Incorporation of calcium in glasses: A key to understand the vitrification of sewage sludge

The quantity of sewage sludge generated daily by wastewater treatment plants represents a major environmental problem and financial burden for plant operators. Valorization strategies focusing on reusing as raw material are currently developed. Vitrification can help us reduce the volume waste binds components in structure chemically stable glasses glass-ceramics. In this study, vitrification inside basaltic rock has been simulated producing glass-ceramic from basalt enriched calcium that lie between stability fields pyroxene melilite system CaO–MgO–SiO2–Al2O3. CaO addition causes oxidation melt at above liquidus, increases crystallization temperature, decreases melting improves microhardness glasses. Glass-ceramic processes properties Ca-doped glass. glass (8.2 GPa) (8.6 leaching tests (in ppb range) place both glass-ceramics high end mechanical chemical resistance ceramic tiles building industry.