refractory brick and
fireclay refractories distinction
Clay refractory bricks are a kind of refractory bricks, the precise definition of refractory products are shaped, from the delivery form of distinction is a series of refractories.
Refractories are divided into ordinary refractories (1580 ~ 1770 ℃), advanced refractories (1770 ~ 2000 ℃) and special refractories (2000 ℃ above); according to the chemical characteristics of acid refractories, Neutral refractories and refractories. In addition, there are special occasions for the refractory material.
Now the definition of refractory, has not only depends on whether the refractoriness of 1580 ℃ or more.
refractory brick for sale refers to the current application of metallurgical, petrochemical, cement, ceramics and other production equipment lining the inorganic non-metallic materials.
Acid refractories to silicon oxide (SiO2) as the main component, commonly used silica brick and clay brick. Silica brick is more than 93% SiO2 silica products, the use of raw materials are silica, waste silica brick. Silica brick acid-resistant slag erosion ability, but susceptible to the erosion of slag, and its load softening temperature is high, close to its refractoriness, after repeated calcination volume does not shrink, or even a slight expansion, but the thermal shock resistance is poor. Silica brick is mainly used for coke oven, glass furnace, acid furnace and other thermal equipment, silica brick in accordance with the SiO2 content and physical and chemical indicators can be divided into several levels, mainly divided into glass kiln silica brick and coke oven silicon Brick two categories. Clay brick or refractory clay clinker as the main raw material, containing 30% to 46% of alumina, refractoriness 1580 ~ 1770 ℃, is a weak acid refractory, good thermal shock resistance, acid slag corrosion resistance , Widely used in clay bricks to refractory clay as the main raw material is called ordinary clay bricks to coke gem clinker as the main raw material made of porosity was 17% below the clay brick known as low porosity clay brick. Two kinds of clay brick and according to which the physical and chemical indicators are divided into several grades, ordinary clay brick and low porosity clay brick between the price difference.
Neutral refractories to alumina, chromium oxide, silicon carbide or carbon as the main component. Neutral
Refractory company in the main products are: corundum bricks, high alumina bricks, silicon Mo brick, mullite bricks, aluminum chrome bricks, aluminum carbon brick, graphite or carbon brick. High alumina products in the main crystalline phase is mullite and corundum, corundum content increases with increasing alumina content, alumina containing 95% of the corundum products is a wide range of high-quality
refractory material containing alumina 95% of the corundum products is a wider use of high-quality refractories. The chrome brick with chromium oxide as the main component has good corrosion resistance to steel slag, but the thermal shock resistance is poor and the softening degree is low. High alumina bricks of the indicators are relatively good, with good cost-effective, so widely used, but because of high alumina brick erosion resistance is poor, it can not be applied to the key conditions of complex conditions, silicon brick is the use of aluminum Bauxite and silicon carbide as the main raw materials, mainly used in the transition zone of cement rotary kiln.
Carbon refractories are carbon brick, graphite products and silicon carbide products. Carbon products is another kind of neutral refractory material, which is divided into three categories: carbon brick, graphite product and silicon carbide based on the composition of carbonaceous material and the mineral composition of products. Carbon brick is a high-grade petroleum coke as raw material, plus tar, asphalt binder, at 1300 ℃ isolated from the firing of air conditions. Graphite products (except natural graphite) with carbonaceous materials in the electric furnace in 2500 ~ 2800 ° C in the graphite system in the system. Silicon carbide products are silicon carbide as raw materials, plus clay, silica and other binder in 1350 ~ 1400 ℃ firing. Silicon carbide plus silicon powder can also be made in the electric furnace nitrogen atmosphere under silicon nitride - silicon carbide products. Carbon products, low thermal expansion coefficient, high thermal conductivity, good thermal shock resistance, high temperature strength. Long-term use at high temperatures do not soften, from any acid erosion, a good salt resistance, not by the metal and slag wetting, light weight, high-quality high-temperature materials. Disadvantage is easily oxidized at high temperatures, should not be used in the oxidizing atmosphere. Carbon products are widely used in high-temperature furnace lining (bottom, hearth, lower furnace, etc.), melting non-ferrous metal furnace lining. Graphite products can do the reaction tank and petrochemical autoclave lining. Silicon carbide and graphite products can also be made of melting copper alloy and light alloy crucible. Carbon brick and graphite products, the main component of carbon (C), the thermal expansion coefficient is very low, high thermal conductivity, good thermal shock resistance, high temperature strength, acid and salt erosion, especially weak acid has good resistance , Free from metal and slag wetting, light, generally used in iron and steel smelting industry, but also for petroleum, chemical industry, autoclave lining. Silicon carbide is an excellent refractory, good corrosion resistance, but at high temperatures (more than 1400 degrees) is easy to oxidize, not suitable for use in the oxidizing atmosphere.
