Machine operator Malcolm Wayne Fowlie was working underground at the mine on February 15, 2014 when he was caught beneath an 18t rockfall.
He died before his co-workers could reach him.
The tunnel where Fowlie was working was meant to have ground control in place to prevent a rockfall.
However, the ground control that was installed was insufficient to prevent the rockfall.
In pleading guilty, CNGC admitted it failed to install adequate ground control in the tunnel where Fowlie was working.
It also admitted failing to maintain an adequate geotechnical program at the mine, which would have reduced the likelihood of the rockfall.
Department of Mines, Industry Regulation and Safety mines safety director Andrew Chaplyn said the dangers of rockfall were well known in underground mining and the incident was preventable.
“Ensuring adequate ground control to protect workers is absolutely critical to the safe operation of an underground mine,” Chaplyn said.
“This incident should not have happened and will have a listing impact on the lives of Mr Fowlie’s family, friends and co-workers.
“It is a tragic reminder of why mining companies need to ensure the safety and health of workers is the highest priority.”