JP2001044013A - Reproducing method for rare earth/iron/nitride magnet material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a regenerating method for a rare earth/iron/nitride magnet material which is low cost and provides magnetic characteristics and mechanical strength equivalent to a rare earth/iron/nitride bonded magnet manufactured of a conventional compound of new material. SOLUTION: A kneaded material or mold where rare earth/iron/nitride magnet material powder is bound with polymer compound is heated in an atmosphere, comprising hydrogen (except for nitrogen) from a room temperature equal to or higher than 600 and lower than 1,000 deg.C so that such rare earth-iron magnetic material as polymer compound and nitrogen are substantially removed from the kneaded material or mold is provided. At least one kind among Ca, Mg, CaH2, MgH2 is blended and mixed by 0.5-2 times of stoichiometric value required for the reduction of the rare earth-iron nitride magnetic material, and then heated in an inert gas atmosphere for reduction, and subsequently nitrided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for regenerating a rare earth-iron-nitrogen based magnetic material.

[0002]

2. Description of the Related Art In recent years, so-called bonded magnets formed by mixing a permanent magnet powder with a polymer compound such as a thermoplastic resin, a thermosetting resin or rubber and forming the mixture into a desired shape have been widely used mainly in the field of the electronic equipment industry. It's being used. Among the bonded magnets, rare-earth bonded magnets are used for spindle motors of hard disk drives and the like because of their higher magnetic properties as compared with ferrite bonded magnets and sintered ferrite magnets. Of the rare-earth bonded magnets, especially rare-earth iron
Nitrogen-based bonded magnets have high magnetic properties and good corrosion resistance, and demand is expected to increase in the motor field in the future. However, as a problem on the cost performance of the rare earth-iron-nitrogen based magnet, there is no established technology for reusing the rare earth-iron-nitrogen based magnet material which is more expensive than the ferrite magnet, and the cost of the magnet material is low. It is difficult to reduce. For example, when a thermoplastic resin and a rare earth-iron-nitrogen magnet powder are blended in a predetermined ratio, a kneaded product (compound) is prepared, and a bonded magnet is formed by an injection molding method. Runner
And other molding by-products. In the case of the extrusion molding method, scraps of the extruded body are generated. Further, scraps of the bonded magnet such as defective magnetic force, defective dimensions, and defective molding occur. Conventionally, for the reuse of molding by-products such as spools and runners, and scraps of bonded magnets, etc., they are mechanically crushed (magnetized products are mechanically crushed after demagnetization) (recycled compounds). After mixing and mixing at most about 10% by weight in an unused new material compound that has not been subjected to molding,
It depends on the method used for molding. The reason that the compounding ratio of the recycled compound is limited to 10% by weight or less is that the binder (resin) of the compound and the rare-earth-iron-nitrogen-based magnetic particles of the filler are deteriorated by repeated molding, and the mechanical strength and the magnetic properties of the molded product are deteriorated. This is because the characteristics are deteriorated. Next, it is difficult to grind the scrap of the bonded magnet using a thermosetting resin or a rubber material as a binder, molding by-products, and the like, and to repeatedly subject the molding to a molding as a regeneration compound because the binder of the regeneration compound has a crosslinked structure. .

[0003] In view of the above-mentioned conventional problems in industrial production,
It is an object of the present invention to regenerate a rare earth-iron-nitrogen based magnet material which is inexpensive and has the same magnetic properties and mechanical strength as a rare earth-iron-nitrogen based bonded magnet manufactured using a conventional new material compound. Is to provide a way.