The main refractory products are magnesia and oxygen. The main products include magnesia brick, magnesia-chrome brick, Spinel brick and so on. Magnesia (MgO) more than 80% of the fire brick called magnesium bricks, according to the index can be divided into many grades of grades, magnesium bricks on the slag and iron slag has a good resistance, refractoriness than clay brick and silica brick high. Mainly used for open hearth, oxygen blowing converter, electric furnace, non-ferrous metal smelting equipment and glass industry and some high-temperature equipment. Magnesia-chrome brick on the resistance of the slag stronger, and the thermal shock stability is also much higher than the magnesium brick, so the application of more extensive, magnesia-chrome brick in the iron and steel smelting and non-ferrous metal smelting industry has almost replaced magnesium brick, Because of its chromium oxide (Cr2O3) can continue to spread, the magnesia-chrome brick can be easily linked to the kiln skin, so in the last 30 years, has been the first choice for cement kiln firing refractories, magnesia chrome brick Cr2O3 Will react with water, trivalent chromium can become hexavalent chromium, will cause pollution of water, is facing the trend of gradually withdraw from the cement industry market. Magnesia-alumina brick using magnesia and alumina as raw materials, compared with magnesia brick, its thermal shock stability and high temperature creep performance is better, use the site and almost the same as magnesium bricks. Dolomite brick and magnesium calcium brick performance is almost the same, dolomite brick to dolomite as raw materials, magnesium calcium bricks to synthetic magnesium calcium sand as raw materials, oxygen content is generally 15-30%, the remaining components are mainly magnesium oxide, with The role of purification of molten steel, generally only for the special steel smelting, magnesium calcium brick production process is more complex, easy to hydration and decomposition of water and steam, not easy to transport, the use of the process must be prepared to prevent work. Manganese iron spinel brick is a new product, mainly used for cement rotary kiln firing zone and transition zone, will be the cement industry alternative to magnesia chrome brick main products.
Refractory materials such as carbides, nitrides, borides, silicides and sulphides, such as alumina, lanthanum oxide, beryllium oxide, oxygen, zirconia and the like, are used in special applications. (Silicon carbide, titanium carbide, tantalum carbide, etc.), nitrides (boron nitride, silicon nitride and the like), borides (borides (borides), and the like); refractory materials having a melting point of 2050 to 3050C or higher; Zirconium, titanium boride, hafnium boride, etc.), silicides (such as molybdenum disilicide), and sulfides (thorium sulfide, cerium sulfide, etc.). Their melting point for the 2000 ~ 3887 ℃, of which the most refractory is the carbide. High temperature composites such as metal ceramics, high temperature inorganic coatings and fiber reinforced ceramics.
Special materials are often used AZS brick (ie, zirconia corundum brick), corundum brick, direct combination of magnesia-chrome brick, silicon carbide brick, silicon nitride bonded silicon carbide brick, nitride, silicide, sulfide, boride, carbonation And other non-oxide refractory materials; oxygen, chromium oxide, aluminum oxide, magnesium oxide, beryllium oxide, and other refractories. Commonly used insulation refractory products are diatomite, asbestos products, such as insulation boards. Refractory refractory materials are often used in refractory castables, refractory mud, refractory ramming material, refractory plastic, fill charge, refractory gunning materials, refractory materials, refractory coatings, lightweight refractory castable, gun mud and so on.
