首页|On the possibility to modify the CsAlSi5O_(12)/CsAlSi2O6 ratio during the thermal transformation of Cs-clinoptilolite
On the possibility to modify the CsAlSi5O_(12)/CsAlSi2O6 ratio during the thermal transformation of Cs-clinoptilolite
扫码查看
点击上方二维码区域，可以放大扫码查看
原文链接
NSTL
Clinoptilolite is a natural zeolite employed in Cs~+ removal, and its cesium form transforms, by heating, into a matrix composed mainly by CsAlSi5O_(12) (CAS) with smaller quantities of glass and CsAlSi2O6 (pollucite). Both crystalline compounds were proposed as host for ~(137)Cs, albeit pollucite is considered superior. This work shows how, by mixing Cs-clinoptilolite and amorphous hydrated aluminum hydroxide (L), it is possible to modify the solid-state transformation of the zeolite and favor the crystallization of pollucite over CAS. Cs-clinoptilolite, L and several mixtures of the two materials were preliminary subjected to thermal and XRD analyses. Muffle treatments of 32 h at 1200 °C and 8 h at 1300 °C, followed by Q-XRD analyses, were performed on some materials. Unlike CAS, pollucite always crystallized. The greater the quantity of L in the mixture, the lower the ratio between the quantities of CAS and pollucite formed. In the range 1200-1300 °C, the CAS/pollucite ratio decreases with temperature. Al2O3-polymorphs (mainly corundum) and glass were ubiquitous in the fired mixtures, whereas mullite was not. By varying the content of L in the mixture, the distribution of cesium among the Cs-bearing phases varied, and for some compositions most of the cesium was trapped inside pollucite.
CASPolluciteZeoliteSolid state reactionNuclear waste
Antonio Brundu、Guido Cerri
展开 >
Department of Architecture, Design and Urban Planning - GeoMaterials Lab, Sassari University, Via Piandanna 4, 07100, Sassari, Italy
NSTL
