When working, the spiral classifier relies on the principle that the solid particles have different sizes and specific gravity, so the sedimentation speed in the liquid is different. The fine ore particles float in the water and overflow, and the coarse ore particles sink to the bottom of the tank. It is a kind of grading equipment that is pushed to the upper part by the screw to carry out mechanical grading. It can classify and filter the powder ground in the mill, and then use the spiral blade to screw the coarse material into the feed port of the mill, and discharge the filtered fine material from the overflow pipe.