Xstrata first lodged an application in April with the New South Wales Department of Planning to add Longwall 12 to its development consent, but in July the company decided to leave the block in situ as mining it would be uneconomical.

Xstrata has since withdrawn the Longwall 12 mining and gas management aspects of the planning approval application but kept the first workings component covering the Woodlands Hill and Blakefield seams, which received approval this month.

The first workings component was kept to provide Xstrata options in the future while the company continues a prefeasibility study in the area to investigate further mining opportunities.

An Xstrata spokesperson told ILN there was no time limit on the study.

With United working on its last block, Longwall 10, the mine closure is expected slightly before the previous March guidance.

“We are definitely closing the mine down at the end of February,” the spokesperson said.

In September, more than 100 miners at United went on strike.

The Construction Forestry Mining and Energy Union was aiming to insert a job security clause and other conditions into a new enterprise agreement at the mine and held the view Xstrata would resume mining in the area in 2012.