Abstract

In this study, the possibility of using colemanite mineral (2CaO.3B₂O₃.5H₂O) which cannot be used directly as an additive for fast firing ceramic bodies due to execution of its crystal water through the micropores, was examined after microwave-assisted calcination. For this purpose, domestic microwave oven which was modified with fiber boards, SiC susceptors and thermocouple setup was used. Colemanite powders heat-treated in a porcelain crucible under microwave condition with three different power levels of 385, 539 and 700 W. Temperature profiles of samples were defined as a function of time and calcination states were determined by confirming volumetric expansion and weight loss. When findings were systematically evaluated by X-ray diffraction (XRD) and thermal analysis (DTA/TG), surface area (BET), volume expansion analysis, the results were in favor of microwave-assisted calcination than conventional one in terms of efficiency for both time and temperature of heat treatments.