Ball Mill Process Equipments 1) Pebble Mill. Lined with bricks and utilizes Pebbles or Balls as Grinding Media. It is milling machine for wet and dry milling. They are also lined with burrs tone (silica), alumina, steatite, ceramic,porcelain, urethane rubber etc. 2) Steel Ball Mill. It is used for DRY as well as LIQUID grinding.