Transport of yttrium(III) from nitrate medium through liquid membrane containing tri-n-octyl-phosphine oxide (TOPO) in n-dodecane, supported on a nucleoporous filter, into a strip solution with ethylenediaminetetraacetic acid (EDTA) has been studied. The kinetic dependences of transport were obtained and compared with a model, resulting in calculation of permeability coeffients and initial fluxes of yttrium. The influence of salting-out agent, initial metal and nitric acid concentrations in the feed, and of concentration of carrier in membrane are discussed.
Transport of trivalent rare earth elements-REE (Sc, Y, Ce, Eu, Gd, Tm, Yb) from nitrate medium through SLM containing TOPO in n-dodecane, supported on a nucleoporous filter, into a strip solution with EDTA, has been studied. Permeability coefficients of metal transport decreased with increasing of their atomic number except for Ce and Tm. At higher concentration of TOPO in the membrane, metal transport was faster, but the differences among the transport rates of the investigated elements decreased. A good separation of Ce from its binary mixtures with other investigated REE was achieved using DTPA as masking agent, added the feed solution.
Transport of tervalent REEs–Sc, Y, Ce, Eu, Gd, Tm, Yb—from nitrate medium through flat-sheet SLM containing DEHPA in n-dodecane, supported on a nucleoporous filter, has been studied. Influences of both aqueous phase acidities, concentrations of metal and carrier were investigated. Transport courses of the metals in question had been obtained and their premeation coefficients or initial fluxes were evaluated. Separation of some binary mixtures Ce–Tm, Ce–Yb, Ce–Sc was experimentally achieved.