Exploration of Microstructural and Physical Characteristics in a Newly Formulated Ceramic Utilizing Kaolin and Waste MgO-C Refractory Bricks

The investigation focused on the densification and phase transition of cordierite ceramic made from the Algerian raw material kaolin DD1 and spent refractory bricks (MgO-C) with a ratio weight of 85:15. The samples were sintered for 2 h at 1200–1400°C. All samples were studied in terms of phase evolution on heating and microstructure by XRD, Fourier-transform infrared spectroscopy (FTIR), differential thermal analysis (DTA), density, hardness and SEM observations. The findings indicated that with the elevation of temperature, the crystallinity of α-cordierite exhibited a rising trend, reaching its peak at 1400°C with a value of 54.48%. Conversely, the mullite content suffered a decline as the sintering temperature increased. The utilization of waste brick sources containing magnesia (MgO) at different firing temperatures resulted in an enhanced formation of cordierite and spinel at the expense of mullite, which exhibited a decreasing trend.