Refractory Ceramics of Clay and Alumina Waste

Abstract Refractory ceramics were produced from clays and alumina waste. Specimens shaped by uniaxial pressing, subjected to thermal analysis dilatometry heat-treated in a conventional furnace at 1300 1400oC, applying heating rate of 5oC/min dwell time 2 3 hours the maximum temperature. The samples characterized X-ray diffraction (XRD), scanning electron microscopy (SEM) physicomechanical properties. dilatometric before heat treatment indicated that formulation containing largest amount fluxing oxides presented highest linear shrinkage. XRD revealed mullite was major phase needle crystals typical obtained clay minerals observed SEM. increase firing temperature improved properties specimens. expansion coefficient (TEC) range 25 1000oC varied 6.2 6.9 x 10-6°C-1.