Mixed Alkali and Mixed Alkaline-Earth Effect in Ceramic Sanitaryware Bodies Incorporated with Blast Furnace Slag

Abstract

Raw materials and energy are among the most important costs in ceramic sanitaryware production. With the decrease in raw material sources and increasing costs of energy in recent years, researches on alternative raw materials and energy have started to gain importance. In this study, blast furnace slag and spodumene were used to reduce both energy and raw material costs. In standard vitreous china ceramic sanitaryware, a maximum of 15% blast furnace slag and 4% spodumene was used instead of sodium feldspar. In this study, the effects of CaO, MgO, and Li2O on microstructure, technological properties such as flexure strength, water absorption, porosity, bulk density; and also, thermal properties such as sintering analysis were investigated by using a non-contact optical dilatometer and thermal expansion. The dry strength and flexure strength of fired samples increased. The increase in dry strength was approximately 47%. The increase in flexure strength was approximately 67%. The reduction in the thermal expansion coefficient values was approximately 17%, which is also important in terms of stability of the final product. As a result, the use of blast furnace slag and spodumene will result in a reduction in both energy and raw material costs. The spodumene and BFS provided a reduction in sintering temperature at a rate of approximately 60 °C. The flue gas emissions may also reduce because flue gas emissions are higher as the temperature inside the furnace is higher. The spodumene and blast furnace slag addition provide a decrease in the peak of sintering temperatures so that flue gas emissions will reduce.