Shares in BHP spinoff South32 dipped earlier this week, after the miner announced operations at its Appin colliery in the Illawarra would remain suspended due to elevated gas concentrations in the underground mine.
Workers were evacuated from the colliery in May, and in June, due to concerns over gas levels.
While the company said there was “no gas exceedance or breach of gas limits,” it made the decision this week that the colliery would remain closed while a lengthy review takes place.
“Underground operations at the Appin colliery, which forms part of [South32’s] broader Illawarra Metallurgical Coal operation, remain suspended,” the company told the ASX on July 10.
“A review of the operation’s systems and operating practices is currently being undertaken to ensure its ongoing safety and reliability.
“Given the scope of this review, an extended outage is now anticipated before production at Illawarra Metallurgical Coal can be restored to historic levels.”
The announcement comes after the miner revealed in May gas-related stoppages at Appin would likely result in at least 10% fewer tonnes mined for its Illawarra operation in FY17.
Monday’s news saw South32’s share price dip from a $2.77 open to a low of $2.70, before bouncing back to a close of $2.77 on Tuesday evening.