[0004]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a kneaded product or molded product obtained by binding a rare earth-iron-nitrogen based magnetic material powder with a polymer compound to hydrogen or hydrogen and an inert gas. In a non-oxidizing atmosphere (excluding nitrogen) substantially consisting of
By heating at a rate of 0.1 to 5 ° C./min to a temperature of less than or less, a rare earth-iron-based magnetic material in which a polymer compound and nitrogen have been substantially removed from the kneaded product or molded product is obtained. rare earth - 0.5-2 times that of Ca stoichiometric amount required for the reduction of the iron-based magnetic material, _Mg, with CaH 2, MgH ₂ formulation was mixed after an inert gas atmosphere at least one 900
This is a method for regenerating a rare earth-iron-nitrogen based magnet material that is heated to about 1200 ° C. to perform a reduction reaction and then nitrided. Denitrification and debinding by heating from room temperature to a temperature of 600 ° C. or more and less than 1000 ° C. at a rate of 0.1 to 5 ° C./min in a hydrogen atmosphere or a non-oxidizing atmosphere containing hydrogen (excluding nitrogen) Is performed. If the heating temperature is lower than 600 ° C., denitrification does not proceed, and if it is higher than 1000 ° C., oxidation becomes remarkable. If the rate of temperature rise is less than 0.1 ° C./min, the efficiency in industrial production is poor, and if it exceeds 5 ° C./min, binder removal hardly progresses. It is most efficient to remove the binder in a hydrogen stream. However, considering safety, a mixed gas of hydrogen and an inert gas (excluding nitrogen) is often used, and the lower limit of the contained hydrogen concentration is 30 mol to realize a debinding efficiency suitable for industrial production. % Or more is preferable. In order to efficiently remove the binder, it is necessary to instantaneously exhaust the decomposed gas of the polymer compound and supply the debinding gas to the interface of the undecomposed polymer compound at all times. Therefore, as a debinding furnace, hydrogen or a mixed gas of hydrogen and an inert gas (excluding nitrogen) from one end
Atmosphere control furnace in which the decomposition gas of the polymer compound is exhausted from the other end while jetting at a predetermined flow rate. In order to obtain magnetic properties and mechanical strength equivalent to those of a bonded magnet produced using a new material compound, the amount of residual carbon in the rare earth-iron magnetic material after denitrification and debinding is 0.5 wt.
% Or less, and the residual nitrogen content is preferably 0.3 wt% or less. When the reduction temperature is lower than 900 ° C., the reduction does not proceed, and when it is higher than 1200 ° C., the oxidation becomes remarkable. Reduction reaction temperature: 900 to 120
The time for heating to 0 ° C. is preferably 1 to 10 hours. If the time is less than 1 hour, the reduction reaction does not sufficiently proceed, and if the time exceeds 10 hours, the reduction reaction is saturated. A stoichiometric amount of 1.0 means a chemical reaction of a reducing agent (at least one of Ca, Mg, CaH ₂ , and MgH ₂ ) required to absorb and reduce 100% of oxygen contained in the rare-earth-iron-based magnetic material. This is the required quantity in the formula (theory). If the stoichiometric amount of the reducing agent is less than 0.5 times, the reducing effect is poor,
If it is more than twice, the residual amount of the reducing agent increases and causes the magnetic properties to decrease. The rare-earth-iron-nitrogen-based magnet material is obtained by directly nitriding and washing and drying the reduced reactant, or by washing and drying and nitriding the reduced reactant. The rare earth-iron-nitrogen based magnetic material powder regenerated according to the present invention has an average particle diameter of 10 to 300 μm and an oxygen content of 0.
4% by weight or less (more preferably 0.2% by weight or less, particularly preferably 0.1% by weight or less). If the average particle size is less than 10 μm, the density of the bonded magnet decreases and the maximum energy product (BH) max decreases. If the average particle size exceeds 300 μm, the non-uniformity of nitridation increases and the magnetic properties decrease significantly.
In anisotropic applications, the average particle size is 1 to 5 μm (more preferably 1.8 to 3.3 μm), and the oxygen content is 1.0% by weight or less (more preferably 0.6% by weight or less, particularly Preferably 0.5% by weight or less). Average particle size is 1
If it is less than μm, deterioration of magnetic properties due to oxidation becomes remarkable,
If it exceeds 5 μm, it becomes difficult to impart anisotropy.

