Refractory bricks are an indispensable material in high-temperature industries. Whether used in steel smelting furnaces, cement rotary kilns, glass kilns, or electric furnace linings, refractory bricks play a vital role in providing insulation, heat preservation, and corrosion resistance. However, in actual purchase, refractory brick size is often a key factor affecting construction efficiency and performance. This article will provide a detailed introduction to common refractory brick sizes, standard specifications, and selection guidelines to help you make informed choices and applications.

1. What are Refractory Bricks?

Refractory bricks, also known as refractory bricks or refractory blocks, are made from high-temperature-resistant inorganic non-metallic materials (such as high-alumina, clay, silica, and magnesia) fired at high temperatures. Their key characteristics include:

High temperature resistance (generally capable of withstanding temperatures exceeding 1580°C);

High mechanical strength;

Corrosion and thermal shock resistance;

Custom fabrication is possible based on the furnace structure.

II. Common Refractory Brick Sizes and Specifications

Refractory brick sizes are not fixed but are determined based on the intended use, furnace structure, and construction requirements. The following are common standard sizes for reference:

Type Common Dimensions (mm) Features and Applications
Standard Refractory Bricks: 230×114×65 Most commonly used, suitable for most industrial furnace walls
Thickened Bricks: 230×114×75 or 230×114×80 For high-temperature or thick-walled structures
Thin Bricks: 230×114×40 For lining repairs or refractory transition zones
Special-Shaped Bricks: Custom-made according to drawings For special locations such as vaults, corners, and furnace doors
Large Refractory Bricks: 300×150×100 and larger Mostly used in large blast furnaces or rotary kilns

In China, the commonly used standard is GB/T 2992.1-2017, "Dimensions of Refractory Products," which details the standard specifications and tolerances for refractory bricks.

III. Dimensional Characteristics of Refractory Bricks of Different Materials

Clay Refractory Bricks

Size: Mainly 230 × 114 × 65mm

Suitable for general industrial furnaces, flues, and other areas, economically priced.

High-Alumina Refractory Bricks

Size: 230 × 114 × 65mm or custom-made special shapes

Highly refractory, commonly used in high-temperature areas such as steel smelting furnaces and electric furnace roofs.

Silica Refractory Bricks

Size: 230 × 114 × 65mm

Suitable for use in acidic environments such as coke ovens and glass kilns.

Magnesia Refractory Bricks

Size: 300 × 150 × 100mm or custom-made

Strongly alkali-resistant, commonly used in cement rotary kilns and steelmaking converters.

Insulating Refractory Bricks (Lightweight Bricks)

Size: 230 × 114 × 65mm or 230 × 114 × 75mm

Mainly used for insulation of the outer layer of the furnace body, lightweight and excellent thermal insulation.

IV. Considerations for Selecting Refractory Brick Sizes

When determining refractory brick size, the following factors should be considered:

Furnace Design Structure: Different furnace types (e.g., round, square, and arched) require different brick size requirements.

Construction Technology: Standard-sized bricks are easy to construct, while special-shaped bricks require custom processing.

Temperature Gradient and Thermal Expansion: Bricks in high-temperature areas should be slightly thicker to resist thermal shock.

Masonry Joints and Refractory Mortar Thickness: Maintain a reasonable range of 1.5-2.5mm to ensure structural stability.

Economy and Maintainability: Standard-sized bricks are lower cost and easier to replace.

V. Customized Refractory Brick Sizes and Processing

With the diversification of modern industrial equipment, customized refractory brick sizes have become commonplace. Professional manufacturers can manufacture the following according to user drawings:

Special-shaped bricks (curved, wedge-shaped, arched, etc.);

Large-sized integrally cast blocks;

Bricks with special angles or bends.

Detailed specifications, including furnace structure diagrams, brick joint design, refractory temperature rating, and material requirements, must be provided during customization to ensure dimensional accuracy and longevity.

VI. Conclusion

In general, the size of refractory bricks not only affects furnace construction efficiency but also directly impacts furnace safety and energy efficiency. Standard sizes, such as 230×114×65mm, are the most widely used, while special-shaped and customized bricks for specialized needs can better meet the requirements of complex structures and high-temperature environments.

When purchasing, it is recommended to select a manufacturer with national standard production qualifications and to select a model based on actual operating conditions to maximize the performance and economic value of the refractory bricks.