Hydrous Titanium Oxide Ion Exchanger, (I)

Synthesis of hydrous titanium oxide ion exchanger was tried from three systems: (a) TiCl4-NaOH-H2O, (b) ATS (ammonium titanyl sulphate monohydrate)-NaOH-H2O and (c) TiCl4-NH4OH-H2O. The first method gave the best results under the conditions covered in the present work. It was found that repeated washing and aging of the hydrous titanium oxide precipitate were indispensable in order to obtain reproducible results, and that this operation further obviated the need of precisely adjusting the conditions for mixing the reagents. Both the yield of exchanger and the ion exchange capacity of the resulting product increase with concentration of the reagents. A cation exchange capacity of about 3 meq·Na+/g could be obtained, which is considerably higher than any corresponding value reported in literature. The value decreased with increasing drying temperature. Irrespectively of the conditions of synthesis, the chemical composition was TiO2·(2.0–2.2) H2O, and the impurities contained in the product were found to be less than 0.1%. The exchanger produced is in granular form suitable for use in column operation. It is fairly stable in alkaline solution, and also in mineral acid solutions of <0.1 n concentration.