US-based Consol Energy will close its Mine 84 near Washington and idle its Emery mine near Price, Utah, due to higher mining costs.

Consol said costs of mining coal at the operations are too expensive relative to local market prices.

The mines utilise the room-and-pillar method, in which a machine carves a network of rooms in the operation by ripping away the coal while leaving some intact to support the roof.

Employees of Mine 84, which produces utility and steelmaking coal, will have the option of taking a position at another Consol operation, the company said.