Preparation method of rare earth neodymium-based regenerated magnetic powder

Abstract

The invention discloses a preparation method of rare earth neodymium-based regenerated magnetic powder. The method comprises the following steps: in an inert atmosphere, mixing rare earth neodymium-based mixed magnetic powder with an organic solvent, and carrying out ball milling to obtain a ball-milled material; under an inert atmosphere, mixing the ball-milled material with a decalcification washing solution according to a mass-volume ratio of 1g: (30-60) ml, performing ultrasonic treatment, and rinsing with a dehydration solvent to obtain rare earth neodymium-based regenerated magnetic powder; the decalcification washing liquid comprises 0.2-1.5 wt% of ammonium salt and the balance of water. According to the method, the ammonium salt is used as a core active component of the decalcification washing liquid, the concentration of the ammonium salt is low, the dosage of the ammonium salt is small, hydrogenation of Nd2Fe14B main phase magnetic powder is reduced, and efficient separation of a main product and a by-product in a reduction diffusion product is achieved; according to the ammonium salt decalcification washing liquid provided by the invention, other byproducts cannot be introduced in the decalcification process, and the saturation magnetization of the decalcified rare earth neodymium-based regenerated magnetic powder is improved by 125%, so that the ammonium salt decalcification washing liquid is crucial for later preparation of regenerated high-performance magnets.

Description

Technical Field

[0001] This invention relates to the field of rare earth functional magnetic materials technology, and in particular to a method for preparing rare earth neodymium-based regenerated magnetic powder. Background Technology

[0002] Currently, the reduction-diffusion technique is commonly used to recover NdFeB sludge (i.e., rare earth NdFeB-based sludge) waste. The reduction-diffusion reaction uses calcium hydride or hydrogen as a reducing agent to reduce rare earth compounds with transition metals to their elemental forms. The rare earth elements then combine with the transition metal elements to form rare earth intermetallic compounds, which are the main products of the reaction. Simultaneously, the reaction also produces byproducts, such as rare earth oxides and calcium oxides; therefore, these byproducts are mixed within the rare earth intermetallic compounds. In other words, after the reduction-diffusion process, rare earth NdFeB-based sludge waste yields a mixed rare earth NdFeB magnetic powder containing both the main product (rare earth NdFeB-based magnetic powder) and byproducts (rare earth oxides and calcium oxides). Therefore, after the reaction is complete, it is necessary to separate the main product from the byproducts in the rare earth NdFeB-based mixed magnetic powder.

[0003] Currently, the main methods for removing byproducts of reduction-diffusion reactions are solvent dissolution and density separation. For example, Chinese patent application (ZL201811438940.3) uses deionized water to dissolve calcium oxide generated by reduction-diffusion; however, deionized water has low impurity removal efficiency and is difficult to dissolve rare earth oxides, affecting the purity of the final regenerated magnetic powder. Another example is Chinese patent application (ZL202210424762.9), which uses ammonium chloride-methanol solution to separate the byproduct calcium oxide, but the introduction of Cl... - This has an adverse effect on the performance of regenerated NdFeB magnets, and the use of methanol will cause a significant environmental burden. For example, Chinese patent application (CN202310276900.8) uses liquid gallium as a separation medium, achieving separation of the main and byproducts of the reduction-diffusion reaction through density. Although this does not introduce new impurities during the separation process, liquid gallium is expensive, which is not conducive to large-scale production. Summary of the Invention

[0004] This invention provides a method for preparing rare earth neodymium-based regenerated magnetic powder, thereby solving at least one of the technical problems existing in the prior art.

[0005] A method for preparing rare earth neodymium-based regenerated magnetic powder, the method comprising: The recycled rare earth neodymium-based mixed magnetic powder tablets were placed in an inert gas glove box, ground and coarsely crushed using a corundum mortar, and passed through a 150-mesh sieve to obtain rare earth neodymium-based mixed magnetic powder containing main products and by-products. Under a protective atmosphere (nitrogen or inert gas), the rare earth neodymium-based mixed magnetic powder is mixed with an organic solvent and ball-milled to obtain a ball milling material; Under a protective atmosphere, the ball milling material and decalcification washing liquid are mixed at a mass-volume ratio of 1g:30~60ml, ultrasonicated, and rinsed with dehydrating solvent to obtain the rare earth neodymium-based regenerated magnetic powder. The decalcification washing solution comprises the following raw materials by weight percentage: 0.2-1.5 wt% ammonium salt and the balance being water.