[0005] The present invention also provides a kneaded product or a molded product obtained by binding a rare earth-iron-nitrogen-based magnetic material powder with a polymer compound to a non-oxidizing material substantially composed of hydrogen or hydrogen and an inert gas. In an atmosphere (excluding nitrogen), the polymer compound and nitrogen are removed from the kneaded product or molded product by heating from room temperature to a temperature of from 600 ° C. to less than 1000 ° C. at a rate of 0.1 to 5 ° C./min. A substantially removed rare earth-iron magnetic material is obtained, and then 0.5 to 2 times the stoichiometric amount of Ca, M required for the reduction of the rare earth-iron magnetic material.
g, CaH ₂ , and MgH ₂ are mixed and mixed, and then heated to 900 to 1200 ° C. in an inert gas atmosphere to perform a reduction reaction. Thereafter, the reaction product is washed and dried to reduce the oxygen content to 0. A rare earth-iron magnetic material powder of 4% by weight or less is obtained, and then the rare earth-iron magnetic material powder is compression-molded into pellets having a particle size of 0.5 to 100 mm. This is a method of regenerating a rare earth-iron-nitrogen based magnet material in which a master alloy is melted and then the master alloy is nitrided to produce a rare earth-iron-nitrogen based magnet material. In this regenerating method, the composition deviation prevention and the yield (the ratio of the total weight of the recovered smelted alloy to the total weight of the raw material alloy input for melting) during the smelting of the rare earth-iron-based master alloy are improved, In addition, in order to reduce the oxygen content to 0.4% by weight or less, the sieving particle size of the pellets is preferably set to 0.5 to 100 mm. If the oxygen content of the pellet exceeds 0.4% by weight, the oxygen content of the rare earth-iron base alloy melt increases, and the ratio of the R component in the melt oxidizing and transferring to the slag on the melt surface increases, and The compositional deviation of the produced rare earth-iron-based master alloy and the decrease in yield become remarkable. Furthermore, it is difficult to obtain magnetic properties that can be put to practical use when nitriding is finally performed to form a bonded magnet. If the particle size of the pellets is less than 0.5 mm, the specific surface area increases remarkably, so that a large amount of air is involved in the molten metal to increase the oxygen content of the molten metal. For this reason, the composition deviation of the melted mother alloy and the decrease in yield become remarkable. Making the particle size of the pellets more than 100 mm is not practical because a large-sized compression molding machine is required.

The rare earth-iron-nitrogen based magnetic material to be regenerated according to the present invention is R _α T _100-α-β N _β , wherein R is one or more of rare earth elements including Y and Sm T is Fe or Fe and Co), α and β are each atomic percentage and have a main component composition represented by 5 ≦ α ≦ 20 and 5 ≦ β ≦ 30. Specifically, for example, Th ₂ Zn
Sm-TN-based magnet alloy powder (T is Fe or Fe and Co) whose crystalline structure phase of any of ₁₇ type, Th ₂ Ni ₁₇ type and TbCu ₇ type is a magnetic property expressing phase (main phase) I do.
The R content is preferably 5 to 20% in atomic percentage. If the R content is less than 5%, the coercive force is significantly reduced, and if it is more than 20%, Br is significantly reduced. R is one of rare earth elements including Y
Although it is permissible to inevitably contain one or more species,
In order to obtain a coercive force (iHc) of 5 KOe or more, the Sm ratio in R should be 50% or more in atomic percentage, more preferably 90% or more, and ideally R = S excluding unavoidable impurities.
m or (Sm + La). R = Sm +
In the case of La, the magnetization can be improved by setting the La content to 0.05 to 1% with the total of the main components being 100% in atomic percentage, which is preferable. If the La content is less than 0.05%, it is difficult to improve the magnetization, and if it exceeds 1%, the square shape of the demagnetization curve deteriorates. Nitrogen is preferably in an atomic percentage of 5 to 30%. If it is less than 5%, the magnetic anisotropy will be small, and the coercive force will be greatly reduced. If it exceeds 30%, the magnetic anisotropy and saturation magnetization become small, and it is difficult to obtain a practical magnet material. Part of Sm and / or Fe is Co, Ni, T
i, Cr, Mn, Zn, Cu, Zr, Nb, Mo, T
a, W, Ru, Rh, Hf, Re, Os, and Ir may be substituted. These substitution amounts are about 10 atomic% or less based on the total amount of Sm and Fe excluding Co. If it is more than this, the saturation magnetization becomes small, which is not preferable. In the case of Co substitution, since the decrease in saturation magnetization is small, substitution can be made in the range of 0.1 to 70 atomic% with respect to the Fe amount, and the Curie temperature can be increased. Further, a part of N may be replaced with at least one of C, P, Si, S, and Al. The substitution amount is about 10 atomic% based on the N content.
It is not preferable because the coercive force is greatly reduced if the substitution amount is larger than this. Further, the regenerated rare earth-iron-nitrogen based magnet material is allowed to contain 0.01 to 10 atomic% of hydrogen.

