Impurities in white corundum have a great impact on its lifespan. The main impurities contained in the production process of white corundum are SiO2, Fe2O3, TiO2, the fewer impurities, the higher the quality of white corundum. The content of AL2O3 in white corundum also directly indicates the quality of white corundum.
When white corundum is used as a refractory material, the impurities it contains can affect its fire resistance. Some of the impurities of refractory materials are fusibles, and some have a high melting point, but when they coexist with the principal components, they can produce fusibles. Therefore, the presence of impurities often plays a strong role in the main components. Although the flux aid sometimes helps the liquid phase sintering of the material, it is seriously harmful to the material’s resistance to high temperature.
White corundum is mainly used as an abrasive. In recent years, it has been widely used in refractory materials, such as iron hook castable, blister-free mud, steel jade bricks, prefabricated parts, breathable bricks, ladle bricks, magnesium aluminum carbon bricks, etc. The advantages of white corundum for refractory materials are high refractory resistance, wear resistance, erosion resistance, high bulk density, high alumina content, mainly used for high aluminum and alumina systems. When making products, there is also a high load softening temperature and high temperature volume stability. The impurities of white corundum determine the life of the product during use. Since the impurities have not been completely removed during smelting, white corundum also contains calcium hexaaluminate, calcium plagioclase feldspar, spinel, rutile and other secondary crystal phases, glass phases, ferroalloys and solid solutions.
White corundum is made of carbon, bauxite, iron filings three materials, because of iron filings so high-quality white corundum should appear brownish yellow, observing the color is a way to identify white corundum. Alumina is one of the substances that make up white corundum, and the amount of alumina content is directly related to the quality of white corundum.