Rawmill,Vertical Roller Mill for Raw material

A rawmill is the equipment used to grind raw materials into "rawmix" during the manufacture of cement. Rawmix is then fed to a cement kiln, which transforms it into clinker, which is then ground to make cement in the cement mill. The rawmilling stage of the process effectively defines the chemistry (and therefore physical properties) of the finished cement, and has a large effect upon the efficiency of the whole manufacturing process.

Vertical Roller Mill(VRM) is a kind of rawmill which is used in dry grinding technology. It is a very advanced rawmill which is replacing traditional ball mill and rod mill. hydraulic control systems make up a functional unit. Large or small modules with a different number of rollers (between two and six) can be deployed in the same mill sizes (grinding table diameter). This makes it possible to customise the product to meet specific customer requirements.

when grinding cement raw material the metallic particles usually cause uniform wear throughout their entire service life so that the mill throughput only declines when mill parts are completely worn. Partial wear may occur if, for reasons of cement chemistry, free quartz sand needs to be used as concrete aggregate. This can be offset by targeted hard facing in the mill.

Cement raw material is principally a compound made of limestone and argillaceous rock, which undergoes mechanical and thermal treatment to create cement clinker. The geological formation, material composition and water content influence the grinding dryness and energy requirements.

The raw materials are classified according to their origin into natural mineral raw materials and synthetic mineral materialsthat are by-products or waste products from other branches of industry deploying raw materials. The suitability of natural and synthetic mineral raw materials for manufacturing binding agents is primarily determined by their chemical composition.