Mechanical behavior and slag corrosion resistance of ZrSiO4/SiC reinforced MgO-C refractories

Abstract

This investigation proposes a novel solution to enhance the thermal shock and slag corrosion resistance of low-carbon MgO-C refractories by integrating yttria-stabilized zirconium silicate (YSZS) and silicon carbide (SiC) powders in them. The results of this study revealed that incorporating YSZS and SiC particles in low-carbon MgO-C refractories improved the overall qualities of the refractories synergistically and increased the thermal shock resistance (TSR) from 11 cycles (for MgO) to 18 and 15 cycles, respectively, owing to their lower coefficients of thermal expansion (CTE) compared to magnesite. The addition of YSZS caused the cold compressive strength (CCR) of the MgO-C refractories to increase from 450 to 480 kg/cm2. The mechanical properties of the refractories were elevated as a result of fracture toughness enhancement and crack propagation within and between grains on the fracture surface. CaZrO3, Mg2SiO4, and MgSiO3 phases developed in the grain boundaries and served as corrosion-resistant materials, thereby resulting in reduced porosity and pore closure. Additionally, the TSR of the reinforced bricks was significantly improved due to their low CTE as compared to MgO, while slag resistance enhancement was caused by the formation of the CaZrO3, Mg2SiO4, and MgSiO3 phases.