Chilean miner Antofagasta PLC (LON:ANTO) reported an increase in second-quarter copper production as higher output at its Centinela and Antucoya mines mitigated declines at Los Pelambres and Zaldívar.
Total copper production for the quarter rose 6.1% to 163,200 tonnes from 153,800 tonnes the previous year, boosted by increased sulphide grades and higher throughput at all operations.
Production at the Los Pelambres mine came to 78,000 tonnes, 3.8% lower than the previous quarter, due to a blockage in the concentrate pipeline in April and May.
The mining operation and the processing plant continued to operate normally during the blockage. Concentrates containing 9,200 tonnes of copper were stockpiled at the plant, which will be pumped down to the port in the third quarter.
READ: Antofagasta clears blockage at Los Pelambres pipeline
At Zaldívar, copper production fell 2.8% to 10,500 tonnes, although throughput increased 22.4% and grades and recoveries grew 8.65 and 7.2% respectively.
Centinela copper output increased 19.2% to 56,400 tonnes as grades improved in the Esperanza pit.
Antucoya production was up 25.4% to 18,300 tonnes as throughput jumped 43.8% to the highest level since output began in 2016.
Net cash costs for the quarter were US$1.50 per pound, down 2.6% on the previous quarter due to lower cash costs before by-product credits.
"We continue our disciplined approach to costs, but we have seen higher input prices and the impact of a stronger Chilean peso coupled with lower grades during the first half of the year,” said chief executive Ivan Arriagada.
“However, with grades and by-product volumes expected to increase in the second half, we expect a reduction in net cash costs.”
Antofagasta left its full-year guidance unchanged at a production of 705-740,000 tonnes and a net cash cost of US$1.35 per pound.
Shares fell 1.3% to 961.4p in morning trading.