Fabrication of Foamed Glass and Its Properties Using Recycled Blast Furnace Slag
In this study, foamed glass was fabricated by adjusting the final heat treatment temperature. The heat treatment temperatures ranged from 900 °C to 1,100 °C at 50 °C intervals. Blast furnace slag (BFS) powder was mixed with foaming agent such as CaCO3, Ca3(PO4)2, Na2SiO3 and NaOH, pressed under compression, then heat treated to form a porous and stable glass structure. Their optical, thermal, and physical properties, including thermal coefficient, density, glass transition temperature (Tg) and X-ray diffraction patterns, were investigated. As the heat treatment temperature increased, the apparent density decreased from 1.44 g/cm3 to 1.03 g/cm3 while the porosity increased from 46.03 % to 58.89 %. Thermal coefficient decreased from 9.997 × 10-6 /K to 9.417 × 10-6 /K. The main XRD peak gradually shifted toward a lower angle, indicating an expansion of the glass network structure. Results showed that foamed glass based on BFS, developed with a porous structure, can be used as an effective thermal insulation material, suggesting the potential for the commercial utilization of slag.