Neodymium-iron-boron magnetic material produced from waste sintered magnetic material and method for producing neodymium-iron-boron magnetic material from waste

Abstract

The present invention provides a use of the blended alloy in the manufacture of neodymium-iron-boron magnetic material from waste sintered magnetic material, and further provides a manufacturing method of neodymium-iron-boron magnetic material from waste sintered magnetic material. The present invention proposes a blended alloy with a specific composition used in the manufacturing process of neodymium-iron-boron magnetic material from waste sintered magnetic material. This blended alloy with a specific composition can flexibly adjust the composition and performance of the product to meet the design requirements, ensure the consistency of the batch product, and not only improve the utilization rate of the waste sintered magnetic material, but also help improve the diffusion performance. The present invention provides a utilization method that can directly crush the waste magnetic material into an alloy without smelting and mix it with a rare earth-rich alloy, solving the defects of the rich phase of the scrap of alnico magnets and greatly improving the magnetic performance; no need to smelt, reducing the processing cost, and at the same time, it can realize 100% utilization of the scrap raw material of alnico magnets without being limited by the amount of smelting added.

Description

cross reference

[0001] This application claims priority to a Chinese patent application filed with the China Patent Office on November 16, 2021, bearing application number 202111354828.3 and entitled "Neodymium-iron-boron magnetic body produced from waste sintered magnetic body and method for producing neodymium-iron-boron magnetic body from waste", the entire contents of which are incorporated herein by reference. [Technical field]

[0002] The present invention relates to the technical field of magnetic material production, and relates to the use of a blended alloy in the production of a neodymium-iron-boron magnetic body from waste sintered magnetic bodies, a neodymium-iron-boron magnetic body produced from waste sintered magnetic bodies and a method thereof, in particular to the use of a blended alloy in the production of a neodymium-iron-boron magnetic body from waste sintered magnetic bodies, a neodymium-iron-boron magnetic body produced from waste sintered magnetic bodies, and a method for producing a neodymium-iron-boron magnetic body by recycling waste sintered magnetic bodies. [Background technology]

[0003] NdFe 14 It is well known that R-Fe-B type rare earth sintered magnets, which have B type compounds as the main phase, are the most high-performance permanent magnets among all magnetic materials, and are widely used in voice coil motors (VCM) for hard disk drives, servo motors, motors for inverter air conditioners, motors for hybrid cars, etc. The traditional manufacturing method of R-Fe-B type rare earth sintered magnets is mainly to produce magnetic bodies through processes such as melting alloys, crushing, pressing, and sintering. However, with the large-scale use of rare earth magnets, there is an increasing amount of scrap of alnico magnets generated in the manufacturing process and by consumers, so it is very important to recycle rare earth resources well and efficiently, which not only protects the environment but also saves resources. In the conventional process, the surface of the waste magnet is mainly washed and added to the smelting process as raw material, and then the waste magnetic material and raw materials are added to produce new alloys, but this causes some combustion loss during the smelting process, forming a lot of slag, which affects the yield, and the amount of scrap alnico magnet added is very limited, generally not exceeding 20%. Another method is to electrolytically refine the waste magnetic material, but this method usually only extracts rare earth elements, so other elements are wasted. Therefore, how to find a more rational way to utilize waste magnetic materials, reduce the loss of magnetic materials, improve the processing capacity of waste magnetic materials, make better use of the components of waste magnetic materials, and achieve the purpose of multi-directional recycling has become one of the urgent problems that many manufacturers and researchers in the industry need to solve. Summary of the Invention

[0004] In view of the above situation, the technical problem to be solved by the present invention is to provide a method for recycling magnetic waste and a new method for producing magnetic materials, especially a method for producing neodymium-iron-boron magnetic materials from waste. In the present invention, the scrap of alnico magnets does not need to go through a melting process, and the scrap of alnico magnets is directly crushed into powder and used. However, the directly recycled scrap of alnico magnets has defects in the grain boundary phase and impurities such as organic matter exist during the recycling process. Therefore, the present invention introduces the blending of the first alloy and the second alloy to well solve the defects of the rich phase of the scrap of alnico magnets, greatly improve the magnetic properties, and realize 100% utilization of the raw material of the scrap of alnico magnets. The blending alloy further improves the grain boundary structure, improves the efficiency of grain boundary penetration, and reduces the waste of heavy rare earth resources. At the same time, the process is simple and suitable for large-scale industrial production.

[0005] The present invention provides the use of a blended alloy in the manufacture of neodymium-iron-boron magnetic bodies from waste sintered magnetic bodies. The blended alloy has the general formula shown in Formula II. RE x -M y -T z -Bm II; (Wherein, 28 wt%≦x≦32 wt%, 0.35 wt%≦y≦1.6 wt%, 66 wt%≦z, 0.90 wt%≦m≦0.98 wt%, and x+y+z+m=100 wt%. RE is one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. T is selected from Fe and / or Co.

[0006] The present invention provides a neodymium-iron-boron magnetic body produced from waste sintered magnetic body, the neodymium-iron-boron magnetic body being obtained by production from raw materials including waste neodymium-iron-boron magnetic body, a first alloy, and a second alloy. The second alloy has the general formula shown in Formula II. RE x -M y -T z -B m II; (Wherein, 28 wt%≦x≦32 wt%, 0.35 wt%≦y≦1.6 wt%, 66 wt%≦z, 0.90 wt%≦m≦0.98 wt%, and x+y+z+m=100 wt%. RE is one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. T is selected from Fe and / or Co. Preferably, the second alloy is a compound alloy; The formulation includes a component formulation and / or a performance formulation, the second alloy has an oxygen content of less than 1000 ppm; The grain size of the second alloy is 2 to 5 μm. Preferably, the first alloy has the general formula shown in Formula I: RE x -M y -H z I; (Wherein, 80 wt%≦x≦97 wt%, 2.5 wt%≦y≦20 wt%, 0.05 wt%≦z≦0.5 wt%, and x+y+z=100 wt%. RE is one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. H is the element hydrogen. Preferably, the first alloy is a grain boundary additive phase alloy; the first alloy has an oxygen content of less than 1000 ppm; The grain size of the first alloy is 2 mm or less; The oxygen content of the waste neodymium-iron-boron magnetic material is less than 2000 ppm; The particle size of the waste neodymium-iron-boron magnetic material is 0.2 to 2 mm; The mass ratio of the waste neodymium-iron-boron magnetic material to the first alloy is (90-99):(1-10). Preferably, the mass ratio of the total mass of the waste neodymium-iron-boron magnetic material and the first alloy to the mass of the second alloy is (10-95):(90-5); The raw material further comprises an antioxidant and / or a lubricant; The feedstock further comprises a surface-infiltrated heavy rare earth element; The heavy rare earth element includes Dy and / or Tb, The content of the surface-penetrating heavy rare earth element in the total amount of the neodymium-iron-boron magnetic material is 0.2 wt % to 0.8 wt %.

