I. Cesium Leaching in CsA and CsX Zeolites

Abstract

Sodium zeolite X and sodium zeolite A have been exchanged with cesium solutions prepared from three cesium salts (chloride, nitrate, and acetate). Depending on the solution, the cesium cations were found to be located in different sites of the zeolite networks. If cesium acetate solution is used, then cesium reaches sites SII and SIII in the large cavity whereas if nitrate or chloride solutions are put in contact with zeolites, cesium is positioned only in sites SIII. This distribution determines the leaching behavior of the studied zeolites. When the samples were thermally treated to encapsulate partially the cesium cations, it was found that their behavior was different from the one observed in a previous work on cobalt exchanged X and A zeolites

Cesium leaching from γ-irradiated CsA and CsX zeolites

“…Safe retention depends on the location of cesium in the zeolite structure as shown in our previous paper [13]. We found that depending on the anions present in the exchange solution the cesium cations were located in different sites of the zeolite, A or X, network.…”

“…As described in our previous work [13], the framework of zeolite A heated at 1073 K is partially destroyed. A high amount of amorphous material is present.…”

“…Cation exchange with CsCl, CsNO 3 or CsOOC 2 H 3 was performed as described elsewhere [13]. The exchanged zeolites with the CsCl solution are referred in this paper as CsX-1 or CsA-1, the samples exchanged with the CsNO 3 solution are labeled as CsX-2 or CsA-2 and finally, the solids denoted as CsX-3 or CsA-3, correspond to samples exchanged with the CsOOC 2 H 3 solution.…”

Fractal Extra-Framework Species in De-aluminated LaY Zeolites and Their Catalytic Activity

“…It is generally agreed that steaming promotes the removal of framework aluminum from zeolite structure to form amorphous aluminum oxides [10]. De-alumination induces modifications in the acidity as well as in the positions of the exchangeable cations into zeolite because of non-rigid character of such sites [11]. In order to characterize the variation in acidity or cation positions, probe molecules and spectroscopy are highly suitable.…”

Cadmium leaching from thermal treated and gamma irradiated Mexican aluminosilicates

“…Some studies in cation exchanged synthetic zeolites have reported that these materials are susceptible to both radiation and thermally-induced amorphization [4,5,[12][13][14]. The same effect was observed in various types of natural cation exchanged zeolitic materials [15][16][17].…”