JP5560848B2 - Manufacturing apparatus and manufacturing method of raw material alloy for rare earth magnet - Google Patents

Description

  The present invention relates to a manufacturing apparatus and a manufacturing method of a raw material alloy for a rare earth magnet.

Two types of high-performance rare earth magnets are widely used: samarium / cobalt magnets and neodymium / iron / boron magnets.
In particular, neodymium / iron / boron magnets (hereinafter referred to as “R-T-B magnets”) exhibit the highest magnetic energy product among various magnets and are relatively inexpensive. Has been adopted.
The rare earth-based magnet is formed by press-molding an alloy powder formed by roughly pulverizing and finely pulverizing a raw material alloy obtained by a casting method (for example, centrifugal casting method) or a rapid cooling method (for example, strip casting method). It is manufactured through a heat treatment process. In the production of rare earth magnets, hydrogen pulverization is frequently used in the process of coarsely pulverizing a raw material alloy because of high pulverization efficiency.
The hydrogen pulverization is a method of pulverizing the raw material alloy by causing the raw material alloy to absorb hydrogen and embrittle it, and is performed by the following steps.
First, an alloy as a raw material is inserted into a hydrogen furnace, and then the inside of the hydrogen furnace is depressurized by evacuation. Thereafter, hydrogen gas is supplied into the hydrogen furnace, and hydrogen is stored in the raw material alloy (hydrogen storage step). After the elapse of a predetermined time, the raw material alloy is heated while evacuating the hydrogen furnace (heating step), hydrogen is released from the raw material alloy, and then cooled (cooling step) to complete the hydrogen pulverization. As a result, the raw material alloy becomes brittle and becomes coarsely pulverized powder. The coarsely pulverized powder after hydrogen pulverization is pulverized into a finely pulverized powder of several μm in the subsequent fine pulverization step.
Patent Document 1 describes a method for determining the quality of a rare earth magnet alloy ingot by measuring the temporal change in the amount of hydrogen occluded in the rare earth magnet alloy ingot, and the hydrogen storage behavior of the alloy at a temperature of 273 K or less is described. It is described that the time required for hydrogen storage becomes very long.
Patent Document 2 describes that in the hydrogen storage step, the time required for hydrogen storage can be shortened by heating the temperature in the reaction vessel to about 350 ° C. in a vacuum exhaust state before introducing hydrogen into the reaction vessel. ing.
As described in Patent Documents 1 and 2, it is known that the hydrogen storage time is shortened by heating the temperature of the alloy above a certain temperature in the hydrogen storage step.
On the other hand, Patent Document 3 describes a pretreatment step of a hydrogen occlusion process for facilitating hydrogen occlusion. In this pretreatment step, the container in which the alloy is sealed is evacuated, and the container is rotated and shaken. It is described that the temperature of the alloy lump is maintained at 0 to 600 ° C. while applying motion by motion or vibration.

JP 2002-275598 A (paragraph number 0056) Japanese Patent Laying-Open No. 2005-82891 (paragraph number 0081) JP-A-4-147908

As can be seen from each patent document, in the process of hydrogen storage in hydrogen pulverization, shortening the hydrogen storage time to improve the production capacity is an important factor for reducing the production cost.
However, in Patent Documents 1 and 2, since the inside of the furnace is heated to a constant temperature in an evacuated state before introducing hydrogen, even if the hydrogen storage time is shortened, the time required for heating is required, and the entire hydrogen pulverization process is performed. Then, there is a problem that it is difficult to shorten the time.
In particular, when the hydrogen crusher is a continuous furnace type, if the treatment time in the hydrogen storage chamber becomes long, processing waits occur in the heating and cooling processes, and unnecessary heating and unnecessary cooling are required for time adjustment. For example, the processing cycle of the entire apparatus is disturbed, leading to an increase in the processing time of the entire hydrogen pulverization process. In addition, an increase in the processing time of the hydrogen pulverization process has a problem of affecting the subsequent pulverization process, molding process, and sintering process.
Moreover, in patent document 3, although the heat processing process is performed as a pre-process of a hydrogen storage process, also in this pre-processing process, it heat-processes after evacuating a container, The processing time in a pre-processing process Will become longer.
As can be seen from Patent Document 3 in particular, there is a technical common sense that even before hydrogen pulverization, heating the alloy in the atmosphere causes the surface of the alloy to oxidize and the magnetic properties of the finally obtained magnet to deteriorate. is there.
In particular, when a raw material alloy by a rapid cooling method is used, since the thickness of the raw material alloy is very thin and the structure is refined, the activity against oxygen is high, and even the raw material alloy has a risk of ignition due to rapid oxidation. There is sex.
In such technical common sense, the inventors have determined that even if it is in the atmosphere, if the alloy is at a predetermined temperature not exceeding 100 ° C., the oxidation of the raw material alloy is not advanced, It has been found that it does not cause deterioration of the magnetic properties obtained.

  Therefore, the present invention provides a rare earth magnet raw material alloy that can reduce the manufacturing cost by shortening the hydrogen occlusion process without deteriorating the magnetic properties in the hydrogen occlusion process in which hydrogen is stored in the rare earth magnet raw material alloy. An object is to provide a manufacturing apparatus and a manufacturing method.

