WO2014121861A2

WO2014121861A2 - Method for utilizing and device for cleaning permanent magnets

Info

Publication number: WO2014121861A2
Application number: PCT/EP2013/074136
Authority: WO
Inventors: Gabriele Hörnig; Jens-Oliver Müller
Original assignee: Siemens Aktiengesellschaft
Priority date: 2013-02-06
Filing date: 2013-11-19
Publication date: 2014-08-14
Also published as: WO2014121861A3; DE102013201895A1

Abstract

The invention relates to a method for utilizing permanent magnets (2), in which the permanent magnets (2) removed from an assembly, in particular from an electric motor, are treated. For cleaning, the permanent magnets (2) are subjected to an abrasive (8). This takes place preferably in a container (1) in which the permanent magnets (2) are set into a relative motion with respect to the abrasive (8). In this way, gentle and rapid cleaning of the permanent magnets (2) is achievable. Furthermore, the invention relates to a device for cleaning permanent magnets (2).

Description

description

Method of use and apparatus for cleaning

permanent magnets

The invention relates to a method for the use of permanent magnets, in which the entnomme from an assembly NEN permanent magnets are treated. Furthermore, the invention relates to a device for cleaning removed from a sammenbau to permanent magnet.

Permanent magnets contain important raw materials such as ^¬ rare earth metals (neodymium, praseodymium, dysprosium). There are therefore efforts to provide permanent magnets, such as those used in devices such as electric motors, for further use. Namely, as electric motors disposed of as scrap steel, the ent ^¬ preserved valuable resources are lost.

The object of the present invention is therefore to provide a method and a device of the type mentioned at the beginning which simplifies the use of permanent magnets removed from an assembly.

This object is achieved by a method having the features of patent claim 1 and by an apparatus having the Merkma ^¬ len of patent claim 10. Advantageous Ausgestaltun conditions with expedient developments of the invention are specified in the dependent claims.

In the inventive method for cleaning the permanent magnets are the same beauf beat ^¬ with an abrasive. This is based on the realization that it simplifies the groove ^¬ wetting of samples taken from a permanent magnet assembly, when to be removed by cleaning the permanent magnets contaminants such as glue residues of these. The presented cleaning method has the advantage that edges of the permanent magnets are not abraded and rounded. Rather, only adhesive residues and the like soils are removed from the permanent magnets, and the metallic material of the permanent magnets is not attacked. Also hardly arise grinding residues and at most a negligible loss of material. The Ver ^¬ drive is also very gentle, so the group consisting of a ver ^¬ tively brittle material permanent magnets are produced by applying the same with the

Abrasive not destroyed.

Also, a large number of permanent magnets can be processed at once. Thus, in particular automated and on a large scale permanent magnets can be cleaned of residues. Also, no water or solvent needs to be added to effect the cleaning of the permanent magnets. The risk of water or the like caused by oxi- dation of the metallic material of the permanent magnets can thus be particularly far sheet redu ^¬ at such a dry process. In addition, a cleaning of the permanent magnets can be achieved in a relatively short time. Also, the shape of the permanent magnets does not matter, and even fragments of permanent magnets having widely different geometries can be cleaned without any restriction.

The use of the cleaned permanent magnets can preferably be done by reusing the used permanent magnets in a new assembly, such as in a new electric motor. In recycling, in principle, the reuse of a material or raw material recovery is preferable. However However, when reuse is not possible, as a plant material or raw ^¬ recycling of the material of the purified Perma ^¬ nentmagnete is possible. The material utilization of the required permanent magnets may be used in their use as a secondary ^raw material for producing a starting alloy for the production of new permanent magnets, for example in one Sintering are. These new magnets made from the used and cleaned permanent magnets then have comparable magnetic properties to the used permanent magnets.

In the raw material recovery, the metals contained in the permanent magnets, in particular rare earth metals, recovered, so that they can be supplied for further use.

Due to the fast and gentle cleaning of Permanentmag ^¬ which is achieved by the in-contacting with the granular abrasive designated, is in particular a REUSE ^¬ application of the permanent magnets particularly easy to reach.