[0007] The present invention further provides a method for producing a neodymium-iron-boron magnetic body by recycling waste sintered magnetic bodies, comprising: 1) crushing the waste neodymium-iron-boron magnetic material, and then subjecting it to hydro-grinding to obtain scrap coarse powder; smelting a first alloy raw material into a cast sheet or ingot; and then subjecting it to hydro-grinding to obtain a first alloy coarse powder; 2) mixing and pulverizing the scrap coarse powder and the first alloy coarse powder obtained in the above step to obtain a mixed fine powder; 3) mixing the second alloy powder with the mixed fine powder obtained in the above step again to obtain a mixed powder; 4) Orienting and compacting the mixed powder obtained in the above step, and then sintering the powder to obtain a neodymium-iron-boron magnetic material. Preferably, the particle size after the hydrogen pulverization is 2 mm or less. The thickness of the cast sheet obtained by melting and casting is 0.1 to 0.6 mm, The waste neodymium-iron-boron magnetic material includes magnetic waste of the same grade or magnetic waste of different grades; In the hydrogenation pulverization process, the hydrogen absorption time is 60 to 180 min, and the hydrogen absorption temperature is 20 to 300° C.; In the hydrogenation pulverization process, the hydrogen release time is 3 to 7 hours, and the hydrogen release temperature is 550 to 600°C; After the hydrogenation grinding, a water cooling step is further included, The water cooling time is 0.5 to 3 hours. Preferably, the particle size of the first alloy coarse powder is 0.2 to 2 mm; In the mixing step, an antioxidant is further added and mixed; The antioxidant is present in an amount of 0.02% to 0.1% by mass of the mixed fine powder; The second alloy powder is obtained by melting a second alloy raw material, hydrogen pulverization, and air flow pulverization, In the remixing step, further lubricant is added and mixed again; The content of the lubricant in the mass of the mixed powder is 0.02% to 0.1%; The particle size of the mixed powder is 2 to 5 μm. Preferably, the orientation molding includes orientation pressing and isostatic pressing, Specifically, the orientation molding and isostatic pressing are performed under an oxygen-free or low-oxygen condition, The sintering temperature is 1030 to 1060°C. The sintering time is 6 to 10 hours, After the sintering, a further aging step is included, The aging treatment includes a first aging treatment and a second aging treatment, The temperature of the first aging treatment is 700 to 950°C, The time of the first aging treatment is 2 to 15 hours, The temperature of the second aging treatment is 350 to 550°C. The time of the second aging treatment is 1 to 8 hours, After the sintering, the method further includes a penetration and diffusion step, Specifically, the infiltration and diffusion step is to apply a heavy rare earth to the surface of a magnetic blank that has been sintered and aged, and then to perform a heat treatment. The heat treatment includes a first heat treatment and a second heat treatment, The temperature of the first heat treatment is 850 to 950°C. The duration of the first heat treatment is 5 to 15 hours; The temperature of the second heat treatment is 450 to 600° C. The time for the second heat treatment is 3 to 6 hours.

[0008] The present invention relates to a method for producing a neodymium-iron-boron magnetic material from waste sintered magnetic material, comprising the steps of: x -M y -T z -B mThe present invention provides a method for producing a neodymium-iron-boron magnetic material by using waste sintered magnetic material. Compared with the prior art, the present invention uses waste magnetic material as raw material to melt in the prior process, which causes some combustion loss, forms a lot of slag, which affects the yield, and the amount of scrap alnico magnet added is very limited. According to the research of the present invention, after the surface of such waste magnetic material is cleaned, it is added to the melting process as raw material, and the melted alloy is hydro-pulverized and air-flow pulverized to produce fine powder of the waste, and the coercive force of the regenerated magnet is improved by adding heavy rare earth rich powder. In addition, in order to make it easy to sinter and mold, rare earth rich powder is mixed in to increase the content of rare earth in the waste sintered neodymium-iron-boron powder, and finally, in the method for producing a performance that meets the design requirements in the process of pressing, sintering, etc., adding heavy rare earth powder to mix the powder leads to a waste of heavy rare earth resources, and there are many impurities in the waste, and the gap between the grain boundaries is small, so that the subsequent grain boundary penetration is not easy, which affects the diffusion efficiency. Based on the above, the present invention creatively proposes a blended alloy with a specific composition used in the manufacturing process of neodymium-iron-boron magnetic material from waste sintered magnetic material. This blended alloy with a specific composition can flexibly adjust the composition and performance of the product to meet the design requirements, ensure the consistency of batch products, and not only improve the utilization rate of waste sintered magnetic material, but also help improve the diffusion performance, so the present invention provides a utilization method that can directly crush waste magnetic material into alloy without smelting and mix it with rare earth-rich alloy, solving the defects of rich phase of Alnico magnet scrap and greatly improving the magnetic performance; no need to smelt, reducing processing costs, and at the same time, realizing 100% utilization of Alnico magnet scrap raw material without being limited by the amount of smelting addition.

[0009] The method for producing neodymium-iron-boron magnetic material by recycling waste sintered magnetic material provided in the present invention is to prepare the waste magnetic material into alloy powder, and then mix it with the corresponding rare earth-rich alloy powder according to the alloy composition. This process can improve the utilization rate of waste material recovery, and solve the problems of the limited amount of waste magnetic material added in the smelting process, some burning loss, low yield, or waste of other elements in the electrolytic refining of rare earth. Compared with the case where waste material is added in the smelting process, this process does not require smelting, reduces costs, is simple and flexible, and can mass-produce magnetic material of different grades; and the resulting product Adding a small amount of the first alloy with a different composition can optimize the grain boundary diffusion path of the base material, improve the efficiency of grain boundary penetration, effectively improve the impurity composition of the grain boundary phase, improve the grain boundary defects of the waste, significantly improve the coercive force performance, improve the grain boundary diffusion effect, and reduce the waste of heavy rare earth resources; in addition, adding fine powder of the compounded alloy (second alloy) with a different composition ratio can flexibly adjust the composition and performance of the product to meet the design requirements, not only ensure the consistency of the batch product, but also further improve the grain boundary diffusion performance, improve the grain boundary diffusion effect, improve the efficiency of grain boundary penetration, improve the grain boundary defects of the waste, and further enhance the coercive force. The utilization method provided by the present invention aims to increase the recycling rate of rare earths, save resources, and reduce production costs. The present invention can efficiently recycle waste, has a high recycling rate, can be used at nearly 100%, save resources, and reduce costs. The present invention directly produces the required alloy powder A from the treated waste magnetic material through coarse crushing and hydrogen pulverization, and adds alloy B (first alloy) to improve the grain boundary defects of the waste material, improve performance, and improve the grain boundary diffusion effect; further, the addition of fine powder C of an alloy (second alloy) with a different compounding ratio can be used to produce different grades of substrates, which can further improve the performance of the magnetic material, and then process the substrates into semi-finished products, which are finally infiltrated to obtain the required neodymium-iron-boron finished products, with strong production flexibility and high comprehensive utilization rate of resources. As shown by the experimental results, the utilization method provided by the present invention can efficiently recycle waste, has a high recycling rate and can be used at nearly 100%, thereby saving resources and reducing costs. [Brief description of the drawings]

