China's Refractories

Abstract: In order to improve the performance of Al₂O₃-SiC-C castables for iron trough, samples were prepared using brown corundum, dense corundum, activated alumina micropowder, ball pitch, and silicon as main raw materials, calcium aluminate cement as the binder. Several kinds of silica fumes (93SiO₂, 96SiO₂, and 99SiO₂) with different particle size distributions and chemical composition were added to research the effects on the properties of castables. The results show that the sample with 99SiO₂ fume has high water requirement for molding, but the bulk density is the lowest, the apparent porosity is the highest, the oxidation resistance is the worst, and the permanent linear change on heating is low after firing at 1 450 ℃ for 3 h. The bulk density and the apparent porosity of the sample with 93SiO₂ fume or 96SiO₂ fume are equivalent, the hot modulus of rupture of the sample with 93SiO₂ fume is the lowest, and the slag resistance of the sample with 96SiO₂ fume is the best. The comprehensive performance of the sample with 96SiO₂ fume is the best.

Key words: alumina-silicon carbide-carbon iron trough castables, silica fume, strength, oxidation resistance, slag resistance