Freeport's Grasberg mill runs at full capacity

Freeport-McMoran Copper & Gold Inc., the largest publicly traded copper producer, said that the mill at its Grasberg mine is running at full capacity even after subsurface mining was halted last week following an accident, The Jakarta Post reported Wednesday.

Ore for the mill is being sourced from its inventory and the open-pit section at the mine in Indonesia?s Papua province, Ramdani Sirait, a Jakarta-based spokesman at PT Freeport Indonesia, said in an emailed response to Bloomberg News. Ore is also coming from the site?s Big Gossan reserve, Sirait said.

The halt to underground mining after the April 18 accident in the Deep Ore Zone, which left two workers dead, helped boost copper futures in London last week.

The Deep Ore Zone ?operation has been suspended temporarily as investigation of the incident is conducted and we work to restore a safe working environment in the affected area;? Sirait wrote in the email.

The mill, which processes mined ore into copper concentrate, gets about 20 percent of its usual daily supply of ore from the underground zone, chief executive officer Richard Adkerson said on a teleconference on April 20. The Grasberg mine has the world?s largest recoverable reserves of copper and the biggest single gold reserve.

The Deep Ore Zone has been expanded to 80,000 metric tons of ore a day, while Big Gossan, which began output in the fourth quarter of last year, is expected to reach a full rate of 7,000 tons of ore a day by the end 2012, according to an earnings statement from Freeport on April 20.

Copper production from Grasberg rose to 284 million pounds in the three months ended March 31, from 279 million a year earlier, according to the statement Gold output increased to 441,000 ounces from 429,000 ounces. (*)