Method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste

Abstract

The invention belongs to the technical field of regenerated magnetic powder, and relates to a method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste. The invention discloses a method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste. R is one or more of rare earth elements; the method comprises the following steps: mixing purified RFeB oil sludge with a reducing medium, putting the mixture into a vacuum rotary furnace into which inert gas is introduced, carrying out rotary heating at a first temperature of 70-150 DEG C, adjusting the vacuum degree, carrying out primary reduction treatment at a second temperature of 600-890 DEG C, carrying out secondary diffusion treatment at a third temperature of 900-1100 DEG C to obtain an alloy ingot, and pulverizing to obtain the regenerated RFeB magnetic powder. According to the method for efficiently preparing the regenerated RFeB magnetic powder from the RFeB oil sludge waste, the associated oil sludge waste in the processing process of rare earth functional materials can be regenerated, and the regeneration efficiency of rare earth elements can exceed 80%.

Description

Technical Field

[0001] The invention belongs to the technical field of regenerated magnetic powder and relates to a method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste. Background Art

[0002] In addition to primary ore, renewable rare earth functional materials, such as RFeB materials (R is one or more rare earth elements), will be accompanied by a large amount of waste during the production and processing of rare earth resources, including powders and small blocks during raw material preparation, slag left after alloy smelting, ultrafine powder produced during the powder making process, heavily oxidized powder, slightly oxidized block materials during the sintering process, cutting blocks, scraps, magnetic chips, low magnetic performance and unqualified products during surface treatment, oil sludge, and pre-electroplating chamfering and pickling liquid, etc., which will become more important raw material support for rare earth resources through secondary recycling. Among them, R-type oil sludge waste is mainly formed by the combination of lubricating oil and coolant used in the cutting and grinding process, and cleaning agent used in the cleaning process with other waste materials, accounting for 35-50% of the total waste, causing serious waste of rare earth resources. At the same time, the long-term accumulation of oil sludge waste has brought serious pollution to the environment.

[0003] At present, there are two main methods for recycling RFeB oil sludge waste: wet method and pyrolysis. The treatment process is long, the amount of chemical reagents is large, the energy consumption is high, and the pollution is large. The recycled products are rare earth oxides, which have low added value, large composition differences, and unstable product performance. They are still at the middle and low end of the value chain. After separation, about 70% of Fe, Co, Al and other metal oxide solid waste residues will be produced, resulting in a large waste of resources. Therefore, it is necessary to develop efficient treatment technology for the recycling of rare earth resources. Summary of the invention

[0004] The purpose of the present invention is to address the above-mentioned problems existing in the prior art and to propose a method for efficiently preparing regenerated RFeB magnetic powder from RFeB type oil sludge waste. After the purified RFeB type oil sludge is mixed with a reducing medium, high-performance regenerated RFeB magnetic powder is obtained through rotary heating, primary reduction treatment, and secondary diffusion treatment.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste, wherein R is one or more rare earth elements; the method comprises: mixing the purified RFeB oil sludge with a reducing medium, placing the mixture in a vacuum rotary furnace into which an inert gas is introduced, rotating and heating the mixture at a first temperature of 70 to 150°C, adjusting the vacuum degree, performing a primary reduction treatment at a second temperature of 600 to 890°C, performing a secondary diffusion treatment at a third temperature of 900 to 1100°C to obtain an alloy ingot, and powdering the mixture to obtain the regenerated RFeB magnetic powder.

[0007] Preferably, the mass ratio of the purified RFeB type oil sludge to the reducing medium is (1-30):1.

[0008] More preferably, the mass ratio of the purified RFeB type oil sludge to the reducing medium is (6-19):1.

[0009] Preferably, the reducing medium includes one or more of calcium hydride, calcium particles, calcium chloride, and sodium borohydride.

[0010] More preferably, when the reducing medium is calcium hydride, the mass ratio of the purified RFeB type sludge to the reducing medium is (11-19):1.

[0011] More preferably, when the reducing medium is calcium particles, the mass ratio of the purified RFeB type sludge to the reducing medium is (6-9):1.

[0012] Preferably, the vacuum rotary furnace has a rotation rate of 50 to 500 rpm.

[0013] Preferably, the rotary heating comprises: rotary heating at a first temperature of 80 to 100° C. for 1 to 300 minutes.

[0014] Preferably, the primary reduction treatment comprises: maintaining the second temperature at 700-890° C. for 1-300 minutes, with a heating rate of 1-20° C. / minute.

[0015] More preferably, the primary reduction treatment comprises: maintaining the temperature at the second temperature of 780-850° C. for 30-60 minutes, with a heating rate of 5-10° C. / minute.

[0016] More preferably, the primary reduction treatment comprises: maintaining the temperature at the second temperature of 800-850° C. for 30-60 minutes.

[0017] Preferably, the secondary diffusion treatment comprises: maintaining the temperature at a third temperature of 910-1100° C. for 100-1000 minutes, with a heating rate of 1-20° C. / minute.

[0018] More preferably, the secondary diffusion treatment includes: maintaining the temperature at a third temperature of 950-1080° C. for 300-480 minutes.

[0019] More preferably, the secondary diffusion treatment includes: maintaining the temperature at a third temperature of 1020-1040° C. for 300-480 minutes.

[0020] Preferably, the upper pressure limit valve pressure of the vacuum rotary furnace is 0.001-1 MPa.

[0021] Preferably, the powder making comprises: crushing the alloy ingot, jet milling to obtain jet mill RFeB powder, mixing the jet mill RFeB powder with a cleaning liquid to obtain cleaned RFeB magnetic powder, and degassing, activating and drying the cleaned RFeB magnetic powder to obtain regenerated RFeB magnetic powder.

[0022] More preferably, the impurity-removing cleaning solution contains 0.1 to 10 wt % of acetic acid.

[0023] More preferably, the impurity removal cleaning solution comprises acetic acid, water and anhydrous ethanol in a volume ratio of (1-5):(8-20):100.

[0024] More preferably, the impurity-removing cleaning solution contains 0.5 to 5 wt % of acetic acid.

[0025] More preferably, the impurity removal cleaning solution comprises acetic acid, water and anhydrous ethanol in a volume ratio of (1-2.5):10:100.

[0026] More preferably, the average particle size of the jet milled RFeB powder is 1 to 10 μm.

[0027] More preferably, the average particle size of the jet milled RFeB powder is 2-5 μm.

[0028] Further preferably, the mass ratio of the jet mill RFeB powder to the impurity removal cleaning liquid is 1:(10-200).

[0029] More preferably, the mass ratio of the jet mill RFeB powder to the impurity removal cleaning liquid is 1:(20-50).