An apparatus for producing a rare earth based magnet raw material alloy according to claim 1 comprises a hydrogen storage chamber for storing hydrogen in a rare earth based magnet raw material alloy accommodated in a processing container, and the processing container in the hydrogen storage chamber. An apparatus for producing a rare earth-based magnet raw material alloy having a carrying means for carrying it in, wherein the treatment container is accommodated in the treatment container by heating the treatment container in the atmosphere upstream of the carrying means. A heating means for heating at least a part of the rare earth-based magnet raw material alloy to 0 ° C. to 100 ° C. in the atmosphere is provided.
According to a second aspect of the present invention, in the apparatus for producing a rare earth magnet raw material alloy according to the first aspect, the heating means is disposed on a side or upper side of the processing vessel via a space having a predetermined size. It is characterized by that.
According to a third aspect of the present invention, in the apparatus for producing a rare earth-based magnet raw material alloy according to the first or second aspect, the conveying means is a conveyor, and the heating means is on the side or above the conveyor. It is arranged.
According to a fourth aspect of the present invention, in the apparatus for producing a rare earth-based magnet raw material alloy according to the third aspect, the heating means is transported together with the processing container in a state where the heating means is disposed on the side or above the processing container. It is characterized by moving means.
A method for producing a raw material alloy for a rare earth magnet according to a fifth aspect of the present invention is a production method using the apparatus for producing a raw material alloy for a rare earth magnet according to the fourth aspect, wherein the processing vessel is moved. Heating is performed in the atmosphere by the heating means.
The method for producing a rare earth based magnet raw material alloy according to claim 6 of the present invention is a manufacturing method using the rare earth based magnet raw material alloy producing apparatus according to any one of claims 1 to 4, The ambient temperature around the processing vessel is 0 ° C. to 150 ° C.
The manufacturing method of the raw material alloy for rare earth magnets of the present invention according to claim 7 is a manufacturing method using the manufacturing apparatus of the raw material alloy for rare earth magnets according to any one of claims 1 to 4, It is carried into the hydrogen storage chamber in a state where the surface temperature of the processing container is heated to 0 ° C. to 100 ° C.
The method for producing a rare earth-based magnet raw material alloy according to claim 8 of the present invention is a production method using the rare earth-based magnet raw material alloy producing apparatus according to any one of claims 1 to 4, At least a part of the rare earth magnet raw material alloy housed in the processing vessel is carried into the hydrogen storage chamber in a state heated to 0 ° C. to 100 ° C.
According to a ninth aspect of the present invention, in the method for producing a rare earth based magnet raw material alloy according to any one of the fifth to seventh aspects, at least one of the rare earth based magnet raw material alloy accommodated in the processing vessel. The part is carried into the hydrogen storage chamber while being heated to 10 ° C to 100 ° C.
According to a tenth aspect of the present invention, in the method for producing a rare earth based magnet raw material alloy according to the eighth or ninth aspect, at least a part of the rare earth based magnet raw material alloy is heated to 10 ° C to 25 ° C. It is carried into the hydrogen storage chamber in a state.

According to the rare earth magnet raw material alloy production apparatus of the present invention, by heating the processing vessel in the atmosphere before being carried into the hydrogen storage chamber, heating the rare earth based magnet raw material alloy in the processing vessel, Since the hydrogen storage time in the rare earth magnet raw material alloy can be shortened without performing heat treatment in the hydrogen storage chamber, the treatment time in the hydrogen storage chamber can be shortened and the rare earth magnet raw material alloy can be oxidized. A decrease in magnetic properties can be prevented.
In addition, according to the method for producing a rare earth magnet raw material alloy of the present invention, the temperature of the processing vessel is optimized in accordance with the loading time of the hydrogen storage chamber by heating in the atmosphere by the heating means even when the processing vessel is moved. Can be maintained.

Schematic configuration diagram of a rare earth magnet raw material alloy production apparatus according to this example The perspective view which shows the heating means in the manufacturing apparatus Diagram showing behavior characteristics of hydrogen storage depending on temperature difference of raw material alloy Diagram showing the hydrogen storage characteristics depending on the ambient temperature

The rare earth magnet raw material alloy manufacturing apparatus according to the first embodiment of the present invention is for a rare earth magnet housed in a processing vessel by heating the processing vessel in the atmosphere upstream of the transfer means or the transfer means . A heating means for heating at least a part of the raw material alloy to 0 ° C. to 100 ° C. in the atmosphere is provided. According to the present embodiment, the processing vessel is heated in the atmosphere before being carried into the hydrogen storage chamber, and at least a part of the rare earth magnet raw material alloy in the processing vessel is brought to 0 ° C. to 100 ° C. in the atmosphere. Heating can shorten the time for storing hydrogen in the rare earth magnet raw material alloy without performing heat treatment in the hydrogen storage chamber, so the processing time in the hydrogen storage chamber can be shortened and the rare earth magnet can be used. It is possible to prevent a decrease in magnetic properties due to oxidation of the raw material alloy.
According to a second embodiment of the present invention, in the apparatus for producing a rare earth-based magnet raw material alloy according to the first embodiment, the heating means is disposed on the side or upper side of the processing vessel via a space having a predetermined size. It has been done. According to the present embodiment, since the processing container can be heated in an atmosphere of a predetermined temperature, oxidation of the rare earth magnet raw material alloy due to overheating can be prevented.
The third embodiment of the present invention is the rare earth magnet raw material alloy manufacturing apparatus according to the first or second embodiment, wherein the conveying means is a conveyor, and the heating means is disposed on the side or above the conveyor. It has been done. According to the present embodiment, heating can be performed in an existing conveyance path without providing an independent chamber during the manufacturing process.
According to a fourth embodiment of the present invention, in the apparatus for producing a rare earth based magnet raw material alloy according to the third embodiment, the heating means is transported together with the processing container in a state where the heating means is disposed on the side or above the processing container. Is to move. According to the present embodiment, since heating can be performed during conveyance, the conveyance time can be effectively utilized.
The manufacturing method of a rare earth magnet raw material alloy according to the fifth embodiment of the present invention is the same as that of the manufacturing method using the rare earth magnet raw material alloy manufacturing apparatus according to the fourth embodiment. It is heated in the atmosphere by a heating means. According to the present embodiment, it is possible to optimally maintain the temperature of the processing container in accordance with the loading of the hydrogen storage chamber.
According to a sixth embodiment of the present invention, in the method for producing a rare earth-based magnet raw material alloy according to any one of the first to fourth embodiments, the ambient temperature around the processing vessel is set to 0 ° C. to 150 ° C. Is. According to the present embodiment, it is possible to shorten the hydrogen storage time in the rare earth magnet material alloy without accelerating the oxidation of the rare earth magnet material alloy.
7th Embodiment of this invention is the state which heated the surface temperature of the processing container to 0 to 100 degreeC in the manufacturing method of the raw material alloy for rare earth magnets by any one of 1st to 4th embodiment It will be carried into the hydrogen storage room. According to the present embodiment, it is possible to shorten the hydrogen storage time in the rare earth magnet material alloy without accelerating the oxidation of the rare earth magnet material alloy.
According to an eighth embodiment of the present invention, in the method for producing a rare earth based magnet raw material alloy according to any of the first to fourth embodiments, at least one of the rare earth based magnet raw material alloys accommodated in the processing vessel is provided. The part is carried into the hydrogen storage chamber while being heated to 0 ° C to 100 ° C. According to the present embodiment, it is possible to shorten the hydrogen storage time in the rare earth magnet material alloy without accelerating the oxidation of the rare earth magnet material alloy.
According to a ninth embodiment of the present invention, in the method for producing a rare earth based magnet raw material alloy according to any of the fifth to seventh embodiments, at least one of the rare earth based magnet raw material alloys accommodated in the processing vessel is provided. The part is carried into the hydrogen storage chamber while being heated to 10 ° C to 100 ° C. According to the present embodiment, the hydrogen storage time can be further shortened by setting the rare earth magnet raw material alloy to 10 ° C. or higher.
According to a tenth embodiment of the present invention, in the method for producing a rare earth magnet material alloy according to the eighth or ninth embodiment, at least a part of the rare earth magnet material alloy is heated to 10 ° C. to 25 ° C. In this state, it is carried into the hydrogen storage room. According to the present embodiment, the hydrogen storage time can be shortened while minimizing the energy required for heating.

