Chromium corundum bricks are primarily composed of the mineral α-Al2O3-Cr2O3 solid solution. Minor mineral components include a small amount of composite spinel (or without composite spinel) and refractory bricks with chromium oxide content ranging from 1% to 30%.
There are two main types: fused chromium corundum bricks and sintered chromium corundum bricks. In general, when referring to chromium corundum bricks, it typically means sintered chromium corundum bricks.
Using α-Al2O3 as the raw material, a suitable amount of chromium oxide powder and finely ground chromium corundum clinker is added. After shaping, it is fired at high temperatures. The chromium oxide content in sintered chromium corundum bricks is generally lower than that in fused chromium corundum bricks.
They can also be prepared using a slurry casting method, where α-Al2O3 powder and chromium oxide powder are uniformly mixed, along with binders and organic bonding agents to create a thick slurry. Part of the chromium corundum clinker is added, and the bricks are formed by injection casting before being fired.
These bricks are suitable for use as linings in glass furnaces, covers for molten glass flow holes in drawing glass production, and for iron ladle pre-treatment devices, waste incinerators, and coal-water slurry pressurized gasification furnace linings, among other applications.
Currently, chromium corundum bricks have found broader applications. One variety is produced mainly from metallic chromium slag, and these chromium corundum bricks are widely used in zinc smelting electric furnaces and rotary kilns.
They exhibit excellent thermal shock resistance and high-temperature creep performance while meeting the requirements of the national circular economy.