[0010] [Figure 1] FIG. 1 is a photograph of the metal structure of the neodymium-iron-boron magnetic material produced in Example 1 of the present invention. [Diagram 2] FIG. 2 is a photograph of the metal structure of the neodymium-iron-boron magnetic material produced in Comparative Example 1 of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] In order to further understand the present invention, preferred embodiments of the present invention will be described below using examples. It should be understood that the following description is intended to further explain the characteristics and advantages of the present invention and does not limit the scope of the claims of the present invention. All the raw materials of the present invention are not particularly limited in terms of their source, and may be purchased on the market or prepared according to conventional methods well known to those skilled in the art. All raw materials of the present invention are not particularly limited in their purity, but the present invention can use industrial purity or ordinary purity used in the field of neodymium-iron-boron magnetic materials. The present invention provides the use of a blended alloy in the manufacture of neodymium-iron-boron magnetic bodies from waste sintered magnetic bodies. The blended alloy has the general formula shown in Formula II. RE x -M y -T z -B m II; (Wherein, 28 wt%≦x≦32 wt%, 0.35 wt%≦y≦1.6 wt%, 66 wt%≦z, 0.90 wt%≦m≦0.98 wt%, and x+y+z+m=100 wt%. RE is one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. T is selected from Fe and / or Co. In the present invention, the RE is preferably one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb, and more preferably La, Ce, Ho, Gd, Pr, Nd, Dy or Tb.

[0012] In the present invention, M is preferably one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo, and more preferably Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd or Mo. In the present invention, T is preferably selected from Fe and / or Co, and more preferably Fe or Co. In the present invention, x+y+z+m=100wt%, and the x value, which is the proportion of RE, is 28wt% to 32wt%, preferably 28.5wt% to 31.5wt%, more preferably 29wt% to 31wt%, and more preferably 29.5wt% to 30.5wt%. The y value, which is the proportion of M, is 0.35wt% to 1.6wt%, preferably 0.65wt% to 1.3wt%, and more preferably 0.95wt% to 1.0wt%. The z value, which is the proportion of T, is 66wt%, preferably 63wt%, and more preferably 60wt%. The value m, which is the proportion of B, is 0.90 wt% to 0.98 wt%, preferably 0.91 wt% to 0.97 wt%, more preferably 0.92 wt% to 0.96 wt%, and more preferably 0.93 wt% to 0.95 wt%.

[0013] In the present invention, the compound alloy is the second alloy or alloy C. Further selection and parameters of the second alloy having the general formula shown in formula II below can also be used in the above applications. The present invention is not particularly limited to the specific definition of the formula II or formula I, and any such description manner well known to those skilled in the art may be understood as a mass ratio, a general formula, or other similar composition definition. The present invention provides a neodymium-iron-boron magnetic body produced from a waste sintered magnetic body obtained by producing the waste sintered magnetic body from raw materials including a waste neodymium-iron-boron magnetic body, a first alloy, and a second alloy. The second alloy has the general formula shown in Formula II. RE x -M y -T z -B m II; (Wherein, 28 wt%≦x≦32 wt%, 0.35 wt%≦y≦1.6 wt%, 66 wt%≦z, 0.90 wt%≦m≦0.98 wt%, and x+y+z+m=100 wt%. RE is one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. T is selected from Fe and / or Co.

[0014] In the present invention, the RE is preferably one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb, and more preferably La, Ce, Ho, Gd, Pr, Nd, Dy or Tb. In the present invention, M is preferably one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo, and more preferably Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd or Mo. In the present invention, T is preferably selected from Fe and / or Co, and more preferably Fe or Co. In the present invention, x+y+z+m=100wt%, and the x value, which is the proportion of RE, is 28wt% to 32wt%, preferably 28.5wt% to 31.5wt%, more preferably 29wt% to 31wt%, and more preferably 29.5wt% to 30.5wt%. The y value, which is the proportion of M, is 0.35wt% to 1.6wt%, preferably 0.65wt% to 1.3wt%, and more preferably 0.95wt% to 1.0wt%. The z value, which is the proportion of T, is 66wt%, preferably 63wt%, and more preferably 60wt%. The value m, which is the proportion of B, is 0.90 wt% to 0.98 wt%, preferably 0.91 wt% to 0.97 wt%, more preferably 0.92 wt% to 0.96 wt%, and more preferably 0.93 wt% to 0.95 wt%.

[0015] In the present invention, the second alloy is preferably a compound alloy. In the present invention, the oxygen content of said second alloy is preferably less than 1000 ppm, more preferably less than 900 ppm, and even more preferably less than 800 ppm. In the present invention, the second alloy is preferably an alloy powder, and the particle size of the second alloy is preferably 2 to 5 μm, more preferably 2.5 to 4.5 μm, and even more preferably 3 to 4 μm. In the present invention, the blending preferably includes a component blending and / or a performance blending, more preferably includes a component blending and a performance blending. Furthermore, the blending alloy can improve grain boundary defects and / or improve grain boundary diffusion effect, and can also improve the penetration effect, especially when blending with the first alloy. In the present invention, the first alloy preferably has the general formula shown in Formula I: RE x -M y -H z I; (Wherein, 80 wt%≦x≦97 wt%, 2.5 wt%≦y≦20 wt%, 0.05 wt%≦z≦0.5 wt%, and x+y+z=100 wt%. RE is one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. H is the element hydrogen.

[0016] In the present invention, the RE is preferably one or more selected from La, Ce, Ho, Gd, Pr, Nd, Dy and Tb, and more preferably La, Ce, Ho, Gd, Pr, Nd, Dy or Tb. In the present invention, M is preferably one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd, and Mo, and more preferably Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd, or Mo. In the present invention, the H is preferably a hydrogen atom. In the present invention, x+y+z=100wt%, and the x value, which is the proportion of RE, is 80wt% to 97wt%, preferably 82wt% to 95wt%, more preferably 85wt% to 92wt%, and more preferably 87wt% to 9wt%. The y value, which is the mass proportion of M, is 2.5wt% to 20wt%, preferably 4.5wt% to 16wt%, and more preferably 8.5wt% to 12wt%. The z value, which is the mass proportion of hydrogen element, is 0.05wt% to 0.5wt%, preferably 0.15wt% to 0.4wt%, and more preferably 0.25wt% to 0.3wt%. In the present invention, the first alloy is preferably a grain boundary additive phase alloy. Specifically, the grain boundary additive phase preferably includes an improvement in grain boundary defects and / or an improvement in grain boundary diffusion effect, and more preferably includes an improvement in grain boundary defects or an improvement in grain boundary diffusion effect.

