Preparation method of permanent magnetic ferrite magnet

The invention belongs to the technical field of permanent magnetic ferrites, and discloses a preparation method of a permanent magnetic ferrite magnet. The method comprises the following steps of: (1) burdening, namely mixing and crushing compounds containing required elements according to a molar ratio; (2) presintering, namely briquetting the mixed granules, and presintering the granules; (3) crushing the pre-sintered material; (4) ball milling, namely adding an additive, and continuously ball-milling until the average particle size of slurry particles is less than 0.75 mu m; (5) ultrasonic treatment, namely adjusting the water content of the slurry obtained by ball milling, and then carrying out ultrasonic treatment; (6) forming, namely forming in a magnetic field; and (7) sintering, namely sintering the formed body in an oxygen-enriched atmosphere. According to the preparation method disclosed by the invention, the cost is reduced through formula and process optimization, and the use of Co element can be