[0006] In one embodiment, the particle size of the ball milling material is 2~5 μm.

[0007] In one embodiment, the ammonium salt includes at least one selected from ammonium acetate, ammonium citrate, ammonium sulfate, ammonium nitrate, and ammonium carbonate.

[0008] In one embodiment, the mass-to-volume ratio of the rare earth neodymium-based mixed magnetic powder to the organic solvent is 10g:20~40ml.

[0009] In one embodiment, the organic solvent includes at least one of anhydrous ethanol, heptane, and hexane.

[0010] In one embodiment, the mass ratio of the grinding balls used in the ball mill to the rare earth neodymium-based mixed magnetic powder is 40~60:10.

[0011] In one embodiment, the ball mill rotates at a speed of 200-1000 rpm and the milling time is 30-60 min.

[0012] In one embodiment, the dehydrating solvent includes one of acetone and anhydrous ethanol.

[0013] In one embodiment, the method further includes: drying the rare earth neodymium-based regenerated magnetic powder at 40-80°C for 60-240 minutes under an inert atmosphere.

[0014] Compared with the prior art, the advantages of this application are: 1) In the method of the present invention, the decalcification washing liquid uses ammonium salt as the core active component, with a low concentration (0.2~1.5wt%) and a small amount (mass-volume ratio of decalcification washing liquid to ball milling material 1g:30~60ml), which not only reduces Nd2Fe 14 B. Hydrogenation of the main phase magnetic powder enables efficient separation of the main product and by-product in the reduction diffusion product (i.e., rare earth neodymium-based mixed magnetic powder) (the calcium content in the main product is as low as 0.02 wt%), improving the purity of rare earth neodymium-based regenerated magnetic powder; 2) The ammonium salt decalcification washing solution provided by this invention does not introduce other by-products during the decalcification process, and the saturation magnetization of rare earth neodymium-based regenerated magnetic powder is increased by 125% after decalcification, which is crucial for the subsequent preparation of regenerated high-performance magnets; 3) The rare earth neodymium-based regenerated magnetic powder treated by this invention has an oxygen content of less than 3000 ppm, providing reliable technical support for the preparation of high-performance regenerated magnets.

[0015] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0016] The above and other objects, features, and advantages of this disclosure will become readily apparent from the following detailed description of exemplary embodiments, taken in conjunction with the accompanying drawings. Several embodiments of this disclosure are illustrated in the drawings by way of example and not limitation, in which: In the accompanying drawings, the same or corresponding reference numerals indicate the same or corresponding parts.

[0017] Figure 1 The XRD patterns of rare earth neodymium-based hybrid magnetic powder before and after decalcification are shown in the embodiments of this disclosure.

[0018] Figure 2 The SEM test results of rare earth neodymium-based mixed magnetic powder before and after decalcification according to an embodiment of the present disclosure are shown.

[0019] Figure 3 The results of magnetic properties of rare earth neodymium-based hybrid magnetic powder before and after decalcification according to embodiments of the present disclosure are shown.

[0020] Figure 4 A flow chart of the rare earth neodymium-based hybrid magnetic powder decalcification process according to an embodiment of the present disclosure is shown. Detailed Implementation

[0021] To make the objectives, features, and advantages of this disclosure more apparent and understandable, the technical solutions in the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the scope of protection of this disclosure.

[0022] This application provides a method for preparing rare earth neodymium-based regenerated magnetic powder, comprising the following steps: Step 1) The regenerated rare earth neodymium-based mixed magnetic powder tablets are placed in an inert gas glove box, ground and coarsely crushed using a corundum mortar, and passed through a 150-mesh sieve to obtain rare earth neodymium-based mixed magnetic powder containing the main product and by-product.

[0023] Step 2), under an inert atmosphere, rare earth neodymium-based mixed magnetic powder is mixed with an organic solvent and ball-milled to obtain ball milling material; Step 3), under an inert atmosphere, the ball milling material and decalcification washing solution are mixed at a mass-volume ratio of 1g:30~60ml, ultrasonicated, and rinsed with dehydrating solvent to obtain rare earth neodymium-based regenerated magnetic powder; The decalcification washing solution includes the following raw materials by weight percentage: 0.2~1.5wt% ammonium salt and the balance being water.

