Application Research Of Used Al₂O₃-MgO-C Bricks To Medium And Small Blast Furnace Trough

Al2O3-MgO-C bricks are one of the main refractory for ladle's working lining which is an important equipment for storing and refining molten steel. With the rapid development of iron and steel industry, how to reclaim and use a large number of backlogging used Al2O3-MgO-C bricks have already became focus for their pollution to the environment. At present, there are a lot of medium and small blast furnaces of one top hole in china, and their volume is less than 1000m3. The refractory for these blast furnace trough is Al2O3-SiC-C drying-out free ramming mix or quick-drying and explosion-proof castable. Introducing used Al2O3-MgO-C bricks to refractory for blast furnace trough not only reduce cost and save resource, but also decrease environmental pollution. The research work of this thesis is mainly included two parts:1. Al2O3-MA-SiC-C ramming mix for medium and small blast furnace trough was prepared by used Al2O3-MgO-C bricks, brown fused alumina, SiC, and phenol formaldehyde resin as binder. The influence of used Al2O3-MgO-C bricks addition, magnesium-aluminium spinel addition, SiC addition on the physical property and slag resistance property of refractory was studied. The result show that, with the addition of used Al2O3-MgO-C bricks, physical property of refractory decreases, but slag resistance property enhances significantly. Slag resistance property is best when the addition of used Al2O3-MgO-C bricks is 60%. With a small addition of magnesium-aluminium spinel, physical property and slag resistance property of refractory enhance. Physical property and slag resistance property of refractory are best when the addition of SiC is 20%.2. The influence of different binders on physical property, slag resistance property, hot modulus of rupture, explosive spalling resistance of Al2O3-MA-SiC-C blast furnace trough castable was studied, and the effect of different organic fibers of melting point on explosive spalling resistance of Al2O3-MA-SiC-C castable was also studied. The result show that, explosive spalling resistance of the castable specimen used calcium aluminate cement and SiO2 mirco powder as binder is optimum, while explosive spalling resistance of the castable samples used silica-alumina colloid powder as binder is not very well. Physical property, slag resistance property and hot modulus of rupture of the castable sample used magnesia binder is optimum. With the addition of the organic fibers of low melting point, especially the melting point is lower than 100℃, explosive spalling resistance of the castable sample enhances.