[0017] In the present invention, the melting point of the first alloy described in the present invention is lower than the melting point of the grain boundaries of the alloy of the waste neodymium-iron-boron magnetic material. In the present invention, the oxygen content of the first alloy is preferably less than 1000 ppm, more preferably less than 900 ppm, and even more preferably less than 800 ppm. In the present invention, the grain size of the first alloy is preferably 2 mm or less, more preferably 1.8 mm or less, and more preferably 1.6 mm or less. In the present invention, the oxygen content of the waste neodymium-iron-boron magnetic material is preferably less than 2000 ppm, more preferably less than 1900 ppm, and even more preferably less than 1800 ppm. In the present invention, the particle size of the waste neodymium-iron-boron magnetic material is preferably 0.2 to 2 mm, more preferably 0.6 to 1.6 mm, and even more preferably 1.0 to 1.2 mm. In the present invention, the mass ratio of the waste neodymium-iron-boron magnetic material to the first alloy is preferably (90-99):(1-10), more preferably (92-97):(1-10), more preferably (94-95):(1-10), more preferably (90-99):(3-8), and more preferably (90-99):(5-6). In the present invention, the mass ratio of the total mass of the waste neodymium-iron-boron magnetic material and the first alloy to the mass of the second alloy is preferably (10-95):(90-5), more preferably (30-75):(90-5), more preferably (50-55):(90-5), more preferably (10-95):(70-25), and more preferably (10-95):(50-45). In the present invention, the raw material preferably contains an antioxidant and / or a lubricant, and more preferably contains an antioxidant or a lubricant. In the present invention, it is preferable that the raw material further contains a surface-penetrated heavy rare earth element. In the present invention, the heavy rare earth element preferably includes Dy and / or Tb, and more preferably includes Dy or Tb. In the present invention, the content of the surface-penetrated heavy rare earth element in the total amount of the neodymium-iron-boron magnetic body is preferably 0.2 wt% to 0.8 wt%, more preferably 0.3 wt% to 0.7 wt%, and more preferably 0.4 wt% to 0.6 wt%. In the present invention, rare earths mainly mean La, Ce, Ho, Gd, Pr, Nd, Dy and Tb.

[0018] In the present invention, the waste magnet refers to scrap or insufficient magnetic materials in the manufacturing process of magnetic materials, post-consumer motors, and sintered neodymium-iron-boron magnetic materials dismantled after parts are discarded. The present invention provides a method for producing a neodymium-iron-boron magnetic body by recycling waste sintered magnetic bodies, 1) Scrap neodymium-iron-boron magnetic material is crushed and hydrogen-pulverized to obtain coarse scrap powder; A step of melting a first alloy raw material to form a cast sheet or ingot, and then subjecting the first alloy raw material to hydrogen pulverization to obtain a first alloy coarse powder; 2) mixing the scrap coarse powder obtained in the above step with a first alloy coarse powder and pulverizing the mixture to obtain a mixed fine powder; 3) mixing the second alloy powder with the mixed powder obtained in the above step again to obtain a mixed powder; 4) Orienting and compacting the mixed powder obtained in the above step, and then sintering the powder to obtain a neodymium-iron-boron magnetic material. In the present invention, first, the waste neodymium-iron-boron magnetic material is crushed and then hydrogen-pulverized to obtain scrap coarse powder; The first alloy raw material is melted and formed into a cast sheet or ingot, and then subjected to hydrogen pulverization to obtain a first alloy coarse powder. In the present invention, the particle size after crushing is preferably 30 mm or less, more preferably 20 mm or less, and even more preferably 10 mm or less. In the present invention, the particle size after the hydrogen pulverization is preferably 2 mm or less, more preferably 1.9 mm or less, and even more preferably 1.8 mm or less. In the present invention, the thickness of the cast sheet obtained by melting and casting is preferably 0.1 to 0.6 mm, more preferably 0.2 to 0.5 mm, and more preferably 0.3 to 0.4 mm. In the present invention, the waste neodymium-iron-boron magnetic material preferably comprises magnetic waste of the same grade or magnetic waste of different grades. In the present invention, during the hydrogen pulverization process, the hydrogen absorption time is preferably 60 to 180 min, more preferably 80 to 160 min, and more preferably 100 to 140 min. The hydrogen absorption temperature is preferably 20 to 300°C, more preferably 60 to 260°C, more preferably 100 to 220°C, and more preferably 140 to 180°C. In the present invention, during the hydrogenation pulverization process, the hydrogen release time is preferably 3 to 7 h, more preferably 3.5 to 6.5 h, more preferably 4 to 6 h, more preferably 4.5 to 5.5 h, and the hydrogen release temperature is preferably 550 to 600°C, more preferably 560 to 590°C, more preferably 570 to 580°C. In the present invention, it is preferable to include a water cooling step after the hydrogrinding. In the present invention, the water cooling time is preferably 0.5 to 3 hours, more preferably 1 to 2.5 hours, and more preferably 1.5 to 2 hours.

[0019] The present invention further comprises mixing the scrap coarse powder obtained in the above step with the first alloy coarse powder, and pulverizing the mixture to obtain a mixed fine powder. In the present invention, the particle size of the first coarse alloy powder is preferably 0.2 to 2 mm, more preferably 0.6 to 1.6 mm, and more preferably 1.0 to 1.2 mm. In the present invention, it is preferable that an antioxidant is added and mixed in the mixing step. In the present invention, the content of the antioxidant in the mass of the mixed fine powder is preferably 0.02% to 0.1%, more preferably 0.06% to 0.16%, and more preferably 0.1% to 0.12%. The present invention then mixes the second alloy powder with the mixed fine powder obtained in the above step again to obtain a mixed powder. In the present invention, the second alloy powder is preferably obtained by melting a second alloy raw material, and then subjecting the melt to hydrogen pulverization and air flow pulverization. In the present invention, it is preferable to add a lubricant in the remixing step and then mix again. In the present invention, the content of the lubricant in the mass of the mixed powder is preferably 0.02% to 0.1%, more preferably 0.06% to 0.16%, and more preferably 0.1% to 0.12%. In the present invention, the particle size of the mixed powder is preferably from 2 to 5 μm, more preferably from 2.5 to 4.5 μm, and more preferably from 3 to 4 μm. Finally, the present invention obtains a neodymium-iron-boron magnetic material by orienting and compacting the mixed powder obtained in the above steps and sintering it.

[0020] In the present invention, it is preferable to include a penetration and diffusion step after the sintering, and specifically, the penetration and diffusion step is preferably performed by applying a heavy rare earth (surface-penetrated heavy rare earth element) to the surface of the magnetic blank that has been sintered and aging treated, and then further performing a heat treatment. In the present invention, the heat treatment preferably includes a first heat treatment and a second heat treatment. In the present invention, the temperature of the first heat treatment is preferably 850 to 950°C, more preferably 870 to 930°C, and even more preferably 890 to 910°C. In the present invention, the time for the first heat treatment is preferably 5 to 15 hours, more preferably 7 to 13 hours, and more preferably 9 to 11 hours. In the present invention, the temperature of the second heat treatment is preferably 450 to 600°C, more preferably 480 to 570°C, and even more preferably 510 to 540°C. In the present invention, the time for the second heat treatment is preferably 3 to 6 hours, more preferably 3.5 to 5.5 hours, and more preferably 4 to 5 hours. The manufacturing method of the neodymium-iron-boron magnetic material from the waste sintered magnetic material provided by the present invention is to remove the surface plating layer from the waste magnet, then the so-called raw material is crushed first, and the crushed raw material is further crushed by hydrogenation to prepare the alloy powder A. The first alloy mainly composed of rare earth is melted and the first alloy powder B is prepared by hydrogenation crushing; the first alloy powder is mixed with the alloy AB, and the alloy AB is crushed by air flow to obtain the fine powder AB; the C alloy (second alloy) is designed to adjust the component performance according to the composition of the formula of the alloy AB and the target components, and the C alloy is melted from the new raw material, hydrogenation crushed, and air flow crushed to obtain the alloy fine powder C. The fine powder AB and the fine powder C are mixed through processes such as stirring, molding, and sintering to manufacture a blank that meets the design requirements.

