JP4451632B2 - Hydrogen crusher for rare earth magnet materials - Google Patents

Description

  The present invention relates to a hydrogen crusher for rare earth magnet materials.

  There are two types of rare earth magnets: neodymium / iron / boron (Nd-Fe-B) and samarium / cobalt (Sm-Co). Since the size of the applied product can be reduced, it is often used. In particular, Nd-Fe-B magnets are less expensive than Sm-Co magnets and have excellent magnetic properties (residual magnetic flux density, coercive force, maximum energy product). The process is progressing rapidly. The Nd—Fe—B based magnet is manufactured by press-molding a material Nd—Fe—B based alloy powder in a magnetic field and sintering it. However, since the magnetic properties of the Nd-Fe-B magnet are strongly influenced by the oxygen content, efforts are currently being made to reduce the oxygen content as much as possible.

When manufacturing an Nd-Fe-B magnet, a method of pulverizing a massive ingot alloy obtained by gradually cooling a molten rare earth magnet material with a mold, and a flaky alloy quenched by, for example, a strip casting method The quenched alloy is cooled in a shorter time than the annealed alloy, so that the structure is refined and a crystal phase is formed. Specifically, a structure composed of a crystal phase of R ₂ T ₁₄ B, which is an Nd—Fe—B magnet component, and a nonmagnetic R-rich phase that is dispersed and present at the grain boundaries of the crystal phase is formed. . In the above, R represents a rare earth element such as Nd, T represents a transition metal such as Fe, and B represents boron. Examples of the method for producing a quenched alloy by the strip casting method include methods described in JP-A Nos. 11-267793 and 2000-79449.

  The same applies to the case where a slowly cooled ingot alloy is pulverized and used. However, when a quenched alloy obtained by strip casting is pulverized and used, the R-rich phase is formed because the metal structure is fine as described above. Since the powder is made finer, the rare earth element is rapidly oxidized when it comes into contact with the atmosphere, and heat and ignition are likely to occur. Even if heat generation and ignition can be suppressed, the final rare earth magnet It is known that a high oxygen content results in poor magnetic properties. In the production of rare earth magnets from rare earth magnet materials, in recent years, a method has been adopted in which an alloy of rare earth magnet materials is pulverized and a powder molded product obtained by powder molding is sintered. Efforts are being made to produce an excellent magnetic property by reducing the oxygen content of the rare earth magnet as much as possible by carrying out it in an inert gas atmosphere.

  However, even with the above method, there is a problem that productivity is lowered when the alloy powder whose temperature has been increased by hydrogen pulverization is cooled in a hydrogen furnace to a room temperature where oxidation does not easily occur. In order to avoid the decrease in productivity, Patent Document 1 employs a method of cooling by a separately provided rotary cooler, but the oxygen concentration of the manufactured magnet is assumed to be 4500 ppm. It has not been reduced.

A possible reason for this oxygen concentration is that, in the method of Patent Document 1, each process is performed in an inert gas atmosphere, and as shown in FIG. Batch processing using a material transport device 130 that includes a door 131 and is capable of unloading and unloading the material alloy transport rack 140 is performed to carry in the raw material alloy and to carry out the hydrogen crushed alloy from the hydrogen furnace 110 to the rotary cooler. A take-out chamber 120 is provided between the raw material transfer device 130 and the hydrogen furnace 110 and is connected to the take-out port 116 of the hydrogen furnace 110 and includes an argon gas introduction pipe 121 and a door 122 that slides in the vertical direction. However, due to the batch processing of the raw material alloy, the hydrogen-pulverized alloy is not completely shielded from the atmosphere, and water Since the furnace 110 is exposed to the atmosphere, moisture in the atmosphere that is condensed on the cooling gas piping provided in the hydrogen furnace 110, and in the atmosphere that is adsorbed by a graphite heater provided in the hydrogen furnace 110. It is considered that the vaporization of water during hydrogen pulverization is a factor that increases the oxygen content.
JP 2000-303107 A

  This invention is made in view of the above-mentioned problem, and makes it a subject to provide the hydrogen grinding | pulverization apparatus of the rare earth-type magnet material with which oxygen concentration is fully reduced and high productivity.

It is as shown below when describing the solution to the above issues.

