BOROSILICATE GLASS FOAM EXPERIMENTALLY MANUFACTURED BY MICROWAVE IRRADIATION

Abstract

A glass foam obtained by sintering at 790 ºC using borosilicate glass waste, carbon black (1%) as a foaming agent, Na₂HPO₄ (5.9%) as a stabilizing agent, Sb₂O₃ (0.8%) as an oxygen supplying agent and water addition (10%) as a binder was manufactured by microwave irradiation. The glass foam characteristics were: apparent density of 0.34 g/cm³, porosity of 84.5%, thermal conductivity of 0.06 W/m·K, compressive strength of 2.2 MPa. The pore size was between 0.4-0.7 mm. The specific consumption of energy had an extremely low value (0.68 kWh/kg) below the level of the consumptions of glass foam industrially made by conventional techniques.