Abstract：The pre-sintered materials of permanent magnetic ferrite were ground by different processes. The particle size distribution of the granular materials was compared by an average particle size tester in combination with the method of sedimentation. The related magnetic property of the products was tested by a standard measuring device for permanent magnetic ferrite and a product pressure testing machine. The results show that compared with the traditional fine grinding process, there are the following conclusions for fine grinding technology with different speeds, steel ball diameters, mass ratios of materials, ball and water in two stages.The ball milling efficiency is improved by 22%, the molding cycle is shortened more than 8 %. The overall pass rate of the magnet is improved by more than 7.6%. The bearing load limit of the products is increased by8.3%. The residual magnetic flux density and coercive force of the magnet are increased by 1.17% and 4.4%, respectively. The porosity of the molding slurry, green density, microstructure of the magnet and so on are also significantly improved.

Keywords: permanent magnetic ferrite; magnetic property; fine grinding