Low-rare-earth permanent magnetic ferrite double-high material and preparation method thereof

Abstract

The invention discloses a low-rare-earth permanent magnetic ferrite double-high material and a preparation method thereof, and belongs to the technical field of permanent magnetic materials. The invention relates to a low-rare earth permanent magnetic ferrite double-high material, which is prepared from the following raw materials: Fe2O3, SrCO3, La2O3, Co2O3, CaCo3 and a catalyst. The invention relates to a preparation method of a low-rare-earth permanent magnetic ferrite double-high material. The preparation method comprises the following steps: burdening, mixing, dehydrating, carrying out primary forming, crushing, carrying out secondary ball milling, carrying out secondary forming and sintering. The low-cost double-high-ferrite permanent magnet material is prepared by reducing the replacement amount of La and Co combined ions in the material, adding a proper amount of catalyst and adopting a special process. According to the ferrite double-high material prepared by the invention, the raw material use cost is reduced, and the ferrite double-high material has more advantages in market competition.

Description

Technical Field

[0001] The invention belongs to the technical field of magnetic materials, and in particular relates to a low rare earth permanent magnet ferrite double high material and a preparation method thereof. Background Art

[0002] Magnetic materials are basic functional materials for the electronics industry. As an important component of magnetic materials, permanent magnetic materials play an important role in the electronics industry, information industry, motorcycles, power tools industry, automobile industry and other industries. Permanent ferrite materials are functional materials that generate magnetic fields. Permanent ferrites are made of SrO or BaO and ferric oxide as raw materials through ceramic process methods.

[0003] Ferrite materials have always occupied a large proportion in the market due to their stable performance and low price. With the integration and miniaturization of electronic devices, ferrite materials are required to have higher magnetic properties. The high-performance permanent ferrites currently used in the market are all doped with rare earth elements and precious metal cobalt to improve the magnetic properties of ferrites. However, doping with rare earth elements and precious metal cobalt will increase the raw material cost of ferrite materials and reduce their advantages in market competition.

[0004] Therefore, there is an urgent need for a permanent ferrite with low production cost and excellent performance and a preparation method thereof. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a low rare earth permanent magnet ferrite dual high material and a preparation method thereof. The present invention aims to solve the problems of high preparation cost and low market competitiveness of existing high performance permanent magnet ferrite.

[0006] To achieve the above object, the present invention provides a low rare earth permanent magnet ferrite dual high material, comprising the following raw materials in parts by weight: Fe 2 O 3 80-85 parts, SrCO 3 10~15 servings, La 2 O 3 1.5~6 parts, Co 2 O 3 0.5-1.5 parts CaCo 3 1 to 5 parts, catalyst 0.05 to 0.1 parts.

[0007] Furthermore, the catalyst is boron oxide, and a proper amount of boron oxide is added during the pre-sintering of the primary material to enable the red iron and the rare earth elements La and Co to fully undergo replacement reaction.

[0008] The present invention also provides a method for preparing a low rare earth permanent magnet ferrite dual-high material, comprising the following steps:

[0009] S1. Ingredients: Ingredients according to the weight percentage of raw materials;

[0010] The raw materials are calculated by weight as follows: Fe 2 O 3 80-85 parts, SrCO 3 10~15 servings, La 2 O 3 1.5~6 parts, Co 2 O 3 0.5-1.5 parts CaCo 3 1-5 parts, catalyst 0.05-0.1 parts;

[0011] S2. Mixing: The prepared raw materials are wet mixed in a ball mill for 1 to 2 hours using a wet mixing process;

[0012] S3. Dehydration: The wet mixed slurry is dehydrated with a dehydrator;

[0013] S4. One-step forming: using a press to press the dehydrated raw material into shape;

[0014] S5. Pre-sintering: The pressed raw materials are pre-sintered in a 60-meter double push plate tunnel, oxidized for 1.5 hours, and naturally cooled to obtain pre-sintered blanks;

[0015] S6. Crushing: The pre-burned blank is crushed by dry ball milling, and the crushed pre-burned powder is sieved and graded by an ultrasonic vibrating screen;

[0016] S7. Secondary ball milling: Add CaCO by weight to the crushed pre-sintered powder sieved in step S6 3 :0.8%、H 3 BO 3 :0.15%、SiO 2 :0.3% for wet grinding for 11 to 12 hours, and the particle size after grinding is controlled at 0.80 to 0.90 μm;

[0017] S8. Secondary molding: The slurry after secondary ball milling is pressed and molded using an automatic hydraulic press and a carbide runner mold;

[0018] S9. Sintering: The green body after forming is sintered in a double-push plate tunnel electric kiln. The heat preservation is carried out for 2.5 hours. After natural cooling, the cooked body is obtained. The cooked body is ground by an automatic grinder to obtain the sample.

