Aqua-impregnated resins. 2. Separation of polyvalent metal ions on iminodiacetic and polyacrylic resins using bis(2-ethylhexyl) phosphoric and bis(2-ethylhexyl) dithiophosphoric acids as organic eluents

This paper dedicated to the further development of the novel aqua- impregnated-resin (AIR) technique reports the results obtained by studying the column separation of equimolar mixtures of Cu2+, Al3+, and Zn2+ on iminodiacetic (IDA) and polyacrylic (PAR) resins by using 0.2 M heptane solutions of either bis(2-ethylhexyl) phosphoric acid (DEHPA) or bis(2- ethyhexyl) dithiophosphoric acid (DEHDTPA) as selective eluents for extractive desorption of metal ions from the resin phase. The quantitative separation of Cu2+-Al3+ mixtures has been achieved by sequential elution of metals from PAR with DEHDTPA and H2SO4 solutions. Purification of Cu2+ from Al3+ and/or Zn2+ and Al3+ from Cu2+ and Zn2+ is achieved by extractive elution of metal mixtures from IDAR or PAR with DEHPA or DEHDTPA solutions, respectively, followed by stripping of the purified metals with 1.1 M H2SO4. The resulting purity of metals obtained with the yield of >96% exceed 95%.