Studies on separation of rare earths from aqueous media by polyethersulfone beads containing D2EHPA as extractant

Polyethersulfone beads containing D2EHPA as extractant have been prepared by phase inversion method and characterized by optical microscope, SEM and TG-DTA. Subsequently these beads were tested for their suitability for separation of rare earths from various aqueous media. Except nitrate medium, the extraction of rare earths was found to be comparable in perchlorate, chloride and sulfate medium. Effect of aqueous acidity, metal ion concentration in aqueous feed, concentration of organic extractant inside the beads, extractant to polymer ratio, liquid to solid (L/S) ratio, additive concentration, and temperature on the extraction of rare earths was studied. Increase in acidity, L/S ratio, metal ion concentration and polymer to extractant ratio led to decrease in extraction of rare earths. Increase in extractant concentration inside the bead resulted in enhanced extraction of metal ion. Extraction of rare earths increased in the range of 30-50 degrees C and thereafter showed a decreasing trend in between 50 and 70 degrees C. Stripping of rare earth from composite beads was found to be effective (>90%) with 40% HCl and 30% H2SO4. (C) 2013 Elsevier B.V. All rights reserved.