A low-cost ferrite permanent magnet material and a method for preparing the same

Abstract

The application discloses a low-cost ferrite permanent magnet material and a preparation method thereof, and belongs to the technical field of permanent magnet materials. The low-cost ferrite permanent magnet material comprises the following raw materials: Fe2O3, SrCO3, La2O3, Co2O3, CaCo3 and a cosolvent. The preparation method of the low-cost ferrite permanent magnet material comprises the following steps: batching, mixing, dewatering, primary forming, crushing, secondary ball milling, secondary forming and sintering. In the process of preparing the ferrite permanent magnet material, Fe2O3 is replaced by common iron red, the replacement amount of combined ions in the material is increased, a proper amount of cosolvent is added, and a low-cost ferrite permanent magnet material is prepared by using a special process. The ferrite permanent magnet material prepared by the application has a performance close to that of TDK-FB9, and the raw material cost is reduced, so that the application has more advantages in market competition.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of permanent magnetic material, and particularly relates to a low-cost ferrite permanent magnetic material and a preparation method thereof. BACKGROUND

[0002] Permanent magnetic material is an indispensable material in the electronic industry, and occupies an important position in the research and development of magnetic materials due to its wide raw material sources, low price and excellent magnetic performance. It is widely used in household appliances, automobiles, computers, communications, medical treatment, aerospace, military and other fields. With the wide application of permanent magnetic material, the performance requirement of permanent magnetic material is higher and higher. In order to meet the market demand, after the Japanese TDK company, the kingpin enterprise of ferrite industry, launched FB9 series high-performance permanent magnet ferrite product, various raw material manufacturers also launched high-performance permanent magnet ferrite pre-fired material with performance close to FB9. At present, the high-performance permanent magnet ferrite pre-fired material with performance close to FB9 produced by various manufacturers needs to use soft magnetic iron red, and the cost is relatively high, so the selling price is also increased, so that the produced permanent magnetic material has no advantage in market competition. SUMMARY

[0003] Therefore, the purpose of the application is to provide a low-cost ferrite permanent magnetic material and a preparation method thereof. The application uses ordinary iron red with low market price, adds a solubilizing agent in the pre-fired material formula, and uses a special production process to prepare high-performance ferrite permanent magnetic material with performance close to FB9, thereby greatly reducing the cost.

[0004] To achieve the above purpose, the application provides a low-cost ferrite permanent magnetic material, which comprises the following raw materials in parts by weight: Fe2O3: 80-85 parts; SrCO3: 10-15 parts; La2O3: 2-7 parts; Co2O3: 1-2 parts; CaCo3: 1-5 parts; and a solubilizing agent: 0.05-0.1 parts.

[0005] Further, a low-cost ferrite permanent magnetic material comprises the following raw materials in parts by weight: Fe2O3: 81 parts; SrCO3: 12 parts; La2O3: 4 parts; Co2O3: 1.2 parts; CaCo3: 1.73 parts; and a solubilizing agent: 0.07 parts.

[0006] The application also provides a preparation method of the low-cost ferrite permanent magnetic material, which comprises the following steps:

[0007] S1. Dosing: dosing according to the weight percentage, and Fe2O3 in the dosing is replaced by ordinary iron red;

[0008] S2. Mixing: the prepared raw materials are wet mixed in a ball mill for 1-2 hours by using a wet mixing process; in this way, the mixing uniformity can be ensured;

[0009]

[0009] S3. Dewatering: the mixed slurry is dewatered by a dewatering machine;

[0010] S4. Primary forming: the dewatered raw material is formed by a press; thus the consistency of size and density is ensured, and the solid phase reaction during pre-sintering is facilitated; thus the substitution rate of rare earth ions is improved;

[0011] S5. Pre-sintering: the formed raw material is pre-sintered by a 50-meter double push plate tunnel for 1.5 hours, and the pre-sintered blank is obtained after natural cooling;