Rare earth-iron-nitrogen regenerated according to the invention
The system magnet material is ThMn₁₂Magnetic properties
Nd expressed in atomic% as the development phase (main phase)_5-10T
_balN _{3 to 13}Having the main component composition of
You. Nd deviates from 5 to 10 at%, N deviates from 3 to 13 at%
In this case, the magnetic properties are remarkably reduced, which is not preferable.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples. (Example 1) The sum of Sm, Fe, Co, and N of the main components was 1
The main component is Sm 26.5 wt% -Fe
Spools and runners, which are by-products of injection molding of magnet powder and nylon 12 represented by 70 wt% -Co 0.5 wt% -N 3.0 wt%
0 volume%, nylon 12 is 40 volume%)
Crushed to 0 mesh under. Next, in the vicinity of a mixed gas gas flow outlet in an atmosphere control furnace of a type in which a mixed gas gas flow of (hydrogen + inert gas) is supplied from one end having a vacuum exhaust device at one end facing the vacuum exhaust device. The pulverized material of 200 mesh under was introduced into the furnace. Next, the mixture was heated at a rate of 0.5 ° C./min from room temperature to 950 ° C. while evacuating with a vacuum pump while flowing a predetermined amount of a gas mixture of (hydrogen 70 mol% + Ar 30 mol%). After reaching 950 ° C., the mixed gas was introduced to 0.8 atm.
The mixture was heated at 0 ° C. for 2 hours to remove the binder and remove nitrogen, and then cooled to room temperature to obtain a Sm—Fe—Co-based magnetic alloy. This magnetic alloy has an oxygen content of 0.75 wt% and a nitrogen content of 0.0 wt.
1 wt%, and nylon 12 was almost decomposed.
Next, 1 kg of the magnetic alloy powder was mixed with a 1.0 stoichiometric amount of Ca metal, mixed, heated at 1200 ° C. for 5 hours in an Ar atmosphere, and then cooled to room temperature. Next, the reaction product was pulverized and then charged into a washing solution to remove CaO as a reaction by-product as Ca (OH) ₂ together with the washing solution, and then removed, followed by heating and drying while evacuating with a vacuum pump. Next, after pulverization in an Ar atmosphere, the mixture was crushed at 550 ° C. for 10
The mixture was heated for a period of time to cause a solid solution of nitrogen. Thus, the main component S
Assuming that the total of m, Fe, Co, and N is 100 wt%, the main component is Sm 26.5 wt% -Fe 70 wt% -Co 0.5
A rare earth-iron-nitrogen based magnetic material powder having an average particle size of several μm represented by wt% -N3.0 wt% was obtained. The magnetic properties of this powder at room temperature were measured by a vibrating sample magnetic fluxmeter. In addition, the amount of oxygen and the amount of Ca were analyzed. Table 1 shows the results. (Comparative Example 1) A melted Sm-Fe-Co-based mother alloy was nitrided to have a main component composition of Sm 26.5 wt% -Fe 70 wt%.
-Co 0.5 wt% -N 3.0 wt%, Example 1
Magnet powder having the same particle size distribution as the regenerated magnet powder (ne)
w material). The magnetic properties of this powder, oxygen content, Ca
The amount was measured as in Example 1. Table 1 shows the results.

[0009]

[Table 1]

[0010] From Table 1, the Ca content of the regenerated rare earth-iron-nitrogen based magnet powder of Example 1 is suppressed to less than 0.2 wt%, and the rare earth-iron-iron of comparative example 1 (new material). It can be seen that it has the same oxygen content and magnetic properties as the nitrogen-based magnet powder.

Example 2 Rare Earth Regenerated in Example 1
Nylon 1 to 90 parts by weight of iron-nitrogen based magnetic material powder
After mixing 10 parts by weight of No.2, A was mixed with a pressure kneader.
A compound for injection molding was prepared by heating and kneading in an r atmosphere. Next, the compound was injected at an injection temperature of 250 ° C.
Injection pressure 1000 kgf / cm ² , orientation magnetic field strength 10 k
Injection molding was performed in a predetermined mold for injection molding under the conditions of Oe to obtain a molded body having an outer diameter of 20 mm, an inner diameter of 16 mm and a thickness of 5 mm, and having anisotropy in the thickness direction. The room-temperature magnetic properties and radial crushing strength (mechanical strength) of this molded body were measured. Table 2 shows the results
Shown in (Comparative Example 2) Except for using the magnet powder of Comparative Example 1 (new material), in the same manner as in Example 2, an outer diameter of 20 mm and an inner diameter of 16 m
A molded product having a size of mx 5 mm was obtained. The magnetic properties and radial crushing strength of this molded body were measured. Table 2 shows the results.