[0019] Further, in step S1, the iron red raw material is selected: Fe 2 O 3 Content ≥99%, chloride ion content ≤0.2%.

[0020] Furthermore, in step S3, the water content of the slurry after dehydration is 29% to 35%.

[0021] Furthermore, in step S4, the press is a 230-ton automatic molding press.

[0022] Furthermore, in step S5, the pre-sintering temperature is 1180-1230°C.

[0023] Furthermore, in the wet grinding process of step S7, the ratio of crushed pre-sintered material: ball: water is 1:7:1.5.

[0024] Furthermore, in step S8, the density of the green body obtained by secondary molding is 2.9-3.5 g / cm 2 .

[0025] Beneficial effects:

[0026] 1. The present invention provides a method for preparing a low rare earth permanent magnet ferrite dual-high material and a preparation method thereof, which has a lower manufacturing cost. By increasing the replacement amount of combined ions in the material and an appropriate amount of catalyst, a green body with consistent size and water content is obtained by a unique molding process, and then pre-sintered at a set pre-sintering temperature in a sufficient oxidizing atmosphere to generate a permanent magnet ferrite M phase, thereby obtaining a dual-high permanent magnet ferrite pre-sintered material.

[0027] 2. The dual-high ferrite permanent magnet material prepared by the present invention has good particle size consistency after secondary ball milling, which makes the slurry have higher production efficiency and qualified rate in secondary molding and subsequent processes, and the performance can reach FB9B performance, and reduces the addition of rare earth materials. The raw material cost is saved by about 30% compared with external purchase, which has more advantages in market competition.

[0028] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a flow chart of a method for preparing a low rare earth permanent magnet ferrite dual-high material of the present invention;

[0030] Figure 2 The performance test results of the samples produced in Example 1 are as follows;

[0031] Figure 3 The performance test results of the samples produced in Example 2;

[0032] Figure 4The performance test results of the samples produced in Example 3;

[0033] Figure 5 These are the performance test results of the samples produced in Example 4. DETAILED DESCRIPTION

[0034] In order to make the technical solutions, advantages and purposes of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work belong to the protection scope of this application.

[0035] The present invention provides a low rare earth permanent magnet ferrite dual high material, comprising the following raw materials in parts by weight: Fe 2 O 3 80-85 parts, SrCO 3 10~15 servings, La 2 O 3 1.5~6 parts, Co 2 O 3 0.5-1.5 parts CaCo 3 1 to 5 parts, catalyst 0.05 to 0.1 parts.

[0036] Among them, boron oxide is selected as a catalyst. When a proper amount of catalyst is added during the pre-sintering of the primary material, the iron oxide red and the rare earth elements La and Co can fully carry out the replacement reaction.

[0037] like Figure 1 As shown, the present invention also provides a method for preparing a low rare earth permanent magnet ferrite dual high material, comprising the following steps:

[0038] S1. Ingredients: Ingredients according to the weight percentage of raw materials;

[0039] The raw materials are calculated by weight as follows: Fe 2 O 3 80-85 parts, SrCO 3 10~15 servings, La 2 O 3 1.5~6 parts, Co 2 O 3 0.5-1.5 parts CaCo 3 1-5 parts, catalyst 0.05-0.1 parts;

[0040] Among them, ordinary iron red is selected as Fe 2 O 3 Raw materials, ordinary iron red: Fe 2O 3 Content ≥99%, chloride ion content ≤0.2%;

[0041] S2. Mixing: The prepared raw materials are wet mixed in a ball mill for 1 to 2 hours using a wet mixing process;

[0042] S3. Dehydration: The wet mixed slurry is dehydrated with a dehydrator;

[0043] The moisture content of the slurry after dehydration is 29% to 35%;

