As a leader in high-temperature refractory materials, tijolo de alta alumina ocupa uma posição importante em muitos campos. It is widely used in the field of high temperature with its excellent performance and has become an indispensable material in many industrial production.
High alumina bricks are mainly made of raw materials such as high alumina clinker and bonded clay, of which the alumina content is high, generally above 48%. According to the different alumina content, high alumina bricks can be divided into several grades, such as special grade, first grade, second grade, third grade and so on. Different differ in performance and use, but all have high refractoriness, temperatura de amolecimento da carga, e resistência à escória. PER Company produces various high-quality high-alumina bricks. Contact us for the best prices on high-alumina bricks.
In the field of high-temperature industry, high alumina bricks are widely used. Por exemplo, in the metallurgical industry, high alumina bricks are commonly used in the lining of smelting furnaces, such as blast furnaces, altos-fornos, electric furnaces and so on. It can withstand high temperatures and chemical corrosion, ensuring a stable and efficient smelting process. In the iron and steel industry, high alumina bricks are widely used in the lining of iron and steel furnaces, such as blast furnaces, converters and other equipment. It can withstand high temperatures and metallurgical reaction erosion, protecting the service life and productivity of the equipment.
Na indústria química, high alumina bricks are used in the lining of chemical kilns, storage tanks, reactors, refiners and other equipment. These equipments need to withstand the erosion of various chemicals and high temperatures during the production process, and high alumina bricks can provide reliable refractory protection. In the electric power industry, high alumina bricks are mainly used for the refractory lining of power boilers, turbines, chimneys and other equipment. These equipments need to withstand high temperatures and flue gas erosion during power generation, and high alumina bricks can provide reliable protection to ensure the safe and stable operation of the equipment.
Além disso, high alumina bricks are widely used in construction, vidro, cerâmica, casting, textile and other industries. In the construction industry, high alumina bricks can be used for refractory lining of high temperature kilns, flues, furnace walls and other industrial facilities, as well as for heat insulation and thermal insulation layer of buildings to improve the energy-saving performance of buildings. In the glass industry, it is used in the lining of glass kilns to ensure the quality of glass production and process stability. In the ceramic industry, it can be used as the lining of ceramic sintering kiln to improve the sintering effect and energy-saving performance. In the foundry industry, it can be used as the lining material of iron ladle, pouring channel, etc. to improve the casting efficiency. In the textile industry, it can be used in the refractory lining of hot air ducts and furnaces of textile machinery to provide a stable heat source.
Resumidamente, high alumina brick with its excellent performance in the field of high temperature plays an important role, and its wide range of applications for many industrial production provides a reliable guarantee.
High alumina bricks in the alumina content is high, generally more than 48%. Alumina is a high hardness compound, melting point of 2054 ℃. It is because of the excellent refractory properties of alumina, high alumina brick can withstand high-temperature environments, its refractory temperature can reach 1750 – 1790 ℃. Por exemplo, in some molten aluminum furnace, alto-forno quente, blast furnace and other high temperature kiln masonry, high alumina brick is widely used, fully demonstrated its excellent performance in high temperature stability.
High alumina brick load softening temperature is higher than the clay brick, but not as high as the silica brick, generally in the 1420 ℃ – 1550 ℃. In the process of experiencing high temperatures, high alumina bricks are not easy to deform, able to support the entire structure of the furnace. This is one of the most important indicators of how good a high alumina brick is. Por exemplo, in the blast furnace of the iron and steel industry, high alumina bricks are able to maintain stability at high temperatures and heavy loads to ensure the normal operation of the blast furnace.
High-alumina bricks can resist the erosion of acidic slag and alkaline slag, in some of the medium for acidic and alkaline kiln, high alumina bricks can withstand the erosion of acidic or alkaline media, to ensure that the kiln is not penetrated by the media in the kiln work process. Por exemplo, in the chemical industry in the kiln, high alumina brick can resist the erosion of various chemicals to ensure the safe operation of the kiln.
According to the different alumina content, high alumina brick pressure strength is generally in the 50 – 80Mpa. It is because of this high pressure strength, to ensure the stability of the furnace in the process of kiln work. Por exemplo, in the metallurgical industry smelting furnace, high alumina bricks can withstand high temperatures and heavy loads to ensure the stability of the smelting process.
High alumina bricks contain a large number of mullite, and the main component of mullite is also alumina, so the product made of the particle structure is very perfect, which improves the stability of high alumina bricks. In the high temperature environment, high alumina bricks can maintain the stability of the wall to ensure work safety. Ao mesmo tempo, high alumina brick texture is hard, has very good wear resistance, in the media constantly in and out of the process can slow down the degree of wear and tear of the surface, improve the service life of the high temperature kiln. Por exemplo, in the ceramic industry sintering kiln, high alumina bricks can withstand high temperatures and material friction, to ensure that the sintering effect and energy-saving performance.
