Particle size distribution refers to the proportion (expressed in percentage) of particles in natural kaolin within a given continuous range of different particle sizes (expressed in mm or micron mesh). The particle size distribution characteristics of kaolin are of great significance to the separability of ore and process application. Its particle size has a great impact on its plasticity, slurry viscosity, ion exchange capacity, molding performance, drying performance and sintering performance. Kaolin ores need technical processing. Whether it is easy to process to the fineness required by the process has become one of the standards to evaluate the ore quality. Various industrial departments have specific requirements for particle size and fineness of kaolin for different purposes. For example, the requirements for kaolin used as coating in the United States are less than 2 μ The content of M accounts for 90-95%, and the papermaking filler is less than 2 μ Accounting for 78-80% of M.