[0044] S4. One-step molding: Use a 230-ton automatic molding press to press and mold the dehydrated raw materials;

[0045] S5. Pre-sintering: The pressed raw materials were pre-sintered at 1180-1230°C in a 60-meter double push plate tunnel, oxidized for 1.5 hours, and naturally cooled to obtain pre-sintered blanks;

[0046] S6. Crushing: The pre-burned blank is crushed by dry ball milling, and the crushed pre-burned powder is sieved and graded by an ultrasonic vibrating screen;

[0047] S7. Secondary ball milling: Add CaCO by weight to the crushed pre-sintered powder sieved in step S6 3 :0.8%、H 3 BO 3 :0.15%、SiO 2 :0.3% for wet grinding for 11 to 12 hours, and the particle size after grinding is controlled at 0.80 to 0.90 μm;

[0048] During the wet grinding process, the ratio of crushed pre-burned material: ball: water is 1:7:1.5;

[0049] S8. Secondary molding: The slurry after secondary ball milling is pressed and molded using an automatic hydraulic press and a carbide runner mold;

[0050] The green density of the secondary molding is 2.9-3.8g / cm 2 ;

[0051] S9. Sintering: The green body after forming is sintered in a double-push plate tunnel electric kiln. The heat preservation is carried out for 2.5 hours. After natural cooling, the cooked body is obtained. The cooked body is ground by an automatic grinder to obtain the sample.

[0052] Example 1

[0053] This embodiment provides a low rare earth permanent magnet ferrite dual high material, including the following raw materials in parts by weight: Fe 2 O 3 82 parts, SrCO 3 12. La2 O 3 1.5 parts, Co 2 O 3 0.5 parts, CaCo 3 3.9 parts, catalyst 0.06 parts.

[0054] The preparation method of the low rare earth permanent magnet ferrite dual high material of this embodiment is as follows, comprising the following steps:

[0055] S1. Ingredients: Ingredients according to the weight percentage of raw materials;

[0056] Among them, ordinary iron red is selected as Fe 2 O 3 Raw materials, ordinary iron red: Fe 2 O 3 Content ≥99%, chloride ion content ≤0.2%;

[0057] S2. Mixing: The prepared raw materials are wet mixed in a ball mill for 2 hours using a wet mixing process;

[0058] S3. Dehydration: The wet mixed slurry is dehydrated with a dehydrator;

[0059] S4. One-step molding: Use a 230-ton automatic molding press to press and mold the dehydrated raw materials;

[0060] S5. Pre-sintering: The pressed raw materials were pre-sintered at 1230°C in a 60-meter double push plate tunnel, oxidized for 1.5 hours, and naturally cooled to obtain pre-sintered blanks;

[0061] S6. Crushing: The pre-burned blanks are crushed by dry ball milling, and the crushed pre-burned powder is sieved and graded using an ultrasonic vibrating screen;

[0062] S7. Secondary ball milling: Add CaCO by weight to the crushed pre-burned powder sieved in step S6 3 :0.8%、H 3 BO 3 :0.15%、SiO 2 :0.3% for wet grinding for 11 to 12 hours, and the particle size after grinding is controlled at 0.80 to 0.90 μm;

[0063] During the wet grinding process, the ratio of crushed pre-burned material: ball: water is 1:7:1.5;

[0064] S8. Secondary molding: The slurry after secondary ball milling is pressed and molded using an automatic hydraulic press and a carbide runner mold;

[0065] S9. Sintering: The green body after forming is sintered in a double-push plate tunnel electric kiln. The heat preservation is carried out for 2.5 hours. After natural cooling, the cooked body is obtained. The cooked body is ground by an automatic grinder to obtain the sample.

[0066] Example 2

[0067] This embodiment provides a low rare earth permanent magnet ferrite dual high material, including the following raw materials in parts by weight: Fe 2 O 3 83 parts, SrCO 3 12.2 parts, La 2 O 3 1.5 parts, Co 2 O 3 0.5 parts, CaCo 3 The preparation method of the low rare earth permanent magnet ferrite dual high material in this embodiment is the same as that in the first embodiment.

[0068] Example 3

[0069] This embodiment provides a low rare earth permanent magnet ferrite dual high material, including the following raw materials in parts by weight: Fe 2 O 3 84 parts, SrCO 3 10 copies, La 2 O 3 2 copies, Co 2 O 3 1 part, CaCo 3 The preparation method of the low rare earth permanent magnet ferrite dual high material in this embodiment is the same as that in the first embodiment.