The hydrogen pulverization apparatus of the present invention is a hydrogen pulverization apparatus for hydrogen pulverizing a rare earth magnet material, and at least a hydrogen storage chamber, a dehydrogenation chamber, a cooling chamber, and a recovery chamber are connected in order from the upstream side, Each of the chambers can be independently evacuated and introduced with an inert gas introduction pipe and an evacuation pipe and an inert gas introduction pipe, respectively. A coarsely pulverized product of flaky quenched alloy is carried into the hydrogen storage chamber, where hydrogen is stored, and hydrogen is pulverized by being dehydrogenated in the dehydrogenation chamber, and reaches the recovery chamber via the cooling chamber, The rare earth-based magnet material pulverized with hydrogen is discharged from the transport container into the recovery chamber and recovered into a recovery container connected to the recovery outlet of the recovery chamber, and the transport container is transported from the recovery chamber. It is configured to be, and those which are configured so as not to contact with the atmosphere during the period until the rare earth magnet material is collected in the collection container is carried into the hydrogen storage chamber.

  Such a hydrogen pulverization apparatus roughly pulverizes a flaky quenching alloy of a rare earth magnet material manufactured in an inert gas atmosphere, and then hydrogen pulverizes the resulting hydrogen pulverized rare earth magnet material. Since the process up to this step is performed in an inert gas atmosphere, oxidation is extremely suppressed even when the rare earth magnet material is in a high-temperature powder state, and then transferred to the next process in an inert gas atmosphere. By doing so, it is possible to produce a rare earth magnet having a remarkably small oxygen content.

The hydrogen pulverizer includes a plurality of box-shaped cylindrical containers that are transported as a single unit in parallel with a gap in a direction perpendicular to the transport direction, and the plurality of box-shaped cylindrical containers are placed on a tray. Each of the box-shaped cylindrical containers is individually mounted and transported, and a bottom plate is attached to a discharge port formed by squeezing a lower end portion so that the bottom plate can be opened and closed by a hinge on one side thereof. The discharge port is closed by being supported by the crosspiece of the tray, and the box-shaped cylindrical container is sequentially lifted upward for each piece, so that the bottom plate loses the support by the crosspiece and opens.

  In such a hydrogen pulverizer, since the transport containers are a plurality of box-shaped cylindrical containers arranged in parallel at intervals, the contained hydrogen-pulverized rare earth magnet material is effectively cooled. be able to. In addition, the box-shaped cylindrical container can be opened and closed without directly operating the bottom plate attached to the discharge port. By opening the box-shaped cylindrical container to each individual in the collection chamber, the bottom plate is opened and discharged from the discharge port. The hydrogen-pulverized rare earth based magnet material can be recovered.

In the hydrogen pulverizing apparatus, the tray is formed in a ridge shape at the upper end of the crosspiece.
Such a hydrogen pulverization apparatus prevents the rare earth magnet material crushed by hydrogen discharged when the box-shaped cylindrical container mounted on the crosspiece of the tray is lifted from remaining on the crosspiece.

In the hydrogen pulverizer, each of the box-shaped cylindrical containers has a surface on the upstream side by the cold air of the inert gas flowing between the plurality of box-shaped cylindrical containers and the upstream end and the downstream end in the cooling chamber. It is cooled from both the downstream surface and the downstream surface.
Such a hydrogen pulverization apparatus can effectively cool the accommodated hydrogen-pulverized rare earth magnet material.

In the hydrogen pulverization apparatus, the box-shaped cylindrical container has a beam passed between the upstream surface and the downstream surface.
Such a hydrogen pulverizer can prevent the box-shaped cylindrical container from being deformed by being heated and cooled.

In the hydrogen pulverization apparatus, the recovery chamber is formed with a recovery outlet for the rare earth-based magnet material crushed by hydrogen at the lower end of a funnel-shaped portion formed on the bottom side thereof. A first on-off valve capable of airtight sealing is provided, and the box-like shape is connected to the first on-off valve and connected to the vacuum exhaust system and the inert gas introduction system. A plurality of recovery containers having a volume equivalent to that of the cylindrical container are alternately connected by a second on-off valve capable of being hermetically sealed provided at each opening.
Such a hydrogen pulverization apparatus makes it possible to collect the hydrogen-pulverized rare earth-based magnet material discharged for each box-shaped cylindrical container into a collection container in an inert gas atmosphere.

According to the hydrogen treatment apparatus of the present invention , the coarsely pulverized product of the flaky quenched alloy of the rare earth-based magnet material is carried into the hydrogen storage chamber of the hydrogen pulverizer and then hydrogen-pulverized into the recovery container connected to the recovery chamber. Since the magnet is cut off from the atmosphere until the magnet material is recovered, the rare earth magnet material can be transported to the next process with extremely low oxidation even when it is in a high temperature powder state. Makes it possible to produce magnets with extremely low magnetic properties.

