Recycling rare earth from ultrafine NdFeB waste by capturing fluorine ions in wastewater and preparing them into nano-scale neodynium oxyfluoride  

作　　者：He Sun Tuoyao Wang Chengxiang Li Yusheng Yang 

机构地区：[1]Department of Chemistry,Baotou Teachers’College,Baotou 014030,China [2]School of Energy and Environment,Inner Mongolia University of Science and Technology,Baotou 014010,China [3]Key Laboratory of Integrated Exploitation of Bayan Obo Multi-Metal Resources,School of Material and Metallurgy,Inner Mongolia University of Science and Technology,Baotou 014010,China [4]Collaborative Innovation Center of Integrated Exploitation of Bayan Obo Multi-Metal Resources,Inner Mongolia University of Science and Technology,Baotou 014010,China

出　　处：《Journal of Rare Earths》2022年第5期815-821,I0005,共8页稀土学报（英文版）

基　　金：Project supported by the Natural Science Foundation of Inner Mongolia(2020BS05033,2020MS05012);Inner Mongolia Major Basic Research Open Project(0406091701)。

摘　　要：Ultrafine NdFeB waste is a relatively clean waste produced during NdFeB magnet processing.Fluorinecontaining wastewater is a common type of industrial wastewater,such as stainless steel pickling wastewater.In this work,rare earth element neodynium was recycled from ultrafine NdFeB waste by capturing fluorine ions in the fluorine-containing wastewater and prepared into neodynium oxyfluoride.The reaction process was investigated through UV-Vis-NIR,thermogravimetry/differential thermogravimetry(TG/DTG),X-ray diffraction(XRD)and X-ray photoelectron spectroscopy(XPS).The neodymium hydroxide in the ultrafine NdFeB waste reacted with fluorine ions to form Nd(OH)_(2) F,and Nd(OH)_(2) F was then transformed into neodymium oxyfluoride after decomposition.The formed neodymium oxyfluoride is found to be particles with rhombohedral structure and a particle size of around 50 nm.The reaction kinetics of forming Nd(OH)_(2) F was investigated.The reaction kinetic equation was established and the reaction activation energy was calculated.The effect of fluorine ion concentration on the reaction rate and products was evaluated.The results show that the reaction rate increases with the increase of fluorine ion concentration in the range of 0.01-1.5 mol/L,but it has little effect.In addition,the fluorine ion concentration affects the crystallinity of formed neodymium oxyfluoride.The recycling process not only realizes the sustainable utilization of rare earths,but also reduces the concentration of fluorine ions in the fluorine-containing wastewater,achieving two goals with one stone.

关 键 词：RECYCLING Ultrafine NdFeB waste Capturing fluorine ions Neodymium oxyfluoride Rare earths 

分 类 号：X703[环境科学与工程—环境工程] TQ133.3[化学工程—无机化工]