South32 has again suspended operations at its Appin underground coal mine in NSW over concerns of a build-up of methane gas levels.
The diversified miner says it had withdrawn the mine’s workforce on Wednesday as a precautionary measure and notified the NSW department of planning and environment authorities.
While the company said it had not breached gas limits at the site, the regulator had issued a prohibition notice for the mine.
The regulator also had expressed broader concern about recent events at the Illawarra Metallurgical Coal operation – when gas limits had been exceeded – as well as its operating practices, South 32 said in a statement on Friday.
The company said it was working with the regulator to address these issues.
Operations are continuing at the Illawarra Metallurgical Coal unit’s other mine, Dendrobium.
Ongoing problems at the Appin mine has prompted South32 to repeatedly lower the Illawarra unit’s production guidance.
Production was disrupted in September 2016 due to roofing problems at one of the longwalls, and again in November and May when methane gas levels forced temporary suspensions of operations.
The miner on Friday said that having already achieved production of 7.05 million tonnes by June 28, it did not expect the unit’s most recent full-year production guidance to be affected by the latest incident.
The company in May lowered its forecast for full-year production to 7.1 million tonnes.
South32 will detail production guidance for the 2018 financial year when it releases its full-year results in August.