Production is expected to ramp up over coming weeks.

Mining development activities at Anglo American's nearby Grosvenor mine also resumed this week, as part of the mine's staged approach to restarting longwall mining operations later this year.

Anglo American Metallurgical Coal business CEO Tyler Mitchelson said the milestones were an important step.

"I would like to thank our workforces at Moranbah North and Grosvenor mines for their patience and dedication in actioning a range of measures to ensure a safe return to mining activities," he said.

"We will continue our ambitious program of work in the automation, remote operation and the use of data science areas to deliver on further step changes in safety improvement in underground mining."

However, Construction, Forestry, Mining and Energy Union district president Stephen Smyth told Australia's Mining Monthly that the union was not completely satisfied with safety at the mine.

"These matters do not address the gas drainage issues either pre or post drainage, the use of the cavity fill products for strata consolidation, and the workforce concerns," he said.

"If you cannot manage the gas, the ventilation and strata now these other measures mean little."

In regards to Moranbah North, the CFMEU has industry safety & health representative Steve Watts on site reviewing the mines risk assessments for the restart of operations.

"The union still has reservations relating to the event [Anglo American was forced to evacuate workers from Moranbah North following a change in gas conditions underground at the mine in February]," Smyth said.

"Has the company established the measures to control the potential of the event happening again? 

"The company needs to ensure they have the confidence and trust of the workforce on this matter.

"I have never personally seen any of the technical data or reports on the event so unable to make an informed decision on if in fact they have addressed the cause and nature of the event."

In regards to Grosvenor, Smyth said the union would wait to see if changes at the mine brought an opportunity for workers to speak up.

"The mine has recently changed out its SSE [site senior executive] and we are hoping as a part of the changes in the SLT [site leadership team] that focus will be on the health and safety of the Grosvenor employees, that they are engaged, and their concerns listened to and that the company continue on these SLT changes," he said.

"The real change needed at this mine is the scrapping of the LH [labour hire] business model and the introduction of full-time employment for these workers, that will bring job security and along with that people feeling able to speak up. 

"We are watching this very carefully and have our safety reps reviewing and participating in the process where able to.

"This is the time the RSHQ [Resources Safety and Health Queensland] needs to be all over the ongoings at these mines as the regulator.

"The fact that they are relying on automation and remote operations to make the safety improvements demonstrates that they haven't really listened or took on board the inquiry outcomes.

"The word ambitious can be seen as either ruthless or pushy as well. So not the best use of a word after two explosions at one mine, and a spontaneous combustion event at another."