Foam glass production from waste bottle glass using silicon cutting waste of loose abrasive slurry sawing as foaming agent

Abstract

This study created foam glass from waste bottle glass employing silicon cutting waste (SCW) of loose abrasive slurry sawing as the foaming agent. The influence of affecting parameters, namely sintering temperature, glass powder particle size, SCW dosage, heating rate, holding time, were investigated. The produced foam glass was characterized to examine its microstructure, bulk density, compressive strength, porosity, and thermal conductivity, and was compared with that produced using silicon carbide (SiC) reagent as the foaming agent. The results indicated that under the optimal conditions of sintering temperature of 775 °C, glass powder particle size of 0.15 mm, SCW dosage of 1 wt% (the D50 of SiC in SCW was ca. 10 μm), heating rate of 10 °C/min, and holding time of 30 min, the produced foam glass had a compressive strength of 4.1 MPa, bulk density of 0.56 g/cm3, porosity of 78%, and thermal conductivity of 0.16 W/m·k; these properties meet with standards for thermal insulation materials. In contrast, using SiC reagent with a D50 of ca. 22 μm revealed 900 °C as the optimal sintering temperature, which yielded foam glass having a compressive strength of 5.4 MPa, bulk density of 0.67 g/cm3, porosity of 73%, and thermal conductivity of 0.2 W/m·k. By using SCW as the foaming agent, foam glass is able to be produced under comparatively low temperature and has favorable properties. In addition, the simultaneous waste valorization of waste bottle glass and SCW can be achieved.