Conversion of blast furnace slag into new glass-ceramic material

The devitrification behavior of different sizes of slag-derived glass was investigated using differential thermal analysis, X-ray diffraction and scanning electron microscopy to determine the possibility of preparing glass-ceramic materials. The crystalline phases were identified as gehlenite, diopside pyroxene and barium aluminium silicate. The degree of crystallization was determined by evaluation the changes of density at different temperatures where a maximum density was achieved at 900 °C. A remarkable difference in the glass-ceramic texture was observed by treating the sample at different crystallization temperatures. Both acicular and dendritic morphology have been identified in the sample heat-treated at 1050 °C. A slight variation in peak crystallization temperature with particle size indicated a bulk crystallization mechanism.