Polybenzimidazole resin-based new chelating agents. Ferric ion selectivity of resins with immobilized oligoamines

Abstract

Microporous polybenzimidazole of 250–500 μm bead size from Celanese has been epoxidized and subsequently aminolyzed with ethylenediamine and diethylenetriamine to obtain sorbents having high capacity, selectivity and sorption rate for ferric ion from acidic sulfate solutions. The ferric ion sorption capacity of these sorbents is more than twice that obtained with normal chelating resins. The chelation properties of the new sorbents can be used as a means of removing the ferric ion selectivity from mixtures in acidic sulfate solution containing a wide range of mono- and multivalent metal ions, including some which normally form strong chelate complexes.