Synthetic inorganic ion-exchange materials. XXXIX. Synthesis of titanium(IV) antimonates and their ion exchange properties for alkali and alkaline earth metal ions

Titanium antimonate (TiSbA) cation exchanger, prepared under different molar ratios of titanium and antimony, has been characterized by X-ray diffraction, thermal analysis, infrared spectra, and pH-titration. The pH-titration curves showed apparently monobasic acid type. The uptakes of alkali metal ions increased with increasing pH of the solution and with decreasing the molar ratio (Ti/Sb) in the exchanger. An unusual selectivity sequence of the order Na < K < Rb < Li < Cs was found for microamounts of alkali metal ions on TiSbA, while the regular selectivity sequence Mg < Ca < Sr < Ba was found for alkaline earth metal ions in nitric acid media. The maximum separation factors, α/sub Na//sup Li/ (=55) and α/sub Na//sup Cs/ (=186) were found on the TiSbA with Ti/Sb molar ratio of 1.56, respectively. The effective separations of Li from Na and K, Mg from Ca and Sr have been achieved by using a relatively small column (2 cm x 0.5 cm ID) containing TiSbA of Ti/Sb ratio 1.56