According to the above hydrogen treatment apparatus, since the container has a plurality of box-shaped cylindrical containers arranged in parallel at intervals, and the surface area of the container is increased, the hydrogen-pulverized rare earth magnet material contained therein The cooling rate can be increased. In addition, a plurality of box-shaped cylindrical containers are independently placed on the tray and transported, and even in the recovery chamber, the bottom plate closing the discharge port at the lower end can be opened by lifting the box-shaped cylindrical containers to each individual. Therefore, the housed hydrogen-pulverized rare earth magnet material can be easily discharged and collected.

According to the hydrotreater, when discharging the rare earth magnet materials are hydrogen ground lift the box-like cylindrical container placed on the tray crosspieces, the rare earth magnet materials are hydrogen pulverization upper end Since it is discharged without remaining on the ridge-shaped crosspiece, it is possible to prevent the tray from being carried out of the collection chamber together with the box-shaped cylindrical container with the rare earth magnet material left on the crosspiece.

According to the hydrotreater, the box-shaped cylindrical containers each individual is cooled from both the upstream surface and the downstream surface, a rare earth-based magnet material that are hydrogen pulverization is accommodated effectively It is cooled and shortens the time required for cooling.

According to the hydrotreater, the beam between the upstream face and the downstream face of the box-like cylindrical container is provided, and deformed by the box-shaped tubular container is heated and cooled This prevents the outlet from being fully closed by the bottom plate.

According to the hydrotreater, hermetically sealable first on-off valve to the recovery discharge port formed at the lower end of the funnel-shaped portion of the bottom side of the collection chamber is attached, with respect to the first on-off valve A plurality of recovery containers that can be connected to the evacuation system and the inert gas introduction system and have the same volume as the box-shaped cylindrical container are sequentially provided by the hermetically sealable second on-off valves provided in the openings. Because it is connected, the hydrogen-pulverized rare earth magnet material is recovered in an inert gas atmosphere, the recovery container is filled with the hydrogen-pulverized rare earth magnet material and the space is filled with inert gas Then, it can be conveyed to the next process.

  The hydrogen pulverization apparatus of the present invention performs “hydrogen pulverization / recovery” in the method of manufacturing a rare earth magnet performed in steps as shown in FIG.

  As will be described in detail later, the hydrogen pulverization apparatus of the present invention is a multi-line connected in-line in order to efficiently perform hydrogen pulverization and to prevent the rare earth magnet material from coming into contact with the atmosphere during transportation. The chamber configuration is typically a three-chamber configuration including a hydrogen storage chamber, a dehydrogenation chamber, a cooling chamber, and a recovery chamber in order from the upstream side. When a rare earth magnet material is occluded in a hydrogen storage chamber and is dehydrogenated by heating to a temperature of 500 to 600 ° C. under vacuum in a dehydrogenation chamber, the rare earth magnet material is hydrogen crushed during dehydrogenation. .

  In the hydrogen pulverization apparatus described above, the cooling that requires time is effectively advanced in the cooling chamber, and the rare earth magnet material that has been pulverized in the recovery chamber is not transferred from the transfer container to the recovery container attached to the recovery chamber. In order to transfer and collect efficiently under an active gas atmosphere, the transport container is a flat cylindrical container arranged in parallel at intervals in a direction perpendicular to the transport direction, that is, a plurality of box-shaped cylinders A transport container having a divided structure including a mold container is used. Note that the volume of the box-shaped cylindrical container is substantially the same as the volume of the recovery container. The plurality of box-shaped cylindrical containers are each independently placed on a tray, and are conveyed as a unit by the tray. In addition, the tray has a continuous lattice shape, and the box-shaped cylindrical container is placed on a bar portion of the continuous lattice of the tray. The crosspieces of the lattice are formed with ridges at the top.

  Therefore, each of the box-shaped cylindrical containers is, for example, a frame made of a pipe fixed to the tray so that the box-shaped cylindrical container does not fall over or be displaced on the tray during conveyance in the hydrogen pulverizer. The surroundings are supported. Of course, the frame may be a flat plate or a prism. As will be described later, the box-shaped cylindrical container is operated to lift the whole upward to open the bottom plate closing the discharge port at the lower end, but in order to make the movement of the box-shaped cylindrical container smooth at that time A small caster that works as a roller may be attached to the frame side, and the periphery of the box-shaped cylindrical container may be supported via the caster.

  Each box-shaped cylindrical container has an open upper surface, the lower end is squeezed and a discharge port is formed horizontally at the lower end, and a bottom plate is attached to the discharge port via a hinge attached to the box-shaped cylindrical container The bottom plate is supported on the lower side by a tray bar and closes the outlet of the box-shaped cylindrical container. Then, by lifting the entire box-shaped cylindrical container upward, the bottom plate loses support by the crosspieces and opens the discharge port.