[0030] Further preferably, the degassing activation drying includes: loading the RFeB magnetic powder after impurity removal into a rotary furnace into which hydrogen is continuously introduced, setting the heating rate of the rotary furnace to 1-10°C / min, the heating temperature to 180-400°C, keeping warm for 10-600 minutes, and setting the upper pressure limit valve pressure of the rotary furnace to 0.001-0.1MPa.

[0031] Preferably, the method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste comprises: mixing the purified RFeB oil sludge with a reducing medium, placing the mixture in a vacuum rotary furnace with an inert gas, rotating and heating the mixture at a first temperature of 70 to 150° C., and adjusting the vacuum degree of the vacuum rotary furnace to 10 -4 ~10 -1Pa, a primary reduction treatment is carried out at a second temperature of 600-890°C, a secondary diffusion treatment is carried out at a third temperature of 900-1100°C, and an alloy ingot is cooled. The alloy ingot is crushed and air-jet-milled to obtain air-jet-milled RFeB powder. The air-jet-milled RFeB powder is mixed and cleaned with an impurity-removing cleaning liquid to obtain impurity-removed RFeB magnetic powder. The impurity-removed RFeB magnetic powder is degassed, activated, and dried to obtain regenerated RFeB magnetic powder.

[0032] More preferably, the jet mill RFeB powder is mixed with the impurity removal cleaning liquid and cleaned 1 to 6 times.

[0033] More preferably, the jet mill RFeB powder is mixed with the impurity removal cleaning liquid and cleaned 2 to 5 times.

[0034] Preferably, the purified RFeB oil sludge is obtained by purifying RFeB oil sludge waste.

[0035] Preferably, the purification comprises: separating RFeB type oil sludge powder from RFeB type oil sludge waste material by physical and / or chemical methods.

[0036] Preferably, the purification comprises: drying the RFeB type oily sludge waste material and mixing it with a diluent, filtering the bottom oily sludge material and performing two-stage baking; the two-stage baking comprises a primary baking at 100-300°C and a secondary baking at 300-500°C in an inert gas.

[0037] Preferably, the purification comprises: placing the pretreated RFeB type oil sludge waste in a vacuum rotary furnace with an inert gas flowing therein, and performing a purification at 100-300° C.;

[0038] When the vacuum degree of the vacuum rotary furnace reaches a set threshold, purified gas is introduced into the vacuum rotary furnace to perform secondary purification on the RFeB type oily sludge waste material after the primary purification at 300-500°C.

[0039] More preferably, the pretreatment of the RFeB type oily sludge waste includes one or more of drying, activation, and pre-purification.

[0040] More preferably, the activation comprises: adding the dried RFeB type oily sludge waste material and the diluent into an oily sludge material mixing and filtering device and stirring, so that the dried RFeB type oily sludge waste material and the diluent are fully contacted to achieve activation;

[0041] And / or, the pre-purification includes: centrifuging and baking the activated RFeB type oil sludge waste to achieve pre-purification.

[0042] More preferably, the diluent comprises two or more of 60-95% alcohol compounds, 5-80% ketone or ester compounds, 5-10% petroleum derivatives, and 5-40% weak alkaline solution.

[0043] Further preferably, the primary purification includes: increasing the temperature of the vacuum rotary furnace and introducing an inert gas into the vacuum rotary furnace until the temperature of the vacuum rotary furnace is stabilized at 100 to 300°C; continuously introducing the inert gas for 30 to 120 minutes to purify the pretreated RFeB type oily sludge waste material.

[0044] Further preferably, the secondary purification includes: evacuating the vacuum rotary furnace until the vacuum degree in the vacuum rotary furnace reaches a set threshold value, and setting the pressure of the pressure limiting valve of the vacuum rotary furnace to 1-2atm; increasing the temperature of the vacuum rotary furnace and introducing purified gas into the vacuum rotary furnace until the temperature of the vacuum rotary furnace stabilizes at 300-500°C; and continuously introducing purified gas for 60-120 minutes to perform secondary purification on the RFeB type sludge waste after the first purification.

[0045] More preferably, the purified gas is a mixed gas of hydrogen and inert gas, wherein the volume ratio of hydrogen to inert gas is 20:80 to 50:50, and the flow rate of the purified gas is 30 to 70 mL / min.

[0046] A regenerated RFeB magnetic powder with a purity of ≥99.5%.

[0047] Preferably, compared with the purified RFeB oil sludge, the total rare earth element retention rate of the regenerated RFeB magnetic powder is ≥82%.

[0048] Preferably, the saturation magnetization of the regenerated RFeB magnetic powder is ≥90emu / g; and the coercive force is ≥9000Oe.

[0049] More preferably, the saturation magnetization of the regenerated RFeB magnetic powder is ≥100emu / g; and the coercive force is ≥10000Oe.

[0050] A regenerated RFeB magnet comprises 0.1-100 wt% of regenerated RFeB magnetic powder.

[0051] Compared with the prior art, the present invention has the following beneficial effects:

[0052] 1. The method of efficiently preparing and regenerating RFeB magnetic powder from RFeB oily sludge waste of the present invention can be used to regenerate oily sludge waste associated with the processing of rare earth functional materials, especially oily sludge materials that are heavily oxidized, have high impurity content, and have complex components such as wire cutting and water-based slicing, and the rare earth element regeneration efficiency can exceed 80%.

[0053] 2. The method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste of the present invention uses purified RFeB oil sludge, combined with primary reduction treatment and secondary diffusion treatment to obtain high-performance regenerated RFeB magnetic powder.

[0054] 3. In the method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste of the present invention, a cleaning liquid is used to clean the mixed powder after air flow milling, and the total loss rate of rare earth elements is ≤10%, which effectively improves the magnetic properties of the regenerated RFeB magnetic powder.

[0055] 4. The solvents in the impurity removal cleaning solution of the present invention are mostly water and alcohols, and low-content acetic acid can be directly discharged through neutralization and degradation, without polluting the environment.

[0056] 5. The method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste of the present invention has high purity and an impurity content of less than 0.5%.

[0057] 6. The method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste of the present invention can significantly improve the saturation magnetization intensity and coercive force of the regenerated RFeB magnetic powder.

[0058] 7. The method of the present invention for efficiently preparing regenerated RFeB magnetic powder from RFeB oily sludge waste can recover valuable elements in the form of magnetic powder, with higher recovery efficiency, and is suitable for the recycling of batch oily sludge waste. DETAILED DESCRIPTION

[0059] The following are specific embodiments of the present invention, which further describe the technical solutions of the present invention, but the present invention is not limited to these embodiments.

[0060] Unless otherwise specified, the materials used in the present invention are conventional commercial products, and the methods used are conventional technical means.

