Investigating the high temperature properties of MgO-CaO Refractories through the Addition of Nano- and Micro-Sized ZrO2

The present study investigated the effect of ZrO2 powders of different sizes on the performance of MgO-CaO refractories by sintering them together at 1600°C. The densification of the refractories was found to increase with an increase in ZrO2 content, owing to a reaction between the added ZrO2 and CaO, which resulted in volume expansion and subsequently led to the formation of CaZrO3. Such formation caused microstructural modification by introducing CaZrO3 particles at grain boundaries and triple points throughout the microstructure, thereby enhancing the thermal shock resistance (TSR) of the MgO-CaO refractories. According to the study, ZrO2 nanoparticles demonstrated superior efficacy due to their improved dispersion at a smaller amount of 6 mass%. Inclusion of nano- and micro- sized ZrO2 led to a decrease in amount of free CaO particles in the refractories, resulting in densification increase from 3.27 to 3.58 and 3.53 g/cm3, respectively. Additionally, nano-sized ZrO2 enhanced the thermal shock resistance of refractory from 11 to 42 cycles which showed better performance in comparison with micro-sized ZrO2 (35 cycles). Moreover, inclusion of ZrO2 increased slag corrosion resistance by increasing viscosity of liquid phase, thus inhibiting additional slag penetration at high temperatures

Investigating the high temperature properties of MgO-CaO Refractories through the Addition of Nano- and Micro-Sized ZrO2 Keywords:

zirconium dioxide , MgO , CaO , CaZrO3 , slag corrosion , Thermal shock resistance