Separation of heavy metals by parametric pumping with variation of pH - Part II: Application of cation exchangers in ternary systems

In parametric pumping pH becomes a strong parameter If a complexing agent o f medium strength is added. Apart from binary systems also ternary metal mi xtures can be separated. The separation of ternary systems with one metal c omponent forming stable complexes (copper) and two other metals forming les s stable complexes (nickel, zinc, cadmium) develops like that of a binary s ystem. The process leads to a concentration of copper in one solution and t he generation of an almost copper-free mixture of the two other metals in t he Ether solution. The separation can be enhanced by means of a second step . In systems with two divalent and one trivalent kind of metals a separatio n of at least one divalent metal from the trivalent one is achieved. (C) 20 01 Elsevier Science B.V. All rights reserved.