Soda-lime scrap glass and lime for the manufacturing of new ceramics

Starting from a mix of clay and 40wt% of soda-lime scrap glass, different amounts, 5, 10 and 15wt%, of lime (calcium hydroxide), were added and different samples were prepared and sintered, allowing to reach a near 0.0wt% in water absorption. Scanning electron microscopy observation and X-ray diffraction analysis allowed to detect devitrification phenomena of the glass, in terms of devitrite and cristobalite, and the presence of newly wollastonite crystals, when lime was added. The results of mechanical characterization in terms of flexural strength, were explained taking into account the presence of the widespread formation of elongated wollastonite crystals. The present work is promising since it evidences the possibility to prepare ceramic materials, by using great amounts of soda-lime scrap glass, coupled to lime, which could represent by itself a form of waste (in the case lime from fume abatement systems).