Two empty haul trucks turned in front of each other with the resulting collision causing the headboard of one to damage the cabin of the other.
The NSW Resources Regulator said one operator suffered hand fractures and a head laceration that required 52 stitches.
"This incident is under investigation," it said.
"Following a recent awareness campaign on vehicle interactions, the regulator published a video that can be used for training purposes and toolbox talks.
"Mine operators are encouraged to use this resource."