Magnet recycling to create Nd—Fe—B magnets with improved or restored magnetic performance

A recycled Nd—Fe—B sintered magnet comprising:

• a composition of WaRbAc, where waste material W comprises material from a waste Nd—Fe—B sintered magnet, rare earth containing material R comprises Nd and Pr at a ratio of 75 wt. % Nd to 25 wt. % Pr and 0.1 to 1 at. % of the recycled Nd—Fe—B sintered magnet, and elemental additives A comprising a) Co, b) Cu, and c) Fe;
• indices a, b, and c indicate atomic percentages of the corresponding compositions or elements;
• a(t) is the atomic percent of element t in the waste material W relative to the composition of the recycled Nd—Fe—B sintered magnet;
• b(t) is the atomic percent of element t in the rare earth containing material R relative to the composition of the recycled Nd—Fe—B sintered magnet;
• c(t) is the atomic percent of element t in the elemental additives A relative to the composition of the recycled Nd—Fe—B sintered magnet;
• and
• a, b, c, a(t), b(t), and c(t) have values satisfying:
• 81 at. %≦a≦99.9 at. %,
• 0.1 at. %≦b+c≦19 at. %,
• 3 at. %-99.9%*a(Co)≦c(Co)≦3 at.%-81%*a(Co), wherein a(Co)≦3.003003003 at. %,
• 0.3 at. %-99.9%*a(Cu)≦c(Cu)≦0.3 at. %-81%*a(Cu), wherein a(Cu)≦0.3003003 at. %,
• 77 at. %-99.9%*(a(Fe)+a(Co))≦c(Fe)≦77 at. %-81%*(a(Fe)+a(Co)), wherein (a(Fe)+a(Co))<77.07707708 at. %,
• a(Nd)+b(Nd)+c(Nd)+a(Pr)+b(Pr)+c(Pr)>0 at. %,
• a(Nd)+b(Nd)+c(Nd)+a(Pr)+b(Pr)+c(Pr)+a(Dy)+b(Dy)+c(Dy)≦18 at. %,
• a(Co)+b(Co)+c(Co)≦3 at. %,
• a(Cu)+b(Cu)+c(Cu)≦0.3 at. %,
• a(Fe)+b(Fe)+c(Fe)+a(Co)+b(Co)+c(Co)≦77 at. %, and
• b(Nd)+c(Nd)+b(Pr)+c(Pr)+b(Dy)+c(Dy)≧0 at. %.