[0012]

[Table 2]

(Embodiment 3) The main components Sm, Fe, Ti,
Assuming that the total of B and N is 100 wt%, Sm 23 wt% −
Fe73wt% -Ti1wt% -B0.5wt% -N
A scrap of a bonded magnet composed of a magnet powder having a main component composition represented by 2.5 wt% and an epoxy resin was mechanically pulverized, and then sieved to 200 mesh under. Next, the above-mentioned 200 mesh under is provided in the vicinity of the debinding gas ejection port of the atmosphere control furnace of a type in which a degassing gas stream is supplied from the other end having a vacuum exhaust device at one end and facing the vacuum exhaust device. The crushed material was entered into the furnace. Next, as a binder removal gas (hydrogen 80 mol% + Ar 2
(0 mol%), and heated at a rate of 1.0 ° C./min from room temperature to 900 ° C. while evacuating while flowing the gas stream. After reaching 900 ° C., hydrogen gas was introduced to 0.8 atm, then heated at 900 ° C. for 2 hours and cooled to room temperature. By this treatment, debinding and denitrification were performed, and an Sm-Fe-Ti-B-based magnetic alloy was obtained.
Assuming that the total weight of the magnetic alloy was 100 wt%, the oxygen content was 0.7 wt%, the nitrogen content was 0.02 wt%, and the epoxy resin was almost decomposed. Next, metal Ca equivalent to 0.8 times the stoichiometric amount was blended and mixed with 1 kg of the Sm-Fe-Ti-B-based magnetic alloy powder. Next, a reduction reaction treatment of heating at 1100 ° C. for 8 hours in an Ar atmosphere was performed, and then the resultant was cooled to room temperature. next,
After crushing the reaction product, it is poured into the washing solution, and the C
aO was changed to Ca (OH) ₂ , discharged together with the washing liquid, and removed. After washing, the powder was heated and dried while evacuating with a vacuum pump to obtain an Sm-Fe-Ti-B-based magnetic alloy powder having an average particle diameter of 50 µm. Next, this powder was compression-molded under a pressure of 10 ton / cm ² to obtain a disk-shaped pellet having an outer diameter of 30 mm and a thickness of 10 mm. Then, 7 kg (30 parts by weight) of the pellet and a mixture of Sm, Ti, Fe, and B having a purity of 99% or more and having the same main component composition as the pellet 21 k
g (70 parts by weight) into a high-frequency melting furnace and melted.
Using a strip caster having an outer diameter of 500 mm and having a single roll for quenching the molten metal, the roll was rapidly solidified at a peripheral speed of 1.0 m / sec to obtain a ribbon-shaped Sm-Fe-Ti-B-based mother alloy. The yield of the master alloy ribbon was very good. Next, the mother alloy ribbon is subjected to a hydrogenation / decomposition reaction treatment of heating at 690 ° C. for 1 hour in 1 atm of hydrogen gas, and 5 to 8 × 10 ^−2.
Dehydrogenation by heating at 800 ° C for 2 hours in Torr vacuum
Recombination reaction treatment was performed. Next, it was pulverized to an average particle diameter of 50 μm using a jaw crusher and a disc mill in an Ar atmosphere, and then heated at 550 ° C. for 10 hours in an atmosphere containing nitrogen for nitriding. Next, 98 parts by weight of the nitrided magnet powder obtained by heat treatment at 400 ° C. for 30 minutes in an Ar gas stream were mixed with 2 parts by weight of an epoxy resin, and kneaded to prepare a compound. Next, at a press pressure of 10 ton / cm ² and an outer diameter of 20 mm
× After compression molding into a ring shape with an inner diameter of 16 mm × thickness of 5 mm,
Heat-curing treatment was performed in air at 150 ° C. for 2 hours to obtain an isotropic bonded magnet. The room-temperature magnetic properties and radial crushing strength of the bonded magnet were measured. Table 3 shows the results. (Comparative Example 3) In Example 3, after washing and drying, 7 kg (30 parts by weight) of an Sm-Fe-Ti-B-based magnetic alloy powder having an average particle diameter of 50 µm and S having a purity of 99% or more were obtained.
Sm-Fe-Ti-B using m, Ti, Fe, B
7 kg of the magnetic alloy powder and 21 kg (70 parts by weight) of the same main component composition were charged into a high-frequency melting furnace and melted. Thereafter, in the same manner as in Example 3, the ribbon-shaped Sm-F
An e-Ti-B-based master alloy was obtained. The yield of the mother alloy ribbon was about 11% lower than that of Example 3. This is mainly because the amount of oxygen in the molten metal increased because 30 parts by weight of the Sm—Fe—Ti—B-based magnetic alloy powder having an average particle diameter of 50 μm was used for melting. (Comparative Example 4) As a comparative material, 30 parts by weight of a 200-mesh under-regenerated compound obtained by pulverizing the scrap of the bonded magnet produced in Example 3 and 70 parts by weight of a new material corresponding to the regenerated compound were blended. A mixed compound was prepared. Except that this compound was used, the outer diameter was 20 mm × in the same manner as in Example 3.
A ring-shaped compression-molded isotropic bonded magnet having an inner diameter of 16 mm and a thickness of 5 mm was produced. Table 3 shows the magnetic properties and radial crushing strength of this bonded magnet.