[0012] S6. Breaking: the pre-sintered blank is dry ball-milled and broken, and the broken pre-sintered material is sieved and classified by an ultrasonic vibrating screen;

[0013] S7. Secondary ball-milling: the broken pre-sintered material sieved in step S6 is wet-milled, and the particle size after milling is controlled to be 0.80-0.90 μm;

[0014] S8. Secondary forming: the slurry obtained by secondary ball-milling is formed by an automatic hydraulic press and a hard alloy runner type mold;

[0015] S9. Sintering: the formed green body is sintered by a 75-meter double push plate tunnel electric kiln for 2.5 hours, and the ferrite permanent magnetic material is obtained after natural cooling.

[0016] Further, in step S1, the content of ordinary iron red: Fe2O3 is ≥98.5%, and the content of chloride ions is ≤0.3%.

[0017] Further, in step S3, the water content of the slurry after dewatering is 29%-35%.

[0018] Further, in step S4, the press is a 230-ton automatic forming press.

[0019] Further, in step S5, the pre-sintering temperature is 1180-1230℃.

[0020] Further, in step S7, the ratio of material: ball: water in wet milling is 1:6:1.5.

[0021] Further, in step S8, the density of the green body obtained by secondary forming is 2.9-3.8 g / cm 2 .

[0022] The beneficial effects of the present application are as follows:

[0023] 1. The present application provides a new preparation method of ferrite permanent magnet material, which has lower manufacturing cost, uses ordinary iron red in the market, increases the replacement amount of combined ions in the material, uses appropriate cosolvents, obtains green body with consistent size and water content through special forming process, and then pre-sintering is carried out under the condition of sufficient oxidation atmosphere to generate permanent magnet ferrite M phase, so as to obtain permanent magnet ferrite pre-sintering material.

[0024] 2. The ferrite permanent magnet material prepared by the present application has good particle size consistency after secondary ball milling, so that the slurry has higher production efficiency and qualification rate in secondary forming and subsequent processes, thereby improving the performance of the ferrite permanent magnet material. The finally sintered ferrite permanent magnet material is closer to the performance requirements of TDK-FB9, and saves about 20% of raw material cost, which has more advantages in market competition.

[0025] Other advantages, objects and features of the present application will be set forth in part in the description which follows, and in part will become apparent to those skilled in the art upon examination of the following or can be learned from practice of the present application. The objects and other advantages of the present application can be realized and attained by the methods and instrumentalities set forth in the description. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Flow chart of the low-cost ferrite permanent magnet material preparation method of the present application;

[0027] Figure 2 Performance detection and analysis chart of the low-cost ferrite permanent magnet material prepared in Example 1;

[0028] Figure 3 Performance detection and analysis chart of the low-cost ferrite permanent magnet material prepared in Example 2;

[0029] Figure 4 Performance detection and analysis chart of the low-cost ferrite permanent magnet material prepared in Example 3;

[0030] Figure 5 Performance detection and analysis chart of the low-cost ferrite permanent magnet material prepared in Example 4. DETAILED DESCRIPTION

[0031] In order to make the technical solutions, advantages and purposes of the present application clearer, the technical solutions of the embodiments of the present application will be described clearly and completely below in combination with the drawings of the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the described embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the protection scope of the present application.

[0032] Example 1

[0033] This embodiment provides a low-cost ferrite permanent magnet material, including the following raw materials in parts by weight: Fe2O3: 81 parts; SrCO3: 12 parts; La2O3: 4 parts; Co2O3: 1.2 parts; CaCo3: 1.73 parts; and a solvent: 0.07 parts.

