Sinterability properties of a ceramic synthesized from Algerian kaolin and spent magnesia-carbon refractory bricks

Abstract

This research aims to study the influence of the sintering temperature on the microstructural and physical properties for application as refractory bricks. Kaolin DD3 (from Djebel Debbagh, Guelma-Algeria) and spent magnesia-carbon refractory bricks mixtures (MgO-C) with relative weight ratios of 95/5 were synthesized by solid oxide reaction route at sintering temperatures of 1000, 1100, 1200, 1300, and 1400°C. The phases and their transformations during heating were investigated using X-ray diffraction analysis (XRD), scanning electronic microscopy (SEM), and helium pycnometer (AccuPyc II 1340). XRD results indicated the changes in the sintered pellets. The phase changes were mullite and α-low cristobalite at the sintering temperature of 1000°C. Cordierite begins to appear at 1100°C, and it increases as the sintering temperature rise, whereas the mullite and cristobalite phases decrease. At 1400°C, a magnesium aluminate spinel is formed with the presence of mullite, α-low cristobalite, and cordierite. SEM analysis was carried out to observe the surface morphology and the density decreased with rising sintering temperature.