What is the main component of refractory bricks?

One or more kinds of viscosity and agent composed of mixed powdery granules, when used must be and one or more kinds of liquid with mixing evenly, has a strong mobility. Different refractory bricks have different raw materials, such as silica-aluminum, clay, etc.:

Based on the different composition of the refractory bricks, it can be divided into five categories, namely: silica-aluminum refractory bricks, alkaline series of refractory bricks, carbon-containing refractory bricks, zirconium-containing refractory bricks, and heat-insulating refractory bricks. Any furnace is not only a refractory brick and masonry, need a different refractory brick with each other. The following is a detailed description of the composition of each of the five categories of refractory bricks.

1, silicon aluminum system refractory bricks, it is reported that it is to AL2O3-SiO2 binary system phase diagram as the basic theory, mainly including the following kinds.

(I) silicon brick, refers to the refractory bricks containing SiO293% or more, is the main varieties of acidic refractory bricks. It is mainly used for masonry coke ovens, also used in a variety of glass, ceramics, carbon calcining furnace, refractory bricks of hot kilns and other load-bearing parts of the vault, in the hot blast stove of high temperature load-bearing parts also used, but not suitable for use in the 600 ℃ below and temperature fluctuations in the thermal equipment.

(ii) clay bricks, clay bricks are mainly composed of mullite (25% to 50%), glass phase (25% to 60%) and square quartz and quartz (up to 30%). Usually hard clay as raw material, pre-calcined mature material, and then with soft clay, semi-dry or plastic method of molding, the temperature of 1300 ~ 1400 C fired into clay brick products. Can also add a small amount of water glass, cement and other binding agents made of non-fired products and unshaped materials. It is a blast furnace, hot blast furnace, heating furnace, power boiler, lime kiln, rotary kiln, ceramics and refractory brick firing kiln commonly used refractory bricks.

(C) high alumina refractory bricks, high alumina refractory bricks mineral composition of corundum, mullite and glass phase, its content depends on the ratio of AL2O3 / SiO2 and the type and number of impurities, according to the AL2O3 content of refractory bricks can be divided into grades. The raw materials are high alumina bauxite and silica wire class natural ores, but also mixed with electrofused corundum, sintered alumina, synthetic mullite, as well as clinker calcined with alumina and clay in different proportions. It is mostly produced by the sintering method. However, the products also include fused cast bricks, fused granulated bricks, unburnt bricks and unshaped refractory bricks. High alumina refractory bricks are widely used in the iron and steel industry, non-ferrous metal industry and other industries.

(D) corundum refractory bricks, corundum bricks refers to the AL2O3 content of not less than 90%, corundum as the main phase of a refractory brick, can be divided into sintered corundum bricks and electrofusion corundum bricks.

2, alkaline series refractory bricks. Alkaline refractory bricks refers to alkaline oxides such as Mg0 and CaO as the main component of the refractory products, the main varieties are as follows.

(A) magnesium refractory bricks, refers to the magnesite as raw material, magnesite as the main crystalline phase, MgO content of 80% to 85% above the refractory bricks. Its products are divided into metallurgical magnesium sand and magnesium products two categories. According to the different chemical composition and use, there are Martin sand, ordinary metallurgical magnesium sand, ordinary magnesium brick, magnesium-silicon brick, magnesium-aluminum brick, magnesium-calcium brick, magnesium-carbon brick and other varieties. Magnesia refractory bricks are the most important products in alkaline refractory bricks, with high refractoriness and good resistance to alkaline slag and iron slag, which is an important high-grade refractory bricks. It is mainly used in flat furnace, oxygen converter, electric furnace and non-ferrous metal smelting.

(2) dolomite brick, is a kind of alkaline refractory brick produced with dolomite as the main raw material. Widely used in alkaline converter, can also be used as the lining of some furnace refining package.

(C) magnesium olivine refractory bricks, magnesium olivine 2MgO-SiO2 as the main composition of a refractory brick. Mainly used in flat furnace heat storage room lattice brick, ingot brick, heating furnace bottom and in the copper furnace also has a good use.

3, carbon-containing refractory bricks. Carbon-containing refractory bricks are made of carbon or carbon compounds, containing different forms of carbon as the main component of the refractory brick products, mainly divided into the following categories.

(a) carbon bricks, carbon materials as the main raw material, add the appropriate amount of binding agent made of high-temperature neutral refractory brick products. Carbon bricks are widely used in masonry blast furnace bottom, furnace cylinder, furnace belly and the lower part of the furnace body. It can improve the continuous operation time of the blast furnace and prolong its service life. In addition, carbon bricks are also widely used in electrochemical industry, chemical industry, petrochemical industry, electroplating industry, ferroalloy industrial furnace (or equipment lining), acid, alkali tank lining and pipeline, and melting of non-ferrous metals (such as lead, aluminum, tin, etc.) furnace lining.

(ii) graphite refractory products, is based on natural graphite as raw material, clay as a binding agent made of refractory materials. Such products are graphite clay crucible, distillation tank, cast steel with plug head brick, water mouth brick and steel drum lining brick. The production of the most widely used is the steelmaking and melting of non-ferrous metals graphite clay crucible.

