Synthesis and Evaluation of Tobermorite from Perlite Using Hydrothermal Synthesis

Abstract

Perlite is a white powder of expanded aluminum silicate manufactured by heat treatment after grinding the perlite ore. Amorphous (glassy) perlite with physical properties such as lightweight, excellent in heat resistance, fire resistance, chemical resistance and heat insulating properties is used in lightweight aggregate and insulation. In particular, it is used as a heat insulating material for LNG tank. These tanks are double-shell-structured, in which perlite is filled as heat insulation material between the outer layer and the inner layer. Perlite is generally withdrawn from the storage tank at the time of the update and the disposal of the tank and is used as landfill materials of industrial waste. Therefore, in this study, we investigated the possibility of synthesizing tobermorite (5CaO·6SiO₂·5H₂O) by hydrothermal treatment using waste perlite as a starting material in order to investigate effective reuse method of natural resources perlite .