In an advantageous embodiment of the invention, the abrasive is introduced together with the permanent magnets in a container and moved in the container relative to the per ^¬ manentmagneten. Thus, particularly largely sicherge ^¬ provides are that the grains of the abrasive are particularly well with all sides of the permanent magnets in contact and there for the shedding of debris, particularly adhesive material residues ^¬ care. In addition, no support for the permanent magnets needs to be used, as would be ^{erforder ¬ Lich to} abrade all sides of the generally cuboid magnets by means of grinding wheels, abrasive belts or the like.

Also, this type of cleaning the permanent magnets, which are ^¬ stick together with the abrasive in the container in motion ge, advantages over purification methods such as sand blasting or shot blasting method used for cleaning metal surfaces, and which are also known under the term shot peening , In such blasting processes, the abrasive is inflated with high pressure on the surface to be cleaned. However, this requires the use of a considerable amount of compressed air, and, in addition, the jet must be directed towards the surface to be ground. be aligned. This can be omitted in the present case, since the relative movement of permanent magnets and abrasive grains in the container ensures the gentle cleaning of the permanent magnets.

The abrasive may be used in particular in a Korngrö ^¬ SSE from 1 mm to 2 mm in this case to ensure that the adhesive residue and the like contaminants very thoroughly and at the same time gently Neten of the Permanentmag- be removed.

The movement of the abrasive relative to the Permanentmag ^¬ Neten can be effected by means of an at least partially disposed in the loading ratio ^¬ agitator. Such an arrangement is particularly inexpensive when it comes to put the abrasive and the permanent magnets in a cleaning effecting relative movement.

Additionally or alternatively, the movement of the permanent magnets relative to the abrasive grains can be effected by moving the container. For example, the Be ^¬ container can be rotated and / or shaken to ensure a cleaning effecting contact of the abrasive grains with the permanent magnet.

In particular, when the container is loaded in consecutive cleaning operations, each with different numbers of permanent magnets and a corresponding amount of abrasive, the cleaning of the permanent magnets by moving the container itself is favorable. The container is particularly flexible without existing for less than ^¬ schiedliche amounts of container in the permanent magnet ^¬ different agitators or even different containers, each on the container voted off stirring devices need to be provided.

Particularly good results are furthermore achieved if, on the one hand, at least one stirring device is provided and On the other hand Permanentmag ^¬ items are subjected to the abrasive grains by moving the container.

In this embodiment, the abrasive and the permanent magnets to be cleaned are kept in motion by the stirring device and / or the proper movement of the container. However, this can additionally or alternatively also be effected by introducing a fluidizing medium which sets a fluidized bed into the container. Here, a gas is used as Wirbelme- dium preferred for use, and both the grinding ^¬ grains as well as the permanent magnets are placed in the fluidized bed in a fluidized state. Such a method is also beneficial for a particularly gentle cleaning of the permanent magnets.

The movement of the abrasive grains on the surfaces and edges of the permanent magnets at CLOSED ^¬ senem container is preferably carried out. The container is therefore closed in a further advantageous embodiment, at least during the movement of the abrasive relative to the permanent magnets. Thus it can be prevented that abrasive and / or dust from the container enters the environment, even if comparatively violent movements of the container ^¬ ses or the stirring done.

It is also advantageous if in the container, a ratio of a volume of the permanent magnets to the volume of the abrasive of 1: 1 to 1:10 is set. In such a mixing ratio at which the volume of the abrasive at least the volume of the permanent magnets correspond, in a particularly high degree for ge ^¬ ensures that all come into contact with the abrasive during the relative movement of the abrasive grains and permanent magnets to be cleaned surfaces of the permanent magnets. Thus can be ensured a particularly extensive cleaning of the Perma ^¬ nentmagnete. This is especially true when providing a mixing ratio of the permanent magnets to the abrasive of 1: 2 to 1: 5, in which at the same time the permanent magnets are treated very gently.

As a further advantage, it has been shown when the Perma ^¬ nentmagnete be demagnetized with the abrasive before Beaufschlagtwerden. Then they are in that

Abrasives sporadically, and the cleaning of the Perma ^¬ nentmagnete done very thoroughly.

