Clay refractory bricks are a widely used refractory material. Their types and characteristics can be categorized based on composition, application, and shape. The following are the main categories and characteristics:

I. Classification by Composition and Performance

Common Clay Refractory Bricks
o The aluminum oxide (Al₂O₃) content is typically between 42% and 48%, with a refractoriness of 1580°C to 1750°C, making them suitable for general industrial furnaces.

o Weakly acidic, with strong resistance to acidic slag corrosion.

High-Alumina Clay Bricks
o By adjusting the formula to increase the Al₂O₃ content, they enhance high-temperature resistance and are suitable for higher temperature environments.

Thermal Shock Resistant Clay Bricks
o Optimized formula improves resistance to sudden temperature changes and are suitable for furnaces with frequent startups and shutdowns.

II. Classification by Shape and Application

Standard Bricks
o General-purpose, uniformly sized, widely used for furnace wall construction.

Knife Bricks (T-38 Bricks)

Other shaped bricks, commonly used in special areas such as blast furnaces and hot blast furnaces.

Half/Quarter Bricks

Other bricks, with the thickness reduced by half or a quarter, are used for local repairs or special structures.

III. Other Classifications

By Density: High-density bricks offer high strength but lower thermal shock resistance, while low-density bricks provide better insulation.

By Function: Bricks such as acid-resistant and thermal insulation bricks require selection based on specific working conditions.

Clay refractory bricks are known as the "evergreen" of refractory materials due to their low cost and wide adaptability. The specific selection depends on the temperature, chemical environment, and mechanical strength requirements.