  By configuring the transport container with a plurality of box-shaped cylindrical containers as described above, in the cooling chamber, each box-shaped cylinder is configured such that the cool air of the inert gas flows between the plurality of box-shaped cylindrical containers. By cooling the mold vessel from both sides, the accommodated rare earth-based magnet material in the hydrogen crushed state can be effectively cooled. In addition, it is possible to provide a beam between the upstream surface and the downstream surface of the box-shaped cylindrical container to form a heat transfer plate, and the heat transfer plate is used for lifting the box-shaped cylindrical container. It can also be used as a gripping part and as a strength member for preventing deformation of the box-shaped cylindrical container. Further, the box-shaped cylindrical container is usually made of stainless steel, but it may be made of copper or a metal having a thermal conductivity equal to or higher than copper to improve the cooling performance.

  The recovery chamber has a funnel-shaped portion formed on the bottom surface side, a recovery outlet for recovering the rare earth magnet material crushed by hydrogen at the lower end of the funnel-shaped portion, and a first on-off valve that can be hermetically sealed Closed with. And in order to collect | recover the rare earth type | system | group magnetic material pulverized by hydrogen to the collection | recovery container in inert gas atmosphere, it is required to replace the air | atmosphere in a collection | recovery container with inert gas. Therefore, the recovery container is connected to the recovery chamber by connecting a second open / close valve capable of hermetically sealing the recovery container itself to a flange of a short pipe connected to the first open / close valve of the recovery chamber. A replacement on-off valve that can be connected to both the vacuum exhaust pipe and the inert gas introduction pipe and can be hermetically sealed is attached to the short pipe.

  2 and 3 are side views schematically showing the configuration of the hydrogen pulverizing apparatus 10 according to an embodiment of the present invention. That is, the right collection chamber 51 broken in FIG. 2 is shown enlarged in FIG. 2 and 3, the hydrogen pulverization apparatus 10 is an in-line type apparatus in which four chambers of a hydrogen storage chamber 21, a dehydrogenation chamber 31, a cooling chamber 41, and a recovery chamber 51 are arranged in a straight line. The transport container 70 is carried into the hydrogen storage chamber 21 and discharged from the collection chamber 51. The figure shows a situation where the rare earth-based magnet material accommodated in the transfer container 70 is processed for a predetermined time in each chamber. And the carrying-in side opening and carrying-out side opening of the magnitude | size which can pass the tray 61 which mounted the conveyance container 70 are provided, and the door which can be airtightly sealed is provided, respectively.

  Each chamber is provided with a vacuum exhaust pipe 81 and an argon (Ar) gas introduction pipe 82 as an inert gas, and each chamber can independently introduce vacuum exhaust and argon gas. The evacuation pipe 81 is used, for example, for evacuating the atmosphere or other gas existing before introducing argon gas into the recovery chamber 51, and before introducing hydrogen gas into the hydrogen storage chamber 21, It is used for evacuating argon gas and other gases present in the storage chamber 21.

The transfer space 29 that opens and closes between the hydrogen storage chamber 21 and the dehydrogenation chamber 31 will be described. The shielding door 23 that hermetically seals the carry-out side opening of the hydrogen storage chamber 21 and the downstream dehydrogenation chamber. A shielding door 32 that hermetically seals the insertion side opening of 31 is attached to a support frame 68 via a parallel link 67, and an opening / closing mechanism 66 a that moves the support frame 68 up and down by a cylinder 69. Is provided. Then, the support frame 68 is lowered, the shielding door 23 faces the carry-out opening of the hydrogen storage chamber 21, and the shielding door 32 faces the insertion opening of the dehydrogenation chamber 31. Although not shown, lowering is prevented by a stopper. When the support frame 68 is further lowered in this state, the shielding door 23 is pressed against the hydrogen storage chamber 21 and the shielding door 32 is pressed against the dehydrogenation chamber 31 to be sealed at the same time. On the contrary, when the support frame 68 is raised, the shielding door 23 and the shielding door 32 open and move upward together with the support frame 68. The same applies to the transfer spaces 19, 39, and 49. And the entrance to the hydrogen storage chamber 21 is an elevating mechanism 65a. Thus, the carry-in door 12 is raised and lowered to be opened and closed, and similarly, the carry-out port from the collection chamber 51 is an elevator mechanism 65b. As a result, the carry-out door 53 is raised and lowered.