[0014]

[Table 3]

From Table 3, it can be seen that the bonded magnet of Example 3 has magnetic properties and radial crushing strength as compared with the bonded magnet of Comparative Example 4 using a compound in which 30% by weight of a compound obtained by crushing and recycling the scrap of the bonded magnet is used. Is high.

[0016]

As described above, according to the present invention, rare earth-iron-nitrogen based magnetic material can be recycled with high efficiency, and rare earth-iron-nitrogen having magnetic properties and mechanical strength that can withstand practical use. A system-based bonded magnet can be provided.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4K018 BA18 BB08 BC01 BC09 BD01 4K028 AA02 AB01 AB06 5E040 AA03 AA19 BB04 BB05 CA01 HB07 HB09 HB11 HB15 HB17 NN17 NN18

Claims (2)

[Claims] 1. A kneaded product or a compact formed by binding a rare earth-iron-nitrogen-based magnetic material powder with a polymer compound to a non-oxidizing atmosphere (but nitrogen) substantially consisting of hydrogen or hydrogen and an inert gas. Above) from room temperature to 600 ° C or higher
By heating the mixture to a temperature of less than 000 ° C. at a rate of 0.1 to 5 ° C./min to obtain a rare earth-iron magnetic material from which the polymer compound and nitrogen have been substantially removed from the kneaded product or molded product, Ca, Mg, CaH ₂ , Mg of 0.5 to 2 times the stoichiometric amount required for the reduction of the rare earth-iron magnetic material
A method for regenerating a rare earth-iron-nitrogen based magnetic material, comprising mixing and mixing at least one of H ₂ , heating the mixture to 900 to 1200 ° C. in an inert gas atmosphere, performing a reduction reaction, and then nitriding. 2. A kneaded product or a compact formed by binding a rare earth-iron-nitrogen-based magnetic material powder with a polymer compound to a non-oxidizing atmosphere (but nitrogen) substantially consisting of hydrogen or hydrogen and an inert gas. Above) from room temperature to 600 ° C or higher
By heating the mixture to a temperature of less than 000 ° C. at a rate of 0.1 to 5 ° C./min to obtain a rare earth-iron magnetic material from which the polymer compound and nitrogen have been substantially removed from the kneaded product or molded product, Ca, Mg, CaH ₂ , Mg of 0.5 to 2 times the stoichiometric amount required for the reduction of the rare earth-iron magnetic material
After mixing and mixing at least one of H _2, the mixture is heated to 900 to 1200 ° C. in an inert gas atmosphere to perform a reduction reaction, and then the reaction product is washed and dried to have an oxygen content of 0.4% by weight or less. A rare earth-iron magnetic material powder is obtained, and then the rare earth-iron magnetic material powder is compression-molded to a particle size of 0.5 to 0.5.
A rare earth-iron-based master alloy is melted using pellets of 100 mm, and then the master alloy is nitrided to form a rare earth-
A method for regenerating a rare earth-iron-nitrogen based magnetic material, comprising producing an iron-nitrogen based magnetic material.