Lower Grades at Argyle Hit Rio Tinto Output

RAPAPORT... Rio Tinto's diamond production dropped in the third quarter amid lower mining grades at its Argyle deposit, the company reported Friday.Output at the Australian mine fell 10% year on year to 3.2 million carats in the three-month period ending September 30. Production was hampered by lower grades, as the company prepares to complete operations before the end of the year and shut the mine, Rio Tinto said.Rio Tinto's share of production at the Diavik mine in Canada rose 1% to 1 million carats for the same period due to a higher ore availability and processing rate. The company owns 60% of the deposit, with Dominion Diamond Mines holding the remainder.Rio Tinto's total diamond production, including its share of Diavik goods, dropped 8% to 4.2 million carats.For the first nine months of the year, the miner produced 11.9 million carats, compared to 12.8 million carats in the same period of 2019. Its 2020 forecast remains unchanged at 12 million to 14 million carats, down from 17 million carats last year.Image: The underground entrance to the Argyle mine. (Rio Tinto)