Effect of Temperature and Water Glass Addition on the Microstructure and Physical Properties of Soda-Lime Foam Glass

This work aims to study the effect of sodium silicate additive on the microstructure and physical properties of foam glass fabricated from the recycled soda-lime glass regarding the process temperature of 700 to 900 degrees C. Sodium silicate was added as a cost-effective environmental foaming agent in 10 to 30 wt % to recycled soda-lime glass powder (maximum size of 63 mu m), pressed and heat-treated for 30 min. X-ray diffraction, scanning electron microscopy, and thermogravimetry analysis were used to characterize the phase evolution, porosity, morphology, and the foam-forming ability, respectively. Bulk and true density, as well as flexural strength, were measured. The results showed that for samples containing 20 wt % water glass treated at 800 degrees C, bulk density and strength values was 0.54 g/cm(3) and 5.3 +/- 0.7 MPa, Theses samples have higher strength than commercial foam glasses with uniformly distributed pores of 66.67% confirmed by the SEM images.