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Method for removing organic matter in waste MQ bonded NdFeB magnetic powder by using sodium hypochlorite chemical reaction method

A sodium hypochlorite and chemical reaction technology, applied in the removal of solid waste, etc., can solve problems such as complex process, long processing time, and unsatisfactory removal effect

Active Publication Date: 2022-04-22
BEIJING UNIV OF TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantage is that the process is complex and the processing time is long, and the purely physical process for similar and compatible removal is not ideal

Method used

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  • Method for removing organic matter in waste MQ bonded NdFeB magnetic powder by using sodium hypochlorite chemical reaction method
  • Method for removing organic matter in waste MQ bonded NdFeB magnetic powder by using sodium hypochlorite chemical reaction method

Examples

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Effect test

example 1

[0016] The mixed solvent formula of a kind of waste and old MQ bonded NdFeB magnetic powder used in the present embodiment to remove carbon and oxygen is: by volume 40% sodium hypochlorite, 60% distilled water.

[0017] The method for removing carbon and oxygen of a kind of waste and old MQ bonded NdFeB magnetic powder involved in the present invention is carried out according to the following steps:

[0018] 1. Remove the solidified organic matter in the waste MQ bonded NdFeB magnetic powder: Put the waste MQ bonded NdFeB magnetic powder and the mixed solvent into the three-necked flask according to the mass ratio of 1:6, keep the pressure of the three-necked flask at normal pressure, and use poly Stir at a constant speed with a tetrafluoroethylene stirring paddle, and control the temperature at 30°C through a water bath, keep it warm for 1 hour, and take it out after the end to obtain the magnetic powder A;

[0019] 2. Remove the decomposition products of cured epoxy resin: ...

example 2

[0028] The mixed solvent formula of a kind of waste and old MQ bonded NdFeB magnetic powder used in the present embodiment to remove carbon and oxygen is: sodium hypochlorite 60% by volume, distilled water 40%.

[0029] The method for removing carbon and oxygen of a kind of waste and old MQ bonded NdFeB magnetic powder involved in the present invention is carried out according to the following steps:

[0030] 1. Remove the solidified organic matter in the waste MQ bonded NdFeB magnetic powder: put the waste MQ bonded NdFeB magnetic powder and the mixed solvent into a three-necked flask at a mass ratio of 1:7, keep the pressure of the three-necked flask at normal pressure, and use poly Stir at a constant speed with a tetrafluoroethylene stirring paddle, and control the temperature at 15°C through a water bath, keep it warm for 2.5 hours, and take it out after the end to obtain the magnetic powder A;

[0031] 2. Remove the decomposition products of cured epoxy resin: Pour the ma...

example 3

[0039] A kind of mixed solvent formula for removing carbon and oxygen in a kind of waste and old MQ bonded NdFeB magnetic powder used in the present embodiment is: sodium hypochlorite 50% by volume, distilled water 50%.

[0040] The method for removing carbon and oxygen of a kind of waste and old MQ bonded NdFeB magnetic powder involved in the present invention is carried out according to the following steps:

[0041] 1. Remove the solidified organic matter in the waste MQ bonded NdFeB magnetic powder: Put the waste MQ bonded NdFeB magnetic powder and the mixed solvent into a three-necked flask at a mass ratio of 1:8, keep the pressure of the three-necked flask at normal pressure, and use poly Stir at a constant speed with a tetrafluoroethylene stirring paddle, and control the temperature at 0°C through a water bath, keep it warm for 2 hours, and take it out after the end to obtain the magnetic powder A;

[0042] 2. Remove the decomposition products of cured epoxy resin: Pour ...

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Abstract

A method for removing organic matter in waste MQ bonded NdFeB magnetic powder by using a sodium hypochlorite chemical reaction method belongs to the field of material recovery. The present invention first uses sodium hypochlorite to react with the cyano functional group in the cured epoxy resin to make it fall off from the waste MQ bonded NdFeB magnetic powder, and then uses distilled water to dissolve the product, which can accelerate or promote the reaction The remaining unreacted cured epoxy resin can also be partially dissolved in absolute ethanol. And the cooling by water bath can greatly reduce the decomposition of sodium hypochlorite and improve the reaction rate of cyano decomposition reaction, which is more conducive to the removal of cured epoxy resin. And the lower reaction temperature alleviates the oxidative damage of hypochlorite to MQ NdFeB magnetic powder, which is more conducive to protecting the NdFeB magnetic powder while removing the cured epoxy resin. At the same time, dilute acetic acid is used to remove the oxides in the waste magnetic powder, so that the regenerated NdFeB magnetic powder with lower carbon and oxygen content can be obtained without destroying the NdFeB magnetic powder itself.

Description

technical field [0001] This patent invents a method for removing organic matter in waste MQ bonded NdFeB magnetic powder by chemical reaction method, which belongs to the technical field of material recovery. Background technique [0002] NdFeB is the third-generation rare earth permanent magnet material, which is widely used in electric vehicles, smart devices, medical equipment, wind power generation, etc. due to its excellent magnetic properties. Among the NdFeB products, the output of sintered NdFeB accounts for more than 90%, but the output of bonded NdFeB is also increasing year by year at a relatively high rate. Sintered NdFeB magnets have better performance, but the production process is more complicated and the cost is higher. Although the magnetic properties of bonded NdFeB magnets are reduced due to the addition of binders, they have the advantages of easy mass production, precise manufacturing dimensions, complex shapes, low density, and stable magnetic properti...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B09B3/70
CPCB09B3/00B09B5/00
Inventor 岳明朱佩鸿刘敏高可刘卫强路清梅
Owner BEIJING UNIV OF TECH