The　structural　and　magnetic　properties　were　studied　for　recycling　Nd-Fe-B　powders　from　Nd-Fe-B　sintered　magnets　sludge　via　reduction　diffusion　(RD)　with　calcium　hydride　(CaH2)　particles.　For　comparison,　traditional　reducing　agent　calcium　granules　were　applied　to　prepare　recycled　Nd-Fe-B　powders.　Finer　particle　size　and　better　size　distribution　as　well　as　lower　impurity　content　are　achieved　by　using　CaH2　instead　of　Ca.　In　detail,　the　average　particle　size　of　the　recycled　Nd-Fe-BB　powder　is　reduced　from　4.66　to　3.43　mm,　and　the　bimodal　distribution　disappears.　Moreover,　the　residual　calcium　content　and　oxygen　content　are　reduced　to　about　0.080　wt%　and　0.32　wt%.　As　a　consequence,　the　room-temperature　magnetization　of　the　CaH2-recycled　Nd-Fe-B　powder　is　increased　to　146.30　emu/g,　6.8%　and　33%,　respectively,　higher　than　that　of　Ca-reduced　powder　and　the　initial　sludge.　Further　analysis　indicates　that　CaH2　is　able　to　reduce　the　sludge　at　lower　temperature　to　fabricate　well-dispersed,　uniform　recycled　powder　with　high　magnetization　arising　from　a　combination　factors　of　its　low　melting　point,　low　thermodynamic　behavior,　and　the　release　of　hydrogen　during　the　reaction.　(c)　2021　Chinese　Society　of　Rare　Earths.　Published　by　Elsevier　B.V.　All　rights　reserved.