Addition of exhausted lime in ceramic bodies: possibilities for an environmentally compatible tile production

Pollution caused by inorganic wastes in the traditional ceramics industry is minimised by utilising exhausted limes, which are the byproducts in bag filters after the purification of flue gases in wet tile production. This study determined which quantities of exhausted lime added to tile bodies did not significantly affect the physico-chemical properties of the slips (i.e. density /viscosity/deflocculant amount) during wet grinding in ball mills. The results demonstrated that these conditions are obtained when exhausted lime in the bodies does not exceed 0.10 to 0.12 mass%. Furthermore, any increase in fluorine emission in the firing of tiles with exhausted lime can be trapped in the bag filters by increasing the lime content by about 10 mass%. The laboratory and industrial results are also compared.