ABSTRACT
Abstract The immobilization of cesium with a mix of calcium aluminate cement (CAC) and silica fume (SF) was studied. The presence of cesium within the solution of hydration leads to the formation of a zeolitic phase of the chabazite family. Cesium is immobilized within the structure of the zeolite during its crystallization. The efficiency of the immobilization is demonstrated by a severe leach test. The kinetic of crystallization depends on the temperature. The same zeolite crystallizes when a prehydrated mix of CAC-SF is in contact with a Cs-solution. Thermal stability of the zeolite has been assessed by simultaneous TGA-TDA analysis. The full destruction of the structure requires temperatures higher than 750°C. Keywords: calcium aluminate cement, silica fume, zeolite, chabazite, cesium immobilization, leaching, thermal stability.
