Vale has released details of the man, Dan Hill, who had been employed by subsidiary company Integra Coal since 2007.
A Vale spokesperson told International Longwall News Hill was assisting with maintenance work on the longwall shearer when the accident happened at about 2:30am on Saturday morning.
The NSW police said Hill, who was from Maitland, died at the scene from head injuries and that he may have been struck by a piece of machinery.
“The entire company is deeply saddened by this incident,” Glennies Creek mine general manager Mick Thew said.
“Our condolences go out to Dan’s family and friends and we have offered our support to the family.”
Operations at the mine have been suspended while investigations are carried out by Hunter Valley police and forensics along with Department of Primary Industries officials.
Vale said support services had been arranged and employees were being provided with as much information as possible.
The Australian coal industry has already been marked this year by two deaths that occurred in February.
One fatality was from a vehicle accident at BHP Billiton Mitsubishi Alliance’s Blackwater open cut coal mine in Queensland’s Bowen Basin, while the other was from an accident that crushed the cabin of a coal reject truck at Xstrata Coal’s Ravensworth longwall mine (formerly Newpac No. 1) in the Hunter Valley.