An apparatus for producing a rare earth magnet raw material alloy according to an embodiment of the present invention will be described below.
FIG. 1 is a schematic configuration diagram of an apparatus for producing a rare earth magnet raw material alloy according to this embodiment.
As shown in FIG. 1, the apparatus for producing a rare earth magnet raw material alloy according to the present embodiment includes a hydrogen storage chamber 10 in which hydrogen is stored in the rare earth magnet raw alloy, and a rare earth magnet that is hydrogen-pulverized by hydrogen storage. A heating chamber 20 for dehydrogenating the hydrogen pulverized powder of the raw material alloy by heating, a cooling chamber 30 for cooling the heated hydrogen pulverized powder, and a recovery chamber 40 for recovering the cooled hydrogen pulverized powder in the recovery container 1 are provided. ing.
A heating means 60 for heating the processing container 50 is provided on the upstream side of the hydrogen storage chamber 10. In the present embodiment, the heating unit 60 is disposed on the transport unit 5, but may be disposed on the upstream side of the transport unit 5. In this embodiment, a conveyor is shown as the conveying means 5, and the heating means 60 is disposed on the side or above the conveyor. The heating unit 60 is disposed at a predetermined position of the transport unit 5, but is preferably provided so as to be movable along the transport unit 5. In particular, it is preferable to be configured so that it can move with the processing container 50 at the same transport speed.

The hydrogen storage chamber 10 has a shut-off door 11 at the carry-in port and a cut-out door 21 at the carry-out port to the heating chamber 20, and is configured to keep the inside of the room sealed. The hydrogen storage chamber 10 includes an inert gas introduction unit 12 that introduces an inert gas, a vacuum exhaust unit 13 that exhausts indoor gas, a hydrogen introduction unit 14 that introduces hydrogen gas, and a conveyor that conveys the processing vessel 50. Means 15 are provided.
The heating chamber 20 has a shut-off door 21 at the carry-in port from the hydrogen storage chamber 10 and a shut-off door 31 at the carry-out port to the cooling chamber 30 so as to keep the inside of the room sealed. The heating chamber 20 includes an inert gas introduction unit 22 for introducing an inert gas, a vacuum exhaust unit 23 for discharging the indoor gas, a heating source 24 for heating the room, and a conveyor unit 25 for conveying the processing container 50. I have.
The cooling chamber 30 has a shut-off door 31 at the entrance to the heating chamber 20 and a shut-off door 41 at the exit to the recovery chamber 40 so as to keep the room sealed. The cooling chamber 30 includes an inert gas introduction means 32 for introducing an inert gas, a vacuum exhaust means 33 for discharging the indoor gas, a cooling means 34 for cooling the room, and a conveyor means 35 for conveying the processing container 50. I have.
The recovery chamber 40 has a shut-off door 41 at the carry-in port from the cooling chamber 30 and a shut-off door 2 at the carry-out port to the outside of the furnace, and is configured to keep the room sealed. The recovery chamber 40 includes an inert gas introduction unit 42 that introduces an inert gas, a vacuum exhaust unit 43 that discharges the indoor gas, an inversion unit 44 that vertically inverts the processing container 50, and a conveyor that conveys the processing container 50. Means 45 are provided. In addition, a valve 70 is provided below the collection chamber 40, and the collection container 1 is connected via the valve 70. The collection container 1 is provided with a valve (not shown) for sealing the container.
The processing vessel 50 is transferred to the heating means 60 outside the furnace, the hydrogen storage chamber 10, the heating chamber 20, the cooling chamber 30, and the recovery chamber 40 inside the furnace in a state in which the rare earth magnet raw material alloy is housed.

