Inorganic ion exchangers based on tin(IV), antimony(V) and silicon

Abstract

Five samples of stannic antimony silicate inorganic ion exchanger have been synthesized under different conditions of preparation. The sample possessing the maximum ion exchange capacity (0.90 meq g−1 of dry exchanger) was selected for detailed studies and its chemical composition was determined. The exchanger was found to be thermally stable, possessing good ion exchange capacity and exhibiting regeneration phenomenon after heating at elevated temperatures when compared to the corresponding ion exchanger stannic antimonate. The ion exchange capacity is almost completely regained when determined on regenerated exchanger samples. The gain/loss of ion exchange capacity has been studied in the temperature range 40–800 °C. The reproducibility in the properties of the exchanger has been checked by duplicate preparations. The X-ray, pH titrations, TG and FTIR spectral studies have been performed. TG curve of the exchanger shows a higher percent mass loss in H+ form than that in K+ form and also gives an idea of the internal and the external water molecules present in the exchanger. On the basis of the above studies, the empirical formula of stannic antimony silicate has been proposed. Quantitative separations of Zn2+ from Mn2+, Cu2+ and Ni2+ have been carried out on the exchanger columns.