Production of foamed glass-ceramics using furnace bottom ash and glass

This research has produced foamed glass-ceramics from coal fired power station furnace bottom ash (FBA) and soda-lime-silica glass. The as-received FBA was wet milled with different additions of glass. The resultant slurry was dried and formed into a powder. The powder was pressed and sintered at a range of temperatures with additions of a fluxing agent (sodium tetraborate decahydrate), a bubble stabilising additive (tri-sodium phosphate) and a bloating agent (calcium carbonate) and this produced foamed FBA-glass-ceramics. The effect of glass content and sintering temperature on the properties of the sintered ceramic foams are reported. A range of potential applications including thermal insulation and biological filters for water and wastewater treatment are discussed. The research demonstrates that it is possible to engineer the properties of FBA derived glass-ceramic foams by careful control of the composition and processing conditions in order to transform a problematic waste into commercially interesting materials.