Formation of Structure and Closed Porosity under High-Temperature Firing of Granules of Porous Glass-Ceramic Material

Abstract

On the basis of broken glass, clay, and organic additives, granular insulating glass crystalline material and technology of its production is developed. The regularities of the effect of composition and firing temperature on the properties of the granules are specified. The resulting granular thermally insulating material is produced with a bulk density of 200–290 kg/m³, pellet strength of 0.82–2.5 MPa, thermal conductivity of 0.067–0.087 W/(m °C), and water absorption of 2.6–3.2% by weight. The effect of the basic physical characteristics of the components of the charge on the process of pore formation is studied. According to the results of investigations, the basic parameters affecting the sustainability of the swelling glass are specified. The rational charge composition and thermal and gas synthesis mode are chosen so that the partial pressure of gases is below the surface tension of the melt. This enables the formation of granules with small closed pores and vitrified surface. The article presents the results of studies on the use of foamed glass ceramic materials for pipe insulation of heating mains.