[0061] In this paper, RFeB type oil sludge waste comes from rare earth magnet processing enterprises.

[0062] In this article, the purified RFeB type oil sludge is prepared by the purification method described in a Chinese patent document (publication number: CN118389859A).

[0063] In this article, the purified RFeB type oil sludge in the examples is prepared according to the purification method described in any one of Examples 1 to 20 of the Chinese patent text (publication number: CN118389859A).

[0064] In this article, a method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste includes:

[0065] (1) mixing the purified RFeB oil sludge with a reducing medium in a mass ratio of (1-30):1;

[0066] (2) then loading into a stirring mixing tank, the mixing tank speed is 50 to 500 rpm, the mixing time is 1 to 600 minutes, and the stirrer speed is 60 to 500 rpm;

[0067] (3) After the mixing is completed, the mixture is transferred to a rotary furnace at a rotation rate of 50 to 500 rpm, a heating temperature of 70 to 150° C., and a heating time of 1 to 300 minutes;

[0068] (4) Turn on the secondary vacuum pump system while heating. When the pressure is 10 -4 ~10 -1 Pa, set the rotary furnace heating rate to 1-20°C / min, heat to the second temperature of 600-890°C, and keep it warm for 1-300 minutes to perform primary reduction treatment; then heat to the third temperature of 900-1100°C, keep it warm for 100-1000 minutes, perform secondary diffusion treatment, and control the pressure of the rotary furnace upper pressure valve to 0.01-0.1MPa;

[0069] (5) After the diffusion treatment, the exhaust hole of the rotary furnace is opened, and the inert gas flow rate at the air inlet end is increased to rapidly cool the alloy ingot. When the temperature in the furnace is lower than 100° C., the inert gas is filled into the furnace to maintain the pressure of 0.001 to 0.1 MPa, and then cooled to room temperature to obtain a cooled alloy ingot;

[0070] (6) the alloy ingot is loaded into a crusher and crushed to an average particle size of 100 to 200 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 1 to 10 μm;

[0071] (7) mixing acetic acid, water, and anhydrous ethanol in a volume ratio of (1-5):(8-20):100 to prepare an impurity removal cleaning solution;

[0072] (8) Loading the jet mill RFeB powder and the impurity removal cleaning liquid in a mass ratio of 1:(10-200) into the cleaning device;

[0073] (9) placing the cleaning device in an ultrasonic generator, setting the ultrasonic frequency to 50 to 200 Hz, cleaning for 1 to 60 seconds, allowing the mixed solution to stand for 0.1 to 10 minutes after cleaning, pouring out the solution at the top of the cleaning device and adding the cleaning solution again, repeating this process several times; then washing with anhydrous ethanol to obtain RFeB magnetic powder after impurities are removed;

[0074] (10) The impurity-removed RFeB magnetic powder is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to have a heating rate of 1 to 10°C / min, a heating temperature of 180 to 400°C, and to be kept warm for 10 to 600 minutes, and degassing, activation, and drying treatment is performed. The pressure of the rotary furnace upper pressure valve is set to 0.001 to 0.1 MPa, and the regenerated RFeB magnetic powder is obtained;

[0075] (11) The regenerated RFeB magnetic powder is ball-milled, sieved, mixed with AB glue, and then solidified and oriented in a magnetic field of 1 to 5 T; the magnetic properties of the regenerated RFeB magnetic powder are tested by a magnetic measuring instrument.

[0076] In this paper, the total rare earth element regeneration rate of the recycled RFeB magnetic powder is ≥80% compared with the original RFeB type oil sludge waste.

[0077] In this paper, compared with the purified RFeB oil sludge, the total rare earth element regeneration rate of the regenerated RFeB magnetic powder is ≥82%; and the total rare earth element regeneration rate can reach 92%.

[0078] In this paper, the total loss rate of rare earth elements in the regenerated RFeB magnetic powder before and after impurity removal is ≤10%.

[0079] In this paper, the purity of the recycled RFeB magnetic powder is ≥99.5%.

[0080] In this paper, the saturation magnetization of the regenerated RFeB magnetic powder is ≥90emu / g; the coercive force is ≥9000Oe.

[0081] In this article, RFeB type oily sludge waste is purified according to the physical and / or chemical methods in the prior art, and then the performance of the regenerated RFeB magnetic powder obtained by the method for efficiently preparing regenerated RFeB magnetic powder from RFeB type oily sludge waste according to the present invention is also improved.

[0082] Example 1

[0083] (1) Weigh the purified RFeB oil sludge and mix it with the reducing medium calcium hydride at a mass ratio of 19:1;

[0084] (2) Then put it into a stirring mixing tank, the mixing tank speed is 150 rpm, the mixing time is 60 minutes, and the stirrer speed is 100 rpm;

[0085] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation speed of 60 rpm, a heating temperature of 100°C, and a heating time of 30 minutes;

[0086] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 300 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.02 MPa;

[0087] (5) After the diffusion treatment, the exhaust hole at the outlet of the rotary furnace is opened, and the argon flow rate at the inlet end is increased to 0.01 MPa, and the alloy ingot after the reaction is rapidly cooled. When the temperature in the furnace is lower than 100°C, argon is filled into the furnace to maintain the pressure of 0.01 MPa. When the rotary furnace is cooled to room temperature of 30-40°C, the cooled alloy ingot is obtained;

[0088] (6) the alloy ingot is loaded into a crusher and crushed to an average particle size of 200 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 5 μm;

[0089] (7) acetic acid, deionized water, and anhydrous ethanol are mixed in a volume ratio of 2.5:10:100 to prepare an impurity removal cleaning solution;

[0090] (8) Loading the jet mill RFeB powder and the impurity removal cleaning liquid in a mass ratio of 1:20 into the cleaning device;

[0091] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 30 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 5 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0092] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 200°C, and to be kept warm for 60 minutes for degassing, activation, and drying. The upper pressure limit valve pressure of the rotary furnace is set to 0.01 MPa, thereby obtaining regenerated RFeB magnetic powder;

[0093] (11) The regenerated RFeB magnetic powder was loaded into a ball mill with a ball-to-material ratio of 10:1, a rotation speed of 50 rpm, and a ball milling time of 2 h; after ball milling, the powder was sieved through an 800-mesh stainless steel sieve; the powder was mixed at a ratio of regenerated RFeB magnetic powder to AB glue of 1:2 (mass ratio), and then cured and oriented in a 3 T magnetic field; after curing, the magnetic properties of the regenerated RFeB magnetic powder were tested using a magnetic measuring instrument.

