Gearless Mill Drives ABBAntamina Compania Minera Antamina Peru Project One SAG Mill and 3 Ball Mill Drive Systems Capacity SAG Mill 1000 t/h Ball Mills 1000 t/h Consultant Bechtel USA Mill Builder FFE Minerals USA Mill Size SAG Mill 38 feet/11 58 m Ball Mills 24 feet/7 32 m Ore processed Copper/Zinc Drive Rating SAG Mill 20 1 MW 9 23 rpm Ball Mills 11 2 MW 11 38 rpm