A kind of preparation method of high performance permanent magnet ferrite

Abstract

The invention discloses a method for preparing a high-performance permanent magnet ferrite. The steps are: (1) batching: mixing the main component and a primary additive; (2) mixing: mixing the prepared raw materials through dry mixing (3) pelletizing: pelletize the mixture to obtain pellets with a diameter of 5-12 mm; (4) pre-sintering: sinter the pellets at 1290-1390°C for 1.5-2.5 hours to obtain pre-sintered pellets; (5 ) Secondary grinding: After crushing the calcined material into coarse powder, it is mixed with secondary additives and wet ball milled to obtain fine slurry. The secondary additives include calcium carbonate, silicon dioxide and clinker calcined powder; (6) Sintering: the fine slurry is wet-pressed and then sintered to obtain the high-performance permanent magnet ferrite. The invention uses a dry process to mix materials, which reduces the cost of the process, and adds clinker pre-calcined powder to the secondary additive to obtain a permanent magnet oxide with high remanence, intrinsic coercive force and maximum magnetic energy product. body.

Description

technical field [0001] The invention relates to the technical field of magnetic material preparation, in particular to a preparation method of high-performance permanent magnet ferrite. Background technique [0002] Permanent ferrite, also known as hard ferrite, has the characteristics of maintaining a constant magnetic field or magnetic moment after magnetization. It is an important class of magnetic materials and can be widely used in automotive DC motors, starter motors, inductors, audio Converters, splitters and many other applications. With the development of science and technology, more equipment requires more miniaturization, light weight, energy saving and high efficiency. As an important permanent magnet material in many equipment, permanent ferrite has put forward more stringent requirements for its performance. [0003] The performance indicators of permanent ferrite mainly include remanence (Br), magnetic induction coercive force (Hcb), intrinsic coercive force ...

AI Technical Summary

Problems solved by technology

[0005] The present invention aims to overcome that when the wet process is used to mix materials in the prior art, because the mixed material contains too much water, it will cause excessive loss of combustion heat when entering the rotary kiln for pre-combustion, and the process cost is relatively high; The method of adding additives such as calcium carbonate and silicon dioxide in stages can effectively improve the intrinsic coercive force of permanent ferrite, but at the same time it will also lead to a significant decrease in the remanence of permanent ferrite, which cannot make the overall performance of the magnet effective. To improve the problem, provide a preparation method of high-performance permanent magnet ferrite, use dry process mixing, reduce the process cost, and add clinker pre-calcined powder in the secondary additive, can obtain high residual ferrite at the same time Magnetic, intrinsic coercivity and maximum energy product of permanent ferrite