Minegraveyard

Mills Grinding

Generally ball mills are more common than Rod mills or Sag Mills, there are other types of mills available such as Vertical mills but the last three mentioned are by far the most common. Ball and mills use steel balls or ceramic balls as their grinding media. Rods mills as the name suggest use rods as their grinding media. The larger mills are a continuous process which means the ore comes in one end and exits via the trommel end and the process does not stop unless new grinding media needs to be inserted, some don’t even need to stop during this process. Other mills used a batch process where the ore is put into the mill with the grinding media and locked up, the mill is rotated for a predetermined time and then emptied.

When purchasing a second-hand or used mill make sure that the drive units are in good working order, most mines keep good maintenance records of these important pieces of equipment. Always check the trunnion and pinions for excessive wear. Try to obtain a copy of the drawings as most of the larger mills will need new footings to be constructed before they can be set up and used. Also, see if you can acquire  the inching drive and the greasing system