Views: 0 Author: Site Editor Publish Time: 2025-06-06 Origin: Site
In modern industrial production, high-temperature furnaces are indispensable and important equipment, and clay refractory bricks are the "guardians" of these high-temperature furnaces. Clay refractory bricks play a key role in many industries such as steel, building materials and chemical industry because of their excellent high temperature resistance, corrosion resistance and wear resistance.
Clay refractory brick is a kind of refractory material with refractory clay as the main raw material and fired at high temperature. It belongs to a kind of aluminosilicate refractory, and its main components are Al₂O₃ (alumina) and SiO₂ (silica). According to the different Al₂O₃ content, clay refractory bricks can be divided into ordinary clay bricks and high alumina clay bricks. The ALO content of ordinary clay bricks is generally between 30% and 45%, while the ALO content of high alumina clay bricks is higher, usually between 45% and 85%. The fire resistance and mechanical strength of high-alumina clay brick are better than those of ordinary clay brick, so high-alumina clay brick is the first choice in some occasions with higher requirements for refractory materials.
The production process of clay refractory brick mainly includes four stages: raw material preparation, molding, drying and firing.
Raw materials are the basis of the quality of clay refractory bricks. Refractory clay is the main raw material, which is rich in ALO and SiO₂, and also contains some other impurities. In order to improve the quality of bricks, some additives, such as clinker and mineralizer, are usually added. These additives can improve the sintering performance of bricks, increase the strength or give bricks some special properties. After the raw materials are crushed, screened and mixed, a uniform mixture is formed to prepare for the subsequent molding process.
Molding is the process of making mixed raw materials into bricks with a certain shape and size. Common molding methods include press molding, extrusion molding and casting molding. Press molding is to put the raw material powder into the mold and press it under high pressure. The green brick produced by this method has high density and accurate size. Extrusion molding is to make raw materials into mud and extrude them through an extruder, which is suitable for producing bricks with complex shapes. Pouring molding is to make raw materials into slurry and pour it into a mold for curing. This method is suitable for producing large or irregular bricks. After molding, the brick blank needs to be trimmed to ensure that its size and shape meet the requirements.
The purpose of drying is to remove the moisture in the brick and prevent cracks from occurring due to excessive evaporation of moisture during firing. There are two drying methods: natural drying and artificial drying. Natural drying is to put the adobe in a well-ventilated place and let it dry naturally. This method is simple, but the drying speed is slow, which is greatly affected by the weather. Manual drying is the use of drying equipment, by controlling the temperature and humidity, quickly remove the moisture in the brick. The moisture content of the dried brick should be controlled within a certain range to ensure the firing quality.
Sintering is the key link in the production of clay refractory bricks. Brick blanks go through preheating, firing and cooling stages in a high-temperature kiln. In the preheating stage, the brick is mainly heated slowly to remove residual moisture and organic matter. The firing stage is the process of physical and chemical changes of the brick at high temperature, the mineral phase in the raw materials changes, and sintering occurs between particles, which makes the brick compact and increases its strength. In the cooling stage, the burned bricks are cooled slowly to prevent cracks from occurring due to rapid temperature change. The control of firing temperature and time is very important to the quality of brick. Different brick types and raw material formulas need different firing systems.
Clay refractory bricks can work stably in high temperature environment for a long time, and their fire resistance is generally between 1580℃ and 1850℃. Refractory refers to the temperature at which bricks do not melt at high temperature, which is an important index to measure the high temperature resistance of refractories. The fire resistance of clay refractory bricks enables them to withstand the erosion of high-temperature flames and melts in industrial furnaces and protect the furnace structure from damage.
In industrial production, there are often various corrosive substances in furnaces, such as acid gas and alkaline slag. Clay refractory bricks have good corrosion resistance and can resist the erosion of these corrosive substances. This is because the main components of clay refractory bricks, Al₂O₃ and SiO₂, have chemical stability and are not easy to react with corrosive substances. At the same time, the dense structure of brick can also prevent the penetration of corrosive substances and prolong the service life of brick.
During the operation of the furnace, the flow of materials and the erosion of airflow will wear the refractories. Clay refractory bricks have high hardness and strength and can resist these abrasion. Its wear resistance mainly comes from its compact structure and high Al₂O₃ content. Al₂O₃ is a kind of material with high hardness, which can improve the wear resistance of brick. In addition, clay refractory bricks can form a dense protective layer at high temperature, further enhancing their wear resistance.
