The Investigation Of Compositions,Structures,Properties Of Used Refractory And Damage Mechanism In Hot-blast Furnace

The hot-blast furnace is an important equipment for steel industry. The properties of refractory impact on life-time and energy consume of hot-blast furnace. In this paper, chemical and physical properties of used and original refractory for hot-blast furnace were investigated, and the damage and slag mechanism of refractory were discussed.The results showed that refractory used in hot-blast furnace were damaged to a certain extent because of bad work condition. The surface of the big arch silica brick was eroded badly and resulted in crackles even scraps under long-term impact of high-temperature fume with changes of physical properties, chemical composition and phase structure compared with original state. Al2O3 CaO and Fe2O3 could be deposited on the surface of cordierite brick under action of high temperature fume, resulting in the fall of refractoriness and the destroy of brick structure. The surface of mullite brick was corrupted slightly because of the strong resistance on acid and alkaline gas. Although chamotte brick were used on low-temperature section of hot-blast furnace, it was also eroded by big load and strong heat-shock and refractoriness under load. The damage will influence performance of bricks and shorten operating life of hot-blast furnace. So, measurements such as designing reasonably, using first-rate fireproof material, ensuring the quality of furnace etc, were necessary for extending operating life of hot-blast furnace.