[0094] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0095] Example 2

[0096] (1) Weigh the purified RFeB oil sludge and mix it with the reducing medium calcium hydride at a mass ratio of 17:1;

[0097] (2) Then put it into a stirring mixing tank, the mixing tank speed is 120 rpm, the mixing time is 40 minutes, and the stirrer speed is 100 rpm;

[0098] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation speed of 60 rpm, a heating temperature of 100°C, and a heating time of 40 minutes;

[0099] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 810 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 300 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.04 MPa;

[0100] (5) The same as step (5) in Example 1;

[0101] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 150 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 4.9 μm;

[0102] (7) acetic acid, deionized water, and anhydrous ethanol are mixed in a volume ratio of 2:10:100 to prepare an impurity removal cleaning solution;

[0103] (8) The same as step (8) in Example 1;

[0104] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 30 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 4 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0105] (10) is the same as step (10) in Example 1;

[0106] (11) is the same as step (11) in Example 1;

[0107] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0108] Example 3

[0109] (1) Weigh the purified RFeB oil sludge and mix it with the reducing medium calcium hydride at a mass ratio of 15:1;

[0110] (2) Then put it into a stirring mixing tank, the mixing tank speed is 150 rpm, the mixing time is 50 minutes, and the stirrer speed is 150 rpm;

[0111] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation speed of 80 rpm, a heating temperature of 80°C, and a heating time of 40 minutes;

[0112] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 800 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 300 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.04 MPa;

[0113] (5) The same as step (5) in Example 1;

[0114] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 150 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 4.1 μm;

[0115] (7) The same as step (7) in Example 2;

[0116] (8) The same as step (8) in Example 1;

[0117] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 30 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 3 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0118] (10) is the same as step (10) in Example 1;

[0119] (11) is the same as step (11) in Example 1;

[0120] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0121] Example 4

[0122] (1) Weigh the purified RFeB oil sludge and mix it with the reducing medium calcium hydride at a mass ratio of 13:1;

[0123] (2) The mixture was placed in a stirring mixing tank at a speed of 60 rpm, a mixing time of 50 min, and a stirrer speed of 150 rpm;

[0124] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation speed of 80 rpm, a heating temperature of 80°C, and a time of 50 minutes;

[0125] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 800 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1000 ° C, keep it warm for 300 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.04 MPa;

[0126] (5) The same as step (5) in Example 1;

[0127] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 120 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 4.1 μm;

[0128] (7) The same as step (7) in Example 2;

[0129] (8) Loading the jet mill RFeB powder and the impurity removal cleaning liquid in a mass ratio of 1:40 into the cleaning device;

[0130] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 30 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0131] (10) is the same as step (10) in Example 1;

[0132] (11) is the same as step (11) in Example 1;

[0133] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0134] Example 5

[0135] (1) Weigh the purified RFeB oil sludge and mix it with the reducing medium calcium hydride at a mass ratio of 11:1;

[0136] (2) Then put it into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 30 minutes, and the stirrer speed is 150 rpm;

[0137] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation speed of 80 rpm, a heating temperature of 80°C, and a time of 60 minutes;

[0138] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 780 ° C, and keep it warm for 60 minutes to perform a primary reduction treatment; then heat to the third temperature 1000 ° C, keep it warm for 300 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.04 MPa;

[0139] (5) The same as step (5) in Example 1;

[0140] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 120 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0141] (7) acetic acid, deionized water, and anhydrous ethanol are mixed in a volume ratio of 1:10:100 to prepare an impurity removal cleaning solution;

[0142] (8) The same as step (8) in Example 4;

[0143] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 40 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again, repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0144] (10) is the same as step (10) in Example 1;

[0145] (11) is the same as step (7) in Example 1.

[0146] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0147] Example 6

[0148] (1) The same as step (1) in Example 1;

[0149] (2) The mixture was then placed in a stirring mixing tank at a speed of 100 rpm, a mixing time of 60 min, and a stirrer speed of 180 rpm;

[0150] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation rate of 150 rpm, a heating temperature of 100°C, and a time of 50 minutes;

[0151] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 980 ° C, keep it warm for 480 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.02 MPa;

[0152] (5) The same as step (5) in Example 1;

[0153] (6) The same as step (6) in Example 3;

[0154] (7) The same as step (7) in Example 2;

[0155] (8) Loading the jet mill RFeB powder and the impurity removal cleaning liquid in a mass ratio of 1:30 into the cleaning device;

[0156] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 40 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 3 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0157] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 250°C, and to be kept warm for 60 minutes for degassing, activation, and drying. The upper pressure limit valve pressure of the rotary furnace is set to 0.01 MPa, thereby obtaining regenerated RFeB magnetic powder;

[0158] (11) is the same as step (11) in Example 1.

[0159] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0160] Example 7

[0161] (1) The same as step (1) in Example 2;

[0162] (2) Then put it into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 60 minutes, and the stirrer speed is 150 rpm;

[0163] (3) The same as step (3) in Example 1;

[0164] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 980 ° C, keep it warm for 480 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0165] (5) The same as step (5) in Example 1;

[0166] (6) The same as step (6) in Example 4;

[0167] (7) The same as step (7) in Example 2;

[0168] (8) The same as step (8) in Example 4;

[0169] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 50 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 5 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0170] (10) is the same as step (10) in Example 6;

[0171] (11) is the same as step (11) in Example 1.

[0172] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0173] Example 8

[0174] (1) The same as step (1) in Example 3;

[0175] (2) The mixture was then placed in a stirring mixing tank at a speed of 80 rpm, a mixing time of 50 min, and a stirrer speed of 150 rpm;

[0176] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 100°C, and a time of 40 minutes;

[0177] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 800 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 980 ° C, keep it warm for 480 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0178] (5) The same as step (5) in Example 1;

[0179] (6) the alloy ingot was loaded into a crusher and crushed to an average particle size of 120 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.5 μm;

[0180] (7) The same as step (7) in Example 2;

[0181] (8) The same as step (8) in Example 4;

[0182] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 60 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again, repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0183] (10) is the same as step (10) in Example 1;

[0184] (11) is the same as step (11) in Example 1.

[0185] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0186] Example 9

[0187] (1) The same as step (1) in Example 4;

[0188] (2) The mixture was then placed in a stirring mixing tank at a speed of 80 rpm, a mixing time of 50 min, and a stirrer speed of 150 rpm;

[0189] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 100°C, and a time of 40 minutes;

[0190] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 810 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 950 ° C, keep it warm for 480 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0191] (5) The same as step (5) in Example 1;

[0192] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 110 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0193] (7) The same as step (7) in Example 5;

[0194] (8) Loading the jet mill RFeB powder and the impurity removal cleaning liquid in a mass ratio of 1:50 into the cleaning device;

[0195] (9) The same as step (9) in Example 5;

[0196] (10) is the same as step (10) in Example 6;

[0197] (11) is the same as step (11) in Example 1.

