Corundum brick Features: Alumina content is higher than 90%. High compressive strength at room temperature (up to 340MPa). High load softening starting temperature (greater than 1700 ℃). Good chemical stability, strong resistance to acidic or basic slag, metal and glass fluid, etc.
Corundum brick Advantages
1.high density& temperature resistibility
2. low bulk density, high compressive strength,
3. resistance to high temperature(≥1790℃)
4.good thermal shocking resistance
5.Excellent corrosion resistant to acids and alkalis
6. They are not influenced by H2, CO gases during use
It is divided into two kinds of corundum bricks, sintered corundum brick and fused corundum brick.
Sintered Corundum brick is a refractory material with alumina content higher than 90% and often containing trace impurity elements Cr, Ti, Fe, and V. The corundum bricks on the market can also be divided into these types according to the composition:
1. Brown corundum bricks are made of bauxite and coke (anthracite) as the main raw materials. The main chemical components are alumina. The titanium oxide ring contains a small amount of silicon oxide and iron oxide. The micro hardness is HV1800-2200, and the toughness is higher than SIC. High, the abrasive tool made of brown corundum is suitable for grinding metals with high tensile strength, such as various general steels, malleable cast iron, hard bronze, etc. It can also be used to make brown corundum bricks, which is a kind of advanced refractory material.
2. High-alumina corundum bricks are made of high-quality bauxite as the main raw material, and sub-white corundum bricks are produced on the basis of high-quality brown corundum bricks. Because its chemical composition and physical properties are similar to white corundum, subwhite corundum is produced on the basis of high-quality brown corundum. Because its chemical composition and physical properties are similar to white corundum, it is called sub-white corundum. Bulk density≥3.8g/cm3, refractoriness≥1850℃. This product has the hardness of white corundum bricks and the toughness of brown corundum bricks. It is an ideal high-grade refractory and abrasive material.
3. White corundum bricks are made by high temperature smelting with alumina powder as raw material. White, harder than brown corundum The brick is slightly higher and the toughness is slightly lower. Made into abrasive tools suitable for the grinding of high carbon steel, high speed steel and quenched steel. White corundum can also be used for grinding and polishing materials, as well as precision casting sand, spraying materials, chemical catalysts, special ceramics, and advanced refractory materials.
4. Zirconium corundum brick is made by smelting alumina and zirconia as raw materials in an electric arc furnace at a high temperature of over 2000℃. Tough texture, dense structure and high strength. The main mineral phase of zirconium corundum is a eutectic formed by a-alumina and alumina-zirconia. In order to ensure the quality of zirconium corundum, in addition to reasonable selection of smelting parameters and processes, cooling processes and processing techniques, it is also important to select appropriate additives to reduce the silica content in zirconium corundum bricks, and to make alumina and zirconia eutectic and have a uniform structure. The key to the production of zirconium corundum bricks.
5. Chrome corundum bricks is a solid solution synthesized by high-temperature melting of aluminum oxide and chromium oxide in a certain proportion. The use of special refractory material production technology to make refractory bricks can improve and enhance the internal quality of the product and the high temperature performance of the product.
Fused corundum brick have 3 types: α-Al2O3, β-Al2O3 and α, β-Al2O3
fused cast corundum brick (fused cast corundum brick) refers to a corundum refractory product made by fusion casting method with corundum as the main crystal phase. Including α-Al2O3, β-Al2O3 and α, β-Al2O3 3 kinds of corundum products composed of different crystal phases. Among them, β-Al2O3 fused cast bricks, namely Na2O·(11-12)Al2O3, contain about 5% Na2O. Fused cast corundum bricks are composed of α-Al2O3 and β-Al2O32 crystal phases. about the details we'll talk in fused corundum brick.