Vertical roller mill is a kind of grinding machine for cement, raw material, cement clinker, slag and coal slag. It has the features of simple structure and low cost of manufacture and use. Vertical roller mill has many different forms, but it works basically the same. All of these forms of machine come with a roller (or the equivalent of roller grinding parts), and roller along the track of the disc at the level of circular movement imposed by external grinding roller in the vertical pressure on the disc on the material being the joint action of compression and shear, and to crush.