[0024] In the method of this application, by refining the rare earth neodymium-based mixed magnetic powder (such as by ball milling), the contact time, solution concentration and solution volume between the rare earth neodymium-based mixed magnetic powder and the decalcification washing solution are reduced, thereby achieving efficient removal of impurity byproducts without causing corrosion to the neodymium iron boron main phase alloy (i.e., the main product).

[0025] This application employs a two-stage process of ball milling to refine particle size followed by ammonium salt solution treatment, which can improve the purity of rare earth neodymium-based regenerated magnetic powder. The calcium content in the rare earth neodymium-based regenerated magnetic powder is as low as 0.02 wt%, and scanning electron microscopy (SEM) energy dispersive spectroscopy analysis shows that there are almost no residual calcium oxide impurities on its surface (e.g., Figure 2 As shown in the figure, the oxygen content of the magnetic powder was effectively controlled. This method provides effective technical support for the preparation of rare earth neodymium-based regenerated magnetic powder from rare earth neodymium-based sludge waste. Furthermore, this method is simple, uses inexpensive raw materials, reduces the separation cost of the main product and by-products, and is easy to mass-produce.

[0026] In this application, the reduction-diffusion product (i.e., rare earth neodymium-based mixed magnetic powder) generated from the rare earth neodymium-based sludge waste through a reduction-diffusion reaction can be achieved using existing known technologies. For example, Chinese patent application (CN104690277A) discloses a method for recovering neodymium iron boron sludge using reduction-diffusion technology, wherein the neodymium iron boron sludge waste undergoes pretreatment in steps 1)-2) and then reduction-diffusion in step 3) to obtain the reduction-diffusion product. Chinese patent application (CN109338113A) discloses a method for recovering neodymium iron boron perforated sludge waste using calcium-chloride reduction-diffusion technology, wherein the neodymium iron boron sludge waste undergoes pretreatment in step 1) and then reduction-diffusion in step 2) to obtain the reduction-diffusion product. Chinese patent application (CN117936261A) discloses a two-step calcium reduction diffusion technology for high-performance regeneration of NdFeB sludge, wherein the NdFeB sludge waste undergoes pretreatment in step 1) and then reduction diffusion in step 2) to obtain reduction diffusion products.

[0027] In one embodiment, in step 2), the mass-to-volume ratio of rare earth neodymium-based mixed magnetic powder to organic solvent is 10g:20~40ml. Exemplarily, the mass-to-volume ratio of rare earth neodymium-based mixed magnetic powder to organic solvent is 10g:20ml, 10g:30ml, or 10g:40ml.

[0028] For example, organic solvents include, but are not limited to, anhydrous ethanol, heptane, and hexane.

[0029] In one embodiment, in step 2), the mass ratio of grinding balls to rare-earth neodymium-based mixed magnetic powder used in the ball mill is 40-60 g:10 g. Exemplarily, the mass ratio of grinding balls to rare-earth neodymium-based mixed magnetic powder is 40 g:10 g, 50 g:10 g, or 60 g:10 g. For example, the grinding balls are made of 304 stainless steel and have a size of 4.7 ± 0.7 mm.

[0030] For example, the ball mill rotation speed is 200~1000 rpm and the ball milling time is 30~60 min.

[0031] For example, in step 2), the particle size of the ball milling material is 2~5 μm.

[0032] In one embodiment, in step 3), the ammonium salt includes at least one selected from ammonium acetate, ammonium citrate, ammonium sulfate, ammonium nitrate, and ammonium carbonate. Preferably, the ammonium salt is ammonium sulfate. Preferably, the mass percentage of the ammonium salt in the decalcification washing solution is 0.2 wt%, 0.5 wt%, 0.75 wt%, and 1.5 wt%.

[0033] For example, in step 3), the dehydration solvent includes one of acetone and anhydrous ethanol.

[0034] Preferably, in step 3), the mass-to-volume ratio of the ball milling material to the decalcification washing liquid is 1g:30ml, 1g:40ml, 1g:50ml, or 1g:60ml.

[0035] In one embodiment, the method of this application further includes: step 4), drying rare earth neodymium-based regenerated magnetic powder at 40~80℃ for 60~240 min under an inert atmosphere to obtain dried rare earth neodymium-based regenerated magnetic powder.

[0036] For example, the inert atmosphere includes, but is not limited to, nitrogen, helium, and argon.