[0021] In order to complete and subdivide the entire recycling process, improve the efficiency of grain boundary penetration, further reduce the defects of the rich phase of the Alnico magnet scrap, improve the magnetic properties, better realize 100% utilization of the Alnico magnet scrap raw material, and better ensure the performance of the finished magnetic body, the recycling method of the above waste sintered magnetic body is specifically as follows: 1. In the present invention, the waste neodymium-iron-boron magnetic material is in the form of a lump of magnetic material and has an oxygen content of 5000ppm or less. The magnetic material is pre-treated by removing the plating layer, degreasing, washing, etc. to clean the surface, so that the oxygen content is 2000ppm or less. The magnetic material is then crushed primarily to a particle size of less than 30mm. The magnetic material is then crushed by hydrogenation to a particle size of 200um-2mm. The alloy is called A alloy. 2. R.E. x -M y -H z The powder is prepared as a grain boundary additive phase, and the size of the powder is 2 mm or less. The alloy is called B alloy (first alloy). RE x -M y -H zThe alloy powder is added to Alloy A as a rich phase alloy, where RE is at least one element selected from La, Ce, Ho, Gd, Pr, Nd, Dy, and Tb, M is at least one element selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd, and Mo, H is hydrogen, and 80 wt%≦x≦97 wt%, 2.5 wt%≦y≦20 wt%, 0.05 wt%≦z≦0.5 wt%, and x+y+z=100 wt%. The RE x -M y -H z The oxygen content of the alloy powder is less than 1000ppm. In the present invention, the melting point of the B alloy is lower than that of the A alloy grain boundary. The main function of the B alloy is to improve the grain boundary defects of the waste material to enhance its performance and improve the grain boundary diffusion effect. In the present invention, there is no special limitation on the manufacturing process of the B alloy, and any manufacturing process known to those skilled in the art can be used.

[0022] 3. RE x -M y -T z -B m The remaining powder is made into a blended alloy and used for performance blending, and the powder size is 2 to 5 μm. The alloy is called C alloy (second alloy). RE x -M y -T z -B m The alloy powder is mixed with the AB powder to form a compound alloy, where RE is at least one element selected from La, Ce, Ho, Gd, Pr, Nd, Dy, and Tb, M is at least one element selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd, and Mo, and R is at least one element of Fe and Co, where 28wt%≦x≦32wt%, 0.35wt%≦y≦1.6wt%, 66wt%≦z, 0.90wt%≦m≦0.98wt%, and x+y+z+m=100wt%. The RE x -M y -T z -B mThe oxygen content of the alloy powder is less than 1000ppm, and the C alloy is used to flexibly adjust the composition and properties of the product to meet the design requirements. The present invention does not have any special restrictions on the manufacturing process of the C alloy, and uses manufacturing processes well known to those skilled in the art. 4. Mix alloy A and alloy B in the appropriate ratio (A x -B 1-x Here, they are mixed at 90wt%≦x≦99wt%) to obtain alloy AB, an antioxidant is added to the alloy AB and mixed by stirring, and then air-flow pulverization is performed to obtain fine powder AB with an average particle size of 2 to 5μm. 5. Design alloy C to adjust the component performance according to the formulation composition of fine powder AB and the target components. Alloy C is produced from new raw materials through melting, hydro-pulverization, and airflow pulverization to obtain fine powder C with an average particle size of 2~5um. 6. Mix powder AB and powder C in the appropriate ratio ((AB) y C 1-y After mixing at 10wt%≦y≦95wt%), lubricant is added and stirred to mix uniformly, and then further processes such as orientation molding and sintering are carried out to produce sintered neodymium-iron-boron magnetic material. The addition of C improves the diffusion performance. 7. The sintered neodymium-iron-boron magnetic body is processed into a 2 mm sheet sample, and the sheet sample is infiltrated with 0.6 wt% Tb to obtain an infiltrated body.

[0023] The above steps of the present invention provide the use of the blended alloy in the manufacture of neodymium-iron-boron magnetic material from waste sintered magnetic material, the neodymium-iron-boron magnetic material manufactured from waste sintered magnetic material, and the method for manufacturing neodymium-iron-boron magnetic material by recycling waste sintered magnetic material. The present invention proposes a blended alloy with a specific composition for use in the process of manufacturing neodymium-iron-boron magnetic material from waste sintered magnetic material. The blended alloy with the specific composition can flexibly adjust the composition and performance of the product to meet the design requirements, ensure the consistency of the batch product, and not only improve the utilization rate of the waste sintered magnetic material, but also help improve the diffusion performance. Therefore, the present invention provides a utilization method that can directly crush the waste magnetic material into an alloy without smelting and mix it with a rare earth-rich alloy, solving the defects of the rich phase of the scrap of alnico magnets and greatly improving the magnetic performance; no need to smelt, reducing the processing cost, and at the same time, not limited by the amount of smelting added, can realize 100% utilization of the scrap raw material of alnico magnets. The method for producing neodymium-iron-boron magnetic material by recycling waste sintered magnetic material provided in the present invention is to prepare the waste magnetic material into alloy powder, and then mix it with the corresponding rare earth-rich alloy powder according to the alloy composition. This process can improve the utilization rate of waste recovery, and solve the problems of the limited amount of waste magnetic material added in the smelting process, the partial combustion loss, and the low yield, or the waste of other elements in the electrolytic refining of rare earth. Compared with the addition of waste in the smelting process, this process does not require smelting, reduces costs, is simple and flexible, and can mass-produce magnetic materials of different grades; and the components are different. Adding a small amount of the first alloy, which is composed of the first alloy, optimizes the grain boundary diffusion path of the base material and improves the efficiency of grain boundary penetration, so as to effectively improve the impurity composition of the grain boundary phase, improve the grain boundary defects of the waste, significantly improve the coercive force performance, and improve the grain boundary diffusion effect, so as to reduce the waste of heavy rare earth resources; In addition, adding fine powder of a compounded alloy (second alloy) with a different compounding ratio, so as to flexibly adjust the composition and performance of the product to meet the design requirements, not only to ensure the consistency of the batch products, but also to further improve the grain boundary diffusion performance, improve the grain boundary diffusion effect, improve the efficiency of grain boundary penetration, improve the grain boundary defects of the waste, and further increase the coercive force.