[0034] like Figure 1 As shown, this embodiment also provides a method for preparing a low-cost ferrite permanent magnet material, comprising the following steps:

[0035] S1 Ingredients: Ingredients according to the following weight percentages: Fe2O3: 81 parts; SrCO3: 12 parts; La2O3: 4 parts; Co2O3: 1.2 parts; CaCo3: 1.73 parts; Solvent: 0.07 parts;

[0036] The Fe2O3 in the ingredients is replaced with ordinary iron oxide (Fe2O3 content ≥ 98.5%, chloride ion content ≤ 0.3%);

[0037] S2 mixing: wet mixing process will be prepared with the raw materials in a ball mill wet mixing 1 to 2 hours;

[0038] S3. Dehydration: The wet mixed slurry is dehydrated with a dehydrator. The moisture content of the slurry after dehydration is 29% to 35%;

[0039] S4. One-step molding: A 230-ton automatic molding press is used to press the dehydrated raw materials into shape;

[0040] S5 pre-sintering: using a 50-meter double push plate tunnel to pre-sinter the pressed raw materials, the pre-sintering temperature is 1180 ~ 1230 ℃, holding treatment for 1.5 hours, after natural cooling to obtain a pre-sintered blank;

[0041] S6. Crushing: The pre-sintered blanks are subjected to dry ball milling and the crushed pre-sintered materials are screened and graded using an ultrasonic vibrating screen;

[0042] S7 secondary ball milling: Step S6 sieved out of the crushed pre-sintered material was wet abrasive, wet abrasive material: ball: water ratio of 1:6:1.5, the particle size after abrasive control at 0.80 ~ 0.90μm;

[0043] S8. Secondary molding: The slurry obtained by secondary ball milling is pressed and molded using an automatic hydraulic press and a carbide runner mold. The density of the green embryo obtained by secondary molding is 2.9-3.8g / cm 2 ;

[0044] S9. Sintering: the green body after molding is sintered by using a 75-meter double push plate tunnel electric kiln, and is kept for 2.5 hours, and the low-cost ferrite permanent magnet material is obtained after natural cooling.

[0045] Magnetic property detection: the sintered products are detected by using a magnetization characteristic automatic measuring instrument produced by Mianyang High-tech Zone Bipolar Electronics Co., Ltd.

[0046] In this embodiment, three ferrite permanent magnet materials are prepared, and the three ferrite permanent magnet materials prepared in Example 1 are tested by using a magnetization characteristic automatic measuring instrument, and the test results are shown in Table 1 and Table 2. Figure 2

[0047] Table 1

[0048]

[0049] Example 2

[0050] In this embodiment, the raw materials of the ferrite permanent magnet material are prepared according to the following weight percentage: Fe2O3: 82 parts; SrCO3: 10 parts; La2O3: 5 parts; Co2O3: 1.6 parts; CaCo3: 1.3 parts; and a fluxing agent: 0.1 part. The Fe2O3 in the preparation is ordinary iron red. The remaining preparation steps and conditions are the same as those in Example 1.

[0051] In this embodiment, three ferrite permanent magnet materials are prepared, and the three ferrite permanent magnet materials prepared in Example 2 are tested by using a magnetization characteristic automatic measuring instrument, and the test results are shown in Table 1 and Table 2. Figure 3

[0052] Table 2

[0053]

[0054] Example 3

[0055] In this embodiment, the raw materials of the ferrite permanent magnet material are prepared according to the following weight percentage: Fe2O3: 80 parts; SrCO3: 11.3 parts; La2O3: 5 parts; Co2O3: 1.6 parts; CaCo3: 2 parts; and a fluxing agent: 0.1 part. The Fe2O3 in the preparation is ordinary iron red. The remaining preparation steps and conditions are the same as those in Example 1.

[0056] In this embodiment, three ferrite permanent magnet materials are prepared, and the three ferrite permanent magnet materials prepared in Example 3 are tested by using a magnetization characteristic automatic measuring instrument, and the test results are shown in Table 1 and Table 2. Figure 4

[0057] Table 3

[0058]

[0059] ​​​Example 4

[0060] The raw materials of the ferrite permanent magnet material in this example are prepared according to the following weight percentage: Fe203: 80 parts; SrCO3: 11 parts; La203: 5 parts; Co203: 1.9 parts; CaCO3: 2 parts; and a fluxing agent: 0.1 part. The Fe203 in the preparation is ordinary iron red. The remaining preparation steps and conditions are the same as those in Example 1.

