The withdrawal of workers from Moranbah North is the latest in a series of events that has left Queensland underground coal miners rattled, a key union says.
Operations have been suspended at Moranbah North after mine management identified carbon monoxide and ethylene gas levels in the gas monitoring system, pointing to indicated a potential spontaneous heating in the longwall panel.
CFMEU Mining and Energy Queensland president Stephen Smyth said it was a relief no-one was hurt when all crews were withdrawn on Saturday night.
“But we should not lose sight of the seriousness of this event. Managing gas levels is core business in underground coal mines,” he said.
“To have gases detected that indicate the presence of advanced heating, in an area of the mine that has high gas, is extremely concerning.”
Mr Smyth said the focus now must be on fully understanding what caused the event and ensuring the mine was 100 per cent safe before re-entry.
“The regulator must leave no stone unturned,” he said.
Resources Safety and Health Queensland (RSHQ) said mine operator Anglo American reported that gas concentrations in the mine had returned to normal levels by Sunday.
However the operation had not yet identified the cause of the elevated levels and actions that would be taken to prevent a reoccurrence of this high-potential incident, the regulator said.
“Under the Coal Mining Safety and Health Act 1999, a mine’s site senior executive must investigate a high-potential incident to determine its causes and make recommendations to prevent the incident happening again,” RSHQ said in a written statement.
“The Queensland Mines Inspectorate has issued a directive to the mine operator suspending all operations underground until the site senior executive can demonstrate the risk is at an acceptable level for coal mine workers to return underground.”
Anglo American said it had internal and external experts assessing various information sources to more accurately determine the cause of the event.
“The conclusions from the expert review of the incident will inform a comprehensive risk assessment prior to re-entry, which will require regulatory approval,” a spokeswoman said.
“The safety of our workforce remains our priority and we are keeping them closely informed.”
Mr Smyth said the confidence of Queensland underground coal miners had been rattled by a series of events in the sector over the past couple of years.
“We’ve had the terrible explosion at Anglo’s Grosvenor mine last year, severely injuring five miners. We’ve had the fire that burnt out of control at Peabody’s North Goonyella mine.
“We’ve also had a number of other ignition events such as spontaneous combustion (Cook and Ensham mines) and repeated damage to electrical equipment in explosion zones (Oaky North mine).
“Coal miners should not fear for their lives when they head underground to work. Underground mine operators and regulators have a lot of work to do to reassure workers of their safety and we will hold them to account every step of the way.”