Selective transport of yttrium(III) in the presence of iron(III) through liquid-membrane impregnating acidic organophosphonate mobile carrier

The extraction and stripping behavior of yttrium(III) and iron(III) with 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester (EHPA) was investigated and applied to liquid-membrane transport for their mutual separation. The extractability of yttrium(III) with EHPA was less than that of iran(III) at equilibrium, but the rates of extraction and stripping of iron(III) were slow. The carrier-mediated transport of yttrium(III) in the presence of iron(III) was investigated through a supported liquid membrane (SLM), impregnated with EHPA as a mobile carrier. Yttrium(III) with fast kinetics was selectively transported across an SLM from a dilute-acid solution into a sulfuric-acid stripping solution, while iron(III) with slow kinetics was hardly transported and was retained in the feed solution. Yttrium(III) was separated from iron(III) through the SLM and quantitative recovery was realized.