During the operation of the furnace, the temperature changes frequently, so the refractories need to have good thermal shock resistance to prevent cracks caused by too fast temperature change. Clay refractory bricks have good thermal shock resistance and can maintain structural integrity under the condition of rapid temperature change. This is because the thermal expansion coefficient of clay refractory brick is low, and the micro-cracks inside it can absorb thermal stress to a certain extent and reduce the influence of temperature change on brick.
Clay refractory bricks are widely used, covering steel, building materials, chemical industry, energy and other industries.
In iron and steel production, clay refractory bricks are mainly used for lining of blast furnace, hot blast stove, ladle, hot metal ladle and other equipment. Blast furnace is an important equipment for ironmaking, and its lining needs to withstand the corrosion of high temperature, high pressure and molten iron. Clay refractory bricks can meet these requirements. Hot-blast stove is used to heat air and raise the temperature in the furnace. The high temperature resistance of clay refractory brick makes it an ideal material for lining of hot-blast stove. Ladle and ladle are used to hold high-temperature molten steel and molten iron, and the corrosion and wear resistance of clay refractory bricks can ensure their service life.
In building materials industry, clay refractory bricks are mainly used for lining of cement kilns, glass kilns, ceramic kilns and other equipment. Cement kiln is an important equipment for producing cement, and its lining needs to withstand high temperature and wear of cement clinker, and clay refractory bricks can provide good protection. Glass kiln is used to melt glass raw materials, and its lining needs high temperature resistance and corrosion resistance, and clay refractory bricks can meet these requirements. Ceramic kiln is used for firing ceramic products. The high temperature resistance and chemical stability of clay refractory bricks make it an ideal choice for ceramic kiln lining.
In the chemical industry, clay refractory bricks are used for lining of various reaction furnaces, cracking furnaces and other equipment. These equipments will produce high temperature, high pressure and corrosive gases during operation. The corrosion resistance and high temperature resistance of clay refractory bricks can ensure the safe operation of the equipment. For example, in an oil cracking furnace, clay refractory bricks can withstand the heat generated by high-temperature cracking reaction and the corrosion of corrosive gases, thus prolonging the service life of the equipment.
In the energy industry, clay refractory bricks are used for lining of boilers, garbage incinerators and other equipment. Boiler is an important equipment for power generation, and its lining needs to withstand high temperature and high pressure, and clay refractory bricks can provide good protection. The garbage incinerator is used to incinerate garbage and generate high-temperature flue gas for power generation. The corrosion resistance and wear resistance of clay firebrick can ensure its service life in harsh environment.
With the continuous development of industrial technology, the performance requirements of clay refractory bricks are getting higher and higher. In the future, the development of clay refractory bricks will show the following trends:
In order to meet the requirements of higher temperature and worse environment, clay refractory bricks will develop towards high performance. By optimizing raw material formula and improving production technology, the fire resistance, corrosion resistance, wear resistance and thermal shock resistance of brick are improved. For example, develop clay refractory bricks with high aluminum content to improve their high temperature resistance; Add special additives to enhance its corrosion resistance.
In today's increasingly tense energy, energy conservation has become an important topic. The energy-saving development of clay refractory bricks is mainly reflected in two aspects: first, reducing the energy consumption in brick production, and reducing the energy consumption in the production process by improving production technology and improving energy utilization efficiency; The second is to improve the thermal insulation performance of bricks and reduce the heat loss of furnaces. For example, developing clay refractory bricks with low thermal conductivity can reduce heat transfer and improve the thermal efficiency of furnaces.
Environmental protection is an important theme in today's society, and the refractory industry is no exception. The development of environmental protection of clay refractory bricks is mainly reflected in reducing pollutant emissions in the production process and reducing the impact on the environment. For example, using clean energy instead of traditional coal fuel to reduce exhaust emissions; Improve the production process to reduce the production of waste water and waste residue; Develop chromium-free or low-chromium clay refractory bricks to reduce the pollution of harmful substances such as chromium to the environment.
Different industrial furnaces have different requirements for refractories, so clay refractory bricks will develop in the direction of customization. According to the specific needs of users, such as furnace type, temperature, medium and other conditions, custom-made production of suitable clay refractory bricks. Through close cooperation with users, personalized solutions are provided to improve the applicability and service life of clay refractory bricks.
Clay refractory brick, as a traditional refractory material, plays an important role in industrial production with its excellent performance and wide application. With the progress of science and technology and the development of industry, clay refractory bricks will be constantly innovated and improved to meet higher requirements and provide more reliable guarantee for industrial production.
