A PROCESS FOR SELECTIVE EXTRACTION OF LANTHANUM, CERIUM AND NEODYMIUM FROM BLAST FURNACE SLAG AS OXALATES/OXIDES

摘要

The present invention relates to the recovery of rare earth elements from blast furnace slag using hydrochloric acid to extract lanthanum, cerium, and neodymium. The multi-step process involves digesting blast furnace slag containing rare earth elements with a dilute HCL solution while leaving calcium and silica in the blast furnace slag substantially undissolved; separating the solution obtained from the solid residue and recovering the rare earth elements from the solution by ion exchange cum precipitation using amide based resin, and recycling of spent acid in next cycle of leaching as stated in the flowsheet. The rare earth product obtained was essentially a composite of La-Ce-Nd with 93% purity which was confirmed by chemical analysis and SEM. The extraction of rare earth elements from blast furnace slag was benign enough to ensure no alteration to the original matrix of blast furnace slag, making it still competent for cement making.