6533b85efe1ef96bd12bfb8c

RESEARCH PRODUCT

Pyroxene-based glass-ceramics as glazes for floor tiles

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Abstract Crystallization of a glass with composition in the diopside primary crystallization field in the MgO–CaO–Al 2 O 3 –SiO 2 quaternary system was investigated. Also the action of some additives, nucleants and fluxes, in the pyroxene development was examined. Glasses were prepared by conventional melting of a mixture of raw materials and cooled by pouring in water. Pellets of glass powder specimens were thermally treated at several temperatures up to 1200 °C. The crystallization path was followed by X-ray diffraction powder (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX). The results proved that, in addition to the effect of B 2 O 3 and TiO 2 in the development of the final pyroxene phase, some amount of alkaline oxides, Na 2 O and/or K 2 O, are required to obtain well-defined morphologies of pyroxene crystals. Fast fired under industrial conditions glass-ceramic glazes on to porcelain stoneware supports improved hardness of final products