Avraham Patchornik

Polymeric pseudocrown ethers. III. The complexation with iron(III) in phosphoric—hydrochloric acid mixtures

Abstract Polymeric pseudocrown ethers, incorporating oxyethylene and oxypropylene units, extract FeCl 4 − from mixed hydrochloric and phosphoric acids. The complexation depends on hydrochloric acid concentration and becomes efficient when the HCl concentration exceeds 4 M . The regeneration of the polymers is accomplished with water. Column tests have been shown to separate iron very efficiently from phosphoric acid, which is recovered quantitatively. In comparison, Amberlyst A-21, a weak-base anion exchanger, shows affinity for phosphoric acid, making the separation between iron and phosphorus difficult.