Ceramics from blast furnace slag, kaolin and quartz

Three new ceramic batches with no traditional fluxes and 30, 50 and 70 wt.% blast furnace slag were studied. The processes of phase formation and densification were estimated in non-isothermal conditions by differential thermal analysis and dilatometry, respectively. After that the degrees of sintering, obtained after heat-treatment at different temperatures and times, were evaluated measuring the variations of linear shrinkage and water absorption. The structures of final materials and their phase compositions were studied with scanning electron microscopy, pycnometry and X-ray diffraction. Mechanical properties of the final ceramics were also measured.The obtained ceramics are characterized with a narrow sintering interval at 1200–1220 °C and good degrees of densification. Due to the formation of pyroxene and anorthite solid solution the new materials show high crystallinity. As a result, the measured bending strength and hardness surpass the values of traditional building and tiling materials.