Extraction of rare earth metals using liquid surfactant membranes in a mixco extractor

The extraction of rare earth metals with liquid surfactant membranes, which contained 2-ethylhexyl-mono-2-ethylhexyl phosphonic acid (PC-88A) as a carrier and sorbitan monooleate (Span 80) or L-glutamic acid dioleyl ester quaternary ammonium chloride as a surfactant, was conducted in a Mixco extractor. The concentration profile of rare earth metals along the column was measured. The experimental results were analysed by the backflow model taking into account the interfacial reaction between rare earth metals in the continuous aqueous phase and the carriers in the liquid membrane phase. The concentration profile for each of the two rare earth metals (La, Y) in a dual-component solution along the column was successively simulated by using the interfacial reaction rate constants obtained in previous batchwise experiments.