Views: 0 Author: Site Editor Publish Time: 2025-06-06 Origin: Site
In modern industrial production, high-temperature furnaces are indispensable key equipment in many industries, and refractory bricks, as the core material of furnace lining, undertake the important mission of resisting high temperature and preventing furnace body damage. This paper will deeply discuss the types, characteristics, applications, manufacturing and other aspects of refractory bricks, and reveal their indispensable and important position in the industrial field.
Refractory brick, also known as fire brick or firebrick block, is a kind of refractory product with regular shape. It is mainly made of clay, bauxite and other raw materials, combined with clay and other binders, through high-pressure molding and high-temperature sintering. According to their different compositions and uses, refractory bricks can be divided into many types, such as clay brick, high alumina brick, corundum brick and insulating brick. Among them, the alumina (ALO) content of clay brick is generally between 30% and 48%, the ALO content of high alumina brick is above 48%, and the ALO content of corundum brick is as high as 80%. These refractory bricks with different compositions have their own characteristics in terms of fire resistance and corrosion resistance, and are suitable for different industrial furnace environments.
Refractory bricks can work stably at high temperature, mainly due to a series of excellent characteristics:
The fire resistance of refractory bricks is usually between 1580℃ and 1850℃, and the fire resistance of some high-performance refractory bricks can even exceed 2000℃. This means that they can keep the structure stable in high temperature environment for a long time, and will not be melted or deformed due to high temperature, thus providing reliable guarantee for the high temperature process in the furnace.
In industrial furnaces, in addition to high temperature, refractory bricks will be corroded by chemicals. For example, in iron and steel smelting furnace, molten iron and slag will have a strong chemical attack on refractory bricks. Refractory bricks have good corrosion resistance to acid, alkali and salt, which can effectively resist the corrosion of these chemicals and prolong their service life.
During the operation of the furnace, the temperature changes frequently and violently, and the refractory bricks need to be able to withstand this rapid temperature change without cracking. Its good thermal shock resistance enables it to maintain integrity under the environment of rapid temperature change and reduce the damage caused by thermal stress.
In high temperature environment, refractory bricks also need to bear certain mechanical loads, such as the impact of burden and the vibration of furnace body. Refractory bricks have high cold compressive strength and high temperature strength, which can bear these mechanical loads and ensure the structural stability of the furnace.
Refractory bricks are widely used, covering almost all industrial fields that need high temperature treatment:
In iron and steel production, ironmaking blast furnace, steelmaking converter, ladle, tundish and other equipment are inseparable from the protection of refractory bricks. Refractory bricks can withstand the high temperature corrosion of molten iron and molten steel, prevent the furnace body from being damaged, reduce heat loss and improve production efficiency.
Refractory bricks also need to be used as lining for rotary kiln in cement production and melting furnace in glass production. Refractory bricks can withstand the high temperature erosion of cement clinker and glass melt, ensure the normal operation of furnaces and improve product quality.
In chemical production, many reactions need to be carried out in high-temperature furnaces, such as oil cracking furnaces and coal gasification furnaces. Refractory bricks can withstand the chemical erosion and high temperature of chemical raw materials, providing reliable equipment guarantee for chemical production.
In the field of energy, such as boilers in thermal power plants, garbage incinerators and other equipment also need to use refractory bricks. Refractory bricks can withstand the erosion of high temperature flame and the erosion of combustion products, and improve the thermal efficiency and service life of furnaces.
The production of refractory bricks is a complicated process, which mainly includes raw material preparation, molding, drying and firing.
The raw materials for producing refractory bricks mainly include clay, bauxite, corundum, etc. These raw materials need to be crushed, screened and mixed to achieve appropriate particle size and chemical composition distribution.
Molding is the process of making mixed raw materials into bricks with a certain shape and size. Common molding methods include press molding and extrusion molding. Press molding is to put the raw material powder into the mold and press it under high pressure; Extrusion molding is to make raw materials into mud strips and then extrude them through an extruder.
The formed brick blank needs to be dried to remove the moisture in it. It is necessary to control the temperature and humidity during the drying process to prevent the brick from cracking or deformation during the drying process.
The dried green bricks need to be fired in a high temperature furnace. The firing temperature is usually between 1300℃ and 1600℃, and the specific temperature depends on the composition and performance requirements of refractory bricks. During the firing process, the organic matter and water in the brick will completely volatilize, and sintering reaction will occur between raw material particles, forming a dense refractory brick structure.
With the continuous progress of industrial technology, the performance requirements of refractory bricks are getting higher and higher. The future development of refractory bricks will show the following trends:
In order to meet the needs of industrial furnaces with higher temperature, more complex chemical environment and more severe mechanical load, refractory bricks will develop in the direction of higher refractoriness, stronger corrosion resistance, better thermal shock resistance and higher mechanical strength. For example, new ceramic binders and high-temperature sintering technology are developed to improve the performance index of refractory bricks.
Under the background of energy shortage and increasingly strict environmental protection requirements, the production of refractory bricks will pay more attention to energy conservation and environmental protection. On the one hand, by optimizing production technology and equipment, energy consumption in the production process is reduced; On the other hand, we should develop new types of heat insulation refractory bricks to reduce the heat loss of furnaces and improve the energy utilization efficiency.
Different industrial furnaces have different structural and technological requirements, and also have different requirements for the shape, size and performance of refractory bricks. In the future, more attention will be paid to customized production of refractory bricks, and refractory brick products that meet the requirements of specific furnaces and kilns will be designed and manufactured according to the specific needs of users.
As the key material of industrial high-temperature furnaces, refractory bricks play an irreplaceable role in many industrial fields because of their excellent high-temperature tolerance, corrosion resistance, thermal shock resistance and mechanical strength. With the continuous development of industrial technology, the performance of refractory bricks will be continuously improved, the production process will be more energy-saving and environmentally friendly, and the products will be more diversified and customized. In the future, refractory bricks will continue to provide a solid guarantee for industrial production and help the sustainable development of industry.
