High alumina refractory brick for blast furnace refers to the refractory products made of high alumina clinker as the main raw material with Al2O3 content more than 48%. Blast furnace is the main equipment of ironmaking, clay brick is the earlier lining material used in blast furnace. Since the 1950s, the volume of blast furnace has developed to large scale, and 8-12m diameter hearth has become more common. Productivity has increased rapidly. However, the erosion of waist and belly obviously affects the production of Ruo blast furnace.
In the early 1950s, China began to produce high alumina bricks for blast furnace, which are used for the lower part of furnace body. Since 1980s, fused corundum re bonded brick has been used. Its Al2O3 content is more than 95%, the load softening temperature (T2) at high temperature reaches 1740-1770 ℃, the temperature is kept at 1600 ℃ for 3 hours, and the linear shrinkage rate of re firing is zero. In 1984, silicon carbide series products were successfully developed, and gradually formed production capacity. The products have been used in the lower part of blast furnace.
Natural bauxite should be well calcined and strictly graded. The content of iron oxide in chemical analysis shall be controlled below 1.2%, and no centralized iron spot or iron core is allowed. High grade and purity are required. The brick is formed by high tonnage press, the shape of the brick is regular, and there is no net crack on the surface and internal layer crack. Ensure high brick density and firing temperature not less than 1500 ℃

Project Indicators		GL-65	GL-55	GL-48
AL2O3,%		≥65	≥55	≥48
Fe2O3,%		≤2.0	≤2.0	≤2.0
Fire resistance,℃		≥1790	≥1770	≥1750
Apparent porosity,%		≤19	≤19	≤18
Normal temperature  compressive strengthMPa		≥58.8	≥49.0	≥49.0
0.2MPa load softening  start temperature ℃		≥1500	≥1480	≥1450
Change rate of reheating line,%	1500℃×2h	0～-0.2	0～-0.2	/
	1450℃×2h
Air permeability		This inspection is required. The measured data shall be indicated in the quality certificate.