Separation of zinc and cadmium ions from aqueovs chloride solutions by ion flotation and liquid membranes
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Technical University of Częstochowa
Wrocław University of Technology
Publication date: 2000-01-01
Physicochem. Probl. Miner. Process. 2000;34(1):141–151
An experimental investigation is presented on zinc(II) and cadmium(II) ions separation from aqueous chloride solutions, containing equimolar mixture of both metals ions, by ion flotation (IF) and polymer inclusion membrane (PIM) processes. The IF experiments from dilute aqueous chloride solutions (cMe = 1x10-5 M) with an anionic surfactant (sodium dodecylbenzene sulfonate) and a cationic surfactant (cetylpyridinium chloride) are shown. With a cationic surfactant, the flotation separation of Cd/Zn grows with Cl- concentration increase. In addition, a selective transport of Zn(II) and Cd(II) from aqueous chloride source phase (cMe = 1x10-3 M) through PIM containing celulose triacetate (support), o-nitrophenyl pentyl ether (plasticizer) and tri-n-octylamine (ion carrier) is shown. The transport selectivity of Cd/Zn is decreasing with HCI concentration increase in source phase. In both studied separation methods zinc(II) and cadmium(II) are removed from an aqueous chloride solution in the form of ZnCl3- + ZnCl42- and CdCl3- + CdCl42-, respectively. Results are discussed in terms of the stability of chloride complex species for zinc(II) and cadmium(II).