[0024] The application method provided by the present invention aims to increase the recycling rate of rare earth, save resources, and reduce production costs. The present invention uses the treated waste magnetic material to prepare the required alloy powder A through coarse crushing and hydro-grinding, and adds alloy B (first alloy) to improve the grain boundary defects of the waste material, improve performance, and improve the grain boundary diffusion effect; the addition of fine powder C of alloy (second alloy) with a different compounding ratio can also be used to produce different grades of substrate, which can further improve the performance of the magnetic material; the substrate is then processed into semi-finished products, and finally infiltrated to obtain the required neodymium-iron-boron finished products, which has strong manufacturing flexibility and high comprehensive utilization rate of resources. The experimental results show that the utilization method provided by the present invention can efficiently recycle waste, has a high recycling rate, can be used at nearly 100%, saves resources, and reduces costs. In the following, in order to further explain the present invention, the use of the blended alloy in the manufacture of the neodymium-iron-boron magnetic material from the waste sintered magnetic material provided by the present invention, the neodymium-iron-boron magnetic material manufactured from the waste sintered magnetic material and the manufacturing method thereof will be described in detail by way of examples. However, these examples are carried out on the premise of the technical means of the present invention, and provide detailed embodiments and specific operation procedures, only to further explain the features and advantages of the present invention, but do not limit the scope of the claims of the present invention, and it should be understood that the protection scope of the present invention is also not limited to the following examples.

[0025] Example 1 1. Preparation of alloy A 1.1 Neodymium-iron-boron waste was pretreated by removing the plating layer, degreasing, cleaning, etc. 1.2 The bulk raw materials are primarily crushed, and the particle size after crushing is <30mm. The present invention does not have any special restrictions on the crushing equipment and conditions, and those skilled in the art can select different equipment according to the actual production conditions. 1.3 In the production process of alloy sheet treated by hydrogrinding (HD), hydrogen absorption time was 75 min, then hydrogen was released at 580°C for 5 h, and finally water-cooled for 2 h to obtain coarse powder A alloy. The composition of coarse powder A was measured and referred to Table 1. Table 1 shows the composition of A alloy in Example 1. [Table 1] 2. Preparation of B alloy 2.1. Based on the alloy composition, the B-rich phase alloy composition [1] Pr21 Nd70 Cu2 Al4 Ga3 was designed. 2.2. The casting method may be a method for producing alloy sheet by using a vacuum induction furnace, which is well known in the art; the thickness of the cast sheet is 0.10-0.60 mm. 2.3. In the production process of alloy sheet treated by hydrogrinding (HD), the hydrogen absorption time was 75 min, then hydrogen was released at 580℃ for 5 h, and finally water-cooled for 2 h to obtain coarse powder (Alloy B). 3. Alloy A and alloy B were mixed in a ratio of A:B=98%:2% to obtain alloy AB; an antioxidant was added to alloy AB and the mixture was stirred. 4. The coarse powder of the alloy AB was subjected to airflow pulverization to obtain fine powder AB with an average particle size of 3.0 μm. 5. Depending on the alloy composition, alloy C composition [1] Pr 6.3 Nd 23.5 B 0.94 Cu 0.1 Al 0.15 Ga 0.1 Ti 0.1 Fe 残部 Alloy C was made from new raw materials through melting, hydrogenation crushing, and airflow crushing to obtain fine powder C with an average particle size of 2 μm to 5 μm. 6. Fine powder AB and fine powder C were mixed in a ratio of 70%:30%, and then a lubricant was added and the mixture was stirred to mix uniformly. 7. The blended powder ABC is subjected to magnetic field orientation pressing and isostatic pressing processes; the magnetic field orientation pressing is carried out in a sealed oxygen-free or low-oxygen glove box to ensure that the product is oxygen-free or low-oxygen during the entire operation and isostatic pressing process. 8. The neodymium-iron-boron magnetic material was obtained by vacuum sintering and aging heat treatment. It was carried out in a vacuum sintering furnace, the sintering temperature was 1050℃, and the sintering time was 6h; the aging treatment was carried out in two stages, the first aging heat treatment temperature was 920℃, and the aging time was 2h; the second aging heat treatment temperature was 550℃, and the aging time was 5h. 9. The sintered magnetic material was processed into a 2mm sheet, and heavy rare earth was applied to both sides of the sheet, and then heat-treated to obtain a permeable body. The amount of heavy rare earth applied was 0.5wt%, and the heat treatment process was 900℃8h+490℃*5h. The neodymium-iron-boron magnetic material prepared in Example 1 of the present invention was characterized. Please refer to FIG. 1, which is a photograph of the metal structure of the neodymium-iron-boron magnetic material prepared in Example 1 of the present invention. The neodymium-iron-boron magnetic bodies prepared in Example 1 of the present invention and Comparative Example 1 were measured. Please refer to Table 3, which shows the performance data of the magnetic body before and after the implementation of Example 1 and Comparative Example 1.

[0026] Comparative Example 1 1. Preparation of alloy A 1.1 Neodymium-iron-boron waste was pretreated by removing the plating layer, degreasing, cleaning, etc. 1.2 The bulk raw materials are primarily crushed, and the particle size after crushing is <30mm. The present invention does not have any special restrictions on the crushing equipment and conditions, and those skilled in the art can select different equipment according to the actual production conditions. 1.3 In the production process of processing the alloy sheet by hydrogrinding (HD), the hydrogen absorption time was 75 min, then hydrogen was released at 580°C for 5 h, and finally water-cooled for 2 h to obtain coarse powder A alloy. The composition of coarse powder A was measured and referred to Table 2. Table 2 shows the composition of A alloy in Comparative Example 1. [Table 2] 2. An antioxidant was added to alloy A and mixed. 3. The above alloy A coarse powder was subjected to airflow pulverization to obtain fine powder A with an average particle size of 3.0 μm. 4. Preparation of alloy B 4.1, according to the alloy composition, rich phase B alloy composition [1] Pr21 Nd70 Cu2 Al4 Ga3 was designed. 4.2. In the melting step, any method known in the art can be used to produce an alloy sheet using a vacuum induction melting furnace; the thickness of the produced cast sheet is 0.10-0.60 mm. 4.3. In the production process of alloy sheet by hydrogrinding (HD), the hydrogen absorption time was 75 min, then hydrogen was released at 580℃ for 5 h, and finally water-cooled for 2 h to obtain coarse powder (Alloy B). 5. Alloy A and alloy B were mixed in a ratio of A:B=98%:2% to obtain alloy AB; an antioxidant was added to alloy AB and the mixture was stirred. 6. The above coarse powder of alloy AB was subjected to airflow pulverization to obtain fine powder AB with an average particle size of 3.0 μm. After magnetic field oriented pressing and isostatic pressing, the magnetic field oriented pressing was carried out in a sealed oxygen-free or low-oxygen glove box to ensure that the product was oxygen-free or low-oxygen during the entire operation and isostatic pressing process. 7. The neodymium-iron-boron magnetic material was obtained by vacuum sintering and aging heat treatment. It was carried out in a vacuum sintering furnace, the sintering temperature was 1050℃, and the sintering time was 6h; the aging treatment was carried out in two stages, the first aging heat treatment temperature was 920℃, and the aging time was 2h; the second aging heat treatment temperature was 550℃, and the aging time was 5h. 8. The sintered magnetic material was processed into a 2mm sheet, and heavy rare earth was applied to both sides of the sheet, and then heat-treated to obtain a permeable body. The amount of heavy rare earth applied was 0.5wt%, and the heat treatment process was 900*8h+490*5h. The neodymium-iron-boron magnetic material prepared in Comparative Example 1 of the present invention was characterized. Referring to FIG. 2, FIG. 2 is a photograph of the metal structure of the neodymium-iron-boron magnetic material prepared in Comparative Example 1 of the present invention. The neodymium-iron-boron magnetic bodies prepared in Example 1 of the present invention and Comparative Example 1 were measured. See Table 3, which shows magnetic material performance data of Example 1 and Comparative Example 1 before and after infiltration. [Table 3]

