Optimisation of low temperature sinter crystallisation of waste derived glass

Abstract

Mixtures of inorganic waste materials are commonly converted into glasses, in turn to be transformed into glass ceramics. Specific composition designs may lead to glasses with a low crystallisation temperature, useful for low cost ceramisation by bulk nucleation. This feature, however, may be disadvantageous if the same glasses are subjected to sintering, since intensive crystallisation hinders the viscous flow. This paper illustrates the optimisation of simultaneous sintering and crystallisation of a waste derived glass, originally intended for bulk nucleation, when coupled with recycled glasses, at a very low temperature (800°C). The mixing with secondary glasses did not merely enhance the densification (residual porosity of ∼3%) but modified the crystallisation. Owing to the mechanical properties (e.g. Young's modulus and bending strength exceeding 80 GPa and 90 MPa respectively), the obtained sintered glass ceramics may find profitable applications in the building industry.