Recovery of a composite powder from NdFeB slurry by co-precipitation

A co-precipitation process was used to recover composite powders from a NdFeB slurry. The most appropriate concentration of HCl and a v/w ratio were obtained in the leaching process. The optimum pH range for the coprecipitation process was determined by the log[Me(Nd, Fe, Co, Pr)]-pH curve simulated using a thermodynamics model. Fe2O3, Fe2O3 center dot Nd2O3, and Pr2CoO4 phases were detected in the final composite powders after firing the co-precipitated products at 1273 K for 2 h. The content of the valuable metals (Nd, Pr, Co, Fe) in the obtained composite powders was greater than 99.4%, which meets the raw material requirements for preparing recycled NdFeB magnetic powders. The main advantages of the co-precipitation process are that it is efficient, low-cost, and environmentally friendly. (C) 2014 Elsevier B.V. All rights reserved.