Magnetic property recovery in Nd-Fe-B bonded magnet wastes with chemical reaction and physical dissolution  

作　　者：Min Liu Haiyuan Cui Qingyan Li Peihong Zhu Weiqiang Liu Qingmei Lu Dongtao Zhang Zaisheng Pang Xi Yu Chunhui Yu Shanshun Zha Youhao Liu Xiaofei Yi Ming Yue 

机构地区：[1]Laboratory of Advanced Functional Materials,Ministry of Education,Faculty of Materials and Manufacturing,Beijing University of Technology,Beijing 100124,China [2]Ganzhou Fortune Electronic Co.,Ltd.,Canzhou 341000,China [3]Earth-Panda Advanced Magnetic Materials Co.,Ltd.,Hefei 231500,China

出　　处：《Journal of Rare Earths》2021年第11期1396-1401,I0003,共7页稀土学报（英文版）

基　　金：Project supported by the National Key Research and Development Program of China (YFC1903405);Major Science and Technology Projects of Anhui Province (201903a07020002);the Beijing Municipal Natural Science Foundation (2172012);Program of Top Disciplines Construction in Beijing(PXM2019014204500031),China。

摘　　要：The main difficulty for the recovery of Nd-Fe-B bonded magnet wastes is how to completely remove the epoxy resins.In this study,chemical reaction and physical dissolution were combined to remove the epoxy resins by adding ammonia-water and mixed organic solvents.Ammonia-water can react with the epoxy functional group of epoxy resin to generate polyols.Mixed organic solvents of alcohol,dimethyl formamide(DMF),and tetrahydrofuran(THF) can dissolve the generated polyols and residual epoxy resins.Under the optimum processing conditions,the epoxy resins in the waste magnetic powders are substantially removed.The oxygen and carbon contents in the recycled magnetic powder are reduced from 13500 × 10^(-6) to 1600 × 10^(-6) and from 19500 × 10^(-6) to 2100 × 10^(-6) with the reduction ratio of88.1% and 89.2%,respectively.The recycled magnetic powder presents improved magnetic properties with MS of 1.306 × 10^(-1) A·m^(2)/g,Mr of 0.926 × 10^(-1) A·m^(2)/g,Hcj of 1.170 T,and(BH)max of 125.732 kJ/m^(3),which reach 99.8%,99.4%,95.9%,and 96.9% of the original magnetic powders,respectively.

关 键 词：Nd-Fe-B bonded magnet wastes Epoxy resin Open-loop reaction Physical dissolution Recycled magnetic powders Rare earths 

分 类 号：X705[环境科学与工程—环境工程] TM27[一般工业技术—材料科学与工程]