[0198] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0199] Example 10

[0200] (1) The same as step (1) in Example 5;

[0201] (2) Then put it into a stirring mixing tank, the mixing tank speed is 120 rpm, the mixing time is 50 minutes, and the stirrer speed is 150 rpm;

[0202] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 80°C, and a heating time of 50 minutes;

[0203] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 810 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 950 ° C, keep it warm for 480 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0204] (5) The same as step (5) in Example 1;

[0205] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 110 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.1 μm;

[0206] (7) The same as step (7) in Example 5;

[0207] (8) The same as step (8) in Example 3;

[0208] (9) The same as step (9) in Example 3;

[0209] (10) is the same as step (10) in Example 6;

[0210] (11) is the same as step (11) in Example 1.

[0211] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0212] Embodiment 11

[0213] (1) The same as step (1) in Example 1;

[0214] (2) Then put it into a stirring mixing tank, the mixing tank speed is 110 rpm, the mixing time is 60 minutes, and the stirrer speed is 200 rpm;

[0215] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation rate of 120 rpm, a heating temperature of 100°C, and a heating time of 60 minutes;

[0216] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 810 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 480 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0217] (5) The same as step (5) in Example 1;

[0218] (6) the alloy ingot was loaded into a crusher and crushed to an average particle size of 120 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.5 μm;

[0219] (7) The same as step (7) in Example 5;

[0220] (8) The same as step (8) in Example 4;

[0221] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 60 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again, repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0222] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 300°C, and is kept warm for 30 minutes for degassing, activation, and drying. The pressure of the rotary furnace upper pressure valve is set to 0.01 MPa, thereby obtaining regenerated RFeB magnetic powder;

[0223] (11) is the same as step (11) in Example 1.

[0224] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0225] Example 12

[0226] (1) The same as step (1) in Example 2;

[0227] (2) The mixture was then placed in a stirring mixing tank at a speed of 100 rpm, a mixing time of 50 min, and a stirrer speed of 180 rpm;

[0228] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation rate of 120 rpm, a heating temperature of 100°C, and a heating time of 60 minutes;

[0229] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 810 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 480 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0230] (5) The same as step (5) in Example 1;

[0231] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0232] (7) acetic acid, deionized water, and anhydrous ethanol are mixed in a volume ratio of 1.5:10:100 to prepare an impurity removal cleaning solution;

[0233] (8) The same as step (8) in Example 9;

[0234] (9) The same as step (9) in Example 5;

[0235] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 300°C, and is kept warm for 30 minutes for degassing, activation, and drying. The pressure of the rotary furnace upper pressure valve is set to 0.01 MPa, thereby obtaining regenerated RFeB magnetic powder;

[0236] (11) is the same as step (11) in Example 1.

[0237] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0238] Example 13

[0239] (1) The same as step (1) in Example 3;

[0240] (2) The mixture was then placed in a stirring mixing tank at a speed of 100 rpm, a mixing time of 60 min, and a stirrer speed of 180 rpm;

[0241] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation rate of 120 rpm, a heating temperature of 100°C, and a heating time of 60 minutes;

[0242] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 810 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 980 ° C, keep it warm for 400 minutes, perform secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0243] (5) The same as step (5) in Example 1;

[0244] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0245] (7) The same as step (7) in Example 12;

[0246] (8) The same as step (8) in Example 6;

[0247] (9) The same as step (9) in Example 3;

[0248] (10) The same as step (10) in Example 11;

[0249] (11) is the same as step (11) in Example 1.

[0250] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0251] Embodiment 14

[0252] (1) The same as step (1) in Example 4;

[0253] (2) Then put it into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 60 minutes, and the stirrer speed is 150 rpm;

[0254] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 100°C, and a time of 60 minutes;

[0255] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 810 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 950 ° C, keep it warm for 300 minutes, perform secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0256] (5) The same as step (5) in Example 1;

[0257] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0258] (7) The same as step (7) in Example 12;

[0259] (8) The same as step (8) in Example 3;

[0260] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 40 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 3 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0261] (10) is the same as step (10) in Example 1;

[0262] (11) is the same as step (11) in Example 1.

[0263] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0264] Embodiment 15

[0265] (1) The same as step (1) in Example 5;

[0266] (2) Then put it into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 60 minutes, and the stirrer speed is 150 rpm;

[0267] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 100°C, and a time of 60 minutes;

[0268] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 800 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 950 ° C, keep it warm for 300 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0269] (5) The same as step (5) in Example 1;

[0270] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0271] (7) The same as step (7) in Example 12;

[0272] (8) The same as step (8) in Example 9;

[0273] (9) The same as step (9) in Example 5;

[0274] (10) The same as step (10) in Example 11;

[0275] (11) is the same as step (11) in Example 1.

[0276] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0277] Example 16

[0278] (1) Weigh the purified RFeB oil sludge and mix it with reducing medium calcium particles at a mass ratio of 9:1;

[0279] (2) Then put it into a stirring mixing tank, the mixing tank speed is 150 rpm, the mixing time is 60 minutes, and the stirrer speed is 100 rpm;

[0280] (3) The same as step (3) in Example 1;

[0281] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 800 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1040 ° C, keep it warm for 300 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0282] (5) The same as step (5) in Example 1;

[0283] (6) the alloy ingot was loaded into a crusher and crushed to an average particle size of 150 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 4.2 μm;

[0284] (7) The same as step (7) in Example 2;

[0285] (8) The same as step (8) in Example 1;

[0286] (9) The same as step (9) in Example 1;

[0287] (10) is the same as step (10) in Example 1;

[0288] (11) is the same as step (11) in Example 1.

[0289] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0290] Embodiment 17

[0291] (1) Weigh the purified RFeB oil sludge and mix it with reducing medium calcium particles at a mass ratio of 8:1;

[0292] (2) Then put it into a stirring mixing tank, the mixing tank speed is 120 rpm, the mixing time is 60 minutes, and the stirrer speed is 100 rpm;

[0293] (3) The same as step (3) in Example 1;

[0294] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 800 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1040 ° C, keep it warm for 300 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0295] (5) The same as step (5) in Example 1;

[0296] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 130 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.8 μm;

[0297] (7) The same as step (7) in Example 2;

[0298] (8) The same as step (8) in Example 9;

[0299] (9) The same as step (9) in Example 2;

[0300] (10) is the same as step (10) in Example 1;

[0301] (11) is the same as step (11) in Example 1.

