Multicomponent separation by a combined extraction/electrostatic pseudo-liquid membrane (II): extraction and group separation of rare earths from simulated rare earth ore leach solutions

The extraction of rare earths (REs) from simulated RE ore leachate solution s using an electrostatic pseudo-liquid membrane (ESPLIM) was carried out, f ollowed by group separation of REs by a combined extraction/ESPLIM on the b asis of previous work on the separation of Al, La, Sm and Y. The ESPLIM set -up was modified in such a way that gradient stripping could be easily appl ied. A simulated RE ore leachate containing about 1.0 g/l mixed rare earth elements (REEs), 10 g/l (NH4)(2)SO4, 5 g/l NH4Cl and 0.6 g/l of non-RE ions such as Ca, Al, Si, Fe and Pb was treated using di-(2-ethylhexyl) phosphor ic acid (HDEHP) as carrier in the organic membrane phase. The influences of feed pH, flow rate of feed, stripping and organic phases, and stripping ac id concentration were investigated. RE extraction percentage > 95% and prel iminary group separation and preconcentration of RE were achieved. (C) 1999 Elsevier Science B.V. All rights reserved.