Patent ID: 9044834
Filing Date: 2015-06-02
Classification: B01J,B22F,B23P,B23Q,C22C,H01F,Y02P,Y02W,Y10T

Abstract:
1. A method for manufacturing a recycled Nd—Fe—B permanent magnet comprising: demagnetizing magnetic material from a waste magnet assembly by cyclic heating And cooling of the magnetic material, fragmenting adhesives attached to the magnetic material, cracking coating layers of the magnetic material, and subjecting the magnetic material to at least one of: a) a mechanical treatment or b) a chemical treatment, to remove the coating layers and prepare the magnetic material without impurities; fragmenting the demagnetized magnetic material to form a powder; mixing the powder with a) a rare earth material R that comprises between 0.1 to 1 at. % of the total mixture and b) an elemental additive A to produce a homogeneous powder, wherein the rare earth material R comprises at least one of: i) Nd or ii) Pr with a ratio of 75 wt. % Nd to 25 wt. % Pr, and the elemental additive A comprises at least one of: i) Dy, ii) Co, iii) Cu, iv) Fe; and sintering and magnetizing the homogenous powder to form a recycled Nd—Fe—B magnetic product that comprises 1.98 at. % oxygen or less and has a remanence and a coercivity at least the same as a waste magnet part from the waste magnet assembly.