MULTICOMPONENT SEPARATIONS BY A COMBINED EXTRACTION ELECTROSTATIC PSEUDO-LIQUID MEMBRANE (I) - SEPARATION OF AL, LA, SM, AND Y

The paper reports the results of the development of a combined extract ion/electrostatic pseudo-liquid membrane (ESPLIM) concept for the mutu al separation of multi-component (n > 2) metal ionic mixtures. Multipl e sets of single two-cell ESPLIM equipment were linked up in order to achieve multi-metal separation. The principle of separation is describ ed. A practical demonstration of this concept has been carried out by applying it to a typical mixture of metal ions present in ion-sorbing rare earth ore leachate solution, i.e., Al3+, La3+, Sm3+, and Y3+: an aqueous solution containing in mg/l Al 200-360, La 250-460, Sm 40-60, and Y 160-340 was used as the feed solution and 20% (v/v) di-(2-ethylh exyl) phosphoric acid (HDEHP) in kerosene was employed as organic memb rane phase. The feed solution stream passed through the extraction cel l at a flow rate of 1 l/h in once-through mode and the stripping solut ion passed through the stripping cell at a flow rate of 0.2 l/h in rec irculation mode. By controlling the feed pH, organic membrane phase fl ow rate, and the hydrochloric acid concentration in stripping phase, t he separation of Al, La, Sm and Y was obtained. (C) 1998 Elsevier Scie nce B.V. All rights reserved.