Production is set to ramp up again at Freeport McMoRan’s Grasberg Mine, six weeks after a deadly collapse at a training facility at the mine killed 28 people, Reuters reported.

Trade union workers at the Grasberg mine in remote West Papua were also returning to production work, while postponed pay talks with the Arizona-based firm have been resumed, a union official added. Freeport Indonesia employs about 24,000 workers, of which three-quarters belong to the union.

Production from the mine, the second largest copper operation in the world, was stopped on May 15, a day after the accident at the training tunnel.

The company said it had slowly resumed openpit mining after receiving approval from the Indonesian government, although underground production remained closed.

“We herewith confirm that we have started to ramp up production since Saturday (June 22),” Freeport Indonesia spokeswoman Daisy Primayanti said in an email to Reuters. “(We) also confirm that our workers have returned to work at the production side.”

The openpit mine normally produces around 140 kt/d (155,000 stpd), while output from underground operations is 80,000 mt/d (88,000 stpd). Freeport was forced to declare force majeure on shipments due to the prolonged closure of the mine.

Previously, union officials had demanded that all probes into the accident be completed before production was allowed to resume, and that they wanted to evaluate the final investigation report and see if Freeport implemented all recommendations.

However, Papua-based union official Virgo Solossa told Reuters by telephone. "The union encourages the workers to go back to work."
The Freeport Indonesia management had not consulted the union when asking workers to return to their duties, Solossa said, adding that the government would be held accountable should there be any further accidents at the mining site.

The union successfully demanded the suspension of five senior Freeport employees that it suspected bore responsibility for the accident.
Relations between Freeport and the union have been strained in recent years, after a three-month strike in late 2011 and a series of minor spats.
After the May 14 tunnel collapse, the company and the union put on hold pay negotiations that began on May 13 and were forecast to last for up to 60 days.