Selective separation of copper(II) on a cobalt hexacyanoferrate(III) ion-exchange column

Abstract

Cobalt hexacyanoferrate(III), prepared by adding cobalt chloride to potassium hexacyanoferrate(III) solution and heating at 80 °C, is stable in water, acids and salt solutions. The compound was characterised and its solubility determined in different media. The exchange capacity of the exchanger in the H⁺ form was found to be 0.45 mequiv g^–1. Distribution coefficients determined for various metal ions show that the exchanger is highly selective towards Cu(II) ions, unlike other hexacyanoferrate(II) and -(III) compounds, and can, therefore, be used for its separation from other ions.