Search

CN-115763029-B - Method for removing calcium element in rare earth permanent magnet alloy and application thereof

CN115763029BCN 115763029 BCN115763029 BCN 115763029BCN-115763029-B

Abstract

The invention provides a method for removing calcium element in rare earth permanent magnet alloy and application thereof. The rare earth permanent magnet alloy contains one or more of calcium oxide, calcium hydride and calcium metal, and the method comprises the steps of carrying out a first mixing process on the rare earth permanent magnet alloy and water to obtain a rare earth permanent magnet alloy containing calcium hydroxide, carrying out a second mixing process on the rare earth permanent magnet alloy containing calcium hydroxide and a resin emulsion to obtain a mixed solution of agglomerated particles containing calcium hydroxide and the rare earth permanent magnet alloy, wherein the resin emulsion comprises matrix resin, anionic surfactant and water, the matrix resin is selected from vinyl acetate resin and/or polyacrylate, and separating the rare earth permanent magnet alloy from the mixed solution under the action of a magnetic field. The method can remove the calcium element in the rare earth permanent magnet alloy, and is particularly suitable for removing the calcium element in the rare earth permanent magnet alloy prepared by a reduction diffusion method.

Inventors

  • JIANG YUNTAO
  • LI YUPING
  • SUN YONGYANG
  • ZHANG YUNYI

Assignees

  • 横店集团东磁股份有限公司

Dates

Publication Date
20260508
Application Date
20210902

Claims (12)

  1. 1. The method for removing the calcium element in the rare earth permanent magnet alloy is characterized in that the rare earth permanent magnet alloy contains one or more of calcium oxide, calcium hydride and metal calcium, and the method for removing the calcium element in the rare earth permanent magnet alloy comprises the following steps: Carrying out a first mixing process on the rare earth permanent magnet alloy and water to obtain a rare earth permanent magnet alloy containing calcium hydroxide; Performing a second mixing process on the rare earth permanent magnet alloy containing calcium hydroxide and a resin emulsion to obtain a mixed solution of agglomerated particles containing calcium hydroxide and the rare earth permanent magnet alloy, wherein the resin emulsion comprises a matrix resin, an anionic surfactant and water, and the matrix resin is selected from vinyl acetate resin and/or polyacrylic resin; And separating the rare earth permanent magnet alloy from the mixed liquid under the action of a magnetic field.
  2. 2. The method for removing calcium element from rare earth permanent magnet alloy according to claim 1, wherein the weight ratio of the rare earth permanent magnet alloy, the matrix resin and the anionic surfactant is 100 (2-6): 1-1.5.
  3. 3. The method for removing calcium in a rare earth permanent magnet alloy according to claim 1 or 2, wherein the solid content of the vinyl acetate resin is 28-32%, and the solid content of the polyacrylic resin is 15-18%.
  4. 4. The method for removing calcium element from rare earth permanent magnet alloy according to claim 1, wherein the temperatures of the first mixing process, the second mixing process and the separation process are respectively and independently selected from 1-5 ℃.
  5. 5. The method for removing calcium in a rare earth permanent magnet alloy according to claim 4, wherein the second mixing process is performed under ultrasonic conditions, wherein the ultrasonic conditions are that ultrasonic power is 1-1.2W/cm 2 , and ultrasonic cleaning time is 5-120 min.
  6. 6. The method for removing calcium element from rare earth permanent magnet alloy according to claim 1 or 2, wherein the anionic surfactant is one or more selected from the group consisting of anionic polyacrylamide, sodium alkylbenzenesulfonate and primary alkyl sulfate.
  7. 7. The method for removing calcium element from rare earth permanent magnet alloy according to claim 6, wherein the rare earth permanent magnet alloy is in a block shape or a powder shape, and when the rare earth permanent magnet alloy is in a block shape, the particle size of the rare earth permanent magnet alloy is 0.5-50 mm; when the rare earth permanent magnet alloy is in a powder form, the particle size of the rare earth permanent magnet alloy is 1-5000 mu m.
  8. 8. The method for removing calcium element from rare earth permanent magnet alloy according to claim 7, wherein when the rare earth permanent magnet alloy is in the form of a block, the particle size of the rare earth permanent magnet alloy is 1 to 5mm.
  9. 9. The method for removing calcium element from rare earth permanent magnet alloy according to claim 7, wherein when the rare earth permanent magnet alloy is in powder form, the particle size of the rare earth permanent magnet alloy is 1-50 μm.
  10. 10. The method for removing calcium element from rare earth permanent magnet alloy according to claim 1, wherein the magnetic field strength of the magnetic field is 0.1-0.3 a/m.
  11. 11. The method for removing calcium from a rare earth permanent magnet alloy according to claim 6, wherein the rare earth permanent magnet alloy is one or more selected from the group consisting of samarium iron alloy, samarium cerium iron manganese alloy, neodymium iron nitrogen alloy, cerium iron nitrogen alloy and samarium praseodymium iron alloy.
  12. 12. Use of the method for removing calcium element in rare earth permanent magnet alloy according to any one of claims 1 to 11 in the field of rare earth permanent magnet alloy preparation.

