Effect of Ca in P-doped basaltic glass-ceramics: Application to waste inertization

A sewage sludge composition is simulated by adding CaO and P2O5 to a basalt in order to produce glasses with low viscosity at high temperatures. Raman spectroscopy shows the presence of Q0 and Q2 silicate groups. The increase of Vickers microhardness is related to an nucleation of crystalline phases (magnetite, diopside, akermanite) that crystallize upon thermal treatments. Raman spectroscopy has given information on the presence of Q0 and Q2 silicate groups. These new glass-ceramics may be used as starting compositions for the immobilization of other industrial wastes.