The demagnetization of the permanent magnets can be carried out in particular by heating them to a temperature above the Curie temperature. This heating, which leads to the demagnetization of the permanent magnets, namely, can then be used at the same time to solve the usually bonded together in the co ^¬ menbau with corresponding components permanent magnets. By heating a the permanent magnets is namely ^¬ decomposed in the assembly fixative adhesive least partially. Such a method is less complicated than a possible mechanical de ^¬ assembly of the magnets from the assembly, for example, the electric motor, and a subsequent demagnetization of the permanent magnets by heating.

The heating to the temperature above the Curie temperature, that is, for example, to a temperature of more than 350 ° C., preferably takes place in air, since this is particularly low on ^¬ wandsarm. It has in fact been found that the use of an inert gas atmosphere, for example, the He ^¬ overheat in argon to the temperature above the Curie temperature, if necessary then is advantageous if the rare earth metals used in permanent magnets show a particular susceptibility to oxidation in air.

After cleaning the permanent magnets, the abrasive used for cleaning them can be separated again from the permanent magnets. Then there is the abrasive available for reuse. Such a separation of the permanent magnets of the abrasive can be made by simple size classification, for example by sieving insbeson ^¬ more complete.

Finally, it has been found to be advantageous if silicon carbide is used as the abrasive. Silicon carbide is characterized by its particularly high hardness. In addition, it has been observed with the use of silicon carbide as abrasive that edges of the permanent magnets remain virtually unchanged. The rounding of the edges of the abrasive, as it occurs, for example, in the cleaning of gemstones in sanding drums or polishing drums with abrasives, is therefore present not to worry.

The device according to the invention for cleaning permanent magnets removed from an assembly, in particular from an electric motor, comprises a container in which the permanent magnets and an abrasive are arranged. Wei ^¬ direct the device comprises means for moving the grinding ^¬ means relative to the permanent magnet. With such a device, the permanent magnets can be cleaned particularly ^easily and then be used for further use, in particular reuse or material treatment.

The features and feature combinations mentioned above in the description as well as the features and feature combinations mentioned below in the figure description and / or shown alone in the figures can be used not only in the respectively specified combination but also in other combinations or in isolation, without the To leave frame of the invention.

Further advantages, features and details of the invention ^¬ be gathered from the claims, the following description preferred embodiments and with reference to the drawings. Showing:

1 shows a container with a stirrer for cleaning of a permanent magnet removed from an electric motor; and

2 shows the container according to FIG. 1, in which an abrasive medium and the permanent magnets are moved relative to one another and thus the abrasive particles are applied to the permanent magnets for cleaning.

1 shows a closed container 1, which is used to clean permanent magnets 2 (see FIG. 2). Originating from an assembly such as a (not shown) electric motor, permanent magnets 2 contain valuable raw materials such as Sel ^¬ earth metals. Therefore, it is desirable to supply the Permanentmag ^¬ designated 2 reuse after the electric motor has lost its functionality.

The disassembly of the permanent magnets 2 from the electric motor can be done by mechanical methods, or it can be the electric motor or the component of the electric motor, wel ^¬ che, the permanent magnets 2, heated to cause a self-release of the permanent magnets 2. Namely, the heat destroys the adhesive with which the permanent magnets 2 are attached to the component of the electric motor. Before ^¬ lying heating is to a temperature which is big ^¬ SSER than the Curie temperature of the permanent magnets 2, so ^¬ that the permanent magnets are demagnetized 2 prior to their introduction into the Be ^¬ container. 1 The demagnetization, for example at a temperature of more than 350 ° C., takes place be ^¬ preferably in air or in an inert gas atmosphere.

In order to supply the permanent magnets 2 without chemical preprocessing ei ^¬ ner reuse or mechanical recycling, these are after removal from the electric engine cleaned, about to remove adhesive residue. This cleaning takes place in the container 1 (see FIG. 2). Through a lid 3 of the container 1, a shaft 4 of a stirrer 5 is passed. The shaft 4 of the agitator 5 carries at its end 6 a bottom of the container 1 near a stirring blade 7 (see FIG 1). In this container 1, the permanent magnets 2 are introduced together with a hard, granular abrasive 8 (ver ^¬ same FIG 2). As abrasive 8 is preferred

Silicon carbide with a grain size between 1 mm and 2 mm for use.

