Given　the　increasing　concern　regarding　the　global　decline　in　rare　earth　reserves　and　the　environmental　burden　from　current　wet-process　recycling　techniques,　it　is　urgent　to　develop　an　efficient　recycling　technique　for　leftover　sludge　from　the　manufacturing　process　of　neodymium-iron-boron　(Nd-Fe-B)　sintered　magnets.　In　the　present　study,　centerless　grinding　sludge　from　the　Nd-Fe-B　sintered　magnet　machining　process　was　selected　as　the　starting　material.　The　sludge　was　subjected　to　a　reduction-diffusion　(RD)　process　in　order　to　synthesize　recycled　neodymium　magnet　(Nd2Fe14B)　powder;　during　this　process,　most　of　the　valuable　elements,　including　neodymium　(Nd),　praseodymium　(Pr),　gadolinium　(Gd),　dysprosium　(Dy),　holmium　(Ho),　and　cobalt　(Co),　were　recovered　simultaneously.　Calcium　chloride　(CaCl2)　powder　with　a　lower　melting　point　was　introduced　into　the　RD　process　to　reduce　recycling　cost　and　improve　recycling　efficiency.　The　mechanism　of　the　reactions　was　investigated　systematically　by　adjusting　the　reaction　temperature　and　calcium/sludge　weight　ratio.　It　was　found　that　single-phase　Nd2Fe14B　particles　with　good　crystallinity　were　obtained　when　the　calcium　weight　ratio　(calcium/sludge)　and　reaction　temperature　were　40　wt%　and　1050　degrees　C,　respectively.　The　recovered　Nd2Fe14B　particles　were　blended　with　37.7　wt%　Nd2Fe14B　powder　to　fabricate　Nd-Fe-B　sintered　magnets　with　a　remanence　of　12.1　kG　(1　G　=　1　x　10(-4)　T),　and　a　coercivity　of　14.6　kOe　(1　Oe　=　79.6　A.m(-1)),　resulting　in　an　energy　product　of　34.5　MGOe.　This　recycling　route　promises　a　great　advantage　in　recycling　efficiency　as　well　as　in　cost.　(C)　2020　THE　AUTHORS.　Published　by　Elsevier　LTD　on　behalf　of　Chinese　Academy　of　Engineering　and　Higher　Education　Press　Limited　Company.