Sintered Corundum Refractories

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Introduction of Sintered Corundum Refractories

corundum refractory

To meet the requirements of large and medium-sized rotary kilns and other thermal equipment in cement, metallurgy, lime, and other thermal equipment with large temperature changes and high erosion, corundum bricks came into being. Sintered corundum refractory refers to corundum refractory products made of sintered alumina clinker with an alumina content greater than 90%. Corundum bricks have a high melting point, stable high-temperature performance, good mechanical strength and wear resistance at room temperature and high temperature, excellent resistance to metal erosion, and redox performance.

Sintered corundum refractory with an Al2O3 over 99% is mostly made of uniform fine-grained corundum directly combined, the apparent porosity is below 3.0%, the bulk density reaches 3.60g/cm3, and the refractoriness is close to the melting point of corundum. It has good volume stability and chemical stability, is not easily corroded by reducing atmosphere, molten glass, and molten metal, and has good mechanical strength and wear resistance at room temperature and high temperature.

Sintered Corundum Refractories
Sintered Corundum Refractories

Application of Sintered Corundum Refractories

  • Blast Furnace.
  • Hot Blast Stove.
  • Refining Furnace.
  • Glass Furnace.
  • Petrochemical Industrial Furnaces.
  • All kinds of high-temperature kiln lining in the metallurgical industry.
Sintered Corundum Refractories

Properties of Sintered Corundum Refractories

  • High cold compressive strength reaches up to 340MPa.
  • High initial refractoriness under load, over 1750 ℃.
  • Good chemical stability.
  • With strong resistance to acid and basic slag erosion.
  • With strong resistance to metal and molten goods and glass erosion.
  • Thermal resistance is related to its structure.

Production Process of Sintered Corundum Refractories

The sintered corundum is crushed into 3mm coarse particles and some fine powder less than 0.074mm, part of which is mixed with a small amount of clay and other binders, and then formed by high-pressure friction brick press or hydraulic press, and baked and fired at high temperature. The sintering temperature of high-purity sintered corundum refractory is generally 1750-1800. If a small amount of clay or additives is added, the firing temperature can reach 1600~1700.

Sintered alumina is mainly used as a raw material for the production of sintered corundum bricks and amorphous refractories, and its usable temperature is quite high.

However, this kind of raw material causes crystal growth when the second heating time is long, and as a result, the solid solution limit may be lowered, and precipitates are generated at the grain boundary, which affects its high-temperature performance.

sintered corundum refractories factory

Technical Data

ItemsUltra PurityCorundum brick99 Corundum brick90 Corundum brick
Al2O3  %≥99.3≥ 98.5≥ 90
SiO2  %≤0.15≤0.3≤8.5
Fe2O3  %≤0.1≤0.2≤0.2
Bulk density g/cm3≥3.25≥3.25≥3.1
Apparent porosity %≤18≤18≤18
Cold crushing strength   MPa≥100≥100≥100
Refractoriness under load(0.2Mpa,0.6%)≥1700≥1700≥1700
Reheating linear change rate(1600℃X 8h)-0.2-0.20.2
Thermal expansion %Tem.to 1300℃8.18.18.1
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