Abstract
Authors had elucidated the reason why cesium (Cs) in bottom ash becomes hardly-soluble. From the observation by scanning electron microscope and polarization microscope, it was found that Cs accumulates at peripheral area of specific mineral. In its location, glassy amorphous phase formed and Cs was captured in it physically. However, from where the specific mineral was derived was not known. Was it contained in original waste subjected to combustion? Or was it formed from elements contained in the waste during combustion? In this study, origin of the specific mineral that captures Cs in bottom ash on the amorphous surface was investigated. Inorganic material such as clay etc. and organic matter such as paper, wood etc was selected as the samples subjected to the combustion. Cesium carbonate was added to these samples and then the samples were combusted. After combustion, residues were collected and thin section was created for microscopic analysis. As consequences, the following findings were obtained. Although clay samples captured Cs completely after combustion, these particles were too small compared to the specific mineral that was identified in the past study. When glass was heated with Cs, Cs accumulated at the edge of melted region.