[0037] The present application will be further described in detail below with reference to embodiments: Example 1 A method for preparing rare earth neodymium-based regenerated magnetic powder includes the following steps: Step 1): Place the regenerated rare earth neodymium-based mixed magnetic powder tablets in an inert gas glove box, grind and coarsely crush them using a corundum mortar and pestle, and pass them through a 150-mesh sieve to obtain rare earth neodymium-based mixed magnetic powder. Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:50g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:30ml; the mixture is then ball-milled at 800rpm for 30min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.75 wt% ammonium sulfate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 40 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 80°C for 60 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0038] The ICP test results of the dried rare earth neodymium-based regenerated magnetic powder obtained in Example 1 are shown in Table 1. The XRD patterns of the rare earth neodymium-based mixed magnetic powder before and after decalcification are shown in Table 1. Figure 1 SEM test results of rare earth neodymium-based mixed magnetic powder before and after decalcification are shown in [the table]. Figure 2 ,in Figure 2 a represents the SEM test results of rare earth neodymium-based mixed magnetic powder before decalcification. Figure 2 b represents the SEM test results of rare-earth neodymium-based mixed magnetic powder after decalcification. From... Figure 2 It can be seen that the calcium content is significantly reduced after decalcification of rare earth neodymium-based mixed magnetic powder. Figure 3 The results show the magnetic properties of rare earth neodymium-based mixed magnetic powder before and after decalcification. Figure 3 It can be seen that the magnetic properties of rare earth neodymium-based hybrid magnetic powder are significantly improved after decalcification, with the saturation magnetization increasing by 125%. The process flow diagram for decalcification of rare earth neodymium-based hybrid magnetic powder is shown below. Figure 4 .

[0039] Example 2 The preparation method in Example 2 is largely the same as that in Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:20ml; the mixture is then ball-milled at 200rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5μm. Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium sulfate and the remainder being water); wherein the ratio of ball milling material to decalcification washing solution is 1 g: 30 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 240 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0040] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 2 are shown in Table 1.

[0041] Example 3 The preparation method in Example 3 is largely the same as that in Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:30ml; the mixture is then ball-milled at 800rpm for 45min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.2 wt% ammonium nitrate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 60 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 80°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0042] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 3 are shown in Table 1.

[0043] Example 4 The preparation method in Example 4 is largely the same as that in Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:60g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:40ml; the mixture is then ball-milled at 600rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium nitrate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 30 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0044] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 4 are shown in Table 1.

[0045] Example 5 The preparation method of Example 5 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to heptane, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:50g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to heptane is 10g:30ml; the mixture is then ball-milled at 800rpm for 30min in a high-energy ball mill to obtain grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.75 wt% ammonium acetate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 40 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 240 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0046] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 5 are shown in Table 1.

[0047] Example 6 The preparation method of Example 6 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:20ml; the mixture is then ball-milled at 200rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5μm. Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium sulfate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 30 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 60°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0048] The ICP test results of the dried rare earth neodymium-based regenerated magnetic powder obtained in Example 6 are shown in Table 1.

[0049] Example 7 The preparation method of Example 7 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to hexane, along with grinding beads; the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to hexane is 10g:30ml; the mixture is then ball-milled at 800rpm for 45min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm. Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.2 wt% ammonium acetate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 60 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with anhydrous ethanol to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 80°C for 60 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0050] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 7 are shown in Table 1.

[0051] Example 8 The preparation method of Example 8 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:60g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:40ml; the mixture is then ball-milled at 600rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium carbonate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 30 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 60°C for 180 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0052] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 8 are shown in Table 1.

[0053] Example 9 The preparation method of Example 9 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to heptane, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:50g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to heptane is 10g:30ml; the mixture is then ball-milled at 800rpm for 30min in a high-energy ball mill to obtain grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.75 wt% ammonium nitrate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 40 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0054] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 9 are shown in Table 1.

[0055] Example 10 The preparation method of Example 10 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:30ml; the mixture is then ball-milled at 200rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium sulfate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 30 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 80°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0056] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 10 are shown in Table 1.

[0057] Example 11 The preparation method of Example 11 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to hexane, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to hexane is 10g:30ml; the mixture is then ball-milled at 1000rpm for 30min in a high-energy ball mill to obtain grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.2 wt% ammonium citrate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 50 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0058] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 11 are shown in Table 1.

