The motor drives the reducer to drive the grinding disc to rotate. The roasted spodumene is fed into the center of the rotating grinding disc by the air-locking feeding device. Under the action of centrifugal force, the material moves to the periphery of the grinding disc and enters the grinding roller. Under the action of the grinding roller pressure, the material is crushed by extrusion, grinding and shearing. At the same time, hot air is ejected upward at high speed and uniformly from the wind ring surrounding the grinding disc. The ground material is blown up by the high-speed airflow at the wind ring. On the one hand, the coarser material is blown back to the grinding disc for re-grinding, and on the other hand, the suspended material is dried. The fine powder is brought into the separator by the hot air for classification. The qualified fine powder is discharged from the mill with the air flow and collected by the dust collection equipment as the product. The unqualified coarse powder falls back to the grinding disc under the action of the separator blades and is re-grinded with the newly fed material. This cycle completes the whole process of grinding.