TORONTO (miningweekly.com) – Copper producer Capstone Mining on Thursday reported strong results for the second quarter and six months ended June, as all three of its North American mines were firing on all cylinders.

The TSX-listed miner reported concentrate and cathode output of 27 700 lb for the three months ended June 30, up marginally from the first quarter and half-year output of 55 300 lb of red metal.

"At the midway mark of the year our copper production is on plan with all [are] operations performing well. With operations at Pinto Valley now fully ramped up and essentially stabilised at targeted throughput rates, we can direct all our focus on continued cost and business improvements at Pinto Valley,” Capstone president and CEO Darren Pylot said.

The Vancouver-based miner reported that the average grades and recovery at Pinto Valley, located in Arizona, more than offset lower-than-planned throughput.

One of the six ball mills was down for 25 days in May, as a result of gear failure. Repairs were completed by June 4 and the mill operated at capacity for the month of June.

At Cozamin, in Zacatecas state, Mexico, strong throughput offset slightly lower-than-planned grades. The grade was expected to improve in the third quarter, according to the 2014 mine plan.

At Minto, in the Yukon, Canada, lower-than-expected grades in the openpit were mainly offset by continued “very strong” throughput and recoveries. The mill achieved a quarterly throughput record of 4 124 t/d. Capstone began feeding the mill with ore from the underground M-Zone in April, with grades and tonnage reported to be as planned.

During the quarter, Capstone shipped 24 564 t of payable copper from all three mines.

The company confirmed its 2014 guidance for 102 000 t of copper in concentrates, at a C1 cash cost of $1.90/lb to $2/lb of payable copper, net of zinc, molybdenum, lead, silver and gold by-product credits and selling costs.