[0059] Example 12 The preparation method of Example 12 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:50g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:30ml; the mixture is then ball-milled at 800rpm for 45min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.75 wt% ammonium citrate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 40 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 60°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0060] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 12 are shown in Table 1.

[0061] Example 13 The preparation method of Example 13 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to hexane, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:50g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to hexane is 10g:30ml; the mixture is ball-milled at 400rpm for 60min in a high-energy ball mill to obtain grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium citrate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 40 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0062] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 13 are shown in Table 1.

[0063] Example 14 The preparation method of Example 14 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:50g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:30ml; the mixture is then ball-milled at 1000rpm for 30min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.2 wt% ammonium carbonate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 40 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with anhydrous ethanol to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 180 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0064] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 14 are shown in Table 1.

[0065] Example 15 The preparation method of Example 15 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to heptane, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to heptane is 10g:30ml; the mixture is then ball-milled at 600rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium acetate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 60 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 80°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0066] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 15 are shown in Table 1.

[0067] Example 16 The preparation method of Example 16 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:40ml; the mixture is then ball-milled at 600rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.2 wt% ammonium acetate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 60 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 240 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0068] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 16 are shown in Table 1.

[0069] Example 17 The preparation method of Example 17 is largely the same as that of Example 1, except that: Step 2): Under an argon protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:30ml; the mixture is then ball-milled at 400rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm. Step 3): Under an argon protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.5 wt% ammonium acetate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 60 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under an argon protective atmosphere at a temperature of 60°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0070] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 17 are shown in Table 1.

[0071] Example 18 The preparation method of Example 18 is largely the same as that of Example 1, except that: Step 2): Under an argon protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:40ml; the mixture is then ball-milled at 200rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under an argon protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.2 wt% ammonium sulfate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 60 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with anhydrous ethanol to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under an argon protective atmosphere at a temperature of 80°C for 60 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0072] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 18 are shown in Table 1.

[0073] Example 19 The preparation method of Example 19 is largely the same as that of Example 1, except that: Step 2): Under a helium protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:40ml; the mixture is then ball-milled at 1000rpm for 30min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a helium protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 0.75 wt% ammonium acetate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 60 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a helium protective atmosphere at a temperature of 60°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0074] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 19 are shown in Table 1.

[0075] Example 20 The preparation method of Example 20 is largely the same as that of Example 1, except that: Step 2): Under a helium protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; wherein the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:30ml; the mixture is then ball-milled at 1000rpm for 30min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm; Step 3): Under a helium protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium carbonate and the remainder being water); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 40 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a helium protective atmosphere at a temperature of 60°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0076] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Example 20 are shown in Table 1.

[0077] Comparative Example 1 The preparation method of Comparative Example 1 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:20ml; the mixture is then ball-milled at 600rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm. Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add deionized water; wherein the mass-volume ratio of the ball milling material to the deionized water is 1g:30ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse with acetone 2 times to separate the main product and by-product of rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder. Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0078] The ICP test results of the dried rare earth neodymium-based regenerated magnetic powder obtained in Comparative Example 1 are shown in Table 1.

[0079] Comparative Example 2 The preparation method of Comparative Example 2 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:20ml; the mixture is then ball-milled at 600rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm. Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% ammonium chloride and the remainder being methanol solution); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 30 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0080] The ICP test results of the dried rare earth neodymium-based regenerated magnetic powder obtained in Comparative Example 2 are shown in Table 1. As can be seen from Table 1, although the calcium content in Comparative Example 2 is only slightly different from the calcium content obtained using the method described in this embodiment, Comparative Example 2 used a decalcification washing solution containing ammonium chloride and methanol. During the washing process, Cl...- , and Cl - The introduction of methanol has an adverse effect on the performance of recycled rare earth neodymium-based magnets, while the use of methanol will cause a significant environmental burden.

[0081] Comparative Example 3 The preparation method of Comparative Example 3 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol, along with grinding beads; the mass ratio of rare earth neodymium-based mixed magnetic powder to grinding beads is 10g:40g, and the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:20ml; the mixture is then ball-milled at 600rpm for 60min in a high-energy ball mill to obtain a grinding media with a particle size of 2~5 μm. Step 3): Under a nitrogen protective atmosphere, place the ball milling material into a beaker and add a decalcification washing solution (including 1.5 wt% glycerol and the remainder being methanol solution); wherein the mass-volume ratio of the ball milling material to the decalcification washing solution is 1 g: 30 ml; stir and sonicate, perform chemical rinsing 3 times, and then rinse twice with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0082] The ICP test results of the dried rare earth neodymium-based regenerated magnetic powder obtained in Comparative Example 3 are shown in Table 1.

