반응성 결정화에 의한 네오디뮴 옥살레이트 특성 고찰

Abstract

In this study, neodymium oxalate powders were prepared by injecting oxalic acid to the neodymium chloride solution resulted from the acid leaching solution of NdFeB magnet scrap. The effects of experimental conditions on the characteristics of neodymium oxalate powders were investigated. Neodymium oxalate was aggregated by primary particles formed by nucleation, and average size of aggregates was affected by experimental conditions. In a constant volume, increase of reactants affected the average size of aggregate formed by collision of primary particles. In a constant concentration of reactants, agitation speed decreased the size of aggregate due to breakage of particles attached on the surface of aggregate. The number of primary particles decreased with increasing reaction temperature, and the size of aggregates decreased due to the decrease of collision probability. From the results of decomposition behavior of neodymium oxalate, oxalate decomposed from 400oC, and neodymium oxide began to crystallize at above 620oC.