Method for regenerating high-performance permanent magnet by degenerated rare earth permanent magnet material

A technology for regenerating permanent magnets and rare-earth permanent magnets, applied in the direction of magnetic materials, magnetic objects, inorganic materials, etc., can solve the problems of high requirements for magnetic properties and composition uniformity, increased difficulty in recycling, and low performance indicators of magnetic powder. , to avoid further degradation, easy control of magnetic properties, and good recovery of magnetic properties

Active Publication Date: 2006-11-22
严高林
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Problems solved by technology

However, this process has high requirements on the magnetic properties and compositional uniformity of rare earth permanent magnet waste. The performance index of the magnetic powder is low, and it is difficult to fully restore the magnetic properties of the degraded rare earth materials with poor magnetic properties
Especially some rare earth permanent magnets or their discarded permanent magnet products that are seriously degraded due to corrosion and oxidation. Such degraded rare earth permanent magnets have more oxide impurities, and there are often corrosion-resistant metal or non-metallic coatings on the outer surface of the permanent magnets. layer, which diversifies the impurity composition of degraded rare earth permanent magnet materials, making it more difficult to recycle them

Method used

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  • Method for regenerating high-performance permanent magnet by degenerated rare earth permanent magnet material

Examples

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Embodiment 1

[0055] Embodiment 1: get degenerate Nd 16 Fe 76 B 8 It is 1000 grams of rare earth permanent magnets, mechanically crushed to a material diameter of 3 mm, and 930 grams of degraded rare earth permanent magnet materials are selected by electromagnetism, and placed in 10 -5 -bar vacuum dehumidification for 1.5 hours; at vacuum: 10 -6 bar, temperature: at 70°C, input pure hydrogen (H 2 ), hydrogen pressure: 10bar, carry out hydrogen explosion (HD) for 2 hours, and the degenerated rare earth permanent magnet material becomes hydrogen explosion (HD) micropowder; under the atmosphere of nitrogen protection, carry out jet milling to its hydrogen explosion (HD) micropowder, its The particle size is ground to 3-6 microns; according to the calculated atomic weight ratio, Cu and Co micropowders with a particle size of 3-6 microns are uniformly mixed, wherein the Cu content remains unchanged at 0.25 at%, and the Co content varies from 3.5 at% to 10 at%. See Table 1 below:

[0056] ...

Embodiment 2

[0062] Embodiment 2: take degenerate Nd 16 Fe 76 B 8 1000 grams of rare earth permanent magnets are mechanically crushed to a particle size of 5 mm, and 940 grams of degraded rare earth permanent magnet materials are selected by electromagnets, and placed in 10 -5 -bar vacuum dehumidification for 2 hours; using the hydrogen explosion (HD) method and adding element Cu to mix the powder, under the radial magnetic field, the mixed powder is pressed and molded according to the required magnetic field direction distribution, and the conventional sintering and heat treatment are respectively used Two other heat treatment methods: A, heat treatment at 500°C for 1 hour under vacuum after rapid cooling (liquid nitrogen cooling under vacuum) and B, heat treatment at 630°C under vacuum for 1 hour after rapid cooling (air cooling under vacuum), and made Two sets of anisotropic regenerative permanent magnets. Its magnetic properties can be restored to 100% of the original performance pa...

Embodiment 3

[0070] Embodiment 3: take degenerate Nd 16 Fe 76 B 8 1000 grams of rare earth permanent magnets, crushing and dehumidification steps are the same as in Example 1, adopting disproportionation reaction (HDDR) to recycle the degraded rare earth permanent magnets, and the degraded rare earth permanent magnets after dehumidification are placed in a vacuum for 10 -6 bar, at a temperature of 700-880°C, input pure hydrogen (H 2 ), the hydrogen pressure is 15bar, and the disproportionation reaction of the degraded rare earth permanent magnet material occurs: HydrogenationDisproportionation Desorption Recombination (HDDR), the time is 2 hours, the degraded rare earth permanent magnet material becomes anisotropic magnetic powder, and the fineness of the magnetic powder is about 500 microns . Further add high magnetocrystalline anisotropy field element Dy, the addition amount of Dy is 2at%, or add alloy Dy 3 Co, the addition amount is 5wt%, mix well. Add epoxy resin according to the ...

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Abstract

The invention discloses a permanent magnet regenerating method of degenerated rare earth permanent magnet material, which comprises the following steps: grinding mechanically; removing impurity; dewetting in the vacuum; proceeding hydrogen disposal or hydrogen disproportionating reaction; adding high-magnetocrystalline anisotropic element and auxiliary texture forming element or alloy; moulding through sintering or adhering to produce anisotropic regenerated permanent magnet. The technology is reasonable with little oxide reaction, which can explore new path for degenerated rare earth permanent magnet.

Description

Technical field [0001] The invention relates to a method for preparing a regenerative permanent magnet by sintering or bonding degraded rare earth permanent magnet materials. Specifically, it refers to a method for regenerating high-performance permanent magnets from degraded rare earth permanent magnet materials. technical background [0002] my country is a big country with rare earth resources, accounting for 80% of the world's reserves. Rare earth permanent magnets represented by NdFeB have extremely high magnetic energy density. Therefore, it is the preferred or necessary material wherever efficient conversion of mechanical and electrical energy into each other is required. Such as: computer hard disk drive motor, nuclear magnetic resonance imager, magnetic levitation car, modern family car, magneto-optical data drive, etc., all use this kind of material in large quantities. Although the rare earth permanent magnet material has the most superior magnetic properties, ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F1/053H01F1/06H01F13/00
Inventor 严高林
Owner 严高林
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