  In the present invention, as described above, in addition to the so-called continuous furnace type manufacturing apparatus in which the hydrogen storage chamber 10, the heating chamber 20, and the cooling chamber 30 are independent from each other, the hydrogen storage step, the heating step, and the cooling step are performed in one room. A so-called batch furnace (independent furnace) type manufacturing apparatus can be used. Moreover, in order to improve the processing capacity and the configuration of the hydrogen storage chamber 10 and heating chamber 20 and cooling chamber 30, the hydrogen storage chamber 10 and heating chamber 20 and cooling chamber 30, etc., a plurality of heating chambers 20 and cooling chambers 30 are provided. A manufacturing apparatus having a configuration in which the hydrogen storage chamber 10, the first heating chamber, the second heating chamber, the first cooling chamber, and the second cooling chamber can be used. Furthermore, a manufacturing apparatus having a configuration in which a preparation chamber or a spare chamber is installed in front of the hydrogen storage chamber 10 may be used. In this case, the heating means 60 may be provided in a preparation chamber or a spare chamber installed in front of the hydrogen storage chamber 10. In addition, the heating unit 60 may be provided in the preparation unit or the spare chamber and at the transport unit 5.

The raw material alloy for rare earth magnets to be treated by this apparatus is preferably an R—T—B magnet raw material alloy, desirably an R—Fe (Co) —BM system.
R is selected from at least one of Nd, Pr, Dy, and Tb. However, it is desirable that R always contains either Nd or Pr. More preferably, a combination of rare earth elements represented by Nd-Dy, Nd-Tb, Nd-Pr-Dy, or Nd-Pr-Tb is used.
Of R, Dy and Tb are particularly effective in improving the coercive force. In addition to the above elements, a small amount of other rare earth elements such as Ce and La may be contained, and misch metal or didymium can also be used. Further, R may not be a pure element, and may contain impurities that are unavoidable in the manufacturing process within a commercially available range. A conventionally known content can be adopted as the content, and for example, a range of 25% by mass to 35% by mass is a preferable range. If the amount is less than 25% by mass, high magnetic properties, particularly high coercive force cannot be obtained, and if it exceeds 35% by mass, the residual magnetic flux density decreases.
T necessarily contains Fe, and 50% or less can be substituted with Co. Co is effective in improving temperature characteristics and corrosion resistance, and is usually used in a combination of 10 mass% or less of Co and the balance Fe. The content of T occupies the remainder of R and B or R, B and M.
The content of B may be a known content, and for example, 0.9 mass% to 1.2 mass% is a preferable range. If it is less than 0.9% by mass, a high coercive force cannot be obtained, and if it exceeds 1.2% by mass, the residual magnetic flux density decreases, which is not preferable. A part of B can be replaced with C. C substitution is effective because it can improve the corrosion resistance of the magnet. The content in the case of B + C is preferably set within the range of the above B concentration by converting the number of C substitution atoms by the number of B atoms.
In addition to the above elements, an M element can be added to improve the coercive force. The element M is at least one of Al, Si, Ti, V, Cr, Mn, Ni, Cu, Zn, Ga, Zr, Nb, Mo, In, Sn, Hf, Ta, and W. The addition amount is preferably 2% by mass or less. This is because the residual magnetic flux density decreases when the content exceeds 5 mass%.
Inevitable impurities can also be tolerated. For example, Mn, Cr mixed from Fe, Al, Si, Cu mixed from Fe-B (ferroboron), and the like.

The raw material alloy for rare earth magnets carried into the apparatus is manufactured by a melting method. Ingot casting method that melts the metal that has been adjusted in advance to the final required composition and put it in the mold, or the molten metal is brought into contact with a single roll, twin roll, rotating disk, or rotating cylindrical mold, etc., and rapidly cooled, Manufactured by a rapid cooling method typified by a strip casting method or a centrifugal casting method for producing a solidified alloy thinner than an alloy made by an ingot method. The rare earth magnet raw material alloy according to the present embodiment can be applied to a material manufactured by either an ingot method or a rapid cooling method, but is preferably manufactured by a rapid cooling method.
The thickness of the rare earth magnet raw material alloy (quenched alloy) produced by the rapid cooling method is in the range of 0.03 mm or more and 10 mm or less, and has a flake shape. The molten alloy begins to solidify from the contact surface (roll contact surface) of the cooling roll, and crystals grow in a columnar shape from the roll contact surface in the thickness direction. The quenched alloy is cooled in a short time compared to an alloy (ingot alloy) produced by a conventional ingot casting method (die casting method), so that the structure is refined and the crystal grain size is small. Further, since the area of the grain boundary is wide and the R-rich phase spreads widely within the grain boundary, the dispersibility of the R-rich phase is excellent. For this reason, it is easy to break at the grain boundary by the hydrogen pulverization method, but as described above, the activity to oxygen is high. By subjecting the quenched alloy to hydrogen pulverization, the average size of the hydrogen pulverized powder (coarse pulverized powder) can be set to, for example, 1.0 mm or less.

The manufacturing apparatus according to the present embodiment shows a configuration in which the hydrogen storage chamber 10, the heating chamber 20, the cooling chamber 30, and the recovery chamber 40 are connected to each other. A plurality of chambers 30 may be provided.
The processing container 50 has an opening on the upper surface, and a lid 51 is provided in the opening. Here, the lid 51 does not seal the opening, but has a gap through which hydrogen gas, inert gas, and the like can enter and exit. That is, the opening of the processing container 50 is covered with the lid 51. The processing vessel 50 is suitably made of stainless steel that is heat resistant and relatively easy to process. What is necessary is just to determine a volume and board thickness suitably according to the quantity processed at once and the dimension of a manufacturing apparatus. The processing container 50 does not stick to the shape as long as the upper part is open, but generally has a box shape. In order to improve the efficiency of hydrogen occlusion, heating, and cooling, it is also one of preferable configurations to arrange a plurality of box-shaped containers at a fixed interval on one pedestal. Incidentally, in this embodiment, a processing container 50 is used in which box-shaped containers are arranged on one pedestal at a predetermined interval of 4 rows × 2 rows. Further, it is desirable that the processing container 50 includes a pipe penetrating the inside. Since the raw material alloy is charged and deposited in the processing vessel 50, the temperature change inside the processing vessel 50 due to heating or cooling is slow, and the dehydrogenation or cooling after dehydrogenation is not sufficient, and the finally obtained magnet Therefore, by passing an inert gas for heating or cooling through the pipe passing through the inside, there is a difference in temperature change between the raw material alloy on the surface of the processing vessel 50 and the internal raw material alloy. Reduced and quality stabilized. The pipes can be further improved in temperature change of the raw material alloy by combining pipes having different diameters or selecting an arrangement place and an arrangement interval.
The processing container 50 is transferred to the hydrogen storage chamber 10, the heating chamber 20, and the cooling chamber 30 with the opening covered with the lid 51. In addition, when heating by the heating means 60, the opening may be covered with the lid 51.

