The working principle of mill: compressed air after cooling, filtering and drying, the supersonic nozzle formed air injected into the crushing chamber, under pressure to make the fluidization of material, the material is accelerated in the intersection point of convergence of a plurality of nozzles, resulting in severe shock, collision, friction, shear to particles of ultrafine grinding, fine the powder was crushed with the rising air turbo classifier is transported to the upper part of the wheel in the classification of centrifugal force and air pumping force will meet the fineness of the powder discharge, and into the lower grade to separation or collection, purification of exhaust gas from fan