Selective cation exchange using acidic groups in coals and oxidised coals

Abstract The cation exchange properties of Morwell brown coal and an oxidized vitrain from Liddell bituminous coal were studied. The known exchange properties became more selective for certain metal ions if the coals were first treated with mineral acid to ensure that their acidic groups (carboxylic acids and phenolic acids) are in non-dissociated acid form. Hence a partial separation of a mixture of two metal ions in aqueous solution could be effected.