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Method for reusing sintered NdFeB scraps with protective layer

A technology of NdFeB and protective layer, which is applied in the field of reuse of sintered NdFeB wastes coated with protective layer, which can solve the problems of environmental pollution, difficult control of product quality, and high recycling cost

Active Publication Date: 2018-12-07
湖南稀土新能源材料有限责任公司
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The first type is hydrometallurgy: the waste is crushed and acid-dissolved, and then the rare earth metals are recovered by hydrometallurgy. However, the recovery rate of this method is low and the recovery cost is high.
The second type is the furnace smelting method: the waste materials are returned to the furnace for smelting, hydrogen crushed into powder, formed and sintered to make NdFeB magnets; although this method shortens the process flow and improves the utilization rate, the quality of the obtained products is not easy to control
However, for sintered NdFeB magnets with a protective layer on the surface, it is generally necessary to deplate the protective layer first, but the chemical deplating method must have the problem of environmental pollution

Method used

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  • Method for reusing sintered NdFeB scraps with protective layer
  • Method for reusing sintered NdFeB scraps with protective layer
  • Method for reusing sintered NdFeB scraps with protective layer

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0072] The raw material of the sintered NdFeB waste material for the plating protection layer in Example 1 is the waste material for preparing NdFeB 42SH products. It is a square material with a side length greater than 50mm. The method for reusing the sintered NdFeB waste material of the plating protection layer is as follows.

[0073] Grind the nickel-plated copper epoxy layer on the upper and lower surfaces of the sintered NdFeB scrap with the protective layer using a double-end surface grinder, and then dry it in an electric blast dryer at 120°C. Jaw crusher is used to preliminarily crush the block material into waste particles smaller than 30mm. Waste particle sampling adopts ICP-AES method (atomic emission spectrometry, the instrument used is inductively coupled plasma spectrometer) to analyze each element composition wherein, and obtain the mass percentage content of each element as shown in the column of Example 1A in Table 1 Show.

[0074] Raw materials were prepar...

Embodiment 2

[0081] The raw material of the sintered NdFeB waste material for the protective plating layer in Example 2 is the waste material for preparing NdFeB 40UH products. It is a square material with a side length of 10-20 mm. The method for reusing the sintered NdFeB waste material of the plating protection layer is as follows.

[0082] Grind the nickel-plated copper epoxy layer on the upper and lower surfaces of the sintered NdFeB scrap with the protective layer using a double-end surface grinder and a vertical grinder, and then dry it in an electric blast dryer at 80 °C. Jaw crusher is used to preliminarily crush the block material into waste particles smaller than 10mm. Waste particle sampling adopts ICP-AES method (atomic emission spectrometry, the instrument used is inductively coupled plasma spectrometer) to analyze each element composition wherein, and obtain the mass percentage content of each element as shown in the column of Example 2A in Table 1 Show.

[0083] Raw mate...

Embodiment 3

[0090] The raw material of the sintered NdFeB waste material for the protective plating layer in Example 3 is the waste material for preparing NdFeB 45H products. It is a long flake with a thickness of 7 mm. The method for reusing the sintered NdFeB waste material of the plating protection layer is as follows.

[0091] Slicing and grinding the nickel-plated copper epoxy layers on the upper and lower surfaces of the sintered NdFeB scraps for the protective layer, and then drying them in an electric blast dryer at 100°C. Jaw crusher is used to preliminarily crush the block material into waste particles smaller than 10mm. Waste particle sampling adopts ICP-AES method (atomic emission spectrometry, the instrument used is inductively coupled plasma spectrometer) to analyze each element composition wherein, and obtain the mass percentage content of each element as shown in the column of embodiment 3A in table 1 Show.

[0092] Raw materials were prepared according to the ratio in ...

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Abstract

Disclosed is a recycling method for a sintered neodymium-iron-boron waste material plated with a protective layer. The recycling method comprises the following steps of performing grinding and smashing on the protective layer of the waste material to obtain waste material granules; preparing a neodymium-iron-boron melt-spinning sheet, wherein the neodymium-iron-boron melt-spinning sheet and the waste material granules are the same in element compositions, the waste material granules comprise the elements of Pr, Nd, B and Fe, and the ratio of the sum of the mass percentages of Pr and Nd in the neodymium-iron-boron melt-spinning sheet to the sum of the mass percentages of Pr and Nd in the waste material granules is 1.02-1.1 to 1, and the ratio of the mass percentage of B in the neodymium-iron-boron melt-spinning sheet to the mass percentage of B in the waste material granules is 0.98-1.03 to 1, and the neodymium-iron-boron melt-spinning sheet has the balance of Fe; performing mixing on the waste material granules and the neodymium-iron-boron melt-spinning sheet, and performing hydrogen smashing to obtain a hydrogen smashed material; performing mixing and powder making on the hydrogen smashed material and a first antioxidant, and then mixing with an auxiliary to obtain to-be-pressed powder, and pressing the to-be-pressed powder to obtain a raw blank; and performing isostatic pressing forming and vacuum sintering on the raw blank to obtain a sintered neodymium-iron-boron magnet. The recycling method is pollution free, the utilization rate of the sintered neodymium-iron-boron waste material plated with the protective layer is high, and the obtained neodymium-iron-boron magnet is good in performance.

Description

technical field [0001] The invention relates to the technical field of NdFeB magnets, in particular to a method for reusing sintered NdFeB scraps coated with protective layers. Background technique [0002] Sintered NdFeB magnets have become the most widely used rare earth permanent magnet materials due to their good magnetic properties. Sintered NdFeB is mainly composed of the main phase and the Nd-rich phase. There is a large difference in the electrode potential of the two phases, and it is easy to form galvanic corrosion when the electrolyte solution exists. Therefore, it is necessary to coat the surface of the sintered NdFeB magnet with protective coating layer to increase its service life. Depending on the use environment and requirements, the protective layer includes zinc-plated layer, nickel-plated layer, copper-plated layer, aluminum-plated layer and nickel-plated copper epoxy layer and other protective layers. The nickel-copper epoxy layer can withstand neutral ...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): H01F1/057H01F41/02
CPCH01F1/0573H01F1/0576H01F1/0577H01F41/0266
Inventor 刘宇晖樊玉川游建辉陈云志王川朱望伟彭雁
Owner 湖南稀土新能源材料有限责任公司