Preparation method of anisotropic composite magnet based on samarium-cobalt oil sludge waste

Abstract

The invention discloses a preparation method of an anisotropic composite magnet based on samarium cobalt oil sludge waste, which comprises the following steps: preparing a CeaNdbFecBdTM100-a-b-c-d alloy ribbon by adopting a melt rapid quenching method, and grinding and crushing the CeaNdbFecBdTM100-a-b-c-d alloy ribbon; meanwhile, oil sludge waste in the machining process of the samarium-cobalt magnet slicing machine is subjected to magnetic separation to preliminarily remove non-magnetic substances, then high-energy ball milling is conducted in an acetone solvent, and samarium-cobalt magnet recycled powder is obtained; and then mixing the CeaNdbFecBdTM100-a-b-c-d alloy thin strip and the samarium cobalt magnet recovery powder in proportion, and then carrying out spark plasma sintering and primary heat treatment and secondary heat treatment in a subsequent magnetic field to finally obtain the anisotropic composite magnet. The method is simple in technological process, easy to operate and beneficial to application of the high-performance composite magnet in more permanent magnet devices so as to meet market requirements.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of magnetic materials, in particular to a preparation method of an anisotropic composite magnet based on samarium-cobalt oil slurry waste. BACKGROUND

[0002] Rare earth permanent magnet materials have excellent magnetism superior to other permanent magnet materials, and are the most powerful and most widely used permanent magnet materials in terms of magnetic performance. Nd-Fe-B permanent magnet materials have a high room temperature anisotropy field (HA=7T) and a high saturation magnetization (Js=1.6T), and the theoretical value of the maximum magnetic energy product is as high as 512 kJ / m3, so the Nd-Fe-B permanent magnet material is called a "magnetic king" and is widely valued by people. In comparison, the maximum magnetic energy product of the SmCo permanent magnet material is between 120 kJ / m3 and 260 kJ / m3, but the Curie temperature can reach 720 DEG C, the stable working temperature can reach 500 DEG C, and the SmCo permanent magnet material has high corrosion resistance, so the SmCo permanent magnet material has irreplaceable advantages. In addition, from the pretreatment of raw materials to the final product detection, each process in the production process of the SmCo permanent magnet material inevitably produces waste and defective products. SUMMARY

[0003] In order to solve the above problems, the application provides a preparation method of an anisotropic composite magnet based on samarium-cobalt oil slurry waste. a Nd b Fe c B d TM 100-a-b-c-d alloy ribbons, and the oil slurry waste in a samarium-cobalt magnet machining process is subjected to pyrolysis and oil removal treatment under argon protection after preliminary removal of non-magnetic substances through magnetic separation, and then high-energy ball milling is performed in a acetone solvent to improve the particle size distribution of the solid powder, so that samarium-cobalt magnet recovery powder is obtained. a Nd b Fe c B d TM 100-a-b-c-d alloy ribbons and the samarium-cobalt magnet recovery powder are mixed in proportion, and then discharge plasma sintering, subsequent primary heat treatment and secondary heat treatment under a magnetic field are performed, so that an anisotropic composite magnet is finally obtained.

[0004] The application is implemented by the following technical scheme: a preparation method of an anisotropic composite magnet based on samarium-cobalt oil slurry waste, comprising the following steps:

[0005] (1) Ce a Nd b Fe c B d TM 100-a-β- alloy ribbons are prepared by using a melt quenching method.The c_d alloy thin strip is obtained by using a copper roller with a rotating speed of 10-30 m / s, wherein 10≤a≤20, 5≤b≤10, 65≤c≤80, 2≤d≤8, TM is one or more of Co, Cu, Ga, Al, Ti, Zr and Nb, and the obtained alloy thin strip is ground and broken into magnetic powder with a particle size of 50-500 mesh;

[0006] (2) After the oil sludge waste generated in the machining process of the samarium-cobalt magnet slice is removed of non-magnetic substances through magnetic separation, dry solid powder is obtained by pyrolysis and oil removal treatment at 600-900 ℃ for 8-16 hours under argon protection; then high-energy ball milling is performed in acetone solvent for 4-6 hours, and the samarium-cobalt magnet recovery powder is obtained by drying in a vacuum environment;

[0007] (3) The Ce a Nd b Fe c B d The TM100-a-b-c-d alloy magnetic powder and the samarium-cobalt magnet recovery powder obtained in step (2) are mixed at a mass ratio of 1:0.1-0.5, and then placed in a hard alloy mold to perform discharge plasma sintering, so as to obtain a full-dense block-shaped composite magnet;

[0008] (4) The composite magnet obtained in step (3) is subjected to primary heat treatment and secondary heat treatment under a magnetic field, so as to obtain an anisotropic composite magnet.

