Study on cesium crystallization solidification in fly ash based cesium zeolite

To solidify make ¹³⁷Cs with long half-life solidified in high level waste liquid, cesium zeolite was synthesized from fly ash without adding template. The effects of basic cations (Na⁺ or K⁺) on the binding force and interaction mechanism of cesium zeolite and Cs(I) were calculated and evaluated by first principles. The results indicate that a spherical granular cesium molecular sieve with a particle size of approximately 5 μm can be synthesized from alkali-pretreated fly ash following a hydrothermal reaction at 180 °C for 20 h, achieving a cesium solidification rate exceeding 40%. The coexistence of Na(I), K(I), and Cs(I) had minimal impact on the synthesis of the cesium molecular sieve.