Absorption of cesium on potassium cobalt hexacyanoferrate(II)

Potassium cobalt hexacyanoferrate(II) was synthesized with a composition K_1.70Co_1.12Fe(CN)₆ · 1H₂O, a mixture of K₂CoFe(CN)₆] (85–88%) and K₂CoFe(CN)₆] (12–15%). Ion exchange was found to be stoichiometric, the exchangeable ions being potassium and cobalt in the ratios presented for the corresponding phases. The effective capacity for cesium was 0.35 meq/g, which is only 6% of the theoretical capacity. Cesium is probably only absorbed as a monolayer on the surface of the crystallites.