Permanent magnetic ferrite low-temperature pre-sintering powder and preparation method thereof

A permanent magnet ferrite, low-temperature pre-sintering technology, applied in the direction of inorganic material magnetism, etc., can solve the problems of poor crystallization consistency of pre-sintered materials and high pre-sintering temperature, and achieve the effects of low production cost, low energy consumption and simple process

Active Publication Date: 2013-09-18
东阳市金砖磁业有限公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there is still the problem that the calcining temperature is as high as 1300°C, and the crystallization consistency of the calcined material is poor.

Method used

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Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0016] Weigh the ingredients according to the molar ratio of iron red and strontium carbonate mixed at 5:1, add an appropriate amount of low-melting sintering aid, of which CaCO 3 Addition accounted for 1wt% of the total material weight, SiO 2 The amount added accounts for 10wt% of the total material weight, ZrO 2 Addition amount is 2wt%, wet mixing ball milling for 1 hour, after ball milling, the mixing ingredients are made uniform, and the slurry particle size is controlled at about 0.5 μm; 1240°C, the holding time is controlled at 3 hours, and strontium ferrite is formed after pre-calcination. Put the calcined material into a ball mill for dry rough grinding. After dry grinding, the average particle size is 5 μm, and a narrow particle size distribution is obtained; at this time, the residual magnetism of the powder is Br=410±10mT; the coercive force of the powder (Hcj)= 320±15 kA / m.

[0017]

Embodiment 2

[0019] Weigh the ingredients according to the molar ratio of iron red and strontium carbonate mixed at 6:1, add an appropriate amount of low-melting sintering aid, of which CaCO 3 Addition accounts for 10wt% of the total material weight, SiO 2 The amount added accounts for 0.1wt% of the total material weight, ZrO 2 Adding amount is 5wt%, wet mixing ball milling for 5 hours, after ball milling, the mixing ingredients are uniform, and the slurry particle size is controlled at about 1 μm; after the slurry is pressed into calcined cake, it is put into tunnel kiln for pre-calcination, and the pre-calcination temperature is 1200 ℃, the holding time is controlled at 2 hours, and strontium ferrite is formed after pre-burning. Put the calcined material into a ball mill for dry rough grinding. After dry grinding, the average particle size is 2 μm, and a narrow particle size distribution is obtained; at this time, the residual magnetism of the powder is Br=410±10mT; the coercive force o...

Embodiment 3

[0022] Weigh the ingredients according to the molar ratio of iron red and strontium carbonate mixed at 5.5:1, add an appropriate amount of low-melting sintering aid, of which CaCO 3 The amount added accounts for 8wt% of the total material weight, SiO 2 The amount added accounts for 5wt% of the total material weight, ZrO 2 Addition amount is 1wt%, wet mixing ball milling for 3 hours, after ball milling, make the mixture components uniform, and the slurry particle size is controlled at about 0.6 μm; 1240°C, the holding time is controlled at 1.5 hours, and strontium ferrite is formed after pre-calcination. Put the calcined material into a ball mill for dry rough grinding. After dry grinding, the average particle size is 4 μm, and a narrow particle size distribution is obtained; at this time, the residual magnetism of the powder is Br=420±10mT; the coercive force of the powder (Hcj)= 320±15 kA / m.

[0023]

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PUM

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Abstract

The invention provides a preparation method of permanent magnetic ferrite low-temperature pre-sintering powder. The ferrite pre-sintering material is a permanent magnetic ferrite material of a hexagonal crystal system taking strontium as one of the major raw materials, and the molecular formula is SrO.mFe2O3, wherein m is greater than 5 and less than 6; and a low-melting sintering aid is a mixture of two or more of CaCO3, SiO2 and ZrO2, wherein the dosage of CaCO3 (z%) accounts for 1-10% of the total material weight, the dosage of SiO2 (y%) accounts for 0.1-10% of the total material weight, and the dosage of ZrO2 (wt%) accounts for 0-5% of the total material weight. The preparation method comprises the following steps of: (1) mixing Fe2O3 and strontium carbonate powder; (2) performing wet-process ball milling on the mixture to obtain slurry; (3) pressing the slurry into a cake and drying and directly pre-sintering; and (4) performing dry-type coarse grinding on the pre-sintered material. By adopting the processes such as optimization of a raw material formula, a superfine powder ball milling technology, addition of a low-melting sintering aid and the like, the preparation method provided by the invention produces high-performance strontium ferrite low-temperature pre-sintering powder, and the pre-sintering temperature is 100 DEG C lower than that of a conventional pre-sintering material; and meanwhile, the preparation method has the advantages of simple production technology and low energy consumption, and brings broad social and economic benefits.

Description

technical field [0001] The invention belongs to the field of permanent magnet ferrite, in particular to a permanent magnet ferrite low-temperature calcining powder and a preparation method thereof. Background technique [0002] my country's permanent magnet ferrite output ranks first in the world, and it is a major producer of magnetic materials. China's ferrite industry has basically maintained a growth rate of more than 20% for several years, and its output has doubled every five years on average. The research and development of high-grade permanent magnet oxygen has always been the main direction and goal of Chinese scholars and enterprises. Calcination is one of the important processes in the production of high magnetic performance ferrite. At present, the production process of ferrite calcined material is: iron red + strontium carbonate - mixing material - pressed cake - drying - calcined - pulverized - ferrite calcined powder. The traditional calcined material produ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C04B35/26C04B35/626H01F1/11
Inventor 卢晓梅张朋越赵国法
Owner 东阳市金砖磁业有限公司
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