SIMULTANEOUS USE OF LIQUID AND SOLID FOAMING AGENTS BY A NONCONVENTIONAL TECHNIQUE TO OBTAIN A HIGH-STRENGTH GLASS FOAM WITH FINE POROSITY

Abstract

A glass foam with typical characteristics for a foam glass gravel usable as a thermal insulating material in difficult climatic conditions and with mechanical stress was made by sintering at 834 ºC a powder mixture composed of colorless glass waste (93.1 wt.%), glycerol (1.0 wt.%), sodium silicate (4.8 wt.%), calcium carbonate (0.8 wt.%), kaolin (0.2 wt.%) and water addition (14.5 wt.%). The physical, thermal, mechanical and morphological characteristics of the product were: apparent density of 0.28 g/cm3, porosity of 86.67%, thermal conductivity of 0.063 W/m·K, compressive strength of 7.3 MPa, water absorption of 4.3% and pore size between 0.10-0.35 mm. The specific energy consumption of the manufacturing process was 0.78 kWh/kg. The originality of the work is the use of a nonconventional heating technique based on the microwave energy.

Keywords

• glass foam
• microwave heating
• glass waste
• glycerol
• sodium silicate
• calcium carbonate