  Further, on the bottom surface side in the hydrogen pulverizer 10, transport rollers 60 are arranged at almost equal intervals from the upstream side to the downstream side, and are rotated by driving means (not shown). Accordingly, the tray 61 on the transport roller 60 is transported together with the transport container 70 in the order of the upstream hydrogen storage chamber 21, the dehydrogenation chamber 31, the cooling chamber 41, and the recovery chamber 51 in accordance with a predetermined transport program. The transport container 70 shown in FIG. 2 is actually composed of five box-shaped cylindrical containers 71 that are transported integrally as shown in FIG. 3, which will be described later. In addition, when the tray 61 together with the transport container 70 is heated, for example, in the dehydrogenation chamber 31 and the transport roller 60 is stopped, the transport roller 60 may be heated unevenly and may be deformed. The tray 61 may be moved by periodically rotating the transport roller 60 forward and backward.

The hydrogen storage chamber 21 is provided with a hydrogen (H ₂ ) gas introduction pipe 83 in addition to the vacuum exhaust pipe 81 and the argon gas introduction pipe 82. In the hydrogen storage chamber 21, the hydrogen gas is stored in the coarsely pulverized rare earth magnet material in the transported container 70, using pressurized hydrogen gas of 200 to 500 kPa. Since the hydrogen storage is an exothermic reaction, the chamber wall of the hydrogen storage chamber 21 is not shown, but can be cooled with water.

  In the dehydrogenation chamber 31, a heat reflecting plate 35 is attached to the inner surface side of the heat insulating wall 34, and an electric heater 36 as a heating source is provided on the entire surface of the heat reflecting plate 35. The rare earth magnet material that occludes the transferred hydrogen gas is heated to a temperature of 500 to 600 ° C. under vacuum to dehydrogenate the rare earth magnet material at the time of dehydrogenation. The rare earth magnet material pulverized with hydrogen has a large surface area and is at a high temperature, so that the rare earth element is very easily oxidized. The rare earth magnet material pulverized with hydrogen is transferred to the cooling chamber 41.

  In the cooling chamber 41, a fan 45 is rotated by a motor 44, an argon gas is cooled by a heat exchanger (cooler) 46 installed therein, and a cold air of the argon gas is circulated to circulate a hydrogen-rare earth-based magnet. The material is cooled together with the transfer container 70. At this time, the cooling rate can be improved by using pressurized argon gas. The heat exchanger 44 may be installed outside the cooling chamber 41 and connected to the cooling chamber 41 with a pipe to circulate cool air of argon gas. The rare earth-based magnet material that has been crushed and cooled by hydrogen is conveyed to the recovery chamber 51.

  As shown in FIG. 3, the recovery chamber 51 has a funnel-shaped portion 54 formed on the bottom side, and a recovery outlet 55 is provided at the lower end of the funnel-shaped portion 54. The recovery outlet 55 is an airtight seal. It is closed by a possible first on-off valve 56. A short pipe 57 is attached to the first on-off valve 56, and a collection container 91 is exchangeably connected to the short pipe 57 by a second on-off valve 97 that can be hermetically sealed. The short pipe 57 is provided with a third on-off valve 58 capable of airtight sealing that can be connected to either the vacuum exhaust system or the argon gas introduction system. That is, the recovery container 91 and the short pipe are closed by the vacuum exhaust system connected to the third open / close valve 58 of the short pipe 57 with the first open / close valve 56 of the recovery chamber 51 closed and the second open / close valve 97 of the recovery container 91 opened. In addition to being able to be in a vacuum state, the inside of the collection container 91 and the short tube 57 is filled with argon gas by connecting an argon gas introduction system to the third on-off valve 58 after evacuating. It is also possible. That is, the inside of the collection container 91 can be in a vacuum or argon gas atmosphere independently of the collection chamber 51.

  As shown in the perspective view of FIG. 4, the transport container 70 includes a plurality of thin box-shaped cylindrical containers 71 (five in the embodiment) arranged in parallel in a direction perpendicular to the transport direction. That is, that is, a divided structure composed of a box-shaped cylindrical container 71. This is a structure along the purpose of increasing the surface area of the container and improving the cooling rate. Each box-shaped cylindrical container 71 has an upper surface as an opening 75 and a lower end portion is squeezed to form a discharge port 72 horizontally. As shown in FIG. 4, a pipe-shaped reinforcing member 76 is attached so as to penetrate the central portion of the upper part of each box-shaped cylindrical container 71 in the transport direction. This prevents deformation of the box-shaped cylindrical container 71 that is heated and cooled while being transported in the hydrogen pulverizer 10, and increases the heat transfer area and creates a gas flow in the transport direction and cools it. It improves speed. As will be described later, the discharge port 72 of the box-shaped cylindrical container 71 is closed by the bottom plate 74, but when the box-shaped cylindrical container 71 is deformed, the contact between the discharge port 72 and the bottom plate 74 becomes uneven and accommodates. This is to prevent the rare earth magnet material from flowing out and prevent this.