[0009] As a preferred technical solution, the residual magnetism of the samarium-cobalt magnet recovery powder obtained in step (2) is 0.8-1.0 T.

[0010] As a preferred technical solution, the process parameters of the discharge plasma sintering in step (3) include a sintering temperature of 400-700 ℃, an applied pressure of 500-800 MPa, and a holding time of 5-20 minutes.

[0011] As a preferred technical solution, the primary heat treatment temperature in step (4) is 750-980 ℃, the heating rate is 1-2 ℃ / min, the holding time is 2-4 hours, the applied magnetic field strength is 1-2 T, and the heat treatment is followed by rapid cooling to room temperature.

[0012] As a preferred technical solution, the secondary heat treatment temperature in step (4) is 350-680 ℃, the heating rate is 1-2 ℃ / min, the holding time is 1-2 hours, the applied magnetic field strength is 1-2 T, and the heat treatment is followed by rapid cooling to room temperature.

[0013] As a preferred technical solution, the melt quenching method in step (1) is implemented by using a copper roller spinning device, and the thickness of the alloy thin strip is 30-100 μm.

[0014] As a preferred technical solution, the dry solid powder obtained after the pyrolytic deoiling treatment in step (2) is subjected to particle size control by screening before ball milling to improve the uniformity of the recovered powder.

[0015] As a preferred technical solution, in the high-energy ball milling process, the ball-to-material ratio is 5:1 to 10:1, and the ball milling medium uses zirconia balls or hard alloy balls.

[0016] As a preferred technical solution, the mixed powder in step (3) is subjected to uniform stirring and vacuum pre-pressing before spark plasma sintering to ensure the compactness of the molding.

[0017] The beneficial effects of the present application are: the present application uses melt quenching method to prepare Ce a Nd b Fe c B d TM 100-a-b-c-d alloy ribbons, and grinds and breaks them; at the same time, after the oil sludge waste in the machining process of samarium-cobalt magnet is preliminarily removed of non-magnetic substances by magnetic separation, it is subjected to pyrolytic deoiling treatment under argon protection, and then high-energy ball milling in acetone solvent to improve the particle size distribution of the solid powder, obtaining samarium-cobalt magnet recovery powder; then the Ce a Nd b Fe c B d TM 100-a-b-c-d alloy ribbons and the samarium-cobalt magnet recovery powder are mixed in proportion, and then subjected to spark plasma sintering, followed by primary heat treatment and secondary heat treatment under a magnetic field, to finally obtain anisotropic composite magnets. The process of the present application is simple and easy to operate, which is conducive to the application of high-performance anisotropic composite magnets in more permanent magnet devices to meet market demand. DETAILED DESCRIPTION

[0018] All features disclosed in this specification, and / or all steps of any methods or processes disclosed, may be combined in any combination, except combinations where at least some of the features and / or steps are mutually exclusive.

[0019] Any feature disclosed in this specification, unless stated otherwise, can be replaced by alternative features serving the same, equivalent or similar purpose.

[0020] Example 1

[0021] (1) Ce10Nd10Fe71B6Co2Ti1 alloy ribbons according to atomic percentage are prepared by melt quenching method, the copper roller speed is 10 m / s, and then the alloy ribbons are ground and broken to a particle size of 100 mesh magnetic powder;

[0022] (2) the oil sludge waste in the machining process of the samarium-cobalt magnet slice is subjected to pyrolysis and oil removal treatment under the protection of argon after the non-magnetic substances are preliminarily removed through magnetic separation, the treatment temperature is 600 DEG C, the reaction time is 16h, dry solid powder is obtained; then the high-energy ball milling is carried out in the acetone solvent for 6h, the particle size distribution of the solid powder is improved; then the samarium-cobalt magnet recycling powder is obtained by drying the solid powder in a vacuum environment, the residual magnetism of the samarium-cobalt magnet recycling powder is 0.8T;

[0023] (3) the Ce10Nd10Fe71B6Co2Ti1 alloy magnetic powder obtained in the step (1) is mixed with the samarium-cobalt magnet recycling powder obtained in the step (2) according to the mass ratio of 1:0.1, and then is placed into a hard alloy mold to carry out the spark plasma sintering, the sintering temperature of the spark plasma sintering is 400 DEG C, the pressure is 800MPa, the sintering holding time is 10min, and a full-dense block-shaped composite magnet is obtained;

[0024] (4) the composite magnet obtained in the step (3) is subjected to the primary heat treatment and the secondary heat treatment under a magnetic field, the temperature of the primary heat treatment under a magnetic field is 750 DEG C, the temperature rising rate is 1 DEG C / min, the holding time is 2h, the magnetic field strength is 1T, and then is rapidly cooled to room temperature; the temperature of the secondary heat treatment under a magnetic field is 650 DEG C, the temperature rising rate is 2 DEG C / min, the holding time is 1h, the magnetic field strength is 2T, and then is rapidly cooled to room temperature, and finally an anisotropic composite magnet is obtained.