High-alumina bricks are widely used in a variety of high-temperature equipment, playing a vital role.
Em primeiro lugar, in the blast furnace masonry, high alumina brick with its excellent performance becomes the ideal choice. The internal temperature of the blast furnace is extremely high, and it is exposed to erosion and mechanical scouring by molten iron and slag. The high refractoriness of high alumina bricks can withstand the high temperature environment inside the blast furnace, and their high load softening temperature ensures that they are not easy to be deformed under high temperature and heavy load, which provides support for the stable operation of the blast furnace. Ao mesmo tempo, high alumina bricks have strong slag resistance, which can effectively resist the erosion of acidic and alkaline slag in the blast furnace and prolong the service life of the blast furnace. Por exemplo, for the furnace cylinder of large blast furnace, high alumina bricks can be used in conjunction with other refractory materials to improve the erosion resistance of the cylinder.
Em segundo lugar, hot blast furnace is also an important application area of high alumina brick. Hot blast furnace in the mid-temperature region of the temperature in 600 – 1200 ℃, the temperature drop is large, the refractory bricks of the rapid cooling and heating performance requirements. Low creep high alumina bricks are excellent in this area, using high quality high alumina bauxite with “three stone” refractory raw materials fired, after two mullite crystal transformation, the formation of structural stability of the mullite crystal phase, with good creep resistance. In the high temperature parts such as upper lattice bricks, vault spinning bricks and big walls of hot blast stove, high alumina bricks are commonly used for masonry. According to the hot blast furnace hot air temperature selection of different levels of high alumina bricks, when the wind temperature in 900 – 1100 ℃, the high temperature part of the furnace lining and lattice brick is often used high alumina bricks, mullite bricks or silica bricks.
Furthermore, the roof of electric furnace is also inseparable from high alumina bricks. Furnace in the work temperature can be as high as 1750 – 1790 ℃, high alumina bricks of high refractoriness to meet this requirement. o high refractoriness of high alumina bricks can meet this requirement. Their strong slag resistance can resist acidic and alkaline slag erosion in the electric furnace. Ao mesmo tempo, high alumina bricks have high compressive strength and can withstand the heavy load of the electric furnace roof. Por exemplo, high alumina bricks are widely used in the top of steelmaking electric furnaces to ensure the stable operation and productivity of electric furnaces.
Além disso, high alumina bricks are also used for masonry blast furnace, reflector furnace, rotary kiln lining and so on. In the blast furnace, high alumina bricks can withstand high temperatures and the impact of the furnace airflow. In the reflector furnace, the high refractoriness and slag resistance of high alumina bricks ensure the normal operation of the reflector furnace. In the rotary kiln lining, high alumina bricks can withstand the friction of materials and high temperatures due to their wear resistance and stability.
High-alumina bricks are also widely used as heat-storage lattice bricks for flat furnaces, plugs for pouring systems, water spout bricks and so on. In these parts, high alumina bricks of high refractoriness, slag resistance and compressive strength and other performance advantages can be given full play to, for the smooth progress of industrial production provides a reliable guarantee.
High-aluminum brick production process is more complex, need to go through a number of aspects of the fine operation.
1. Selection of raw materials
The main raw materials of high alumina bricks include high alumina bauxite clinker, binding agent and so on. The binding agent usually uses soft clay as the binding agent, and its main role in the ingredients is to improve the molding properties of the mud, and make the molding and drying of the body has a certain strength. De um modo geral, the addition of clay powder in the ingredients is generally 5%. In order to produce volume-stable high-alumina bricks, high alumina bauxite micro-powder can be used as high-alumina binding agent. Or use high alumina bauxite powder and clay powder according to a predetermined ratio with the preparation of synthetic mullite as a binding agent, can be produced without secondary expansion of the volume stability of high alumina brick.
2. Forming
High-alumina bricks are usually made of coarse, medium and fine clay. The upper limit of coarse particles is usually 2 – 3mm, the addition of 40 – 50% (for shaped products, the upper limit of coarse particles can be reduced to 2 – 1mm). 1 – 0.1mm intermediate particles to add 10 – 20% is appropriate. ＜The addition of <0.1mm fine powder should be controlled at 40-50%. Appropriate increase in the size and number of coarse particles can improve the packing density of the mud, and easy to mold. When sintering, the secondary mullite reaction around the material is weaker, easy to sinter. No entanto, the enlargement of particle size also has certain limits, the maximum particle size of 3mm is appropriate. In order to reduce the porosity of high alumina bricks, improve the quality of high alumina bricks, must improve the molding pressure. For ordinary high alumina bricks, the molding pressure should reach 137MPa. high density high alumina bricks molding pressure should be in the range of 176 – 215MPa.
