First the materials are crushed by the jaw crusher,then the crushed materials are transferred to a hopper by the elevator ,fed uniformly.quantltatively and continously by the vibration feeder to the grinding chamber of the main frame for grinding.the grinded particles are brought up by the air current of the blower into the classifier for classification.the particles with the required fineness are brought up by the air current through the pipe into a collector for separation and collection,the finished particles are discharged from a pipe outlet,Because of some moisture contained in the materials to be grinded,the heat resulting from grinding leads to the vaporized air which changes the airflow volume,Moreover,the outside air inhaled from the narrow gaps of the piping connections can increase the volume of air current.Therefor,it is necessary to adjust redundant air pipe between the blower and the main unit for keeping the balance of the air current.Then the redundant air is quided into a cloth bag of a dust cleaner to collect the fine power in the air,Finally, the redundant air is discharged after purfication.