[0061] Three ferrite permanent magnet materials are prepared in this example. The three ferrite permanent magnet materials prepared in Example 3 are tested by using a magnetization characteristic automatic measuring instrument. The test results are shown in Table 4 and Table 5. Figure 5 and Table 4.

[0062] Table 4

[0063]

[0064] Through the test analysis, the ferrite permanent magnet material prepared in Example 1 has the best performance, and the ferrite permanent magnet materials prepared in Examples 2-4 have slightly lower performance, but can also achieve ideal performance through secondary adjustment.

[0065] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the technical solutions, and they should be covered in the protection scope of the present application.

Claims

1. A method of producing a low cost ferrite permanent magnet material, characterized by, The method comprises the following steps: S1. batching: batching by weight percentage, Fe2O3 in the batching is replaced by ordinary iron red; The batching comprises the following raw materials by weight percentage: Fe2O3: 80-85 parts; SrCO3: 10-15 parts; La2O3: 2-7 parts; Co2O3: 1-2 parts; CaCo3: 1-5 parts; and a solubilizing agent: 0.05-0.1 parts; In the step S1, the ordinary iron red has Fe2O3 content ≥98.5% and chloride ion content ≤0.3%; S2. mixing: wet mixing the prepared raw materials in a ball mill for 1-2 hours; S3. dewatering: dewatering the wet mixed slurry by a dewatering machine; S4. primary forming: pressing and forming the dewatered raw materials by a press; S5. pre-sintering: pre-sintering the pressed and formed green body by a 50-meter double-pushing plate sintering kiln, and naturally cooling the pre-sintered material green body after 1.5 hours of heat preservation; wherein, a solubilizing agent is added in the pre-sintered material; S6. crushing: dry ball milling the pre-sintered material green body, and sieving and grading the crushed pre-sintered material by an ultrasonic vibration sieve; S7. secondary ball milling: wet milling the crushed pre-sintered material sieved out in the step S6, and controlling the particle size of the milled material to be 0.80-0.90 μm; S8. secondary forming: pressing and forming the slurry obtained by the secondary ball milling by an automatic hydraulic press and a hard alloy runner type mold; S9. sintering: sintering the formed green body by a 75-meter double-pushing plate tunnel electric kiln, and naturally cooling the sintered material after 2.5 hours of heat preservation.

2. The method for preparing a low-cost ferrite permanent magnet material according to claim 1, characterized in that: In the step S1, the batching comprises the following raw materials by weight percentage: Fe2O3: 81 parts; SrCO3: 12 parts; La2O3: 4 parts; Co2O3: 1.2 parts; CaCo3: 1.73 parts; and a solubilizing agent: 0.07 parts.

3. The method of claim 1, wherein the low cost ferrite permanent magnet material is prepared by the steps of: In the step S3, the water content of the dewatered slurry is 29%-35%. ​ 4. The method of claim 1, wherein the low cost ferrite permanent magnet material is prepared by the steps of: In the step S4, the press is a 230-ton automatic forming press. ​ 5. The method for preparing a low-cost ferrite permanent magnet material according to claim 1, characterized in that: In the step S5, the pre-sintering temperature is 1180-1230℃.

6. The method for preparing a low-cost ferrite permanent magnet material according to claim 1, characterized in that: In the step S7, the ratio of material: ball: water in the wet milling is 1:6:1.

5.

7. The method for preparing a low-cost ferrite permanent magnet material according to claim 3, characterized in that: The density of the green compact obtained by the secondary molding in the step S8 is 2.9-3.8 g / cm3 2 .

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