Subsequently, the abrasive 8 and to be cleaned ^¬ the permanent magnets 2 are set in motion and kept in motion. In the present case, the movement is generated inter alia by means of the agitator 5, in that the agitating blade 7 is set in rotary motion by way of the shaft 4. This movement is illustrated in FIG. 2 by a movement arrow 9.

Additionally or alternatively, the container 1 itself can be set in motion, for example in a rotary shaking movement, which is illustrated schematically in FIG 2 by further movement ^¬ arrows.

By the movement of the grains of the abrasive 8 relative to the permanent magnet 2, the surfaces of the permanent magnets 2 are freed of adhesive residues and other impurities without the edges of the generally cuboid permanent magnets 2 ground and rounded who ^¬ . The existing of a very brittle material permanent magnets 2 are not destroyed in this gentle and rapid cleaning. In addition, the cleaning of the permanent magnets 2 requires only a comparatively short time, because they can usually be completed in less than two hours. Preferably, a volume of Schleifmit ^¬ set 8 is set in the container 1, which is greater than the volume of the permanent magnets to be cleaned 2. It is therefore preferably the abrasive 8 added in excess.

In the present case, the cleaning of the permanent magnets 2 takes place in the abrasive covering these 8 without addition of water or solvent. By such a dry process, the risk of oxidizing the metals of the permanent magnets 2 re ^¬ duced. A solvent that can be added in principle, which can be beneficial for the removal of adhesive residue, does not need to be removed afterwards. The cleaning of the permanent magnets 2 is thus particularly low in effort.

In principle, it is possible to clean only a single permanent magnet 2 in the container 1. Advantageously, however, a relatively large number of permanent magnets 2 can acted upon at one time in the container 1 with the grinding means 8 and thus gerei ^¬ nigt. Furthermore, can be exempted from Verun ^¬ Cleaners also fragments of the permanent magnet 2 unterschiedlichster geometries without limitation to the presently described manner.

After cleaning, a separation of the abrasive 8 from the permanent magnet 2 by size classification, for example by sieving.

Claims

claims

Method for using permanent magnets (2), in which the permanent magnets (2) removed from an assembly, in particular from an electric motor, are treated, characterized in that

the permanent magnets (2) are subjected to an abrasive (8) for cleaning them.

2. The method according to claim 1, characterized in that the, in particular in a grain size of 1 mm to 2 mm ver ^{¬ used} , abrasive (8) together with the permanent magnet (2) in a container (1) and introduced into the container ( 1) is moved relative to the permanent magnets (2).

3. A method according to claim 2, characterized, in that the movement of the grinding means (8) relative to the permanent ^¬ magnet (2) by means of an at least partially disposed in the loading ^¬ ratio (1) agitating means (5) and / or by moving the Container (1) is effected.

4. The method according to claim 2 or 3, characterized in that the movement of the abrasive (8) relative to the per ^¬ manentmagneten (2) by introducing a fluidized bed adjusting fluidizing medium in the container (1) is effected.

5. The method according to any one of claims 2 to 4, characterized in that the container (1), at least during the movement of the abrasive means (8) relative to the Permanentmag ^¬ Neten (2) is closed.

6. The method according to any one of claims 2 to 5, characterized in that in the container (1) a ratio of a volume of the permanent magnets (2) to the volume of Schleifmit ^{¬ means} (8) of 1: 1 to 1:10, in particular of 1: 2 to 1: 5, a ^¬ is made.

7. The method according to any one of claims 1 to 6, characterized in that the permanent magnets (2) before the

Loading will be demagnetized with the abrasive (8), especially by heating to a temperature above the Curie temperature.

8. The method according to any one of claims 1 to 7, characterized in that for the cleaning of the permanent magnets (2) used abrasive (8) of the permanent magnet (8), in particular by screening, is separated.

9. The method according to any one of claims 1 to 8, characterized in that as the abrasive (8) silicon carbide is used.

10. Device for cleaning of an assembly, in particular of an electric motor, removed permanent magnet (2),

characterized in that

the apparatus comprising a container (1), in which the permanent ^¬ magnets (2) and a grinding means (8) are arranged, and means (5) for moving the grinding means (8) relative to the permanent magnets (2).