Hereinafter, a method for producing a rare earth magnet raw material alloy according to the present embodiment will be described with reference to FIG.
In the processing container 50, for example, a flaky rare earth-based magnet raw material alloy manufactured by a rapid cooling method is accommodated.
The processing container 50 is heated by the heating means 60 while being placed on the transport means 5. The processing container 50 is left at a predetermined position of the transport unit 5, and the ambient temperature around the processing container 50 is maintained at 0 ° C. to 150 ° C. by the heating unit 60.
After the elapse of a predetermined time, the processing container 50 is carried into the hydrogen storage chamber 10 in a state where the surface temperature of the processing container 50 is heated to 0 ° C to 100 ° C. At the time of loading into the hydrogen storage chamber 10, at least a part of the rare earth magnet raw material alloy accommodated in the processing vessel 50 is in a state heated to 0 ° C. to 100 ° C. At least a part of the rare earth magnet raw material alloy is preferably heated to 10 ° C to 100 ° C, and more preferably in the range of 10 ° C to 25 ° C.

If all of the rare earth magnet raw material alloys are below 0 ° C., the time required for hydrogen pulverization is undesirably long. On the other hand, when the temperature exceeds 100 ° C., the raw material alloy may partially ignite due to rapid oxidation when the raw material alloy is used by the rapid cooling method. Therefore, the heating temperature is set so that at least a part of the rare earth magnet raw material alloy is 0 ° C to 100 ° C. More preferably, at least a part of the rare earth magnet raw material alloy is 10 ° C. or higher, and the heating temperature is set so that at least a part of the rare earth magnet raw material alloy is 10 ° C. to 100 ° C. Further, in consideration of the cost of electric power accompanying heating and the results of FIGS. 3 and 4 to be described later, it is further possible to set the heating temperature so that at least a part of the rare earth magnet raw material alloy is 10 ° C. to 25 ° C. preferable.
However, in Japan, the outside air temperature varies depending on the season, and there are regions that exceed 40 ° C in the summer. When manufacturing overseas, the change in outside air temperature is particularly severe. If the heating temperature is different, the treatment time in the hydrogen storage chamber 10 is affected, and the quality (such as the oxygen content) of the obtained raw material alloy may become unstable. It is desirable to unify the heating conditions in order to stably supply products of the same quality throughout the year regardless of the manufacturing area. In this case, if the temperature is set in the range of 10 ° C. to 25 ° C. in which importance is placed on the power cost, if the outside air temperature exceeds 40 ° C., cooling is required, and conversely, the power cost is increased. Therefore, when emphasizing the stability of quality, a specific temperature is set within the range of 40 ° C. to 100 ° C. above the highest temperature expected in each manufacturing region, and the same heating temperature is used in each manufacturing region. It is preferable.

In order to heat at least a part of the rare earth magnet metal alloy to 0 ° C. to 100 ° C., it is desirable to heat the surface temperature of the processing vessel 50 containing the rare earth magnet-based metal alloy to 0 ° C. to 100 ° C.
In order to heat the surface temperature of the processing container 50 to 0 ° C. to 100 ° C., it is desirable to set the ambient temperature around the processing container 50 to 0 ° C. to 150 ° C.
Here, the timing control for carrying in the hydrogen storage chamber 10 is determined by measuring the surface temperature of the processing vessel 50 and the temperature of the rare earth magnet raw material alloy accommodated in the processing vessel 50 or by the time obtained by verification in advance. However, in the continuous furnace type apparatus as in the present embodiment, the heating means 60 continuously keeps the heat-retaining state during the waiting time for loading into the hydrogen storage chamber 10. It is also possible to maintain and not control the heating time in the heating means 60. Thus, particularly when the heating time control in the heating means 60 is not performed, the heating means 60 is arranged on the side or upper side of the processing container 50 via a space of a predetermined size, It is suitable to maintain the atmospheric temperature between 0 ° C and 150 ° C. Thus, according to the present invention, the hydrogen storage time can be shortened without disturbing the processing cycle of the entire hydrogen pulverizer.

Thereafter, the blocking door 11 of the hydrogen storage chamber 10 is opened, and the processing container 50 is carried into the hydrogen storage chamber 10. After carrying in, the shut-off door 11 is closed, and the vacuum exhaust means 13 is operated to evacuate the hydrogen storage chamber 10.
After the inside of the hydrogen storage chamber 10 is evacuated and the operation of the evacuation unit 13 is completed, the hydrogen introduction unit 14 is operated to introduce hydrogen gas into the hydrogen storage chamber 10. By introducing hydrogen gas, the inside of the hydrogen storage chamber 10 is brought to a pressure of 0.1 to 0.18 MPa, and hydrogen is stored in the rare earth-based magnet raw material alloy in the processing vessel 50 to perform the hydrogen storage step. In addition, you may occlude hydrogen by making the inside of the hydrogen storage chamber 10 into a pressurized state.
After a predetermined time has elapsed (after the completion of hydrogen storage), the operation of the hydrogen introduction unit 14 is terminated to stop the introduction of hydrogen gas, and the hydrogen gas in the hydrogen storage chamber 10 is evacuated by operating the vacuum evacuation unit 13. To do. As a result, the hydrogen occlusion process ends, and the process proceeds to the next heating process. At this time, the rare earth-based magnet raw material alloy absorbs hydrogen and becomes brittle and pulverized to form hydrogen pulverized powder (coarse pulverized powder).

