Crushing The haul trucks carry the ore out of the pit along a haulage road with a slope of no more than about nine percent They dump the ore into a gyratory crusher To help the process along eightinchdiameter steel balls are added to the rocks as they tumble inside the rotating mill semiautogenous gets some help Crushing The haul trucks carry the ore out of the pit along a haulage road with a slope of no more than about nine percent They dump the ore into a gyratory crusher To help the process along eightinchdiameter steel balls are added to the rocks as they tumble inside the rotating mill semiautogenous gets some help