[0070] Example 4

[0071] This embodiment provides a low rare earth permanent magnet ferrite dual high material, including the following raw materials in parts by weight: Fe 2 O 3 84 parts, SrCO 3 10 copies, La 2 O 3 2.4 parts, Co 2 O 3 1.2 parts CaCo 3 The preparation method of the low rare earth permanent magnet ferrite dual high material in this embodiment is the same as that in the first embodiment.

[0072] The performance test results of the low rare earth permanent magnet ferrite dual high material samples prepared in Examples 1 to 4 are as follows: Figures 2 to 5 As shown, through analysis, it can be seen that the performance of the sample pressed from the slurry produced in Example 4 is the best, reaching the FB9B performance.

[0073] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the protection scope of the present invention.

Claims

1. A low rare earth permanent magnet ferrite double high material, characterized in that: The invention comprises the following raw materials in parts by weight: 80-85 parts of Fe2O3, 10-15 parts of SrCO3, 1.5-6 parts of La2O3, 0.5-1.5 parts of Co2O3, 1-5 parts of CaCo3 and 0.05-0.1 parts of catalyst.

2. The low rare earth permanent magnet ferrite double high material according to claim 1, characterized in that: The catalyst is boron oxide.

3. A method for preparing a low rare earth permanent magnet ferrite dual high material, characterized in that: The following steps are involved: S1. Ingredients: Ingredients according to the weight percentage of raw materials; The raw materials are calculated in the following weight parts: Fe2O3 80-85 parts, SrCO3 10-15 parts, La2O3 1.5-6 parts, Co2O3 0.5-1.5 parts, CaCo3 1-5 parts, catalyst 0.05-0.1 parts; S2. Mixing: The prepared raw materials are wet mixed in a ball mill for 1 to 2 hours using a wet mixing process; S3. Dehydration: The wet mixed slurry is dehydrated with a dehydrator; S4. One-step forming: using a press to press the dehydrated raw material into shape; S5. Pre-sintering: The pressed raw materials are pre-sintered in a 60-meter double push plate tunnel, oxidized for 1.5 hours, and naturally cooled to obtain pre-sintered blanks; S6. Crushing: The pre-burned blank is crushed by dry ball milling, and the crushed pre-burned powder is sieved and graded by an ultrasonic vibrating screen; S7 secondary ball milling: to the crushed pre-sintered powder sieved in step S6, CaCO3: 0.8%, H3BO3: 0.15%, SiO2: 0.3% was wet-milled for 11 to 12 hours, and the particle size after milling was controlled at 0.80 to 0.90 μm; S8. Secondary molding: The slurry after secondary ball milling is pressed and molded using an automatic hydraulic press and a carbide runner mold; S9. Sintering: The green body after forming is sintered in a double-push plate tunnel electric kiln and kept warm for 2.5 hours. After natural cooling, the cooked body is obtained. The cooked body is ground with an automatic grinder to obtain the sample.

4. The method for preparing a low rare earth permanent magnet ferrite dual high material according to claim 3, characterized in that: In the step S1, a red iron raw material is selected: Fe2O3 content ≥ 99%, chloride ion content ≤ 0.2%.

5. The method for preparing a low rare earth permanent magnet ferrite dual high material according to claim 3, characterized in that: In the step S3, the water content of the slurry after dehydration is 29% to 35%.

6. The method for preparing a low rare earth permanent magnet ferrite dual high material according to claim 3, characterized in that: In step S4, the press is a 230-ton automatic molding press.

7. The method for preparing a low rare earth permanent magnet ferrite dual high material according to claim 3, characterized in that: In the step S5, the pre-sintering temperature is 1180-1230°C.

8. The method for preparing a low rare earth permanent magnet ferrite dual high material according to claim 3, characterized in that: During the wet grinding process of step S7, the ratio of crushed pre-sintered material: ball: water is 1:7:1.

5.

9. The method for preparing a low rare earth permanent magnet ferrite dual high material according to claim 3, characterized in that: In step S8, the density of the green embryo obtained by secondary molding is 2.9-3.5 g / cm 2 .

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