  Then, the five box-shaped cylindrical containers 71 are independently placed on the tray 61 and conveyed as a unit. 5 is a diagram showing the relationship between the tray 61 and the box-shaped cylindrical container 71, FIG. 5-A is a plan view, and FIG. 5-B is a partially broken side view. That is, the tray 61 is a continuous grid-like tray 61 having five crosspieces 64 formed in a direction perpendicular to the conveying direction immediately below the five box-shaped cylindrical containers 71. The box-shaped cylindrical containers 71 are placed on the five crosspieces 64 of the tray 61, respectively. The other parts of FIG. 5 will be described later.

  FIG. 6 is an enlarged cross-sectional view of the lower end portion of the box-shaped cylindrical container 71 and the tray 61 on which the box-shaped cylindrical container 71 is placed, and the bottom plate 74 that closes the discharge port 72 of the box-shaped cylindrical container 71 is shown. As shown in FIG. 6A, a bottom plate 74 is attached to the discharge port 72 by a hinge 73 fixed to the lower end portion of the box-shaped cylindrical container 71. Since the lower surface is supported by the portion 64 and the discharge port 72 of the box-shaped cylindrical container 71 is closed, the rare earth-based magnet material F pulverized with hydrogen is accommodated therein. With reference to FIG. 6B, the bottom plate 74 is supported by the crosspieces 64 by lifting the individual box-shaped cylindrical containers 71 upward by a distance that allows the bottom plate 74 to be suspended by a lifting mechanism (not shown). The discharge port 72 is opened by the weight of the lost and hydrogen-pulverized rare earth magnet material F, and the hydrogen-ground rare earth magnet material F is discharged.

  As described above, the five box-shaped cylindrical containers 71 are placed on the crosspieces 64 of the tray 61 and can be lifted individually. In order to prevent the box-shaped cylindrical container 71 from falling or being displaced on the tray 61, referring to FIG. 5, each of the box-shaped cylindrical containers 71 is formed by a frame 63 made of pipes fixed to the tray 61. The surroundings are supported. Of course, the frame 63 may be a flat plate.

  The hydrogen pulverizing apparatus 10 of the embodiment is configured as described above, and the operation thereof will be described next. Referring to FIG. 2, first, the carry-in door 12 of the hydrogen storage chamber 21 is opened, and a rare earth magnet material obtained by roughly pulverizing a flaky quenching alloy of a rare earth magnet material in an argon gas atmosphere is placed on the tray 61. It is housed in the five box-shaped cylindrical containers 71 placed therein, is carried into the hydrogen storage chamber 21 by the rotation of the transport roller 60, and the carry-in door 12 is closed. Then, the hydrogen storage chamber 21 is evacuated, hydrogen gas is introduced from the hydrogen gas introduction pipe 83 and a pressure of 300 to 500 kPa is applied, and hydrogen is stored in the coarsely pulverized rare earth magnet material in the transfer container 70. Let When a predetermined time elapses, the introduction of hydrogen gas is stopped, and the existing hydrogen gas is exhausted through the vacuum exhaust pipe 82.

  When the evacuation is completed, the shielding door 23 and the shielding door 32 of the carry-in space 29 between the evacuated dehydrogenation chamber 31 and the transfer container 70 are conveyed into the dehydrogenation chamber 31 together with the tray 61. Thus, the shielding door 23 and the shielding door 32 are closed. Then, the vacuum exhaust pipe 82 evacuates to a pressure of about 1 Pa, and the coarsely pulverized rare earth magnet material storing the hydrogen is heated to a temperature of 500 to 600 ° C. by the electric heater 36 to be dehydrogenated.

  Next, the shielding door 33 and the shielding door 42 between the cooling chamber 41 and the pressurized argon gas atmosphere of about 200 kPa are opened, and the transfer container 70 is transferred into the cooling chamber 41 together with the tray 61, and the shielding door is opened. 23, the shielding door 32 is closed. Then, the fan 44 is rotated by the motor 44, the argon gas is cooled by the heat exchanger 45, and the circulation flow of the cold air is parallel to the five box-shaped cylindrical containers 71 which are the transfer containers 70, that is, in FIG. As indicated by the white arrows, argon gas cold air is allowed to flow between the respective box-shaped cylindrical containers 71 and the entire upstream and downstream sides to cool each box-shaped cylindrical container 71 from both sides.