[0302] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0303] Embodiment 18

[0304] (1) Weigh the purified RFeB oil sludge and mix it with reducing medium calcium particles at a mass ratio of 7:1;

[0305] (2) Then put it into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 60 minutes, and the stirrer speed is 100 rpm;

[0306] (3) The same as step (3) in Example 1;

[0307] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 800 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1040 ° C, keep it warm for 300 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0308] (5) The same as step (5) in Example 1;

[0309] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 120 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 4.1 μm;

[0310] (7) The same as step (7) in Example 2;

[0311] (8) The same as step (8) in Example 3;

[0312] (9) The same as step (9) in Example 3;

[0313] (10) is the same as step (10) in Example 1;

[0314] (11) is the same as step (11) in Example 1.

[0315] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0316] Embodiment 19

[0317] (1) Weigh the purified RFeB oil sludge and mix it with reducing medium calcium particles at a mass ratio of 6:1;

[0318] (2) Then put it into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 60 minutes, and the stirrer speed is 100 rpm;

[0319] (3) The same as step (3) in Example 1;

[0320] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 800 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1040 ° C, keep it warm for 300 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0321] (5) The same as step (5) in Example 1;

[0322] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 120 μm, and then ground by a jet mill under a nitrogen atmosphere to an average particle size of 4.1 μm;

[0323] (7) The same as step (7) in Example 2;

[0324] (8) The same as step (8) in Example 9;

[0325] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 30 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0326] (10) is the same as step (10) in Example 1;

[0327] (11) is the same as step (11) in Example 1.

[0328] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0329] Embodiment 20

[0330] (1) The same as step (1) in Example 16;

[0331] (2) The mixture was then placed in a stirring mixing tank at a speed of 120 rpm, a mixing time of 40 min, and a stirrer speed of 150 rpm;

[0332] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation speed of 80 rpm, a heating temperature of 80°C, and a time of 60 minutes;

[0333] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 60 minutes to perform a primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 480 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0334] (5) The same as step (5) in Example 1;

[0335] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 120 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.8 μm;

[0336] (7) The same as step (7) in Example 2;

[0337] (8) The same as step (8) in Example 3; (9) Place the cleaner in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 40 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution at the top of the cleaner and add the cleaning solution again, repeat the above cleaning process 3 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0338] (10) is the same as step (10) in Example 6;

[0339] (11) is the same as step (11) in Example 1.

[0340] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0341] Embodiment 21

[0342] (1) The same as step (1) in Example 17;

[0343] (2) Then put it into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 40 minutes, and the stirrer speed is 150 rpm;

[0344] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation speed of 80 rpm, a heating temperature of 80°C, and a time of 60 minutes;

[0345] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 60 minutes to perform a primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 480 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0346] (5) The same as step (5) in Example 1;

[0347] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 120 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 4.1 μm;

[0348] (7) The same as step (7) in Example 2;

[0349] (8) The same as step (8) in Example 3;

[0350] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 50 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 3 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0351] (10) is the same as step (10) in Example 6;

[0352] (11) is the same as step (11) in Example 1.

[0353] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0354] Embodiment 22

[0355] (1) The same as step (1) in Example 18; (2) Then put into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 40 minutes, and the stirrer speed is 150 rpm;

[0356] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation speed of 80 rpm, a heating temperature of 80°C, and a time of 60 minutes;

[0357] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 300 minutes, perform secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0358] (5) The same as step (5) in Example 1;

[0359] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 4.1 μm;

[0360] (7) The same as step (7) in Example 2;

[0361] (8) The same as step (8) in Example 4;

[0362] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 50 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0363] (10) is the same as step (10) in Example 6;

[0364] (11) is the same as step (11) in Example 1.

[0365] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0366] Embodiment 23

[0367] (1) The same as step (1) in Example 19;

[0368] (2) The mixture was then placed in a stirring mixing tank at a speed of 80 rpm, a mixing time of 40 min, and a stirrer speed of 150 rpm;

[0369] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation speed of 80 rpm, a heating temperature of 80°C, and a time of 60 minutes;

[0370] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 300 minutes, perform secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.05 MPa;

[0371] (5) The same as step (5) in Example 1;

[0372] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.5 μm;

[0373] (7) The same as step (7) in Example 5;

[0374] (8) The same as step (8) in Example 4;

[0375] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 50 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0376] (10) is the same as step (10) in Example 6;

[0377] (11) is the same as step (11) in Example 1.

[0378] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0379] Embodiment 24

[0380] (1) The same as step (1) in Example 16;

[0381] (2) Then put it into a stirring mixing tank, the mixing tank speed is 120 rpm, the mixing time is 50 minutes, and the stirrer speed is 120 rpm;

[0382] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 100°C, and a time of 40 minutes;

[0383] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature of 850 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature of 980 ° C, keep it warm for 480 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0384] (5) The same as step (5) in Example 1;

[0385] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0386] (7) The same as step (7) in Example 5;

[0387] (8) The same as step (8) in Example 3;

[0388] (9) The same as step (9) in Example 3;

[0389] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 300°C, and to be kept warm for 60 minutes for degassing, activation, and drying. The upper pressure valve pressure of the rotary furnace is set to 0.01 MPa, thereby obtaining regenerated RFeB magnetic powder;

[0390] (11) is the same as step (11) in Example 1.

[0391] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0392] Embodiment 25

[0393] (1) The same as step (1) in Example 17;

[0394] (2) Then put it into a stirring mixing tank, the mixing tank speed is 120 rpm, the mixing time is 50 minutes, and the stirrer speed is 120 rpm;

[0395] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 100°C, and a time of 50 minutes;

[0396] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature of 850 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature of 980 ° C, keep it warm for 480 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0397] (5) The same as step (5) in Example 1;

[0398] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.1 μm;

[0399] (7) The same as step (7) in Example 5;

[0400] (8) The same as step (8) in Example 3;

[0401] (9) The same as step (9) in Example 3;

[0402] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 300°C, and to be kept warm for 60 minutes for degassing, activation, and drying. The upper pressure valve pressure of the rotary furnace is set to 0.01 MPa, thereby obtaining regenerated RFeB magnetic powder;

[0403] (11) is the same as step (11) in Example 1.

[0404] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0405] Embodiment 26

[0406] (1) The same as step (1) in Example 18;

[0407] (2) Then put it into a stirring mixing tank, the mixing tank speed is 100 rpm, the mixing time is 40 minutes, and the stirrer speed is 100 rpm;

[0408] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 80°C, and a heating time of 60 minutes;

[0409] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature of 850 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature of 980 ° C, keep it warm for 480 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0410] (5) The same as step (5) in Example 1;

[0411] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.5 μm;

[0412] (7) The same as step (7) in Example 5;

[0413] (8) The same as step (8) in Example 9;

[0414] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 30 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0415] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 300°C, and to be kept warm for 60 minutes for degassing, activation, and drying. The upper pressure limit valve pressure of the rotary furnace is set to 0.01 MPa to obtain regenerated RFeB magnetic powder;

[0416] (11) is the same as step (11) in Example 1.

