Muller mixers are widely used in mixing foundry sands and the ceramics industries prefer it for the preparation of clay-based mixtures with water. The Muller mixers consist of wheels, pans, plows and surfaces. Based on these parts and their axis and direction of rotation with respect to shaft they are classified into three types. The muller wheels are disk shaped and adjustable. They create pressure and rubbing action. The surface is made up of stone or ceramics but the hub is made of steel. The plows rake and run the material into the path of the muller. The pans may be jacketed for steam or water-cooling. Mixing is carried out in a single round pan with two muller wheels rolling over material in a circular path. This action imparts rubbing, kneading, and smearing to the material being mixed.