Core Natural Resources said Thursday that it has resumed longwall operations at its Leer South metallurgical mine in Barbour County, West Virginia, which had been idle since Jan. 13 following the detection of combustion-related activity in a previously mined area.

Core said it was able to recover the major mining equipment in the mine with limited damage. The company said it has also sealed the impacted area of the mine to eliminate any potential future issues associated with the combustion event.

The company said it expects a "significant step-up" in its financial performance next year, citing the restart at the Leer South mine and the "much improved" geological conditions at its West Elk longwall mine in Colorado, among other factors.