[0027] Example 2 1. Preparation of alloy A 1.1 Neodymium-iron-boron waste was pretreated by removing the plating layer, degreasing, cleaning, etc. 1.2 The bulk raw materials are primarily crushed, and the particle size after crushing is <30mm. The present invention does not have any special restrictions on the crushing equipment and conditions, and those skilled in the art can select different equipment according to the actual production conditions. 1.3 In the production process of alloy sheet by hydrogrinding (HD), hydrogen absorption time was 75 min, then hydrogen release at 580℃ for 5 h, and finally water-cooled for 2 h to obtain coarse powder A alloy. The composition of coarse powder A was measured and referred to Table 4. Table 4 shows the composition of A alloy in Example 2. [Table 4] 2. Preparation of B alloy 2.1, According to the alloy composition, the rich phase B alloy composition [1] Pr20 Nd61Dy10 Cu2 Al4 Ga3 was designed. 2.2. The casting method may be a method of casting alloy sheet by vacuum induction furnace, which is well known in the art; the thickness of the cast sheet is 0.10-0.60mm. 2.3 In the production process of alloy sheet by hydrogrinding (HD), the hydrogen absorption time was 75 min, then hydrogen was released at 580℃ for 5 h, and finally water-cooled for 2 h to obtain coarse powder (Alloy B). 3. Alloy A and alloy B were mixed in a ratio of A:B=97%:3% to obtain alloy AB; an antioxidant was added to alloy AB and the mixture was stirred. 4. The coarse powder of the alloy AB was subjected to airflow pulverization to obtain fine powder AB with an average particle size of 3.0 μm. 5. Depending on the alloy composition, alloy C composition [1] Pr 6.1 Nd 22.7 Dy 0.5 B 0.94 Cu 0.1 Al 0.15 Ga 0.1 Ti 0.1 Fe 残部 Alloy C was designed and fine powder C with an average particle size of 2μm to 5μm was obtained from new raw materials through melting, hydrogenation crushing, and airflow crushing. 6. Mix powder AB and powder C in the ratio of 60%:40%, then add lubricant and stir to mix evenly; 7. The blended powder ABC is subjected to magnetic field orientation pressing and isostatic pressing processes; the magnetic field orientation pressing is carried out in a sealed oxygen-free or low-oxygen glove box to ensure that the product is oxygen-free or low-oxygen during the entire operation and isostatic pressing process. 8. The neodymium-iron-boron magnetic material was obtained by vacuum sintering and aging heat treatment. It was carried out in a vacuum sintering furnace, the sintering temperature was 1050℃, and the sintering time was 6h; the aging treatment was carried out in two stages, the first aging heat treatment temperature was 920℃, and the aging time was 2h; the second aging heat treatment temperature was 550℃, and the aging time was 5h. 9. The sintered magnetic material was processed into a 2mm sheet, and heavy rare earth was applied to both sides of the sheet, and then heat-treated to obtain a permeable body. The amount of heavy rare earth applied was 0.5wt%, and the heat treatment process was 900℃8h+490℃*5h. The neodymium-iron-boron magnetic bodies prepared in Example 2 of the present invention and Comparative Example 2 were measured. See Table 6, which shows the magnetic performance data of Example 2 and Comparative Example 2 before and after infiltration.

[0028] Comparative Example 2 1. Preparation of alloy A 1.1 Neodymium-iron-boron waste was pretreated by removing the plating layer, degreasing, cleaning, etc. 1.2 The bulk raw materials are primarily crushed, and the particle size after crushing is <30mm. The present invention has no special restrictions on the crushing equipment and conditions, and those skilled in the art can select different equipment according to the actual production conditions. 1.3 In the production process of alloy sheet by hydrogrinding (HD), hydrogen absorption time was 75 min, then hydrogen was released at 580℃ for 5 h, and finally water-cooled for 2 h to obtain coarse powder A alloy. The composition of coarse powder A was measured and referred to Table 5. Table 5 shows the composition of A alloy in Comparative Example 2. [Table 5] 2. An antioxidant was added to alloy A and mixed. 3. The above alloy A coarse powder was subjected to airflow pulverization to obtain fine powder A with an average particle size of 3.0 μm. 4. Preparation of alloy B 4.1, according to the alloy composition, rich phase B alloy composition [1] Pr20 Nd61Dy10 Cu2 Al4 Ga3 was designed. 4.2. In the melting step, any method known in the art can be used to produce an alloy sheet using a vacuum induction melting furnace; the thickness of the produced cast sheet is 0.10-0.60 mm. 4.3. In the production process of alloy sheet by hydrogrinding (HD), the hydrogen absorption time was 75 min, then hydrogen was released at 580℃ for 5 h, and finally water-cooled for 2 h to obtain coarse powder (Alloy B). 5. Alloy A and alloy B were mixed in a ratio of A:B=97%:3% to obtain alloy AB; an antioxidant was added to alloy AB and the mixture was stirred. 6. The above coarse powder of alloy AB was subjected to airflow pulverization to obtain fine powder AB with an average particle size of 3.0 μm. Through magnetic field oriented pressing and isostatic pressing, the magnetic field oriented pressing was carried out in a sealed oxygen-free or low-oxygen glove box to ensure that the product was oxygen-free or low-oxygen during the entire operation and isostatic pressing process. 7. The neodymium-iron-boron magnetic material was obtained by vacuum sintering and aging heat treatment. It was carried out in a vacuum sintering furnace, the sintering temperature was 1050℃, and the sintering time was 6h; the aging treatment was carried out in two stages, the first aging heat treatment temperature was 920℃, and the aging time was 2h; the second aging heat treatment temperature was 550℃, and the aging time was 5h. 8. The sintered magnetic material was processed into a 2mm sheet, and heavy rare earth was applied to both sides of the sheet, and then heat-treated to obtain a permeable body. The amount of heavy rare earth applied was 0.5wt%, and the heat treatment process was 900*8h+490*5h. The neodymium-iron-boron magnetic bodies prepared in Example 2 of the present invention and Comparative Example 2 were measured. See Table 6, which shows the magnetic performance data of Example 2 and Comparative Example 2 before and after infiltration. [Table 6]

[0029] The use of the blended alloy in the manufacture of neodymium-iron-boron magnetic material from waste sintered magnetic material provided by the present invention, the neodymium-iron-boron magnetic material manufactured from waste sintered magnetic material, and the method for manufacturing neodymium-iron-boron magnetic material by recycling waste sintered magnetic material are described in detail above. In this specification, the principle and embodiment of the present invention are described by specific examples. The description of the above examples is only used to help understand the method and spirit of the present invention, includes the best mode, and enables a person skilled in the art to carry out the present invention, including the method for manufacturing and using any device or system, and performing any combination. It should be noted that a person skilled in the art can make some improvements and modifications to the present invention without departing from the principle of the present invention, and these improvements and modifications are also within the scope of the claims. The patent protection scope of the present invention is limited by the claims and includes other examples that can be obtained by a person skilled in the art. If these other examples have structural elements that are not different from the literal language of the claims, or include equivalent structural elements that are substantially different from the literal language of the claims, these other examples should also be included in the scope of the claims.

