Method for preparing high-performance permanent magnet via diffusion permeation treatment of sintered neodymium iron boron recycled waste materials

A technology for recycling waste and NdFeB, which is applied in the field of rare earth magnetic materials, can solve the problems of complex processing methods, complex production processes, and environmental pollution, and achieve simple powder-making and molding processes, high powder-making efficiency, and simple processes Effect

Active Publication Date: 2016-11-23
UNIV OF SCI & TECH BEIJING
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, the above methods still have deficiencies: the deficiencies of method one are: the process of the treatment method is more complicated, the investment is large, and the cost is high; the use of chemical purification will produce waste water and waste liquid containing a large amount of acid radicals and chloride radicals, resulting in new "three wastes" "Emission problem, causing environmental pollution
The deficiency of method two is: this process all relates to the preparation of micron magnetic powder (being generally 3-5 μ m) and orientation forming process, both all need to be in N 2 Under protection, the production process is more complicated

Method used

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  • Method for preparing high-performance permanent magnet via diffusion permeation treatment of sintered neodymium iron boron recycled waste materials
  • Method for preparing high-performance permanent magnet via diffusion permeation treatment of sintered neodymium iron boron recycled waste materials
  • Method for preparing high-performance permanent magnet via diffusion permeation treatment of sintered neodymium iron boron recycled waste materials

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0027] (1) The cleaned raw materials are mechanically crushed under nitrogen protection, passed through a 60-mesh sieve, and the powder under the sieve is raw material magnetic powder;

[0028] (2) Combine 99g of the raw material magnetic powder obtained in step (1) with 1g of Dy 2 o 3 The diffusing agent powder is added into the mixer and mixed for 2 hours to obtain mixed magnetic powder;

[0029] (3) Orientate and press the mixed magnetic powder obtained in step (2) in the atmosphere, and the density of the blank is 5.4g / cm 3 ;

[0030] (4) Put the NdFeB blank obtained in step (3) into a vacuum tube furnace, the vacuum degree in the furnace is 0.005 Pa before heating up, heat treatment at 1040° C. for 1 hour, and obtain a magnet.

Embodiment 2

[0032] (1) The cleaned raw materials are mechanically crushed under nitrogen protection, passed through a 60-mesh sieve, and the powder under the sieve is raw material magnetic powder;

[0033] (2) Combine 90g of the raw material magnetic powder obtained in step (1) with 10g of commercially available Dy with a particle size of less than 2500 mesh 2 o 3 The diffusing agent powder is added into the mixer and mixed for 2 hours to obtain mixed magnetic powder;

[0034] (3) Orientate and press the mixed magnetic powder obtained in step (2) in the atmosphere, and the density of the blank is 5.0g / cm 3 ;

[0035] (4) Put the NdFeB blank obtained in step (3) into a vacuum tube furnace, the vacuum degree in the furnace is 0.005Pa before heating up, heat treatment at 1000°C for 1 hour, and obtain a magnet.

Embodiment 3

[0037] (1) The cleaned raw materials are mechanically crushed under nitrogen protection, passed through a 60-mesh sieve, and the powder under the sieve is raw material magnetic powder;

[0038] (2) mix 90g of the raw material magnetic powder obtained in step (1) with 10g of 100 mesh Nd 2 Al diffuser powder is added into the mixer and mixed for 1 hour to obtain mixed magnetic powder;

[0039] (3) Orientate and press the mixed magnetic powder obtained in step (2) in the atmosphere, and the density of the blank is 5.2g / cm 3 ;

[0040] (4) Put the NdFeB blank obtained in step (3) into a vacuum tube furnace, the vacuum degree in the furnace is 0.005 Pa before heating up, heat treatment at 1040° C. for 1 hour, and obtain a magnet.

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Abstract

The invention relates to a recycling method of sintered neodymium iron boron recycled waste materials, belonging to the technical field of a rare earth permanent magnet material. The method comprises the steps of carrying out mechanical crushing on cleaned NdFeB recycled waste materials such as machining cutting leftover materials, electroplating non-qualified products and the like, and sieving to obtain large-particle magnetic powder (the size of a screen stencil is 60-300 meshes); after uniformly mixing with a dispersing agent, orienting and molding under an atmospheric environment to prepare into a workblank, wherein the density of the workblank can be up to 6.0g/cm<3>; and then, carrying out vacuum heat treatment on the workblank to obtain a high-coercivity high-performance NdFeB permanent magnet. According to the method disclosed by the invention, as raw material magnetic powder is the approximately hundred-micron magnetic powder obtained by crushing the NdFeB recycled waste materials, and the magnetic powder storage, the magnet orienting-molding process and the molded workblank storage can be carried out in the atmospheric environment, the production process is simplified; and in addition, by adding the dispersing agent to repair a Nd2Fe14B grain boundary, the coercivity of the magnet is further improved.

Description

technical field [0001] The invention relates to a method for preparing high-performance permanent magnets from recycled sintered NdFeB waste produced in machining, electroplating and other links, and belongs to the technical field of rare earth magnetic materials. technical background [0002] In all aspects of sintered NdFeB production, especially the machining process will produce a large amount of waste, the proportion of which exceeds 20% of the weight of raw materials. At present, there are two main types of waste recovery methods: (1) use extraction method and double salt precipitation method to obtain rare earth chlorides and oxides, and then obtain rare earth metals through hydrometallurgical purification, such as CN200410020840.0; (2) After appropriate treatment (such as cleaning, peeling, etc.), return to the smelting furnace for remelting or send it to the pulverizing process for reuse to obtain a sintered NdFeB magnet, such as CN103934450A. However, the above me...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): H01F41/02H01F1/057
CPCH01F1/0576H01F1/0577H01F41/0266
Inventor 孙爱芝许琛马斌郎惠珍
Owner UNIV OF SCI & TECH BEIJING
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