SELECTIVE SEPARATION OF IRON BY TREATMENT WITH AN ION-EXCHANGING RESIN COMPRISING DIPHOSPHONIC ACID GROUPS

摘要

The invention concerns a method for the selective separation of iron from other metal ions in particular ions present in certain oxidation catalysts. The invention also concerns a method for recycling oxidation catalysts in the oxidation reaction of alcohols and/or ketones into carboxylic acids and more particularly the oxidation of cyclic alcohols and/or cyclic ketones into dicarboxylic acids such as oxidation of cyclohexanol and/or cyclohexanone into adipic acid. Said method consists in treating the solution containing the oxidation catalyst, before recycling it, with an ion exchanging resin for selectively separating the iron from other metal elements in particular copper and vanadium, the ion exchanging resin comprising diphosphonic acid groups (for example, Diphonix)