The ion-exchange properties of cesium and strontium into zeolites from boric acid and amine salt solutions have been studied by the use of zeolite A, mordenite (Zeolon, SM), natural mordenite (NM) and clinoptilolite (CP).
The distribution of cesium into mordenite and clinoptilolite from the concentrated boric acid solution (-0.2M) was considerably larger than that into zeolite A. The distribution coefficient of cesium (K
Cs) into mordenite attained about 10
3 from acidic solution of pH 1-3. As for strontium, the K
Sr values into zeolites were in the order of A>SM>>NM.
Cesium ions were also preferentially distributed into mordenite from the concentrated amine salt solutions (-1M), and the K
Cs values exceeded about 7×10
3 even in 1M solution of amine. The effects of diverse ions on the K
Cs values into zeolites were in the order of NH
4+>Na
+>>amines.
The KSr values of zeolite A attained about 4×10
3 in the presence of 1M solution of amine, while those of mordenite were less than 1.7×1010
2. The distribution of strontium into zeolite greatly depended on pH, and the K
Sr values decreased with increasing acidity. Therefore, the pH control of the feed solution is considered to be very important.
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