Characterization of ceramic foam from metakaolin and waste glass by foaming sodium silicate agent

Ceramic foams were prepared by dry pressed and replica methods using metakaolin, waste glass and sodium silicate as starting materials. Starch was added as a pore forming agent. The effects of starch addition, percentage of starting material and methods applied on the bulk density, porosity, compressive strength, thermal conductivity, microstructure and crystalline phases were investigated. The optimum parameter to prepare light weight (foam) ceramic was obtained at 700 °C with a composition of 20 % metakaolin, 40 % waste glass, 40% sodium silicate and 40% starch additive, by dry pressed method. The specimens of this method have low bulk density (0.52 g/cm3), high porosity (68%), a reasonable compressive strength (10MPa) and low thermal conductivity (0.17 W/mK). Based on our data, the prepared light weight ceramic may supply a promising route to achieve thermal insulation material, in which preference in both economic and environmental parts.