Thermal and chemical properties of diopside-wollastonite glass-ceramics in the SiO2-CaO-MgO system from raw materials

The crystallisation process of ternary system SiO2-CaO-MgO from waste raw materials was investigated by DTA and polarising microscopy and the chemical durability for glasses and glass-ceramics was characterised. The effects of compositional changes on bulk crystallisation and growth morphology were also studied. Beta-wollastonite and diopside were identified after heat-treatment. A coarse grained morphology with directional surface crystallisation was seen. Weight loss increased with increasing CaO content at the expense of MgO in both acidic and alkaline solution. 11 refs.