecottmine in Utah and the Escondidamine in Chile slumped 26% to 24,600 tonnes and 4% to 25,600 tonnes,respectively.
Second-quarter thermal coal increased 6% to 4.3 milliontonnes, but hard coking coal production slipped 14% to 1.8 million tonnes andsemi-soft coking coal fell 13% to 893,000 tonnes compared to the same quarterof 2015.
Titanium dioxide slag production tumbled 22% to 236,000tonnes.
Rio Tinto maintained full-year guidance for its expectedshare of bauxite, alumina and aluminum production at 45 million tonnes, 7.8million tonnes and 3.6 million tonnes, respectively.
Mined copper production for this year is expected to bebetween 575,000 tonnes and 625,000 tonnes and refined copper production isforecast to be 220,000 tonnes to 250,000 tonnes.
Rio Tinto has upped its full-year guidance for its share ofthermal coal output to between 17 million tonnes and 18 million tonnes, from 16million tonnes to 17 million tonnes previously.
Semi-soft coking coal and hard coking coal productionexpectations remain unchanged at 3.3 million tonnes to 3.9 million tonnes and 7million tonnes to 8 million tonnes, respectively.