Fused corundum refractory material with industrial alumina as the main raw material for electric melting is a batch melting, refining, and then cast into the model, the casting after solidification, annealing, cutting, grinding and pre assembled, known as the qualified products. According to the chemical and mineral compositions are of three main types.
Casting of a-Al2O3 is also called the fused a-Al2O3 brick, is mainly composed of a-Al2O3 castable refractory phase.About 95% of a-Al2O3, β -Al2O3 for 5%-10%, compared with the little glass. The compact structure of the brick, high refractoriness and high temperature strength, high chemical stability is good, but in the alkali metal oxide under the action of, may be converted to beta -Al2O3 and increase in size, is suitable for building glass kiln cooling pool area of the upper structure, and non-ferrous metal smelting furnace and high temperature tunnel kiln
Casting of β -Al2O3 brick is also called electric melting brick with β -Al2O3, β -Al2O3 as the main crystal phase of casting refractory material, the content of β -Al2O3 about 99.5%, compared with the little glass, accounting for about 0.5% of the following, on the base of steam inert. In the alkali free atmosphere, easy separation of alkali and transformed into a-Al2O3, and accompanied by volume shrinkage, which may be caused by the broken brick. Casting of β -Al2O3 brick thermal shock resistance is good, 700 degrees to the normal temperature air cycle up to 40 times, the upper structure is generally applicable to the construction of glass melting fur
Casting of a, β -Al2O3 brick is also called the fused a, β -Al2O3 brick, is casting products containing a-Al2O3 and β -Al2O3. A-Al2O3 accounted for about 40%-50%, β -Al2O3 about 45%-60%, the glass is rarely. Compared with the beta type -Al2O3 products, erosion resistance of liquid glass is strong, high temperature alkali steam function isgood, can be used for glass kiln structure, but also can be used for low temperature part in direct contact with the molten gl
Manufacturing process of fused corundum products has been the process of casting refractory material of the same.Just because of the difference of material properties, process parameters are slightly different, such as high melting temperature (2300-2500 degrees), high casting temperature (1960-1980 degrees). These characteristics determinethe following key processes fused corundum products:
Raw materials and batch. Fused corundum products with the raw material is mainly industrial alumina and quartz sand. Batch by industrial alumina 97% (Al2O3 content is greater than or equal to 98.5%) and quartz sand 3%, andadding a small amount of additives, the wheel grinding machine by 30-40min mixture.