(C) silicon carbide refractory products, silicon carbide (SiC) as the raw material for the production of advanced refractories. Its wear resistance and corrosion resistance, high temperature strength, high thermal conductivity, small coefficient of linear expansion, good thermal shock resistance. In iron and steel smelting, it can be used in the lining of steel drums, water spout, plug head, blast furnace bottom and furnace belly, iron out trough, converter and electric furnace spout, heating furnace waterless cooling slides and so on. In non-ferrous metal (zinc, copper, aluminum, etc.) smelting, a large number of distillers, distillation tower trays, electrolytic tank side walls, molten metal pipelines, suction pumps and crucibles for molten metal. In the silicate industry, it is used in large quantities as a variety of kilns shed plate and flame materials, such as muffle furnace lining and sagger. In the chemical industry, mostly used in oil and gas generators, organic waste calcining furnace, petroleum gasifier and desulfurization furnace and so on. In addition, in space technology can be used as a rocket nozzle and high temperature gas turbine blades.

4, containing zirconium refractory bricks . Belong to a genus of acidic materials, is a natural zircon sand (ZrSiO2) as raw material products. Zirconium refractory bricks are different from silica-aluminum refractory bricks and carbon containing series of refractory bricks, its slag resistance is good, the thermal expansion rate is small, thermal conductivity with the increase in temperature and reduce the loaded softening temperature is high, wear-resistant strength, thermal shock resistance is good, has now become an important material in various industrial fields. With the development of continuous casting and vacuum degassing technology in the metallurgical industry, the application of zircon refractory bricks is becoming more and more widely used, there are mainly the following classifications.

(A) zircon brick, in the steelmaking process, the use of steel degassing method, and zircon refractory materials on the slag, steel erosion resistance and good thermal shock resistance, and suitable for work under reduced pressure, it is widely used in the metallurgical industry for masonry degassing with the lining of the drum, but also used as a stainless steel drum lining, continuous casting of the drum lining, casting mouth bricks, plug head bricks, cuffs, as well as high-temperature induction furnace linings, etc.. etc. Zircon refractory bricks have high resistance to acidic slag and glass, and are therefore also widely used in severely damaged parts of glass kilns where the most active glass is melted. Zircon refractories also have the property of not being penetrated by metallic aluminum, aluminum oxides and their slag, and thus have also obtained good results in the bottom of aluminum furnaces.

(ii) AZS electrofusion bricks, also known as electrofused zirconia corundum bricks, with the development of the glass industry, AZS electrofusion bricks have become a key part of the glass furnace must be refractory materials. It is more resistant to the erosion of the glass liquid.

(C) AZS re-sintered fused bricks, mainly used for masonry glass kiln bottom, wall and heat storage lattice bricks and other thermal equipment.

(d) zirconium mullite fused bricks, the brick is characterized by dense crystal structure, high load softening temperature, good thermal shock resistance, high mechanical strength at room temperature and high temperature, good abrasion resistance, good thermal conductivity, and excellent resistance to slag erosion. This kind of products are widely used in metallurgical heating furnace, even heat furnace, calcium carbide furnace outlet, glass melting kiln kiln wall, etc., the use of the effect is very good.

5, thermal insulation refractory bricks. Refractory materials with high porosity, low bulk density and low thermal conductivity. Heat-insulating refractories are also known as lightweight refractories. It includes the following classifications.

(a) high aluminum heat-insulating lightweight refractory bricks. Is to bauxite as the main AL2O3 content of not less than 48% of the heat-insulating lightweight refractory bricks. Its production process using the foam method, can also be used to burn out the accession method. High-alumina heat-insulating lightweight refractory bricks can be used for masonry insulation layer and no strong high-temperature molten material erosion and scouring effect of the parts. Directly in contact with the flame, the general high alumina heat-insulating refractory bricks surface contact temperature shall not be higher than 1350 ℃. Mullite heat-insulating refractory bricks can be in direct contact with the flame, with high temperature resistance, high strength, energy-saving effect is remarkable and so on. It is suitable for the lining of pyrolysis furnace, hot air furnace, ceramic roller kiln, electric porcelain drawer kiln and various resistance furnaces.

(ii) clay insulating lightweight refractory bricks, is made of refractory clay as the main raw material of AL2O3 content of 30% to 48% of the insulating refractory bricks. Its production process using burned out plus character method and foam method. Refractory clay, bleaching beads, refractory clay clinker as raw materials, mixed with binding agent and sawdust, after batching, mixing, molding, drying, firing, resulting in a bulk density of 0. 3 ~ 1. 5g/cm3 of the product. Clay heat-insulating brick production accounted for more than half of the total output of heat-insulating refractory bricks.

Chinese standard (GB 3994-1983) will be divided into clay heat-insulating bricks according to the bulk density of NG-1.5, NG-1.3a, NG-1.3b, NG-1.0, NG -0.9, NG-0.8, NG-0.7, NG-0.6, NG-0.5, NG-0.4 10 kinds of grades.

(C) diatomite heat-insulating lightweight refractory bricks, is made of diatomite as the main raw material for heat-insulating refractory products. It is mainly used in 900 ℃ below the heat insulation layer.

Chinese standard (GB 3996-1983) will diatomite thermal insulation products by bulk density into GG-0.7a, GG-0. 7b, GG-0.6, GG-0. 5a, GG-0.5b and GG-0.4 six grades.

(D) bleached beads brick, is made of bleached beads as the main raw material of heat insulation refractory products. Bleached beads from the thermal power plant fly ash levitated aluminum silicate glass hollow beads. It is light, thin-walled, hollow, smooth surface, high temperature resistance, good thermal insulation properties. The use of bleached beads of these excellent characteristics, can be manufactured with excellent thermal insulation performance of lightweight heat-insulating refractory materials. The production of bleached beads brick can be semi-dry molding.