A Sustainable Building Material Developed from Low-Temperature Sintering of Mining Waste with an Alkali-Silicate Solution

The development of glass-ceramic foam has received significant attention in building and construction, given its potential for sustainability. This study investigated the low-temperature route of fabricating glass-ceramic foams from mining waste. The feasibility of one-step or chemical-aided sintering of glass-ceramic foams using granite powder, a naturally sourced mining waste, rather than using already heat-treated wastes such as glass and fly ash has been explored in this study. Glass-ceramic foam samples were synthesized from a homogenous blend of constant percentage by weight of granite-clay mix with varying amounts of alkali-silicate solution. The influence of the alkali-silicate solution on the physicomechanical and microstructural properties of the synthesized samples sintered at 850°C was investigated. The results showed water absorption of 9.5-33.3%, apparent porosity of 18.2-56.7%, bulk density of 1.7-1.91 g/cm3, and compressive strength of 20.7-26.3MPa. The glass-ceramic foam developed in this research can be suitably used for the thermal insulation of buildings.