Claims

1. A use of waste neodymium-iron-boron magnetic material, a first alloy, and a second alloy having a general formula shown in Formula II as raw materials for producing a neodymium-iron-boron magnetic material, comprising: The waste neodymium-iron-boron magnetic body is a waste sintered magnetic body, The first alloy has the general formula shown in Formula I: RE x -M y -H z I; (Wherein, 80 wt%≦x≦97 wt%, 2.5 wt%≦y≦20 wt%, 0.05 wt%≦z≦0.5 wt%, and x+y+z=100 wt%. RE is one or more elements selected from La, Ce, Ho, Gd, Pr, Nd, Dy, and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. H is the hydrogen element. RE ｘ -M ｙ -T ｚ -B ｍ II; (Wherein, 28 wt%≦x≦32 wt%, 0.35 wt%≦y≦1.6 wt%, 66 wt%≦z, 0.90 wt%≦m≦0.98 wt%, and x+y+z+m=100 wt%. RE is one or more elements selected from La, Ce, Ho, Gd, Pr, Nd, Dy, and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. T is selected from Fe and / or Co.

2. the second alloy is a compound alloy; The formulation includes a component formulation and / or a performance formulation, the second alloy has an oxygen content of less than 1000 ppm; 2. The method according to claim 1, characterized in that the grain size of the second alloy is between 2 and 5 μm.

3. the first alloy is a grain boundary additive phase alloy; the first alloy has an oxygen content of less than 1000 ppm; The grain size of the first alloy is less than or equal to 2 mm; The oxygen content of the waste neodymium-iron-boron magnetic material is less than 2000 ppm; The use according to claim 1, characterized in that the grain size of the waste neodymium-iron-boron magnetic material is between 0.2 and 2 mm.

4. The mass ratio of the waste neodymium-iron-boron magnetic material to the first alloy is (90-99):(1-10); the mass ratio of the total mass of the waste neodymium-iron-boron magnetic material and the first alloy to the second alloy is (10-95):(90-5); The raw material further comprises an antioxidant and / or a lubricant; The feedstock further comprises a surface-infiltrated heavy rare earth element; The heavy rare earth element includes Dy and / or Tb, The use according to claim 1, characterized in that the content of the surface-permeated heavy rare earth element in the total amount of the neodymium-iron-boron magnetic material is 0.2wt% to 0.8wt%.

5. 1) Crushing the waste neodymium-iron-boron magnetic material, subjecting it to hydro-grinding to obtain scrap coarse powder, and then melting the first alloy raw material into a cast sheet or ingot, and then subjecting it to hydro-grinding to obtain the first alloy coarse powder; 2) mixing the scrap coarse powder obtained in the above step with the first alloy coarse powder, and pulverizing the mixture to obtain a mixed fine powder; 3) mixing the second alloy powder with the mixed fine powder obtained in the previous step again to obtain a mixed powder; 4) Orienting and molding the mixed powder obtained in the above step, and then sintering the powder to obtain a neodymium-iron-boron magnetic material; Including, The waste neodymium-iron-boron magnetic body is a waste sintered magnetic body, The first alloy has a general formula shown in Formula I: RE x -M y -H z I; (Wherein, 80 wt%≦x≦97 wt%, 2.5 wt%≦y≦20 wt%, 0.05 wt%≦z≦0.5 wt%, and x+y+z=100 wt%. RE is one or more elements selected from La, Ce, Ho, Gd, Pr, Nd, Dy, and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. H is the hydrogen element. The second alloy has the general formula shown in Formula II: RE x -M y -T z -B m II; (Wherein, 28 wt%≦x≦32 wt%, 0.35 wt%≦y≦1.6 wt%, 66 wt%≦z, 0.90 wt%≦m≦0.98 wt%, and x+y+z+m=100 wt%. RE is one or more elements selected from La, Ce, Ho, Gd, Pr, Nd, Dy, and Tb. M is one or more selected from Al, Cu, Zn, Sn, Ga, Ge, Nb, V, W, Ti, Ni, Zr, Ta, Mn, Cd and Mo. T is selected from Fe and / or Co.

2. A method for producing a neodymium-iron-boron magnetic body by recycling waste sintered magnetic body, comprising:

6. The particle size after the hydrogen pulverization is 2 mm or less, The thickness of the cast sheet obtained by melting and casting is 0.1 to 0.6 mm, The waste neodymium-iron-boron magnetic material includes magnetic waste of the same grade or magnetic waste of different grades; During the hydrogenation grinding process, the hydrogen absorption time is 60-180 min, and the hydrogen absorption temperature is 20-300° C.; During the hydrogenation grinding process, the hydrogen release time is 3-7 h, and the hydrogen release temperature is 550-600° C.; After the hydrogrinding, a water cooling step is further included, The method according to claim 5, wherein the water cooling time is 0.5 to 3 h.

7. The particle size of the first alloy coarse powder is 0.2 to 2 mm; In the mixing step, an antioxidant is further added and mixed; The antioxidant is present in an amount of 0.02% to 0.1% by mass of the mixed fine powder; The second alloy powder is obtained from a second alloy raw material through melting, hydrogenation pulverization, and air flow pulverization; In the remixing step, further lubricant is added and mixed again; The content of the lubricant in the mass of the mixed powder is 0.02% to 0.1%; The method according to claim 5, characterized in that the particle size of the mixed powder is 2-5 μm.

8. The orientation molding includes an orientation press and an isostatic press molding step; Specifically, the orientation molding and isostatic pressing are performed under an oxygen-free or low-oxygen condition, The sintering temperature is 1030 to 1060° C. The sintering time is 6 to 10 h, After the sintering, a further aging step is included, The aging treatment includes a first aging treatment and a second aging treatment, The temperature of the first aging treatment is 700 to 950° C. The time of the first aging treatment is 2 to 15 hours, The temperature of the second aging treatment is 350 to 550° C. The second aging treatment is performed for a period of 1 to 8 hours. After the sintering, the method further includes a penetration and diffusion step, Specifically, the penetration and diffusion step is to apply a heavy rare earth to the surface of the magnetic blank after sintering and aging treatment, and then to perform a heat treatment. The heat treatment includes a first heat treatment and a second heat treatment, The temperature of the first heat treatment is 850 to 950° C. The duration of the first heat treatment is 5 to 15 hours; The temperature of the second heat treatment is 450 to 600° C.

6. The method according to claim 5, wherein the duration of the second heat treatment is between 3 and 6 hours.

Images