[0025] The full-dense anisotropic composite magnet prepared by the method has the coercive force of 17.8kOe and the magnetic energy product of 24.6MGOe.

[0026] Example 2

[0027] (1) the Ce11Nd8Fe70B7Ga3Al1 alloy thin strip is prepared by using the melt quenching method, the copper roller rotating speed is 20m / s, and then the alloy thin strip is ground and broken into magnetic powder with the particle size of 230 mesh;

[0028] (2) the oil sludge waste in the machining process of the samarium-cobalt magnet slice is subjected to pyrolysis and oil removal treatment under the protection of argon after the non-magnetic substances are preliminarily removed through magnetic separation, the treatment temperature is 750 DEG C, the reaction time is 10h, dry solid powder is obtained; then the high-energy ball milling is carried out in the acetone solvent for 5h, the particle size distribution of the solid powder is improved; then the samarium-cobalt magnet recycling powder is obtained by drying the solid powder in a vacuum environment, the residual magnetism of the samarium-cobalt magnet recycling powder is 1.0T;

[0029] (3) the Ce15Nd5Fe70.5B8Cu1Zr0.5 alloy magnetic powder obtained in step (1) and the samarium-cobalt magnet recycled powder obtained in step (2) are mixed in a mass ratio of 1:0.3, and then are placed into a hard alloy mold to perform discharge plasma sintering, wherein the sintering temperature of the discharge plasma sintering is 700 ℃, the pressure is 500 MPa, and the sintering holding time is 15 min, so as to obtain a full-dense block-shaped composite magnet;

[0030] (4) the composite magnet obtained in step (3) is subjected to primary heat treatment and secondary heat treatment under a magnetic field, wherein the temperature of the primary heat treatment under a magnetic field is 850 ℃, the temperature rising rate is 1 ℃ / min, the holding time is 3 h, the magnetic field strength is 1.5 T, and then the temperature is rapidly cooled to room temperature; the temperature of the secondary heat treatment under a magnetic field is 450 ℃, the temperature rising rate is 2 ℃ / min, the holding time is 1 h, the magnetic field strength is 1.5 T, and then the temperature is rapidly cooled to room temperature, so as to finally obtain an anisotropic composite magnet.

[0031] The full-dense anisotropic composite magnet prepared by the method has a coercive force of 19.5 kOe and a magnetic energy product of 23.5 MGOe.

[0032] Example 3

[0033] (1) a Ce15Nd5Fe70.5B8Cu1Zr0.5 alloy thin strip is prepared by a melt quenching method, and the copper roller rotating speed is 30 m / s, and then the alloy thin strip is ground and broken into a magnetic powder with a particle size of 450 mesh;

[0034] (2) the oil sludge waste in the machining process of a samarium-cobalt magnet is subjected to pyrolysis and oil removal treatment under argon protection, the treatment temperature is 850 ℃, and the reaction time is 8 h, so as to obtain a dry solid powder; then the dry solid powder is subjected to high-energy ball milling in a solvent of acetone for 4 h, so as to improve the particle size distribution of the dry solid powder; and then the dry solid powder is dried in a vacuum environment, so as to obtain a samarium-cobalt magnet recycled powder, and the residual magnetism of the samarium-cobalt magnet recycled powder is 1.0 T;

[0035] (3) the Ce15Nd5Fe70.5B8Cu1Zr0.5 alloy magnetic powder obtained in step (1) and the samarium-cobalt magnet recycled powder obtained in step (2) are mixed in a mass ratio of 1:0.3, and then are placed into a hard alloy mold to perform discharge plasma sintering, wherein the sintering temperature of the discharge plasma sintering is 700 ℃, the pressure is 500 MPa, and the sintering holding time is 15 min, so as to obtain a full-dense block-shaped composite magnet;

[0036] (4) the composite magnet obtained in step (3) is subjected to a primary magnetic field heat treatment and a secondary magnetic field heat treatment, the temperature of the primary magnetic field heat treatment is 950℃, the heating rate is 2℃ / min, the holding time is 4h, the magnetic field strength is 2T, and then it is rapidly cooled to room temperature; the temperature of the secondary magnetic field heat treatment is 350℃, the heating rate is 1℃ / min, the holding time is 2h, the magnetic field strength is 1T, and then it is rapidly cooled to room temperature, and finally an anisotropic composite magnet is obtained.

