Immobilization of cobalt in collapsed non-irradiated and gamma-irradiated X zeolites

Cobalt exchanged X zeolites were gamma irradiated and heated until the zeolite structure collapsed. Heating destroys the zeolite network as found by X-ray-diffraction and 29Si, 27Al MAS NMR spectroscopy. Gamma irradiation treatment diminished the collapsing temperature of zeolite. Cobalt leaching from crystalline and amorphized zeolites was verified by ion exchange with NaCl solution. Results show that cobalt is not released from the amorphous materials. Furthermore adsorption of xenon and 129Xe NMR spectroscopy reveal that cobalt ions are heterogeneously distributed in the non irradiated amorphous materials. Gamma irradiation causes the mobility of cobalt in the amorphous materials resulting then in a more homogeneous distribution. Cobalt is, thus, retained safely in the amorphous materials.