Separation and utilization of iron, cerium, and other rare earth elements from rare earth waste by chlorination

Abstract

Due to the lack of effective screening systems in the rare earth waste recycling industry, the composition of rare earth elements in rare earth waste is complex and difficult to separate. In response to such problems, by studying the reaction behavior between various elements in rare earth waste and cobalt chloride, we propose a process path for the separation and recovery of iron, cerium and other rare earth elements using cobalt chloride roasting. The experiments on simulated wastes show that the leaching rates of the Nd, Sm, Gd, Pr can reach 98.31%, 94.5%, 93.87% and 72.05% under the optimal process conditions, respectively. Ce and iron remain in the leaching residue in the form of CeO2 and CoFe2O4, respectively. And through a simple magnetic separation process, CeO2 and CoFe2O4 can be enriched in non-magnetic leaching residue and magnetic leaching residue, respectively. The cerium content in the leaching residue composed of cobalt ferrite is only 1.95%. Therefore, this method is beneficial to the separation and high-value utilization of iron, cerium, and other rare earth elements in the waste system. The research results can provide theoretical reference for the low-cost and high-value recovery of rare earth secondary resources.