<p>An apparatus for treating a particulate material comprising a casing defining a treating chamber and rotatable at high speed to produce a centrifugal force for pressing the material in the casing against an inside wall surface of the casing. Treating members such as pulverizing members are disposed in the casing for revolution relative to the inside wall surface of the casing. The treating chamber has a discharge opening for permitting overflows of the material under treatment. The discharge opening is disposed adjacent a center of rotation of the casing, and a limiting device is provided adjacent the discharge opening for limiting the overflows of the material under treatment. A classifier is provided to communicate with the discharge opening of the treating chamber for receiving treated material.</p>
