Vitrification of low silica fly ash: Suitability of resulting glass ceramics for architectural or electrical insulator applications

Abstract The study concerns the recycling of the fly ash (FA) derived from the thermal power stations of Ptolemaida (Greece) and its potential use of this FA as precursor in production of bulk nucleated GCs. The first attempt was addressed to produce a glass from the fine powder of as received FA without any additives. To overcome some drawbacks such as spontaneous crystallisation upon cooling of FA based glass and to improve its working properties, production of pyroxene based glasses from FA was undertaken. The parent glass approached the composition of CaMg0⋅75Al0⋅4Fe0⋅1Si1⋅75O6, derived from CaMg0⋅75Al0⋅5Si1⋅75O6, which belongs to diopside–Ca-Tschermak solid solutions. Cr2O3 nucleated fine grained mono mineral glass ceramics of augite were produced from the glasses comprising FA and additives of SiO2, Al2O3 and MgCO3. The influence of Cr2O3 content on the development of crystalline phases, the properties and the microstructure of the resultant glass ceramics crystallised at different temperatures was investigated.

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