Ball Mills Mineral Processing Metallurgy
If finer grinding is wanted two or three stage grinding is advisable as for instant primary rod mill with 75—100 mm (3″—4″) rods, secondary ball mill with 25—40 mm(1″—1½") balls and possibly tertiary ball mill with 20 mm (¾") balls or cylpebs. To obtain a close size distribution in the fine range the specific surface of the grinding media should be as high as possible. Thus