Corundum Brick

Corundum brick is an advanced refractory material with aluminum oxide (Al₂O₃) as its main component and corundum as its main mineral phase. Its Al₂O₃ content is usually above 90%. It is also called alumina refractory product. Corundum (α-Al₂O₃) is the most stable structure among the various forms of aluminum oxide, with a melting point as high as 2050℃, a density of about 3.96~4.01 g/cm³, belonging to the hexagonal crystal system, and possessing extremely high cold and high-temperature strength as well as excellent chemical stability.

By preparation process, corundum bricks are mainly divided into two major categories: sintered corundum brick and fused corundum brick. Sintered corundum brick uses sintered alumina clinker as raw material and is fired at 1750~1800℃ after high-pressure forming; fused corundum brick uses fused corundum as raw material, or directly pours molten corundum into molds to form fused-cast bricks. In addition, depending on the additives, derivatives such as chrome corundum brick, zirconia corundum brick, and titania corundum brick can also be produced.

Product Advantages

• Extremely high refractoriness
  The refractoriness of corundum brick can reach above 1790℃, and high-purity products can be used at temperatures up to 1800℃. Corundum has a melting point as high as 2050℃ and can maintain structural stability in ultra-high temperature environments.
• High cold and high-temperature strength
  Corundum brick has very high cold compressive strength (up to 340MPa) and high-temperature strength, with good mechanical strength and wear resistance, and can withstand mechanical loads and wear at high temperatures.
• Excellent chemical stability
  It has strong resistance to acidic slag, basic slag, metal melts, and molten glass, and is not affected by reducing gases such as H₂ and CO.
• Good high-temperature creep resistance
  The creep rate of high-purity corundum brick under 1550℃×50h conditions can be as low as 0.5%. It has good high-temperature volume stability and is not easily deformed during long-term use.
• High purity, no contamination of products
  High-purity low-silica corundum brick has SiO₂<0.5% and Al₂O₃>98%. It does not contaminate products in applications sensitive to impurities, such as petrochemicals and electronic ceramics.
• Rich variety, strong adaptability
  By adding components such as Cr₂O₃, ZrO₂, TiO₂, and MgO, erosion resistance and thermal shock stability can be improved to meet different working condition requirements.

Applications

Due to its excellent high-temperature performance, corundum brick is widely used in various high-temperature industrial kilns and thermal equipment:

Metallurgy Industry

• Blast furnace and hot blast stove: Linings for key parts such as stack, hearth, and crucible
• Secondary refining furnace: Linings for secondary refining equipment
• Slide gate: Corundum slide plate bricks
• Induction furnace: High-temperature induction furnace lining

Petrochemical Industry

• Gas producer and gasifier: Key refractory lining material for gas producers and reaction furnaces in the petrochemical industry, capable of replacing imported products
• Ammonia synthesis secondary reformer: Lining for secondary reformers in large fertilizer plants
• Carbon black reaction furnace: Lining for high-temperature reaction furnaces in the carbon black industry

Glass Industry

• Glass melting furnace: Fused-cast corundum bricks are used for the cooling section tank wall, furnace bottom, and float glass flow channel of glass melting furnaces

Other Fields

• Ultra-high temperature electric furnace and kiln: Linings for ultra-high temperature electric furnaces above 1600℃
• Ceramic sintering furnace: High-temperature sintering of zirconia ceramics, electronic ceramics, and magnetic materials
• Chemical and electronic industry: High-temperature furnace tubes, furnace cores, etc.