Mining News: Minto copper output slips as mine upgrades

Capstone Mining Corp. Oct. 11 reported that its Minto Mine in the Yukon produced 3,400 metric tons of copper during the third quarter, a 23 percent drop from the 4,400 metric tons produced there during the second quarter, and a 38 percent decline from the 5,500 metric tons produced in the first quarter. The company attributes this drop in copper production to mine sequencing changes to support extensions to the life of the mine. Underground mining was halted for six weeks in order to upgrade the emergency response capacity in the stoping areas while development to the Minto East deposit continued. Partially oxidized ore from two open-pit areas and low-grade stockpiles supplemented the mill feed during the quarter to offset the resulting underground ore shortfall, resulting in lower head grade and recoveries than originally planned. The mill processed 342,282 metric tons of ore during the third quarter averaging 1.31 percent copper, 5 grams per metric ton silver and 0.62 g/t gold. Capstone’s three operations – Minto, Pinto Valley and Cozamin – produced 22,000 metric tons of copper during the third quarter and 67,000 of the red metals through the first nine months of 2017. The company’s 2017 production guidance is within 5 percent of 94,000 metric tons of copper. "As we enter the fourth quarter, all operations are on track and we expect to achieve the low end of our guided production range for the year,” said Capstone President and CEO Darren Pylot.

–SHANE LASLEY