[0417] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0418] Embodiment 27

[0419] (1) The same as step (1) in Example 19;

[0420] (2) The mixture was then placed in a stirring mixing tank at a speed of 80 rpm, a mixing time of 40 min, and a stirrer speed of 100 rpm;

[0421] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 80°C, and a heating time of 60 minutes;

[0422] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature of 850 ° C, and keep it warm for 60 minutes to perform primary reduction treatment; then heat to the third temperature of 980 ° C, keep it warm for 480 minutes, perform secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0423] (5) The same as step (5) in Example 1;

[0424] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.5 μm;

[0425] (7) The same as step (7) in Example 12;

[0426] (8) The same as step (8) in Example 9;

[0427] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 30 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0428] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 300°C, and to be kept warm for 60 minutes for degassing, activation, and drying. The upper pressure limit valve pressure of the rotary furnace is set to 0.01 MPa to obtain regenerated RFeB magnetic powder;

[0429] (11) is the same as step (11) in Example 1.

[0430] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0431] Embodiment 28

[0432] (1) The same as step (1) in Example 16;

[0433] (2) The mixture was then placed in a stirring mixing tank at a speed of 100 rpm, a mixing time of 50 min, and a stirrer speed of 120 rpm;

[0434] (3) After mixing, the powder was loaded into a rotary furnace in batches at a rotation rate of 120 rpm, a heating temperature of 100°C, and a heating time of 60 minutes;

[0435] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature of 850 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature of 950 ° C, keep it warm for 480 minutes, perform a secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0436] (5) The same as step (5) in Example 1;

[0437] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0438] (7) The same as step (7) in Example 12;

[0439] (8) The same as step (8) in Example 9;

[0440] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 30 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0441] (10) The same as step (10) in Example 11;

[0442] (11) is the same as step (11) in Example 1.

[0443] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0444] Embodiment 29

[0445] (1) The same as step (1) in Example 18;

[0446] (2) The mixture was then placed in a stirring mixing tank at a speed of 80 rpm, a mixing time of 30 min, and a stirrer speed of 100 rpm;

[0447] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 80°C, and a heating time of 60 minutes;

[0448] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature of 850 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature of 950 ° C, keep it warm for 480 minutes, perform a secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0449] (5) The same as step (5) in Example 1;

[0450] (6) the alloy ingot was loaded into a crusher and crushed to an average particle size of 150 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0451] (7) The same as step (7) in Example 12;

[0452] (8) The same as step (8) in Example 3;

[0453] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 40 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 3 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0454] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is set to heat up at a rate of 5°C / min, a heating temperature of 280°C, and is kept warm for 30 minutes for degassing, activation, and drying. The upper pressure limit valve pressure of the rotary furnace is set to 0.01 MPa to obtain regenerated RFeB magnetic powder;

[0455] (11) is the same as step (11) in Example 1.

[0456] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0457] Embodiment 30

[0458] (1) The same as step (1) in Example 16;

[0459] (2) The mixture was then placed in a stirring mixing tank at a speed of 80 rpm, a mixing time of 30 min, and a stirrer speed of 100 rpm;

[0460] (3) After mixing, the powder is loaded into a rotary furnace in batches at a rotation rate of 100 rpm, a heating temperature of 80°C, and a heating time of 60 minutes;

[0461] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature of 850 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature of 950 ° C, keep it warm for 480 minutes, perform a secondary diffusion treatment on the mixed powder, and control the pressure of the rotary furnace upper pressure valve to 0.05 MPa;

[0462] (5) The same as step (5) in Example 1;

[0463] (6) the alloy ingot was placed in a crusher and crushed to an average particle size of 100 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 3.2 μm;

[0464] (7) The same as step (7) in Example 12;

[0465] (8) The same as step (8) in Example 9;

[0466] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 40 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process twice; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0467] (10) The RFeB magnetic powder after impurity removal is again loaded into a rotary furnace into which hydrogen is continuously introduced, and the rotary furnace is heated at a rate of 5°C / min, a heating temperature of 280°C, and kept warm for 60 minutes for degassing, activation, and drying. The upper pressure limit valve pressure of the rotary furnace is set to 0.01 MPa to obtain regenerated RFeB magnetic powder;

[0468] (11) is the same as step (11) in Example 1. The test results of the total amount of rare earth elements, saturation magnetization and coercivity of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this example are shown in Table 1.

[0469] Embodiment 31

[0470] (1) Weigh the purified RFeB oil sludge and mix it with the reducing medium calcium hydride at a mass ratio of 22:1;

[0471] (2~11) are the same as steps (2~11) in Example 1.

[0472] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0473] Embodiment 32

[0474] (1) Weigh the purified RFeB oil sludge and mix it with reducing medium calcium particles at a mass ratio of 4:1;

[0475] (2~11) are the same as steps (2~11) in Example 19.

[0476] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0477] Embodiment 33

[0478] (1-2) is the same as step (1-2) in Example 1. (3) After mixing, the powder is loaded into the rotary furnace in batches, and the secondary vacuum pump system is turned on. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 300 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.02 MPa;

[0479] (4-10) are the same as steps (5-11) in Example 1.

[0480] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0481] Embodiment 34

[0482] (1-3) are the same as steps (1-3) in Example 1.

[0483] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2 Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature of 780 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature of 900 ° C, keep it warm for 300 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.02 MPa;

[0484] (5-11) Steps (5-11) are the same as those in Example 1.

[0485] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0486] Embodiment 35

[0487] (1-3) are the same as steps (1-3) in Example 1.

[0488] (4) Turn on the secondary vacuum pump system while heating. When the pressure gauge shows 10 -2Pa, set the rotary furnace heating rate to 10 ° C / min, heat to the second temperature 820 ° C, and keep it warm for 30 minutes to perform a primary reduction treatment; then heat to the third temperature 1020 ° C, keep it warm for 120 minutes, perform a secondary diffusion treatment on the mixed powder, and control the rotary furnace body upper pressure valve pressure to 0.02 MPa;

[0489] (5-11) Steps (5-11) are the same as those in Example 1.

[0490] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0491] Embodiment 36

[0492] (1-5) Steps (1-5) are the same as in Example 1.

[0493] (6) the alloy ingot is loaded into a crusher and crushed to an average particle size of 200 μm, and then ground by a jet mill under a nitrogen atmosphere to obtain a jet milled RFeB powder with an average particle size of 10 μm;

[0494] (7-11) Steps (7-11) are the same as those in Example 1.

