Workers at the North Mine operated by Perilya were scaling the wall of a section of the mine, knocking loose rock from the side of the wall using a jumbo when the incident happened.
According to the NSW Resources Regulator, a drill bit on one of the arms of the jumbo accidentally slipped into a blast hole containing residual explosives.
The resulting explosion caused pieces of rock to fly from the wall hitting the jumbo operator's offsider.
The worker sustained lacerations to his leg and arm, according to the regulator.
Thankfully, he was standing well away from the wall to the rear of the jumbo, at the time.
Had he been closer to the wall, he could have sustained more serious injuries.
The regulator is still investigating the incident but has released two preliminary findings.
Firstly, a risk assessment should have been undertaken prior to drilling to identify blast hole remnants prior to conducting scaling work.
Secondly, the workers should have been using a scaling bit larger in diameter than the hole it slipped into. Had they used a larger bit, the equipment would not have entered the hole and caused the explosion.
"The Resources Regulator attended the mine and issued improvement notices," the regulator told Australia's Mining Monthly.
"The circumstances surrounding the incident are being assessed by the Regulator."
It is the second incident involving a jumbo during scaling operations at an Australian mine site in recent months.
Several weeks ago, a worker had his ribs crushed when rock from the roof fell at a Queensland underground mine.
The rock was partly deflected by installed steel mesh.
