Method for reusing sintered reclaimed NdFeB material

Abstract

The invention provides a method for reusing a sintered reclaimed NdFeB material. According to the method for reusing the sintered reclaimed NdFeB material, the sintered reclaimed NdFeB material becomes a powder material with a certain granularity after breaking, hydrogen decrepitation, sieving, mixing and crushing through an air stream mill are conducted, a Pr-Nd or Nd rare earth nanometer additive is added to the sieved powder material through a jet-propelled method in an argon atmosphere, and then the sieved powder material and the additive are evenly mixed; magnetic field orientation forming, isostatic pressing and sintering are conducted on the sampled powder material, so that a sintered sample is formed, then performance detection is conducted on the sintered sample, according to a sample detection result and the performance requirement, 0-60 wt% of powder of a relevant grade is added, even mixing is conducted, and after magnetic field orientation forming, isostatic pressing and sintering are conducted on the mixture, a NdFeB finished product is formed. According to the method for reusing the sintered reclaimed NdFeB material, roasting and remelting are not needed, it is only required that rare earth nanometer powder is directly added to reclaimed powder and evenly mixed with the reclaimed powder, and then the product can be prepared according to a conventional technology; in this way, the technology process is simple, task time is shortened, energy consumption is reduced, the amount of used rare earth is reduced by 50% relatively, and the coercivity is increased by 15%-20% relatively; due to the effect of the rare earth nanometer additive, liquid phase mobility is improved during sintering, magnet consistency is improved, the sintering temperature is lowered, and sintering time is shortened.

Description

technical field

[0001] The present invention relates to the technical field of recycling sintered NdFeB reclaimed materials that directly add rare earth nano-additives to form grain boundary phases, in particular to the recycling of sintered NdFeB reclaimed materials for preparing high-coercivity NdFeB permanent magnet materials. Use method. Background technique

[0002] After decades of mining and excavation of rare earth resources in my country, the amount of resources has become less and less, and the recycling of rare earth elements has become an important means to realize the recycling of rare earth elements. Due to the production process and use factors, the production, application, and disposal of NdFeB permanent magnet materials produce a large amount of recycled materials containing rare earths. In 2013, my country produced 335,000 tons of NdFeB, resulting in more than 67,000 tons of NdFeB waste. Among them, the NdFeB waste that can be recycled in the field of mag...

Examples

Embodiment 1

[0023] Example 1: N38

[0024] First, the metal block Pr or Pr-Nd is processed into nano-sized powder with an average particle size of 40-60nm by the rapid-in-situ packaging rare earth nano powder arc method.

[0025] The NdFeB recycled material is roughly crushed into large blocks of 20-40mm with a jaw crusher, and then the large particles are further crushed into small particles with a particle size of less than 10mm with a hammer crusher.

[0026] The powder is heated to 550-650℃ for dehydrogenation for 6-7 hours after absorbing hydrogen at room temperature in the reactor of the hydrogen crushing furnace for 2 to 4 hours to prepare coarse particles with a particle size of 60 to 80 mesh and screen the material with a 10 mesh vibrating screen. Then add 1~5‰ of antioxidant (polyethylene oxide alkyl ether) and mix evenly for 10~30 minutes.

[0027] The waste powder after hydrogen crushing and mixing is ground by QLM-400 jet mill at 0.8MPa working pressure to fine powder with an averag...

Embodiment 2

[0030] Example 2: N40

[0031] First, the metal block Pr or Pr-Nd is processed into nano-sized powder with an average particle size of 40-60nm by the rapid-in-situ packaging rare earth nano powder arc method.

[0032] The NdFeB recycled material is roughly crushed into large blocks of 20-40mm with a jaw crusher, and then the large particles are further crushed into small particles with a particle size of less than 10mm with a hammer crusher.

[0033] The powder is heated to 550-650℃ for dehydrogenation for 6-7 hours after absorbing hydrogen at room temperature in the reactor of the hydrogen crushing furnace for 2 to 4 hours to prepare coarse particles with a particle size of 60 to 80 mesh and screen the material with a 10 mesh vibrating screen. Then add 1~5‰ of antioxidant (polyethylene oxide monofatty acid ester) and mix uniformly for 10~30 minutes.

[0034] The waste powder after hydrogen crushing and mixing is ground by QLM-400 jet mill at 0.8MPa working pressure to fine powder wi...

