Influence of fused zirconium corundum addition on properties of chrome-free castables for RH refining furnace

Based on the operation conditions of RH refining furnace, this paper investigates the influence of fused zirconium corundum (for short ZA or FZA) additive on the performance of corundum–spinel castables, such as the cold modulus of rupture (CMOR), cold crushing strength (CCS), permanent linear change, thermal shock resistance and slag resistance. Corundum and spinel were the main raw materials of the samples with addition of proper amounts of micro powders and high effective dispersant. The samples, after dried at 110 °C for 24 h, then were fired at 1000 °C, 1400 °C and 1550 °C for 3 h, respectively. The monitoring results showed that ZA addition could greatly improve the CMOR, CCS, thermal shock resistance and slag resistance of castables simultaneously.