  When the predetermined time has elapsed and the cooling is completed, the shielding door 43 and the shielding door 52 of the carry-in space 49 between the collection chamber 51 and the argon gas atmosphere are opened, and the transport container 70 is collected together with the tray 61. With reference to a predetermined position in the chamber 51, that is, with reference to FIG. 3, the leading box-shaped cylindrical container 71 a is transported and stopped until it reaches a position immediately above the collection / discharge port 53, and the shielding door 43 and the shielding door 52 are Closed. Then, by lifting the box-shaped cylindrical container 71a by a lifting mechanism (not shown), referring to FIG. 6, the bottom plate 74 is opened and the hydrogen-pulverized rare earth magnet material F accommodated therein is discharged downward. . Then, the rare earth-based magnet material F pulverized with hydrogen is recovered into a recovery container 91a connected to the bottom of the recovery chamber 51 as shown in FIG. In this case, the volume of the box-shaped cylindrical container 71a and the volume of the collection container 91a are substantially equal.

  Subsequently, the tray 61 is moved and stopped until the box-shaped cylindrical container 71b reaches a position immediately above the recovery discharge port 53, and the recovery container 91a is removed and the recovery container 91b is attached below the box-shaped cylindrical container. The hydrogen-pulverized rare earth based magnet material F in 71b is recovered into the recovery container 91b. The process is repeated until the rare earth-based magnet material F crushed by hydrogen in the box-shaped cylindrical container 71e is recovered in the recovery container 91e. Then, the collection containers 91a to 91e on the tray 61 that are empty at that stage are unloaded by opening the unloading door 53 of the collection chamber 51, and returned to a place for storing the coarsely pulverized rare earth magnet material. Since the collection chamber 51 is exposed to the atmosphere when the tray 61 and the five box-shaped cylindrical containers 71 are carried out, the collection chamber 51 is evacuated after the carry-out door 53 is closed, and then argon gas is introduced. The

  In order to recover the rare earth magnet material F crushed by hydrogen from the recovery chamber 51 to the recovery container 91 in an argon gas atmosphere, the following on-off valve is used when the recovery container 91 is attached to the recovery chamber 51. Is performed. That is, in a state where the first opening / closing valve 56 of the recovery chamber 51 is closed, the second opening / closing valve 97 of the recovery container 91 is opened and connected to the short pipe 57 attached to the first opening / closing valve 56, and then the short pipe A vacuum exhaust system is connected to the third open / close valve 58 of 57 to evacuate the short tube 57 and the recovery container 91. Next, an argon gas introduction system is connected to the third on-off valve 58 to fill the short tube 57 and the collection container 91 with argon gas. In such a state, by opening the first on-off valve 56 of the recovery chamber 51, the recovery chamber 51 and the recovery container 91 are connected without being exposed to the atmosphere, and hydrogen discharged from the recovery chamber 51 The pulverized rare earth magnet material F is guaranteed to be recovered in a state of being completely cut off from the atmosphere under an argon gas atmosphere.

  The hydrogen-pulverized rare earth-based magnet material F accommodated in the recovery container 91 includes a subsequent lubricant mixing step under an argon gas atmosphere, a fine pulverization step with a jet mill under an argon gas atmosphere, and a powder in a magnetic field under an argon gas atmosphere. A rare earth magnet is manufactured through a molding process, a sintering process of a powder molded product in an argon gas atmosphere, an aging treatment process in the atmosphere, and other surface treatments, inspections, and magnetization treatments. And the oxygen concentration of the rare earth magnets manufactured using the hydrogen pulverizer of the present invention could be reduced to 300 to 500 ppm.

  Among them, the hydrogen pulverization apparatus 10 of the embodiment has a four-chamber configuration of a hydrogen storage chamber 21, a dehydrogenation chamber 31, a cooling chamber 41, and a recovery chamber 51, and each chamber that processes the transfer container 70 that stores the rare earth magnet material. When a predetermined time elapses, the material is transferred to the next chamber, and the rare earth magnet material is continuously hydrogen crushed. Therefore, hydrogen pulverization is efficiently performed to improve productivity, and in the hydrogen pulverization process, the rare earth The system magnet material is completely cut off from the atmosphere, and the effect that oxidation can be completely suppressed is obtained.

  The hydrogen pulverizing apparatus of the embodiment is configured and operates as described above. However, the hydrogen pulverizing apparatus of the present invention is not limited to this, and various modifications can be made based on the technical idea of the present invention. It is.

  For example, in this embodiment, the hydrogen storage chamber 21, the dehydrogenation chamber 31, the cooling chamber 41, and the recovery chamber 51 are connected to the hydrogen crushing apparatus 10 in a row. However, when cooling takes time, only the cooling chamber 41 is used. For example, may be arranged in two rows in parallel.

