What is high alumina brick

2024-06-14 09:00:36
High alumina brick is a refractory material made of bauxite or industrial alumina with high aluminum content as the main raw material and sintered at high temperature. Its main mineral components are corundum (Al₂O₃), mullite (3Al₂O₃·2SiO₂) and glass phase. High alumina bricks are widely used in high-temperature industrial kilns and thermal equipment due to their high refractory properties and resistance to chemical corrosion.

Classification of high alumina bricks
According to the different aluminum content, high alumina bricks can be divided into three levels:

First-level high alumina brick: Al₂O₃ content is greater than 75%.
Second-level high alumina brick: Al₂O₃ content is between 60-75%.
Third-level high alumina brick: Al₂O₃ content is between 48-60%.
Characteristics of high alumina bricks
High refractoriness: The refractoriness of high alumina bricks is generally between 1750-1790℃, and can withstand high temperature working environments.
Good thermal shock resistance: high alumina bricks have a small thermal expansion coefficient at high temperatures, excellent thermal shock resistance, and are not easy to crack under sudden temperature changes.
Excellent chemical corrosion resistance: high alumina bricks can resist the corrosion of acidic and alkaline slags and are suitable for industries such as metallurgy and chemical industry.
High strength and wear resistance: Due to the mineral composition and dense structure of high alumina bricks, they have high mechanical strength and wear resistance.
Production process of high alumina bricks
The production process of high alumina bricks mainly includes the following steps:

Raw material processing: Select high-quality bauxite or industrial alumina as the main raw material, and after crushing, screening, grinding and other treatments, make it reach the particle size required for production.
Batching and mixing: According to the composition requirements of different types of high alumina bricks, bauxite, clay, binder, etc. are mixed evenly in proportion.
Molding: The mixed material is molded by semi-dry method, plastic method or isostatic pressing method.
Drying: The molded bricks need to be dried to remove moisture and prevent cracks during firing.
Firing: High-temperature firing is carried out in a tunnel kiln or shuttle kiln. The firing temperature is generally between 1400-1600℃, so that the mineral components in the brick body react to form a stable crystalline structure.
Post-processing: The high-alumina bricks after firing need to be post-processed, such as cooling, testing, packaging, etc.
Application of high-alumina bricks
Due to their superior performance, high-alumina bricks are widely used in various high-temperature industrial equipment, mainly including the following aspects:

Steel industry: High-alumina bricks are widely used in refractory linings of blast furnaces, converters, electric furnaces, ladles, molten iron tanks, etc.
Non-ferrous metal industry: High-alumina bricks are used for linings of smelting furnaces and refining furnaces for metals such as aluminum, copper, and zinc.
Building materials industry: High-alumina bricks are also often used as lining materials in equipment such as cement rotary kilns and glass melting furnaces.
Chemical industry: High-alumina bricks are used for linings of various chemical reactors, decomposition furnaces and other high-temperature equipment.
Power industry: High-alumina bricks are also often used in boiler linings of thermal power plants.
Future development of high alumina bricks
With the continuous development of industrial technology, the performance requirements for high alumina bricks are getting higher and higher. The future research and development directions mainly include the following aspects:

Improve purity: Through more advanced purification processes, reduce impurity content, improve the refractory and corrosion resistance of high alumina bricks.
Optimize formula: By studying the ratio of different mineral components, develop high alumina bricks with better performance.
Improve process: Use more advanced molding and firing processes to improve the density and mechanical strength of high alumina bricks.
Develop new materials: Add appropriate amounts of zirconium oxide, chromium oxide and other materials to high alumina bricks to further improve their thermal shock resistance and wear resistance.
In short, high alumina bricks, as an important refractory material, play an important role in industrial production. With the continuous advancement of science and technology and the increase in industrial demand, the performance and application range of high alumina bricks will continue to expand and improve.
 Home  Whatsapp  Mail  Message