Recovery of Rare Earth from Spent NdFeB Magnets by Iron Oxyhydroxide Separation Method
Spent NdFeB magnets are important secondary rare earth resource.Its recycling remains a challenge due to the keytechnical difficulties of separating rare earth elements(REEs)from the major impurity Fe.In the present study,the iron oxyhydroxide separation method for recycling spent NdFeB magnets was studied.And a highly selective leaching of REEs can be obtained by controlling H2O2 concentration,leaching temperature,base HC1 concentration,H2O2 flow rate,final pH value,US ratio etc.The results indicate that the proper con-ditions are 333.00 g·L-1 of H2O2 concentration,75 ℃ of leaching temperature,0.71 mol·L-1 of the base HC1 concentration,29.40×10-3 g·min-1 of H2O2 flow rate,3.0-3.5 of final pH value,4.56 mUg at US ratio.The cor-responding leaching rate of rare earth oxide(REO)is 99.26％,Pr-Nd oxide is 99.52％,cobalt is 90.53％,and s(Fe2O3,REO)in the leaching solution is less than 0.01％.The leaching residue is easy to precipitate and filter,since its main phase is crystalline iron oxyhydroxide(FeOOH)based on the XRD and SEM results.
NETL
NSTL
万方数据
