Fused chrome corundum bricks and sintered chrome corundum bricks belong to chrome corundum bricks products. However, the color of the product produced by the two is different due to the difference in the production process and the difference in the ratio of raw materials. The main mineral composition of fused chrome corundum bricks is α-Al2O3-Cr2O3 solid solution. The secondary mineral composition is a small amount of composite spinel (or no composite spinel), refractory bricks with a chrome oxide content of 1%-30%.
Characteristics of Fused Chrome Corundum Bricks and Sintered Bricks
There are two types of chrome corundum products (fused chrome corundum bricks), cast chrome corundum bricks and sintered chrome corundum bricks.
In general, chrome corundum brick refers to sintered chrome corundum brick. Using α-Al2O3 as raw material, adding the appropriate amount of chrome oxide powder and chrome corundum clinker fine powder, after forming, sintering at high temperature. The chrome oxide content of sintered chrome rigid brick is generally lower than that of fused-cast chrome corundum brick. It can also be prepared by a slurry pouring method. The α-Al2O3 powder and the chrome oxide powder are uniformly mixed, and the gelling agent and the organic binder are added to make a thick slurry. At the same time, add part of the chrome corundum clinker, use the grouting method to make bricks, and then fire. The product has the characteristics of wear resistance, heat shock resistance, acid, and alkali corrosion resistance.
The fused chrome-zirconia corundum brick is produced by the non-shrinkage casting method, abbreviated as AZCS brick, and the French brand is ER2161. The surface and interior of the fused brick are dark green. The fused brick contains a 4.5% shrinkage cavity and no connected pores.
As a result of the formation of aluminum chrome spinel solid solution Al2O3·Cr2O3, about 56%, and the rest are the oblique zircon phase and glass phase. Increases the viscosity of the glass phase and greatly improves the resistance to glass erosion. It is 3.4 times of ERl681 and 2.6 times of ERl711. But Cr2O3 will color the glass liquid and cannot be used for colorless and transparent glass. At the same time, its foaming index is not ideal, so it is an ideal material for the upper structure of the tank kiln.
Characteristics of Chrome Corundum Bricks for Non-Ferrous Glass Melting Furnace
The colored glass melting furnace can use Cr2O3-containing AZCS fused bricks to build the pool wall to improve the corrosion resistance. This type of brick contains about 20% Cr2O3, and the main crystal phase is still (C+Z) eutectic. But the corundum base crystal is (Al2-xCrx)O3, and the primary crystal phase corundum is also (Al2-xCrx)O3. The amount of glass phase is similar to that of ordinary fused AZS bricks, which is about 20%. The chemical composition of the glass phase was measured with the help of micro-area analysis, and it was found that a considerable amount of Cr2O3 was dissolved in it, and the chrome ion forming the glass structure was determined to be Cr2+. That is, cr3+ is reduced to Cr2+ in the melt. This is due to the fact that the melt is in a relatively reducing atmosphere, and more than one zodiac is found.
At present, the application of fused chrome corundum bricks has been widely used. Mainly used for the slideway and tapping platform of carbon black furnace, steel rolling heating furnace. It has excellent thermal vibration stability and high temperature creep performance and meets the requirements of the circular economy.
Sintered chrome corundum bricks are widely used in glass kiln lining, wire drawing glass flow hole cover tiles, glass fiber kiln body and upper air inlet, and non-ferrous glass kiln’s severely corroded parts. The sidewall, bottom, and forehearth of the insulated glass fiber furnace. Hot metal pretreatment device, the backing of coal water slurry pressurized gasifier. The discharge port of the ceramic glaze kiln. Metallurgical baths and rotary kilns, zinc oxide melting furnaces, garbage incinerators, etc.
Features and Performance Introduction of Zirconia Chrome Corundum Brick
Zirconia chrome corundum bricks are made of Cr2O3, Al2O3, ZrO2, and other raw materials. It is used for refractory bricks with special requirements.
Chrome corundum bricks are made of corundum and fused chrome oxide as the primary raw materials, with additives such as micro-powders, and are fired at high temperature in a shuttle kiln through mixing, molding, and drying. Chrome corundum cheese brick products have the characteristics of wear resistance, heat shock resistance, acid, and alkali corrosion resistance. High chrome bricks (Cr2O3≥90%) are mainly used in key parts of kilns such as the coal chemical industry, chemical industry kilns, alkali-free glass fiber kilns, and waste incinerators. Chrome corundum bricks are mainly used for the lining of carbon black furnaces, copper smelting furnaces, molten pools of glass furnaces, slideways of steel rolling heating furnaces, and tapping platforms.
Zirconia Chrome Corundum Brick Features
Zirconia chrome corundum bricks have strong corrosion resistance, high compressive strength, good thermal shock stability, low wear resistance, and resistance to falling off. Corundum brick (zirconia chrome corundum brick) is a special refractory material with Al2O3 as the main component. It has been widely used in the fabrics of important petrochemical thermal equipment such as high temperature, high pressure, chemical corrosion, and severe mechanical wear, such as synthetic ammonia gasifiers, ethylene engineering gas generators, and carbon black reactors. According to the imported synthetic ammonia gasifier, ethylene engineering gas generator, and carbon black reactor working environment. The corundum bricks are required to have high purity and high strength.
Zirconia chrome corundum bricks are corundum refractory bricks containing Cr2O3. Because Cr2O3 and Al2O3 form a continuous solid solution, the high-temperature function of chrome corundum brick is better than pure corundum brick. Chrome corundum bricks have better high-temperature resistance and slag corrosion resistance, and their slag resistance function is enhanced with the addition of Cr2O3 content.