Since the hydrogenation reaction for storing hydrogen is an exothermic reaction, the temperature of the raw material alloy increases with the storage of hydrogen, but at least a part of the raw material alloy is heated to a predetermined temperature. The hydrogen storage start time of the raw material alloy heated to a predetermined temperature is not delayed. And the temperature rise accompanying the hydrogen occlusion of a part of the heated raw material alloy becomes a trigger, and the hydrogen occlusion starts for other raw material alloys that are not heated.
In this way, the hydrogenation reaction of a part of the raw material alloy can be used as a trigger to promote the hydrogenation reaction of the low temperature raw material alloy by utilizing the temperature rise of the raw material alloy due to the exothermic reaction during hydrogen storage. Since hydrogen storage is performed in the R-rich phase of the boundary, it is possible to shorten the time of the hydrogen storage process and reduce the amount of introduced hydrogen while sufficiently progressing embrittlement of the raw material alloy. Moreover, since it can also prevent the temperature fall of the heating chamber 20 if it transfers to the subsequent heating process, maintaining a high temperature holding state, it can shorten the time of the heating process in the heating chamber 20, and can reduce the power consumption required for a heating. it can.

Next, when moving to the heating step, the processing container 50 is transferred from the hydrogen storage chamber 10 to the heating chamber 20, and the inside of the heating chamber 20 is evacuated in advance by the evacuation means 23 during the transfer.
The processing container 50 is carried into the heating chamber 20 from the hydrogen storage chamber 10 by opening the blocking door 21 and driving the conveyor means 15 and the conveyor means 25. After carrying in, the blocking door 21 is closed, and the inside of the heating chamber 20 is further evacuated by the vacuum exhaust means 23 and heated by the heating source 24. The inside of the heating chamber 20 is maintained at a temperature of 500 to 600 ° C. by the heating source 24 and is maintained at a pressure of about 1 Pa by the vacuum exhaust means 23. Thereby, the hydrogen pulverized powder is dehydrogenated. In the heating process of the hydrogen pulverized powder, the inside of the heating chamber 20 is evacuated as described above, but an inert gas (for example, argon gas) is introduced at the same time as the evacuation so as to be in a flowing state at a predetermined pressure. Thus, the temperature raising rate of the raw material alloy can be increased, and the time required for the heating process can be shortened.

After the hydrogen pulverized powder is sufficiently dehydrogenated, the inert gas is introduced into the heating chamber 20 by operating the inert gas introducing means 22, and the inert gas is brought close to the atmosphere in the cooling chamber 30. The operation of the gas introducing means 22 is terminated. Argon gas is preferable as the inert gas.
The processing container 50 in the heating chamber 20 is carried into the cooling chamber 30 from the heating chamber 20 by opening the blocking door 31 and driving the conveyor means 25 and the conveyor means 35. After carrying in, the blocking door 31 is closed, and the inside of the cooling chamber 30 is cooled by the cooling means 34.
Cooling is performed by cooling with a fan, cooling by circulating cooling water in the cooling chamber 30, or using them together.
The processing container 50 in the cooling chamber 30 is carried into the recovery chamber 40 from the cooling chamber 30 by opening the blocking door 41 and driving the conveyor means 35 and the conveyor means 45. In carrying into the recovery chamber 40, an inert gas (argon gas) is introduced into the recovery chamber 40 by operating the inert gas introduction means 42, and after bringing the atmosphere into the cooling chamber 30, the inert gas is introduced. The operation of the means 42 is terminated.
When the processing container 50 is carried into the collection chamber 40, the blocking door 41 is closed, and the inside of the collection chamber 40 is evacuated by operating the evacuation means 43. In a state where the inside of the collection chamber 40 is evacuated to a pressure of 1000 Pa to 1 Pa, preferably 5 Pa to 1 Pa, the lid 51 is removed and the reversing means 44 is operated to remove the hydrogen crushed powder in the processing container 50. Drop on the inner bottom and discharge. The reversing means 44 is a preferable means for discharging the hydrogen pulverized powder in the processing container 50 into the recovery chamber 40, but the main feature of the recovery method of the present invention is that the hydrogen pulverized powder in the processing container 50 is used. That is, the inside of the collection chamber 40 is decompressed when discharged into the collection chamber 40. Therefore, as long as the inside of the collection chamber 40 is depressurized, discharge means other than the reversing means 44 may be used.