  Further, in this embodiment, in order to evacuate the recovery container 91 connected to the recovery chamber 51 and introduce the archon gas, a short opening / closing valve 58 that can be connected to the vacuum exhaust system and the argon gas introduction system is provided. Although the pipe 57 is interposed, if the on-off valve corresponding to the third on-off valve can be attached to the recovery container 91, the short pipe 57 is omitted, and the second on-off valve 56 of the recovery chamber 51 is connected to the second on-off valve 56 of the recovery chamber 51. It becomes possible to connect the on-off valve 97 directly.

It is a figure which shows the manufacturing step of a rare earth magnet. FIG. 4 is a side view schematically showing the hydrogen pulverizing apparatus of the embodiment together with FIG. 3. FIG. 3 is an enlarged side view of the recovery chamber broken in FIG. 2. It is a perspective view of the five box-shaped cylindrical containers in an Example. It is a figure which shows the tray of an Example. It is sectional drawing which shows a lower end part and a tray in the box-shaped cylindrical container of an Example. It is a figure which shows the hydrogen furnace of patent document 3, a raw material conveyance apparatus, and the taking-out chamber provided between them.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 ... Hydrogen grinding | pulverization apparatus, 21 ... Hydrogen storage chamber, 31 ... Dehydrogenation chamber, 25 ... Heat reflection board,
26 ... Electric heater, 35 ... Heat reflector, 36 ... Electric heater, 41 ... Cooling chamber,
51 ... Recovery chamber, 55 ... Recovery outlet, 57 ... Short pipe, 60 ... Conveying roller,
61 ... tray, 64 ... crosspiece, 70 ... transport container, 71 ... box-shaped cylindrical container,
72 ... discharge port, 81 ... vacuum exhaust pipe, 82 ... argon gas introduction pipe,
83 ... Hydrogen gas introduction pipe, 91 ... Recovery container

Claims (5)

A hydrogen crushing apparatus for crushing rare earth magnet material with hydrogen, and in order from the upstream side, at least a hydrogen storage chamber, a dehydrogenation chamber, a cooling chamber, and a recovery chamber are connected, and each chamber is attached to each of them. The vacuum exhaust pipe and the inert gas introduction pipe enable independent vacuum exhaust and inert gas introduction.
A coarsely pulverized product of a flaky quenched alloy of the rare earth-based magnet material contained in a transfer container is carried into the hydrogen storage chamber to store hydrogen, and is hydrogen crushed by being dehydrogenated in the dehydrogenation chamber, The rare earth magnet material that has been pulverized with hydrogen reaches the recovery chamber via a cooling chamber, is discharged from the transfer container into the recovery chamber, and is recovered into a recovery container connected to the recovery outlet of the recovery chamber. The transport container is configured to be unloaded from the collection chamber,
And it is constituted so that it may not come into contact with the atmosphere until the rare earth-based magnet material is carried into the hydrogen storage chamber and recovered in the recovery container ,
The recovery chamber is formed with a recovery outlet of the rare earth magnet material crushed by hydrogen at the lower end of a funnel-shaped portion formed on the bottom side thereof, and the recovery outlet can be hermetically sealed. An opening / closing valve is provided, and for the short pipe attached to the first opening / closing valve and connectable to the vacuum exhaust system and the inert gas introduction system, the recovery container is provided at the opening. A hydrogen pulverizing apparatus, wherein the hydrogen pulverizing apparatus is connected through a second on-off valve capable of being hermetically sealed . The transport container is composed of a plurality of box-shaped cylindrical containers that are transported as a single unit in parallel with a gap in a direction perpendicular to the transport direction, and the plurality of box-shaped cylindrical containers are individually placed on a tray. Each box-shaped cylindrical container has a bottom plate attached to a discharge port formed by squeezing the lower end portion thereof so that the bottom plate can be opened and closed by a hinge on one side thereof, and the bottom plate is supported by a frame portion of the tray. The closed outlet is closed, and the box-shaped cylindrical containers are sequentially lifted upwards one by one, whereby the bottom plate loses support by the crosspiece and opens the outlet. 2. The hydrogen pulverizing apparatus according to 1. The hydrogen pulverizer according to claim 2, wherein the tray is formed in a ridge shape at an upper end of the crosspiece. In the cooling chamber, the upstream side surface and the downstream side surface of the box-shaped cylindrical container are cooled by the inert gas flowing between the plurality of box-shaped cylindrical containers and the upstream end and the downstream end. The hydrogen pulverizer according to claim 2, wherein the hydrogen pulverizer is cooled from both sides. The hydrogen crushing apparatus according to claim 2, wherein the box-shaped cylindrical container has a beam passed between the upstream surface and the downstream surface.

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