[0495] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0496] Embodiment 37

[0497] (1-6) Steps (1-6) are the same as in Example 1.

[0498] (7) acetic acid, deionized water, and anhydrous ethanol are mixed in a volume ratio of 5:10:100 to prepare an impurity removal cleaning solution;

[0499] (8~11) are the same as steps (8~11) in Example 1.

[0500] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0501] Embodiment 38

[0502] (1-8) Steps (1-8) are the same as in Example 1.

[0503] (9) Place the cleaning device in an ultrasonic generator, set the ultrasonic frequency to 100 Hz, and clean for 20 seconds. After cleaning, let the mixed solution stand for about 1 minute, pour out the solution on the top of the cleaning device and add the cleaning solution again. Repeat the above cleaning process 6 times; wash again with anhydrous ethanol to obtain the RFeB magnetic powder after impurities are removed;

[0504] The test results of the total amount of rare earth elements, saturation magnetization and coercive force of the jet milled RFeB powder and the regenerated RFeB magnetic powder in this embodiment are shown in Table 1.

[0505] Table 1. Test results of total rare earth element content, saturation magnetization and coercivity of jet milled RFeB powder and regenerated RFeB magnetic powder

[0506]

[0507] In summary, the method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste of the present invention uses purified RFeB oil sludge, combined with rotary heating, primary reduction treatment, and secondary diffusion treatment, and uses impurity removal cleaning liquid to clean the air flow mill RFeB powder, thereby effectively improving the magnetic properties of the regenerated RFeB magnetic powder.

[0508] The various aspects, embodiments, and features of the present invention should be considered to be illustrative in all aspects and not limiting of the present invention, the scope of which is defined solely by the claims. Other embodiments, modifications, and uses will be apparent to those skilled in the art without departing from the spirit and scope of the claimed invention.

[0509] In the preparation method of the present invention, the order of each step is not limited to the order listed. For those skilled in the art, without creative work, the order of each step is also within the protection scope of the present invention. In addition, two or more steps or actions can be performed simultaneously.

[0510] Finally, it should be noted that the specific embodiments described herein are merely examples of the present invention, and are not intended to limit the implementation methods of the present invention. A person skilled in the art of the present invention may make various modifications or supplements to the specific embodiments described, or replace them in a similar manner. It is not necessary and impossible to provide all examples of all implementation methods here. However, these obvious changes or modifications derived from the essential spirit of the present invention still fall within the scope of protection of the present invention, and interpreting them as any additional limitation is contrary to the spirit of the present invention.

Claims

1. A method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste, characterized in that: The R is one or more rare earth elements; the method comprises: mixing the purified RFeB type oil sludge with a reducing medium, placing it in a vacuum rotary furnace with an inert gas, rotating and heating it at a first temperature of 70 to 150°C, adjusting the vacuum degree, performing a primary reduction treatment at a second temperature of 600 to 890°C, performing a secondary diffusion treatment at a third temperature of 900 to 1100°C to obtain an alloy ingot, and obtaining recycled RFeB magnetic powder through pulverizing.

2. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 1, characterized in that: The mass ratio of the purified RFeB oil sludge to the reducing medium is (1-30):

1.

3. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 1 or 2, characterized in that: The reducing medium includes one or more of calcium hydride, calcium particles, calcium chloride, and sodium borohydride.

4. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 3, characterized in that: When the reducing medium is calcium hydride, the mass ratio of the purified RFeB type sludge to the reducing medium is (11-19):

1.

5. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 3, characterized in that: When the reducing medium is calcium particles, the mass ratio of the purified RFeB type oil sludge to the reducing medium is (6-9):

1.

6. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 1, characterized in that: The rotary heating includes: rotary heating at a first temperature of 80 to 100° C. for 1 to 300 minutes.

7. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 1, characterized in that: The primary reduction treatment comprises: maintaining the temperature at a second temperature of 700 to 890° C. for 1 to 300 minutes.

8. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 1, characterized in that: The secondary diffusion treatment includes: maintaining the temperature at a third temperature of 910-1100° C. for 100-1000 minutes.

9. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 1, characterized in that: The upper pressure limit valve pressure of the vacuum rotary furnace is 0.001-1 MPa.

10. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 1, characterized in that: The powder making comprises: crushing the alloy ingot, jet milling to obtain jet mill RFeB powder, mixing the jet mill RFeB powder with impurity removal cleaning liquid to obtain impurity-removed RFeB magnetic powder, and degassing, activating and drying the impurity-removed RFeB magnetic powder to obtain regenerated RFeB magnetic powder.

11. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 10, characterized in that: The impurity removal cleaning solution contains 0.1-10 wt % of acetic acid.

12. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 10, characterized in that: The impurity removal cleaning solution comprises acetic acid, water and anhydrous ethanol in a volume ratio of (1-5):(8-20):

100.

13. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 10, characterized in that: The mass ratio of the jet mill RFeB powder to the impurity removal cleaning liquid is 1:(10-200).

14. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 10, characterized in that: The degassing activation drying comprises: placing the impurity-removed RFeB magnetic powder into a rotary furnace into which hydrogen is continuously introduced, setting the rotary furnace heating rate to 1-10°C / min, the heating temperature to 180-400°C, and keeping the temperature for 10-600 minutes.

15. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 1, characterized in that: The purified RFeB oil sludge is obtained by purifying RFeB oil sludge waste.

16. The method for efficiently preparing and regenerating RFeB magnetic powder from RFeB oil sludge waste according to claim 15, characterized in that: The purification includes: placing the pretreated RFeB type oily sludge waste material in a vacuum rotary furnace with inert gas introduced, and performing a primary purification at 100-300°C; when the vacuum degree of the vacuum rotary furnace reaches a set threshold, introducing purification gas into the vacuum rotary furnace, and performing a secondary purification on the RFeB type oily sludge waste material after the primary purification at 300-500°C.

17. A regenerated RFeB magnetic powder, characterized in that: The magnetic powder is prepared by the method for efficiently preparing regenerated RFeB magnetic powder from RFeB oil sludge waste as described in any one of claims 1 to 16.

18. The regenerated RFeB magnetic powder according to claim 17, characterized in that: Compared with the purified RFeB sludge, the total rare earth element retention rate of the regenerated RFeB magnetic powder is ≥82%.

19. A regenerative RFeB magnet, characterized in that The regenerated RFeB magnet comprises 0.1-100 wt % of the regenerated RFeB magnetic powder produced by the method for efficiently producing regenerated RFeB magnetic powder from RFeB type oil sludge waste as claimed in any one of claims 1-16, or the regenerated RFeB magnetic powder as claimed in any one of claims 17-18.

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