Studies on the Synthetic Inorganic Ion Exchangers. I : Synthesis of Stannic Phosphate and Some of Its Properties

For the purpose of developing ion exchangers which are expected to have radiation stability, the author has studied the synthetic inorganic ion exchangers. First, stannic phosphate was prepared by various methods, and its properties, such as composition, exchange capacity, and chemical stability, were investigated in relation to the methods of synthesis. The content of phosphate increases with increase of the mixing ratio of PO_4^/Sn^ up to a value 2 and then becomes constant at the maximum phosphate to stannic ratio of 5/4 of the stoichiometric value. Exchange capacity depends on the phosphate content of the exchanger, and it is assumed that fixed ion originates from phosphate group. The exchanger, which has maximum phosphate to stannic ratio, has maximum exchange capacity of 1.3～1.5meq/g. This exchanger is unstable in concentrated hydrochloric acid and alkali even in dilute solution, but fairly stable in nitric acid as zirconium phosphate. Attempts were made on mutual separation of alkali metals for the examination of the selectivity and availability for the column operation of the exchanger. By using various concentration of ammonium chloride as an eluent, complete separation of sodium, potassium and cesium from each other was achieved with relatively small column