Exploring Blast Furnace Slag As A Secondary Resource For Extraction Of Rare Earth Elements

Abstract

The processing of blast furnace slag as secondary source containing 17ppm La, 16ppm Ce, 4ppm Er and 44ppm Nd for extraction of rare earth elements has been claimed. The extraction of rare earths from BF slag was tested with sulfuric acid while optimising parameters like acid concentration, temperature and pulp density. Experiments showed that recovery of 88% La, 36% Ce, 35% Nd, and 52% Er was achieved at 3-5% (w/v) pulp density using <250m particles with 1M sulfuric acid in 1h at room temperature. The elevation in temperature promoted the dissolution of Ce, Nd to the extent of 89% and 84% respectively at 95oC in same duration and 1M acid concentration. Cyanex 923 is preferred for the purification of REE’s from leach liquor as compared to Cyanex 301. In another route, the leach liquor on being subjected to precipitation with 0.5-1M oxalic acid resulted in 4-5% concentrated REE product.