[0037] The full-dense anisotropic composite magnet prepared by the method has a coercive force of 21.1kOe and a magnetic energy product of 22.4MGOe.

[0038] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any changes or substitutions not through creative labor should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope defined in the claims.

Claims

1. A method for preparing an anisotropic composite magnet based on samarium-cobalt slurry waste, characterized by, The method comprises the following steps: (1) Ce a Nd b Fe c B d TM 100-a-β- c-d alloy thin strips, copper roller rotating speed is 10-30 m / s, wherein 10≤a≤20, 5≤b≤10, 65≤c≤80, 2≤d≤8, TM is one or more of Co, Cu, Ga, Al, Ti, Zr, Nb, and the obtained alloy thin strips are ground and broken into magnetic powder with particle size of 50-500 mesh; (2) After the oil sludge waste generated in the machining process of the samarium-cobalt magnet is removed of non-magnetic substances by magnetic separation, dry solid powder is obtained by pyrolysis and oil removal treatment at 600-900 DEG C for 8-16 hours under argon protection; then high-energy ball milling is carried out in acetone solvent for 4-6 hours, and drying is carried out in a vacuum environment to obtain samarium-cobalt magnet recovery powder; (3) The Ce a Nd b Fe c B d TM 100-a-b-c-d The alloy magnetic powder is mixed with the recovered powder of the samarium-cobalt magnet obtained in step (2) at a mass ratio of 1:0.1-0.5, and then is placed in a hard alloy mold to perform discharge plasma sintering, so as to obtain a full-dense block-shaped composite magnet. (4) The composite magnet obtained in step (3) is subjected to primary and secondary heat treatment under a magnetic field to obtain an anisotropic composite magnet.

2. The method of producing anisotropic composite magnets based on samarium-cobalt oil sludge waste according to claim 1, characterized in that: The residual magnetism of the samarium-cobalt magnet recovery powder obtained in step (2) is 0.8-1.0 T.

3. The method of producing anisotropic composite magnets based on samarium-cobalt oil sludge waste according to claim 1, characterized in that: The process parameters of the spark plasma sintering in step (3) include a sintering temperature of 400-700 DEG C, an applied pressure of 500-800 MPa, and a holding time of 5-20 minutes.

4. The method of producing anisotropic composite magnets based on samarium-cobalt oil sludge waste according to claim 1, characterized in that: The primary heat treatment temperature in step (4) is 750-980 DEG C, the heating rate is 1-2 DEG C / min, the holding time is 2-4 hours, the applied magnetic field strength is 1-2 T, and the temperature is rapidly cooled to room temperature after heat treatment.

5. The method of producing anisotropic composite magnets based on samarium-cobalt oil sludge waste according to claim 1, characterized in that: The secondary heat treatment temperature in step (4) is 350-680 DEG C, the heating rate is 1-2 DEG C / min, the holding time is 1-2 hours, the applied magnetic field strength is 1-2 T, and the temperature is rapidly cooled to room temperature after heat treatment.

6. The method of producing anisotropic composite magnets based on samarium-cobalt oil-cake waste according to claim 1, characterized in that: The melt quenching method in step (1) is realized by using a copper roller tape casting device, and the thickness of the alloy thin strip is 30-100 μm.

7. The method of producing anisotropic composite magnets based on samarium-cobalt oil-cake waste according to claim 1, characterized in that: The dry solid powder obtained after the pyrolysis and oil removal treatment in step (2) is subjected to particle size control by screening before ball milling to improve the uniformity of the recovery powder.

8. The method of producing anisotropic composite magnets based on samarium-cobalt oil-cake waste according to claim 1, characterized by the fact that: In the high-energy ball milling process, the ball-to-material ratio is 5:1-10:1, and the ball milling medium is zirconia balls or cemented carbide balls.

9. The method of producing anisotropic composite magnets based on samarium-cobalt oil-cake waste according to claim 1, characterized in that: The mixed powder in step (3) is uniformly stirred and vacuum pre-pressed before spark plasma sintering to ensure the compactness of the molding.