Rio Tinto 2018 Recoveries Decline. Recovery of lower-grade ore at Rio Tinto’s Argyle and Diavik mines led to a 15% drop in the company’s diamond production to 18.4 million carats in 2018.
Output at the Argyle asset in Australia slid 18% to 14.1 million carats for the full year, Rio Tinto reported Friday. In 2017, operational performance at the mine was enhanced by the processing of higher-grade alluvial tailings, the company said.
Rio Tinto’s share of production at the Diavik mine in Canada declined 3% to 4.4 million carats, also due to lower grades, partially offset by higher ore volumes. Mining began at Diavik’s new A21 extension in March, with the project reaching commercial production during the fourth quarter.
Total recoveries slumped 40% year on year to 4.3 million carats for the fourth quarter. Argyle output fell 48% to 3.2 million carats, while the company’s share of production at Diavik rose 2% to 1.1 million carats.
Rio Tinto owns Argyle outright, and holds a 60% stake in Diavik, with Dominion Diamond Mines owning the remaining 40%. The companies split the Diavik goods accordingly.
The miner expects production to fall to a range of 15 million to 17 million carats in 2019.