The machine has a simple structure, reliable, easy to operate. Grading machine is by means of solid particles of different sizes, different weight, and thus the velocity in the liquid of different principles, fine mineral particles floating in the water into the overflow out of coarse mineral particles sink to bottom. Discharged by the screw into the upper part, to a hierarchical classification of mechanical equipment, the mill can grind the material within the powder level in the filter, then the thick film material using helical screw rotary vane mill feed, to filter out the fine material di