SINGHASINI Tumbling Mill / Ball Mill consists of a cylindrical shell which slowly turns about a horizontal axis & is filled about half its volume with a solid grinding media. The shell is lined with a replaceable liner which may be of high carbon steel, Manganese steel, Porcelain or rubber. The grinding media is metal or rubber balls in a ball mill, Pebbles or Porcelain in a Pebble Mill & metal rods in a Rod Mill.
In Tumbling Mills the material to be grinded is carried up the side of the shell upto the top from where they fall on the particles underneath. In Ball / Pebble Mill the most of the grinding is achieved by the impact of the Ball / Pebble which drop from nearly the top of the shell whereas in a Rod mill the most of the size reduction is due to rolling attrition & compression.
The Tumbling Mills may be batch type or continuous.