Rio Tinto Records 13% Drop in 2014 Rough Output

Rio Tinto's Argyle Diamond Mine (Image: Rio Tinto Diamonds)

(IDEX Online News) – Rio Tinto reports that its diamond production for 2014 fell 13 percent in volume year over year to 13.872 million carats.

At the miner's wholly owned Argyle mine in Western Australia, rough diamond production for the year, totalling 9.188 million carats, was 19 percent lower year over year, reflecting the move from open pit to underground mining and the processing of lower grades as underground production ramped up. In addition, Rio Tinto notes that a maintenance shutdown took place during the fourth quarter to implement some improved design modifications to both underground crushers.

The miner's 60 percent share of diamond production from the Diavik diamond mine in Canada's Northwest Territories remained flat in 2014 at 4.340 million carats, with improved mining rates and processing plant improvements offset by the impact of lower grades. According to Rio Tinto, improved processing rates, which have now fully exhausted the stockpiled ore that was processed in prior quarters, resulted in significantly lower carat recovery during the fourth quarter.

At the Murowa mine in Zimbabwe, of which Rio Tinto owns a 78 percent stake, production grew 7 percent year over year to 344,000 carats due to increased ore processed.

For the fourth quarter of 2014, Rio Tinto saw a year-over-year decrease of 37 percent in rough output to 2.841 million carats.  At Argyle, production fell 43 percent to 1.813 million carats. The miner’s share of production at Diavik fell 25 percent in the fourth quarter to 927,000 carats.  Murowa output dropped 4 percent year over year to 101,000 carats.