[0083] Comparative Example 4 The preparation method of Comparative Example 4 is largely the same as that of Example 1, except that: Step 2): Under a nitrogen protective atmosphere, rare earth neodymium-based mixed magnetic powder is added to anhydrous ethanol (the mass-volume ratio of rare earth neodymium-based mixed magnetic powder to anhydrous ethanol is 10g:30ml), and then manually ground in a mortar and passed through a 150-mesh sieve to obtain finely ground rare earth neodymium-based mixed magnetic powder with a particle size of 60~90 μm. Step 3): Under a nitrogen protective atmosphere, the ground rare earth neodymium-based mixed magnetic powder is placed in a beaker, and a decalcification washing solution (including 0.75 wt% acetic acid and the remainder being water) is added; wherein, the mass-volume ratio of the ground rare earth neodymium-based mixed magnetic powder to the decalcification washing solution is 1 g: 30 ml; the mixture is stirred and sonicated, chemically washed 3 times, and then washed 2 times with acetone to separate the main product and by-product of the rare earth neodymium-based mixed magnetic powder, thereby obtaining rare earth neodymium-based regenerated magnetic powder; Step 4) Dry the rare earth neodymium-based regenerated magnetic powder in a glove box under a nitrogen protective atmosphere at a temperature of 40°C for 120 minutes to obtain the dried rare earth neodymium-based regenerated magnetic powder.

[0084] The ICP test results of the rare earth neodymium-based regenerated magnetic powder dried product obtained in Comparative Example 4 are shown in Table 1.

[0085] Table 1. ICP test results of the dried rare earth neodymium-based regenerated magnetic powder products of the examples and comparative examples. It should be understood that the various forms of processes shown above can be used to rearrange, add, or delete steps. For example, the steps described in this disclosure can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution disclosed in this disclosure can be achieved, and this is not limited herein.

[0086] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this disclosure, "a plurality of" means two or more, unless otherwise explicitly specified.

[0087] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims.

Claims

1. A method for preparing rare earth neodymium-based regenerated magnetic powder, characterized in that: Includes the following steps: Rare earth neodymium-based mixed magnetic powder was mixed with an organic solvent and ball-milled under a protective atmosphere to obtain ball milling material; Under a protective atmosphere, the ball milling material and decalcification washing solution were mixed at a mass-volume ratio of 1g:30~60ml, ultrasonicated, and rinsed with dehydrating solvent to obtain rare earth neodymium-based regenerated magnetic powder; The decalcification washing solution comprises the following raw materials by weight percentage: 0.2-1.5 wt% ammonium salt and the balance being water.

2. The method according to claim 1, characterized in that: The preparation of the rare earth neodymium-based hybrid magnetic powder specifically includes: The regenerated rare earth neodymium-based mixed magnetic powder tablets were placed in an inert gas glove box, ground and coarsely crushed using a corundum mortar, and then sieved to obtain rare earth neodymium-based mixed magnetic powder containing both main and by-products.

3. The method according to claim 1, characterized in that: The particle size of the ball milling material is 2~5 μm.

4. The method according to claim 1, characterized in that: The ammonium salt is at least one selected from ammonium acetate, ammonium citrate, ammonium sulfate, ammonium nitrate, and ammonium carbonate.

5. The method according to claim 1, characterized in that: The mass-volume ratio of the rare earth neodymium-based mixed magnetic powder to the organic solvent is 10g:20~40ml.

6. The method according to claim 5, characterized in that: The organic solvent is at least one of anhydrous ethanol, heptane, and hexane.

7. The method according to claim 1, characterized in that: The mass ratio of the grinding balls to the rare earth neodymium-based mixed magnetic powder used in the ball mill is 40~60:

10.

8. The method according to claim 1, characterized in that: The ball mill rotates at a speed of 200-1000 rpm and the milling time is 30-60 min.

9. The method according to claim 1, characterized in that: The dehydration solvent is one of acetone and anhydrous ethanol.

10. The method according to any one of claims 1-9, characterized in that: The method further includes drying the rare earth neodymium-based regenerated magnetic powder at 40-80°C for at least 60-240 minutes under an inert atmosphere.

Images