After crushed by hammer crusher, the large materials become small ones and are sent to storage hopper by elevator, and then evenly sent to the upper distribution plate of the turn plate by vibrating feeder and sloping feeding pipe. When the grinding mill is at work, the main bearing and each dial are driven by electromotor through reducer, and all the grinding rollers are rolling in the ring channels driving by dial through plunger. The materials are driven to the edge of the turn plate by the centrifugal force and fall down into the grinding chambers. The high-pressure air blower constantly inhales air, airflow with crushed materials are brought to classifier whose high-speed impeller will screen the airflow: The unqualified particle size will fall and return to the mill for being reground while the qualified particle size mixed with air will go into the cyclone powder collector. Most of the qualified powders will fall and exit from the discharging valve at the bottom; A small proportion of the fine powders, with airflow, moves to the dust cleaner. The materials from the above two lots are sent by the conveyor to get finished powders packed. In addition, filtered clean air will be emitted from muffler in the end.