The Effect of Sintering on the Properties of Magnesia-Granite Sludge Ceramics Shaped by Temperature-Induced Forming

Abstract Recycling waste materials have attracted considerable attention owing to the increased interest in depressing the negative impact on the environment. The present work investigates the effect of increasing the granite sludge-waste materials from granite manufacture-on the physical, mechanical and electrical properties of magnesia ceramics. The temperature-induced forming (TIF) method is used to shape magnesia-granite sludge ceramics. The sintered ceramics are characterized by XRD and SEM, in addition to measuring the bulk density, apparent porosity, linear shrinkage, microhardness, and electrical resistivity. Sintering of magnesia-granite bodies resulted in the formation of periclase-forsterite ceramics. The XRD results show that the forsterite phase increases reaching 78% at 40 wt% granite. The increase in granite sludge from 10 to 40 wt% increases the bulk density from 1.86 to 2.69 g/cm3 and the apparent porosity decreases from 40 to 15%, respectively. Microhardness is improved by increasing the granite sludge wt% reaching 7.9 GPa. The microstructure of the formed periclase-forsterite is versatile with a rhombohedral structure for periclase and a flower structure for forsterite. The forsterite phase is formed by the diffusion of granite sludge into the formed periclase.