Stoilensky GOK resumed operations on September 22 in a hot trials mode after output at the asset was stopped on September 7
following an accident, NLMK said.
The restoration works lasted 12 days and were finished two days ahead of plan, while the repair costed about 250 million roubles ($3.4 million), the company said.
The Stoilensky asset has the capacity to produce around 8 million tonnes per year of iron ore concentrate, Fastmarkets data shows.
The company expects the asset to return to its normal output rate in the coming days, NLMK said, but could not make a more precise forecast at the moment.
"It was planned to ramp up its concentrate output to normal levels tomorrow [on Friday September 25], but our plans could still be adjusted so I wouldn't want to give a forecast yet," a source at NLMK said.
NLMK receives all its required iron ore concentrate from Stoilensky GOK, however, neither pig iron nor steel production were affected as a result of the accident, it said.
NLMK has capacity to produce 9.5 million tpy of pig iron and around 13 million tpy of crude steel, Fastmarkets understands.
"NLMK - the main consumer of [Stoilensky] products - sourced iron ore concentrate from its own stocks and external supplies [meaning] the incident did not affect NLMK's steel and rolled product production," the company said.
One source outside of the company had earlier speculated that NLMK was likely receiving its concentrate from Metalloinvest, another Russian major steel producer.
NLMK did not return a request for a comment on the matter before the publication deadline.