In the gravity field, the classification of the material particles is limited by the gravitational acceleration, the classification process is slow, the efficiency is low, and the centrifugal movement can greatly improve the jaw crusher working principle and efficiency.In recent years, the ultrafine grading technology has been continuously developed, the most prominent ones are rapid grading, decompression grading and high-voltage electrostatic grading.In the dry grading process, the slower the particle moving speed is closer to the grading point size (the slower the particle sedimentation is thicker than the kerf particle size, the slower the particle size is finer than the kerf size), and thus the retention in the grading zone.