Workers at the Grosvenor Coal Mine near Moranbah in Central Queensland were safely evacuated after a spark ignited methane gas on Saturday morning.
"It can be caused by friction ignition from rock-on-rock, a pick on a rock, it can be from various other sources of ignition," Mr Smyth said.The only way to extinguish the fire is to starve it of oxygen in a strategic and controlled manner. Industrial-level expanding foam can also be used to form a plug in the shaft, which is then capped with a steel plate that is covered with dirt.
The 12-metre-long GAG unit is mounted on the back of a truck and emits carbon dioxide, nitrogen, and water vapour, which is pumped into the mine to starve the fire of the oxygen it needs to burn.The Grosvenor Coal Mine has a complex network of tunnels as deep as 500m underground. These disasters led to the formation of today's safety and gas detection systems and, decades later, the Mining and Energy Union is confident in the re-sealing plan."They know what they're doing, and they've had a practice over recent years sadly with North Goonyella and Grosvenor .""The sealing efforts mean the amount of oxygen available to the underground fire has greatly reduced," the company said.