Abstract:
The disposal of electric arc furnace (EAF) slag is often problematic, with most of it ending up being landfilled rather than recycled. Incorporating EAF slag into the typical clay-feldspar-quartz system to produce useful ceramic tiles offers a potential and environmentally safer option. Thermodynamics package FactSage 8.2 was employed to predict the equilibrium-products of sintering process of EAF slag mixtures at different temperatures ranging from 600-1600°C. Subsequent ceramic products were fabricated at a temperature of 1150°C following the thermodynamic analysis by considering the fraction of liquid formation and the viscosity of the system. With the addition of EAF slag to the base body, new chemical phases such as anorthite, clinopyroxene and andradite were formulated, which have a positive impact on the ceramic. These products were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses and compared to the thermodynamic predictions. The physical performance of the products was also examined by evaluating the shrinkage, water absorption, apparent porosity, bulk density and modulus of rupture (MOR). When EAF slag was added to the base mixture, there was a positive trend of improvement in the physical properties and specifically, MOR peak value of 37.56 MPa was obtained when 40% EAF slag was added. However, the MOR value as well as other physical properties started to decline when the base mixture had more than 40% EAF slag. Conclusively, incorporating 40% EAF slag improved the final product and correlated with the thermodynamic studies, process parameters and experimental assessments of the ceramic tiles.