Refractory materials are important basic materials in basic industrial fields such as steel, nonferrous metals, building materials, petrochemical energy, and environmental protection. At the same time, it is also an indispensable and important support material for high-temperature industrial thermal equipment.
Classified According to Chemical Composition
There are many ways to classify refractory materials. According to chemical composition, refractory materials can be divided into acid refractory materials, alkaline refractory materials and neutral refractory materials. Refractory bricks produced from refractory materials with different chemical compositions are used in different fields.
Alkaline Refractory Materials
Alkaline refractory materials refer to refractory materials with magnesium oxide (MgO) and calcium oxide (CaO) as the main components. Mainly used in alkaline steel-making furnaces, non-ferrous metal smelting furnaces, glass and cement industrial kilns and other thermal equipment.
Generally, alkaline refractory materials have the characteristics of high refractoriness and strong resistance to alkaline slag. However, its thermal expansion rate is large, so its thermal shock stability and hydration resistance are generally poor. The main varieties of commonly used alkaline refractory materials are magnesite refractory, dolomite refractory, etc.
Acid Refractory Materials
Acid refractory materials usually refer to refractory materials with silica as the main component. It easily reacts chemically with alkaline refractory materials, alkaline slag, or alkali-containing compounds at high temperatures. But it is resistant to acidic slag. Acid refractory materials generally refer to commonly used silica bricks and fire clay bricks. Silica bricks are siliceous products containing more than 93% SiO2. The raw materials used include silica, waste silica bricks, etc.
Acidic refractories are not resistant to alkaline slag and alkaline fluxes. Mainly used in coke ovens, open-hearth regenerators, furnace roofs, refractory firing kilns and glass tank kilns.
Neutral Refractory Materials
The main component of neutral refractory materials is neutral inorganic non-metallic materials. It is neither easy to react chemically with acidic refractory materials, acidic slag, or acidic flux at high temperatures, nor is it easy to react chemically with alkaline refractory materials, alkaline slag, or alkali-containing compounds.
Neutral refractory materials have good slag resistance, high refractoriness, and good resistance to rapid cooling and heating. The main products of neutral refractory materials are: corundum bricks, high alumina fire bricks and mullite bricks.
Classification of Refractory Materials by Appearance
Shaped Refractory Materials
Shaped refractory materials are made of refractory granules, powders and binders in a certain proportion, and are then made through shaping, drying and firing processes. The manufacturing process of shaped refractory materials will give them precise shape, size and sufficient strength.
According to shape and size, shaped refractory materials can be divided into standard, common, special and super-special products.
Amorphous Refractory Materials
Unshaped refractories are refractory materials that are composed of granular and powdery materials and binders and are used directly without shaping and firing. One thing they have in common is that they are all powder-coated and have no fixed shape. It can be applied to the surface of the kiln and can also be used to fill gaps in masonry.
Common unshaped refractory materials include: refractory pouring materials, refractory plastic materials, refractory spray coatings, refractory ramming materials and refractory dry vibrating materials.
Classification according to the Main Chemical Components of Minerals
Under the classification of mineral chemical composition, refractory materials are generally divided into five major categories.
- Aluminum silicate: the main finished products are semi-silica bricks, clay bricks and high alumina bricks.
- Siliceous: the main finished products are silica bricks, fused quartz fired products.
- Magnesium: magnesia bricks, magnesia alumina spinel bricks, magnesia chrome bricks.
- Carbonaceous: carbon bricks, graphite bricks.
- Dolomite and zircon.
Overall, refractory materials are the foundation for all high-temperature industrial operations. It has many types and wide applications. As a long-term refractory company in the high-temperature industry, Kerui has strict quality control over refractory materials. If you have any needs for refractory materials, please contact us on!