In the above, the reason why the pressure in the recovery chamber 40 is set to 1000 Pa to 1 Pa, preferably 5 Pa to 1 Pa is as follows.
After the recovery process is completed, the collection chamber 40 is evacuated after the empty processing container 50 is taken out from the shut-off door 2 and then closed until the next processing container 50 comes from the cooling chamber 30. Exhaust continues. Then, since the pressure is restored by an inert gas (argon gas) in order to bring it closer to the atmosphere of the cooling chamber 30 immediately before the next processing container 50 is carried in, the amount of oxygen in the recovery chamber 40 is sufficiently reduced ( For example, it is not necessary to consider the amount of oxygen from the viewpoint of preventing oxidation of the hydrogen pulverized powder. Therefore, the pressure of 1000 Pa to 1 Pa defines the condition that the hydrogen pulverized powder does not dance in the recovery chamber 40. On the other hand, if the cycle speed of the manufacturing apparatus is high, or if sufficient evacuation is not performed before the next processing container 50 comes from the cooling chamber 30 due to inspection or maintenance in the recovery chamber 40, the recovery chamber In order to sufficiently reduce the amount of oxygen in 40 and preferably to make the amount of oxygen 20 ppm or less, the pressure in the recovery chamber 40 is preferably 5 Pa to 1 Pa. That is, the pressure of 5 Pa to 1 Pa defines conditions for reducing the oxygen content in the recovery chamber 40 to 20 ppm or less. Of course, since 5 Pa is a higher vacuum than 1000 Pa, the hydrogen pulverized powder does not fly in the recovery chamber 40. Thus, the pressure in the collection chamber 40 is usually sufficient at 1000 Pa or less, and more preferably 5 Pa or less.
In the present invention, a vacuum degree of 1 Pa or less is not necessarily required in order to prevent oxidation of hydrogen pulverized powder or dance of hydrogen pulverized powder in the recovery chamber 40, but the present invention can be implemented even if it is 1 Pa or less.

After dropping the hydrogen pulverized powder into the recovery chamber 40, the operation of the vacuum exhaust means 43 is terminated, and the inert gas introduction means 42 is operated again to introduce an inert gas (argon gas) into the recovery chamber 40. After the predetermined pressure is reached, the operation of the inert gas introducing means 42 is terminated. The collection container 1 has a valve (not shown) provided in the collection container 1 opened, and is previously replaced with an inert gas so that the air oxygen concentration in the collection container 1 is 20 ppm or less. Yes. In addition, by introducing an inert gas (argon gas) into the recovery chamber 40, the predetermined pressure in the recovery chamber 40 is the same as the pressure in the recovery container 1. In this state, the valve 70 is opened to collect the hydrogen pulverized powder in the collection container 1.
When the recovery of the hydrogen pulverized powder into the recovery container 1 is completed, the valve 70 and a valve (not shown) provided in the recovery container 1 are closed, and the recovery container 1 is detached from the recovery chamber 40. Thereafter, the blocking door 2 is opened and the processing container 50 is transferred out of the collection chamber 40.

In the present embodiment, the heating means 60 for heating the processing vessel 50 is provided on the upstream side of the transfer means 5 or the transfer means 5, and the rare earth magnet raw material alloy is heated before being loaded into the hydrogen storage chamber 10. Since the hydrogen storage time in the rare earth magnet raw material alloy can be shortened without performing the heat treatment in the storage chamber 10, the processing time in the hydrogen storage chamber 10 can be shortened.
Further, in the present embodiment, the recovery chamber 40 has reversing means 44 for turning the processing vessel 50 upside down. The processing vessel 50 has an opening on the upper surface, and the rare earth magnet raw material alloy in the processing vessel 50 Is discharged by upside down by the inversion means 44. Therefore, compared with the case where the lower part of the processing vessel 50 is opened and the hydrogen pulverized powder is dropped, the hydrogen pulverized powder is less likely to remain around the opening and the lid 51 and is further reduced in pressure. There is no effect of the pulverization of the hydrogen pulverized powder caused by the generation of airflow.

In this embodiment, the conveying means 5 is a conveyor, and the heating means 60 is arranged on the side or upper side of the conveyor, so that heating can be performed in the existing conveying path without providing an independent chamber during the manufacturing process. It can be carried out.
Further, in this embodiment, since the heating means 60 can be moved together with the processing container 50 in a state where the heating means 60 is disposed on the side or above the processing container 50 and heating can be performed during the transportation, the transportation time can be reduced. Can be used effectively.
Further, in the present embodiment, the temperature of the processing container 50 can be optimally maintained in accordance with the loading of the hydrogen storage chamber 10 by heating by the heating means 60 even when the processing container 50 is moved.
Further, in this embodiment, by setting the ambient temperature around the processing vessel 50 to 0 ° C. to 150 ° C., the hydrogen storage time in the rare earth magnet material alloy can be increased without accelerating the oxidation of the rare earth magnet material alloy. Can be shortened.
In the present embodiment, the surface temperature of the processing vessel 50 is heated to 0 ° C. to 100 ° C. and then carried into the hydrogen storage chamber 10, so that the rare earth magnet raw material alloy can be oxidized without accelerating the oxidation. The hydrogen storage time in the raw material alloy can be shortened.
In the present embodiment, at least a part of the rare earth magnet raw material alloy accommodated in the processing vessel 50 is carried into the hydrogen storage chamber 10 while being heated to 0 ° C. to 100 ° C. The hydrogen storage time in the rare earth magnet raw material alloy can be shortened without accelerating the oxidation of.

Next, a more detailed configuration and operation of the heating unit described in FIG. 1 will be described.
FIG. 2 is a perspective view showing a heating means in the manufacturing apparatus.
The heating means 60 includes a heating source holding plate 61 arranged on one side, a heating source holding plate 62 arranged on the other side, and a heating source holding plate 63 arranged on the upper side. These heating source holding plates 61, 62, 63 holds the heating sources 61a, 62a, 63a on the inner space side, and is attached to the frame body 64. Here, the internal space has such a size that a space having a predetermined dimension is formed on the side and above the processing container 50 in a state where the processing container 50 is disposed.
The frame body 64 to which the heat source holding plates 61, 62, and 63 are attached is disposed on the conveyor.

In this embodiment, the heating means 60 is disposed on the side and upper side of the processing container 50 via a space having a predetermined size, and can heat the processing container 50 in an atmosphere of a predetermined temperature. Oxidation of the rare earth magnet raw material alloy due to the above can be prevented.
In this embodiment, since the conveying means 5 is a conveyor and the heating means 60 is disposed on the conveyor, heating can be performed in an existing conveying path without providing an independent chamber during the manufacturing process. it can.

