EFFECTS OF ZIRCONIA ON THE THERMAL SHOCK RESISTANCE OF HIGH CHROME REFRACTORIES FOR COAL SLURRY GASIFIER

摘要

The effects of particle size and amount of zirconia addition on the thermal shock resistance of high chrome refractories for coal slurry gasifier were investigated by using fused chrome oxide and alumina micro powders. Phase transformation, microstructure and phase composition of samples after sintering and thermal shock were analyzed by SEM and XRD. The results show that: zirconia addition with appropriate particle size can improve the thermal shock resistance significantly; zirconia addition with particle size of 2μm～7μm has significant effects on prevention of cracks propagation; crack deflection and bending toughening mechanism play an important role in improving the thermal shock resistance of high chrome refractories.