Performance Optimization of Al2O3-Spinel Castables for RH Liner Lining

摘要

Considering the Cr6+ pollution of magnesia-chrome bricks for secondary refining and ladle lining, Al2O3-spinel castable is a potential choice to replace magnesia-chrome bricks, but the thermal shock stability needs to be optimized.Adopting tabular alumina, fused spinel and high purity spinel and fused zirconium corundum (ZrO2-Al2O3, hereinafter referred as ZA) as the main raw materials, Al2Os-spinel castables have been prepared with the introduction of ZA (respectively adding 0, 2％, 4％, 6％,8％, 10％).Thermal shock stability has been investigated by residual strength ratio.Slag resistance has been investigated by static crucible method and microstructure of specimens after slag test has been analyzed by SEM and EDAX.Permanent linear change (PLC), cold modulus of rupture (CMOR) and cold compression strength (CCS)of the specimens pre-heated at 110℃, 1000℃, 1400℃ and 1550℃ respectively, hot modulus of rupture (HMOR) at 1400℃ were also tested.Results indicate that the castables with fused zirconium corundum cements (ZA) exhibit an excellent thermal shock stability and slag resistance.In this condition, the HMOR gets worse with the replacement of tabular alumina by ZA, all specimens tested are above 20 Mpa.And PLC remains between 0 to +0.5％.