Effect of Organic Extractants on the Extraction of Rare Earth Elements from Sulphuric Acid Leach Liquor

Abstract

In this study, the various organic extractants, namely D2EHPA, PC-88A, TBP, TBPP, TOA, and TOPO, were examined to extract REEs from sulphuric acid leach liquor of apatite ore. Extraction parameters including extractants type, the concentration of extractant, organic to aqueous phase ratio, and contact time were investigated. Stripping experiments were conducted using different concentrations (0.5-4 M) of hydrochloric acid. Results showed that the overall extraction of REEs into the PC-88 extractant were ranged between 20 and 35%, while their extraction with other extractants did not exceed 20%. Interestingly, heavy rare earth elements (Tb, Dy, Er, and Y) were selectively extracted with D2EHPA when the light REEs extraction was lower than 5%.