Embodiment 3

[0037] Example 3: N42

[0038] The difference from Example 2 is that: the existing 048001 (NdFeB380 / 80) brand conventional powder and the need to prepare 048002 (NdFeB350 / 96) brand products, the recycled powder and conventional powder (048001 brand) in a 4:6 ratio Mix evenly in the mixer for 2 to 4 hours. After fully mixing, perform batch magnetic field orientation molding, isostatic pressing, and vacuum sintering. Product performance test data is: Br: 1.32~1.36T, Hcb: 971~1003kA / m, Hcj: 1020~1066kA / m, (BH)max: 338~358kJ / m 3 According to GB / T13560-2009, it is judged that its performance meets the performance requirements of 048002 (NdFeB350 / 96). This batch of recycled materials can be used for mass production of 048002 (NdFeB350 / 96) products; the antioxidant is polyethylene oxide allyl Base ether. Others are the same as in Embodiment 2, so they are omitted.

technical field

[0001] The present invention relates to the technical field of recycling sintered NdFeB reclaimed materials that directly add rare earth nano-additives to form grain boundary phases, in particular to the recycling of sintered NdFeB reclaimed materials for preparing high-coercivity NdFeB permanent magnet materials. Use method. Background technique

[0002] After decades of mining and excavation of rare earth resources in my country, the amount of resources has become less and less, and the recycling of rare earth elements has become an important means to realize the recycling of rare earth elements. Due to the production process and use factors, the production, application, and disposal of NdFeB permanent magnet materials produce a large amount of recycled materials containing rare earths. In 2013, my country produced 335,000 tons of NdFeB, resulting in more than 67,000 tons of NdFeB waste. Among them, the NdFeB waste that can be recycled in the field of mag...

Examples

Embodiment 1

[0023] Example 1: N38

[0024] First, the metal block Pr or Pr-Nd is processed into nano-sized powder with an average particle size of 40-60nm by the rapid-in-situ packaging rare earth nano powder arc method.

[0025] The NdFeB recycled material is roughly crushed into large blocks of 20-40mm with a jaw crusher, and then the large particles are further crushed into small particles with a particle size of less than 10mm with a hammer crusher.

[0026] The powder is heated to 550-650℃ for dehydrogenation for 6-7 hours after absorbing hydrogen at room temperature in the reactor of the hydrogen crushing furnace for 2 to 4 hours to prepare coarse particles with a particle size of 60 to 80 mesh and screen the material with a 10 mesh vibrating screen. Then add 1~5‰ of antioxidant (polyethylene oxide alkyl ether) and mix evenly for 10~30 minutes.

[0027] The waste powder after hydrogen crushing and mixing is ground by QLM-400 jet mill at 0.8MPa working pressure to fine powder with an averag...

Embodiment 2

[0030] Example 2: N40

[0031] First, the metal block Pr or Pr-Nd is processed into nano-sized powder with an average particle size of 40-60nm by the rapid-in-situ packaging rare earth nano powder arc method.

[0032] The NdFeB recycled material is roughly crushed into large blocks of 20-40mm with a jaw crusher, and then the large particles are further crushed into small particles with a particle size of less than 10mm with a hammer crusher.

[0033] The powder is heated to 550-650℃ for dehydrogenation for 6-7 hours after absorbing hydrogen at room temperature in the reactor of the hydrogen crushing furnace for 2 to 4 hours to prepare coarse particles with a particle size of 60 to 80 mesh and screen the material with a 10 mesh vibrating screen. Then add 1~5‰ of antioxidant (polyethylene oxide monofatty acid ester) and mix uniformly for 10~30 minutes.

[0034] The waste powder after hydrogen crushing and mixing is ground by QLM-400 jet mill at 0.8MPa working pressure to fine powder wi...

Embodiment 3

[0037] Example 3: N42

[0038] The difference from Example 2 is that: the existing 048001 (NdFeB380 / 80) brand conventional powder and the need to prepare 048002 (NdFeB350 / 96) brand products, the recycled powder and conventional powder (048001 brand) in a 4:6 ratio Mix evenly in the mixer for 2 to 4 hours. After fully mixing, perform batch magnetic field orientation molding, isostatic pressing, and vacuum sintering. Product performance test data is: Br: 1.32~1.36T, Hcb: 971~1003kA / m, Hcj: 1020~1066kA / m, (BH)max: 338~358kJ / m 3 According to GB / T13560-2009, it is judged that its performance meets the performance requirements of 048002 (NdFeB350 / 96). This batch of recycled materials can be used for mass production of 048002 (NdFeB350 / 96) products; the antioxidant is polyethylene oxide allyl Base ether. Others are the same as in Embodiment 2, so they are omitted.

Images