Separation of copper(II) from palladium(II) and platinum(IV) by di(2-ethylhexyl)phosphoric acid-based liquid membranes during electrodialysis

The process of Cu2+, PdCl42− and PtCl62− separation extracting from binary hydrochloric mixtures by bulk liquid membranes containing di(2-ethylhexyl)phosphoric acid with admixtures of tri-n-octylamine (TOA) is studied at galvanostatic electrodialysis. The effects of the current density as well as of composition of the liquid membrane and aqueous solutions on the rate and selectivity of the copper(II) transport are determined. About 90% of copper(II) was removed from the feed solution containing 0.018 mol dm−3 CuCl2 during 2–2.5 h of electrodialysis. An effective separation of Cu(II) from platinum metals is achieved. Maximum separation factors of ∼1 × 103 (βCu/Pd) and ∼9 × 102 (βCu/Pt) are obtained under optimal conditions.