Effective Recovery of Nd–Fe–B Sintered Magnet Scrap Powders as Isotropic Bonded Magnets

Nd–Fe–B sintered magnet scrap powders, viz. “sludge”, as produced in the sizing and polishing processes for well-shaped magnets of small-sized motors and other equipments were effectively recovered as the raw powders for isotropic Nd–Fe–B bonded magnets (Br = 0.66 T, Hcj = 0.92 MA/m, and (BH)max = 70 kJ/m3) by means of Ca metal reduction and melt-spun.