摘要
Al2O3-SiC-C castables for iron trough with fused magnesia powder （0, 3%, 6%, 9% and 12%） were prepared with brown fused corundum particles （5-3mm, 3-1mm, ≤1mm）, white fused corundum powder （≤0.088mm）, SiC particle （≤1mm） and powder （ ≤0.088mm）, fused magnesia powder （ ≤0. 088mm）, reactive α-Al2O3 micropowder, ultrafine SiO2 , Si powder and sphere pitch as main starting materials and calcium aluminate cement as binder. The specimens were fired at 1100℃ and 1450℃ for 3 h after vibrating moulding, curing, demoulding and drying at 110℃ for 24 h. Bulk density, apparent porosity, linear change rate, modulus of rupture, resistance to blast furnace slag, oxidation resistance, phase composition and microstructure of the specimens were analyzed. The results show that： （1） With fused magnesia addition increasing, apparent porosity increases, while bulk density, modulus of rupture and oxidation resistance decline, slag resistance varies slightly; （2） The main crystal phases in the specimens fired at 1450℃ for 3 h are 3C-SiC, 6H-SiC, corundum, periclase, reaction-synthesized spinel and mullite; the quantity of the formed spinel and mullite increases with the increase of fuzed magnesite addition; （3） Along the corroded side, spinel layer with about 80μm thickness forms at the co- rundum particles boundary.
Al2O3-SiC-C castables for iron trough with fused magnesia powder （0, 3%, 6%, 9% and 12%） were prepared with brown fused corundum particles （5-3mm, 3-1mm, ≤1mm）, white fused corundum powder （≤0.088mm）, SiC particle （≤1mm） and powder （ ≤0.088mm）, fused magnesia powder （ ≤0. 088mm）, reactive α-Al2O3 micropowder, ultrafine SiO2 , Si powder and sphere pitch as main starting materials and calcium aluminate cement as binder. The specimens were fired at 1100℃ and 1450℃ for 3 h after vibrating moulding, curing, demoulding and drying at 110℃ for 24 h. Bulk density, apparent porosity, linear change rate, modulus of rupture, resistance to blast furnace slag, oxidation resistance, phase composition and microstructure of the specimens were analyzed. The results show that： （1） With fused magnesia addition increasing, apparent porosity increases, while bulk density, modulus of rupture and oxidation resistance decline, slag resistance varies slightly; （2） The main crystal phases in the specimens fired at 1450℃ for 3 h are 3C-SiC, 6H-SiC, corundum, periclase, reaction-synthesized spinel and mullite; the quantity of the formed spinel and mullite increases with the increase of fuzed magnesite addition; （3） Along the corroded side, spinel layer with about 80μm thickness forms at the co- rundum particles boundary.
