JAKARTA, Aug 2 (Reuters) - Underground production at Freeport McMoRan Copper and Gold Inc's Indonesian unit is running at 50 percent of capacity, a spokeswoman said, adding that it would take "a couple of months" before full capacity would be reached.
A training tunnel cave-in killed 28 people at the world's second-biggest copper mine in May, shutting operations across the mine site for weeks while safety investigations were carried out.
Open-pit mining has been running at full capacity since July 4, while underground operations re-started in early July. The Arizona-based firm had expected full-capacity to take one month.
"The underground mining has not been running at full capacity," a spokeswoman said in an email in response to questions from Reuters late on Thursday. "It will take up to a couple of months before we are able to produce at full capacity.
"Currently our ramping up progress is at approximately 50 percent at our underground mine," she said, adding that the force majeure status had not been lifted and that the company had not achieved full shipments capacity.
The open-pit mine normally produces between 140,000 tonnes and 150,000 tonnes of ore per day, while output from the underground operations is 80,000 tonnes.