Next, the hydrogen storage behavior characteristics of the rare earth magnet raw material alloy will be described with reference to FIGS.
FIG. 3 is a diagram showing the behavioral characteristics of hydrogen storage depending on the temperature difference of the raw material alloy, and FIG. 4 is a diagram showing the hydrogen storage characteristics depending on the difference in ambient temperature.
FIG. 3 shows a change characteristic of the hydrogen storage amount with time when the temperature of the raw material alloy is classified into three groups of about 20 ° C., about 10 ° C., and about 0 to 5 ° C.
As shown in FIG. 3, when the hydrogen storage amount is 0.4 wt%, the group around 20 ° C. is about 50 minutes, the group around 10 ° C. is about 60-80 minutes, and the group around 0-5 ° C. is about 100 minutes. From 120 minutes to 120 minutes.
Thus, when the temperature of the raw material alloy is low, the time required for hydrogen storage becomes long.
Further, when compared at the hydrogen storage start stage, for example, about 0.01 wt%, if it falls below 10 ° C., it takes a considerable amount of time to rise. Appears prominently.
FIG. 4 shows the relationship between the ambient temperature and time required for hydrogen storage (starting stage of hydrogen storage) of 10% of the saturated hydrogen storage amount, the solid line in FIG. 4 is the average characteristic line, and the two broken lines are all This is a boundary characteristic line drawn to include data. As can be seen from these average characteristic lines and boundary characteristic lines, it can be seen that when the ambient temperature reaches 25 ° C., there is no significant difference in the time required for the start of hydrogen occlusion, and the temporal variation is reduced. In addition, when the ambient temperature is in the range of 0 to 15 ° C., the time required to start hydrogen storage is longer than that when the ambient temperature is 15 ° C. or higher, and the time required to start hydrogen storage increases as the ambient temperature decreases. However, as can be seen from the curvature, it is understood that hydrogen occlusion is started in a short time in comparison with the estimated time at an ambient temperature lower than 0 ° C.
Further, it was found that when a part of the raw material alloy for rare earth magnets was heated to a temperature exceeding 100 ° C., the alloy partially ignited, and it was difficult to set the temperature above 100 ° C.

  INDUSTRIAL APPLICATION This invention can be utilized for the collection | recovery method and collection | recovery apparatus of hydrogen pulverized powder of the raw material alloy for rare earth magnets in the state which is easy to oxidize.

DESCRIPTION OF SYMBOLS 1 Recovery container 2 Shut-off door 10 Hydrogen storage room 11 Shut-off door 12 Inert gas introduction means 13 Vacuum exhaust means 14 Hydrogen introduction means 15 Conveyor means 20 Heating chamber 21 Shut-off door 22 Inert gas introduction means 23 Vacuum exhaust means 24 Heating source 25 Conveyor means 30 Cooling chamber 31 Shut-off door 32 Active gas introduction means 33 Vacuum exhaust means 34 Cooling means 35 Conveyor means 40 Recovery chamber 41 Shut-off door 42 Inert gas introduction means 43 Vacuum exhaust means 44 Inversion means 45 Conveyor means 50 Processing container 60 Heating means

Claims (10)

An apparatus for producing a rare earth magnet raw material alloy, comprising: a hydrogen storage chamber for storing hydrogen in a rare earth magnet raw material alloy accommodated in a processing vessel; and a transport means for carrying the processing vessel into the hydrogen storage chamber. In addition, at least a part of the raw material alloy for the rare earth magnet contained in the processing vessel is heated in the atmosphere by heating the processing vessel in the atmosphere upstream of the conveying unit or the conveying unit. An apparatus for producing a raw material alloy for rare earth magnets, characterized in that a heating means for heating is provided.   The apparatus for producing a raw material alloy for a rare earth magnet according to claim 1, wherein the heating means is disposed on a side or upper side of the processing container via a space having a predetermined size.   3. The apparatus for producing a raw material alloy for a rare earth magnet according to claim 1, wherein the conveying means is a conveyor, and the heating means is disposed on a side or above the conveyor.   The apparatus for producing a raw material alloy for a rare earth based magnet according to claim 3, wherein the conveying means is moved together with the processing container in a state where the heating means is disposed on a side or above the processing container.   5. A method for producing a rare earth based magnet raw material alloy according to claim 4, wherein the heating means is heated in the atmosphere even when the processing vessel is moved. Alloy manufacturing method. It is a manufacturing method using the manufacturing apparatus of the raw-material alloy for rare earth magnets in any one of Claims 1-4 , Comprising: The atmospheric temperature around the said processing container was 0 degreeC-150 degreeC, It is characterized by the above-mentioned. A method for producing a raw material alloy for a rare earth magnet. It is a manufacturing method using the manufacturing apparatus of the raw-material alloy for rare earth magnets in any one of Claims 1-4 , Comprising: The surface temperature of the said processing container is heated to 0 degreeC-100 degreeC, The said hydrogen A method for producing a raw material alloy for a rare earth magnet, which is carried into a storage room. It is a manufacturing method using the manufacturing apparatus of the raw material alloy for rare earth magnets in any one of Claims 1-4 , Comprising: At least one part of the said rare earth system magnet raw material alloy accommodated in the said processing container is used. A method for producing a raw material alloy for a rare earth magnet, which is carried into the hydrogen storage chamber while being heated to 0 ° C to 100 ° C.   8. The method according to claim 5, wherein at least a part of the rare earth magnet raw material alloy accommodated in the processing vessel is carried into the hydrogen storage chamber in a state heated to 10 ° C. to 100 ° C. 8. A method for producing a raw material alloy for a rare earth magnet according to claim 1. 10. The rare earth magnet material alloy according to claim 8, wherein at least a part of the rare earth magnet material alloy is carried into the hydrogen storage chamber while being heated to 10 ° C. to 25 ° C. 10. Manufacturing method.