Also called a shaker mill or high-energy ball mill. equipped with safety interlock system for operator protection. for grinding samples in the 0.2 - 1.5 gram range or mixing up to 5 ml of sample. highly effective laboratory impact grinder and blender offering many advantages over other small.Asarco. sep - jul years 11 months. • 50 ton haul pack operator to haul slag from smelter to mill. • 7x10 ball mill operator. • 5-7 ball mill operator. • 1-4 grinding operator.