Synthesis, characterization and ion exchange properties of zirconium(IV) tungstoiodophosphate, a new cation exchanger

Abstract. Zirconium(IV) tungstoiodophosphate has been synthesized under a variety of conditions. The most chemically and thermally stable sample is prepared by adding a mixture of aqueous solutions of 0⋅5 mol L–1 sodium tungstate, potassium iodate and 1 mol L–1 orthophosphoric acid to aqueous solution of 0⋅1 mol L–1 zirconium(IV) oxychloride. Its ion exchange capacity for Na+ and K+ was found to be 2⋅20 and 2⋅35 meq g–1 dry exchanger, respectively. The material has been characterized on the basis of chemical composition, pH titration, Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis. The effect on the exchange capacity of drying the exchanger at different temperatures has been studied. The analytical impor-tance of the material has been established by quantitative separation of Pb2+ from other metal ions