The manufacturing process of refractory bricks mainly includes the following key steps: raw material preparation, batching and mixing, molding, drying, sintering and subsequent treatment. The following is a detailed production process:

I. Preparation of raw materials

Selection of raw materials: The raw materials of refractory bricks mainly include kaolin, bauxite, quartz sand and expansive soil. These raw materials need to be crushed, screened and mixed to ensure their uniform particle size and meet the technological requirements.

Raw material treatment: raw materials need to be pretreated, such as removing impurities and adjusting particle size distribution, to ensure the quality of the final product.

II. Batching and mixing

Ingredients: according to the type and performance requirements of refractory bricks, various raw materials are mixed in a specific proportion. During the batching process, it is necessary to ensure that the chemical composition, particle size distribution and impurity content of raw materials meet the technological requirements.

Mixing: the ingredients are put into a mixer and fully mixed by mechanical stirring or wet stirring to form a plastic mud. In the process of mixing, a proper amount of water or other liquids should be added.

III. Molding

Forming method: Common forming methods include hydraulic forming, mechanical forming and manual forming. It is necessary to ensure the dimensional accuracy, shape regularity and density uniformity of the brick during the molding process.

Molding process: semi-dry pressing molding process is adopted, and the molding pressure is usually 40MPa.

IV. Drying

Drying method: Drying is the key step to remove moisture from the brick, so as to prevent deformation or cracking caused by evaporation of moisture in the subsequent sintering process. Drying methods include natural drying and artificial drying, and artificial drying usually adopts hot air circulation or microwave heating.

Drying time: The drying time is generally 36 hours.

V. Sintering

Sintering process: Sintering is the key process in the manufacture of refractory bricks, and the physical and chemical changes in the brick blank can reach the required fire resistance through high temperature heating. The parameters such as sintering temperature, time and atmosphere should be accurately controlled according to the type and performance requirements of refractory bricks.

Sintering temperature: The sintering temperature is usually between 1300℃ and 1600℃.

VI. Subsequent treatment

Cutting and grinding: The sintered firebrick may need to be cut and ground to adjust its size and shape.

Surface treatment: spraying can form a protective film on the surface of refractory bricks to improve their corrosion resistance.

Through the above technological process, refractory bricks with excellent fire resistance can be produced and widely used in high-temperature industrial fields such as metallurgy, chemical industry and building materials.