3. Sintering
The sintering temperature varies for different grades of high alumina bricks. When using inverted flame kiln to sinter I grade high alumina bricks, the general sintering temperature is 1430-1450℃, holding time is 40 h. When using II grade high alumina bricks, the sintering temperature is 1390-1400℃, holding time is 24-32 h. If using tunnel kiln to sinter I and II grade high alumina bricks, the sintering temperature is usually 1550-1560℃. The heating speed varies with different raw materials and products. 600 ℃ before the low-temperature stage, the temperature should be increased slowly, 600 – 1200 ℃ heating speed can be slightly faster. 1200 ℃ to the highest firing temperature should be controlled heating speed. Cooling stage should also control the cooling speed. High-alumina brick billet loading kiln (or kiln car) is generally used more flat loading. In order to avoid black heart when firing, can also be used side loading. Firing with inverted flame kiln, the need for high alumina bricks with shelves. If fired in a tunnel kiln, the kiln car table can be used to high alumina clinker sand pads, between each layer of bricks laid a layer of rice husk. In order to make the brick stack solid, at a certain height to pull a layer of flat pad brick. Brick loading height is generally 650 – 1000mm.
(2) quality standards
High-alumina brick quality standards mainly include chemical composition content and physical property requirements.
1. Chemical composition content
The content of alumina in high alumina bricks should be more than 48%, and different grades of high alumina bricks have specific requirements for Al₂O₃ content. Por exemplo, na China, the content of Al₂O₃ in high alumina bricks is usually divided into three grades: Ⅰ – Al₂O₃ content > 75%. Ⅱ and Al₂O₃ content of 60 – 75%. Ⅲ – Al₂O₃ content is 48 – 60%. Ao mesmo tempo, the content of impurities such as SiO₂, Fe₂O₃, TiO₂, etc. should be controlled within a certain range to ensure the refractory performance of high alumina bricks. Por exemplo, 48% high alumina brick raw materials using 60% high alumina clinker, iron content should be within 3.0%. 55% high alumina brick raw materials using 65% high alumina clinker, iron content should be within 2.5%. 65% high alumina brick raw materials using 75% high alumina clinker, iron content should be within 2.2%. 75% high alumina brick raw materials using 85% high alumina clinker, iron content should be within 2.0%. 80% high alumina brick materials using 80% high alumina clinker, iron content should be within 2.0%. 80% high alumina brick raw material using 88% high alumina clinker, the iron content should be within 1.5%.
2. Physical property requirements
(1) Densidade aparente: should meet the standard requirements, usually between 2.3 – 2.8 g/cm³.
(2) porosidade aparente: should be controlled within a reasonable range, generally not more than 23%.
(3) Resistência à compressão em temperatura normal: should meet the requirements of the corresponding grade, usually between 40 – 80 MPa.
(4) re-firing line change: should be controlled within a reasonable range to ensure the dimensional stability of high alumina bricks at high temperatures.
(5) refratariedade: should meet the standard requirements, usually above 1750 ℃.
(6) Load softening temperature: should meet the requirements of the corresponding grade, usually between 1400 – 1600 ℃.
(7) Thermal shock stability: should meet the corresponding standards, usually at 1100 ℃ water cooling times of not less than 10 vezes.
Além disso, the acceptance standard of high alumina bricks also involves dimensional tolerance and appearance quality. Dimensional deviation should be within the range specified in the standard, usually ±1.5 mm. flatness and verticality should be in accordance with the standard requirements to ensure a close fit between the bricks. The surface should be smooth, sem rachaduras, no missing corners, no melting holes and other defects, and the color should be uniform, no obvious color difference.
PER Refractories is famous for producing high alumina refractories, corundum bricks and other high alumina brick related products. In terms of product advantages, the company has a professional technical team and advanced production equipment to strictly control product quality and ensure stable and reliable performance of high alumina bricks. In terms of service features, it provides a full range of technical support, from product selection to installation and use, to provide customers with professional advice and guidance.
Desde outubro, os preços da alumina continuaram a subir, and China's largest bauxite importer - a…
The application of refractory bricks in the kiln immediately endangers the operation rate of the…
Analysis Of The Causes Of Common Quality Problems In Tunnel Kiln Construction And Measures To…
Corundum quality refractory castables are made from corundum to the new jade refractory insulation material…
Análise de matérias-primas refratárias de alumínio-silício Prof. Li Yong of the University of Science and…
Lightweight high-temperature refractory bricks of the leading products Department of polycrystalline mullite fibers have a…
