Chromium corundum brick refers to a refractory product made of corundum containing Cr ₂ O3, with the main mineral composition being α - Al ₂ O3- Cr ₂ O3 solid solution, and minor minerals containing a small amount of composite spinel or chromium oxide. It utilizes the characteristic of forming a continuous solid solution between Cr ₂ O3 and Al ₂ O3, and has higher high-temperature performance than pure corundum products. The conventional Cr ₂ O3 content is 9% -15%. Bricks used in the petrochemical industry need to meet the requirements of low silicon, low iron, low alkali, and high purity. This product is divided into two categories: cast and sintered, usually referring to sintered type. Prepare using α - Al ₂ O3 as the main material, add chromium oxide powder, mix and shape it, and then high-temperature burn it, or use grouting method to make the billet. The product has a room temperature compressive strength of>150MPa and a bulk density of ≥ 3.0g/cm ³, and can resist corrosion from metallurgical slag and glass melt. Mainly used for lining glass kilns, backing gasification furnaces, non-ferrous smelting furnaces, and permeable bricks for steel ladles
1. Introduction:
Chrome corundum brick refers to corundum refractory products containing Cr2O3. At high temperatures, Cr2O3 and Al2O3 form a continuous solid solution, resulting in superior high-temperature performance of chromium corundum products compared to pure corundum products. The chromium corundum bricks used for gasification furnaces in the petrochemical industry should be low silicon, low iron, low alkali, high purity, and also have high density and strength. The widely used chromium corundum products have a Cr2O3 content mostly within the range of 9% to 15%
2. mineral composition
The main mineral composition is α - Al2O3-Cr2O3 solid solution. The secondary mineral composition is refractory bricks with a small amount of composite spinel (or without composite spinel) and a chromium oxide content of 1% to 30%. There are two types of fused chromium corundum bricks and sintered chromium corundum bricks. In general, chromium corundum brick refers to sintered chromium corundum brick
3. The production of chromium corundum bricks
Using α - Al2O3 as raw material, adding an appropriate amount of chromium oxide powder and chromium corundum clinker fine powder, shaping and firing at high temperature. The chromium oxide content of sintered chromium corundum bricks is generally lower than that of fused chromium corundum bricks. Alternatively, the slurry casting method can be used to prepare a thick slurry by uniformly mixing α - Al2O3 powder and chromium oxide powder, adding debonding agents and organic binders, and adding some chromium corundum clinker. The brick body can be made by grouting method and then fired. Can be used as lining for glass kilns, cover bricks for drawn glass flow holes, and as backing for iron pre-treatment devices, garbage incinerators, coal water slurry pressurized gasifiers, etc
4. application
The application of chromium corundum bricks has become more widespread. One type is chromium corundum bricks made mainly from metal chromium slag, which are widely used in zinc smelting electric furnaces and volatilization kilns. Chromium corundum bricks have excellent thermal vibration stability and high-temperature creep performance, and also meet the requirements of the national circular economy.
Another type of refractory brick called aluminum chromium spinel is widely used in copper smelting, breaking the monopoly of magnesia chromium bricks in one fell swoop
