Refractory Structure

Silica is the main component of acid refractory, and silica brick and clay brick are commonly used. Silica brick is a siliceous product containing more than 94% silicon oxide. The raw materials used include silica and waste silica brick. It has strong resistance to acid slag erosion, high load softening temperature, and no shrinkage or even slight expansion after repeated calcination; However, it is easy to be eroded by alkaline slag and has poor thermal shock resistance. Silica brick is mainly used in thermal equipment such as coke oven, glass furnace, acid steel furnace, etc. The clay brick takes refractory clay as the main raw material and contains 30%~46% alumina. It is a weak acid refractory material with good thermal vibration resistance and corrosion resistance to acid slag. It is widely used.
Neutral refractories are mainly composed of alumina, chromium oxide or carbon. Corundum products containing more than 95% alumina are high-quality refractory materials with a wide range of uses. Chromium bricks with chromium oxide as the main component have good corrosion resistance to steel slag, but poor thermal shock resistance, and low load deformation temperature at high temperature. Carbon refractory materials include carbon bricks, graphite products and silicon carbide products, which have low thermal expansion coefficient, high thermal conductivity, good thermal shock resistance, high temperature strength, and resistance to acid, alkali and salt corrosion. Especially weak acid and alkali have good resistance, and are not subject to metal and slag wetting, and are light in weight. It is widely used as high temperature furnace lining material, as well as high-pressure kettle lining for petroleum and chemical industry.
Basic refractories are mainly composed of magnesium oxide and calcium oxide, and magnesium bricks are commonly used. Magnesia bricks containing more than 80% - 85% magnesium oxide have good resistance to alkaline slag and iron slag, and their fire resistance is higher than clay bricks and silica bricks. It is mainly used in open-hearth furnace, oxygen blowing converter, electric furnace, non-ferrous metal smelting equipment and some high-temperature equipment.
Refractory materials used in special occasions include high-temperature oxide materials, such as alumina, lanthanum oxide, beryllium oxide, calcium oxide, zirconia, etc., and refractory compound materials, such as carbide, nitride, boride, silicide, sulfide, etc; High-temperature composite materials mainly include cermets, high-temperature inorganic coatings and fiber-reinforced ceramics.
Frequently used refractory materials include AZS brick, corundum brick, directly bonded magnesia-chrome brick, silicon carbide brick, silicon nitride bonded silicon carbide brick, nitride, silicide, sulfide, boride, carbide and other non-oxide refractory materials; Calcium oxide, chromium oxide, alumina, magnesium oxide, beryllium oxide and other refractory materials.
Frequently used insulating refractory materials include diatomite products, asbestos products, thermal insulation panels, etc.
The frequently used amorphous refractory materials include furnace repair material, ramming material, castable, plastic, refractory mud, refractory gunning material, refractory projection material, refractory coating, lightweight refractory castable, gun mud, etc.
Bulk refractories (unshaped refractories): unshaped refractories are refractories that are made up of reasonably graded granular and powdered materials and binders and are directly used without molding and firing. Generally, the granular material that constitutes this material is called aggregate, the powder material is called admixture, and the binder is called binder. This kind of material has no fixed shape, and can be made into slurry, mud paste and loose, so it is also known as bulk refractory. This kind of refractory can form a jointless integral structure, so it is also called integral refractory.
The basic composition of amorphous refractory is granular and powdery refractory. According to its use requirements, it can be made of various materials. In order to combine these refractory materials as a whole, except for a few special cases, appropriate types and quantities of binders are generally added. In order to improve its plasticity or reduce water consumption, a small amount of appropriate plasticizer and water reducer can be added. In order to meet other special requirements, a small amount of appropriate other additives can also be added separately.