Description

Method for removing calcium element in rare earth permanent magnet alloy and application thereof Technical Field The invention relates to the technical field of preparation of magnetic materials, in particular to a method for removing calcium element in rare earth permanent magnet alloy and application thereof. Background In recent years, research on the preparation of rare earth permanent magnet alloys has been mainly focused on a smelting method, a mechanical alloy method, a rapid quenching method, and a reduction diffusion method. Among them, the reduction diffusion method uses metal calcium or calcium hydride (CaH 2), calcium chloride (CaCl 2) and the like together with inexpensive metal oxide or metal chloride raw materials and metal raw materials such as iron, and uses the strong reducibility of the metal calcium or calcium hydride to perform oxidation-reduction reaction with the metal oxide under high temperature argon or nitrogen atmosphere, thereby being capable of producing a desired alloy. However, the calcium-containing compound is generated and calcium element remains in the process, and if the impurities are mixed in the alloy, the product performance is greatly affected. In order to remove the calcium residue in the rare earth permanent magnet alloy, a water washing method is commonly adopted at present. In the method, rare earth permanent magnet alloy powder prepared by reduction diffusion is put into water together with residual impurities of CaO, caH 2, ca and the like, and the impurities react with water to generate calcium hydroxide (Ca (OH) 2) and react to emit a large amount of heat, so that the alloy can be oxidized and even can catch fire seriously. Meanwhile, ca (OH) 2 is slightly soluble in water, the solubility is reduced along with the temperature rise, so that Ca (OH) 2 in water exists in a large amount in a solid form, ca (OH) 2 residues exist in rare earth permanent magnet alloy powder particles, and Ca (OH) 2 is difficult to remove only by adopting a water method. On the basis, a method for improving the removal rate of calcium in the rare earth permanent magnet alloy prepared by a reduction diffusion method is particularly important to research and develop. Disclosure of Invention The invention mainly aims to provide a method for removing calcium in rare earth permanent magnet alloy and application thereof, so as to solve the problem that residual calcium in the rare earth permanent magnet alloy prepared by a reduction diffusion method in the prior art is difficult to remove. In order to achieve the above purpose, the invention provides a method for removing calcium element in a rare earth permanent magnet alloy, wherein the rare earth permanent magnet alloy contains one or more of calcium oxide, calcium hydride and metal calcium, the method for removing the calcium element in the rare earth permanent magnet alloy comprises the steps of carrying out a first mixing process on the rare earth permanent magnet alloy and water to obtain a rare earth permanent magnet alloy containing calcium hydroxide, carrying out a second mixing process on the rare earth permanent magnet alloy containing calcium hydroxide and a resin emulsion to obtain a mixed solution of agglomerated particles containing calcium hydroxide and the rare earth permanent magnet alloy, wherein the resin emulsion comprises a matrix resin, an anionic surfactant and water, the matrix resin is selected from vinyl acetate resin and/or polyacrylate, and separating the rare earth permanent magnet alloy from the mixed solution under the action of a magnetic field. Further, the weight ratio of the rare earth permanent magnet alloy to the matrix resin to the anionic surfactant is 100 (2-6): 1-1.5. Further, the solid content of the acetic acid vinyl alcohol resin is 28-32%, and the solid content of the polyacrylic resin is 15-18%. Further, the temperatures of the first mixing process, the second mixing process and the separation process are respectively and independently selected from 1-5 ℃. Further, the second mixing process is carried out under the ultrasonic condition, wherein the ultrasonic condition is that the ultrasonic power is 1-1.2W/cm < 2 >, and the ultrasonic cleaning time is 5-120 min. Further, the anionic surfactant is selected from one or more of the group consisting of anionic polyacrylamide, sodium alkylbenzenesulfonate and primary alkyl sulfate. Further, the rare earth permanent magnet alloy is in a block shape or a powder shape, wherein when the rare earth permanent magnet alloy is in a block shape, the particle size of the rare earth permanent magnet alloy is 0.5-50 mm, preferably 1-5 mm, and when the rare earth permanent magnet alloy is in a powder shape, the particle size of the rare earth permanent magnet alloy is 1-5000 μm, preferably 1-50 μm. Further, the magnetic field strength of the magnetic field is 0.1-0.3A/m. Further, the rare earth permanent magnet alloy is selected from one or more of the group