Refractory bricks are inorganic, non-metallic materials that can withstand long-term use at high temperatures without melting or deforming. They are widely used in high-temperature industrial furnaces in metallurgy, building materials, power generation, chemicals, cement, ceramics, and other industries. Refractory bricks can be divided into various types based on their raw material composition, manufacturing process, and operating environment. This article will provide a detailed introduction to the main types of refractory bricks and their performance characteristics to help you make a more targeted purchase.

1. Refractory Brick Types by Chemical Composition

Acidic Refractory Bricks
Acidic Refractory Bricks, such as silica bricks and clay bricks, are primarily composed of silicon dioxide (SiO₂).

Silica bricks: Containing over 93% SiO₂, they have a refractoriness of up to 1700°C and are suitable for high-temperature hot blast furnaces, coke ovens, glass kilns, and other applications.

Clay bricks: Made from high-alumina clay, they contain approximately 30% to 48% Al₂O₃ and offer excellent thermal shock resistance. They are commonly used in heating furnaces, rotary kiln linings, and other areas.

Neutral refractory bricks: Made primarily of alumina, chromium oxide, and carbon oxide, they do not react with acidic or alkaline slags and have strong adaptability.

High-alumina bricks: Containing over 48% Al₂O₃, they have a refractoriness exceeding 1770°C and are widely used in steelmaking furnaces and glass melting furnaces.

Chrome bricks and chrome-magnesia bricks: Offer strong corrosion resistance and are commonly used in cement rotary kilns and non-ferrous metal smelting furnaces.

Basic refractory bricks: Made primarily of magnesium oxide (MgO) and calcium oxide (CaO), such as magnesia bricks, magnesia-chrome bricks, and dolomite bricks.

They resist corrosion from alkaline slag and are commonly used in high-temperature areas such as converters, electric furnaces, and steelmaking furnaces.

II. Refractory Brick Types by Manufacturing Process

Sintered Refractory Bricks
These are the most common type, characterized by high strength and wear resistance, resulting from high-temperature sintering to form a dense structure.

Unfired Refractory Bricks
Use chemical binders (such as phosphates and resins) to harden at room temperature without high-temperature sintering.
This type is easy to install and is often used for temporary or medium-temperature furnace linings.

Electro-Fused Bricks
Use electric arc melting and casting to form a dense structure and high corrosion resistance.
They are commonly used in areas subject to high-temperature corrosion, such as glass kilns and carbon black furnaces.

III. Refractory Brick Types by Application

General-Purpose Refractory Bricks
Such as clay bricks and high-alumina bricks, can be used for linings and insulation in a variety of industrial furnaces.

Specialized Refractory Bricks

Customized for different equipment and environments, such as:

Magnesia-carbon bricks for converters: Excellent slag resistance and long lifespan;

Fused zirconium-corundum bricks for glass kilns: Excellent resistance to slag erosion;

Magnesia-iron spinel bricks for cement rotary kilns: Excellent thermal shock resistance and resistance to spalling.

Insulating Refractory Bricks

Mainly made of lightweight materials with low thermal conductivity, they are used for insulation layers, achieving significant energy savings.

IV. Key Points for Selecting Refractory Bricks

When selecting refractory bricks, consider the following factors:

Operating Temperature and Furnace Type: Different kilns have different temperature ranges, so bricks with corresponding refractoriness grades should be selected.

Chemical Environment: The acidity and alkalinity of the slag directly affect the lifespan of the refractory bricks.

Thermal Shock Stability: Equipment with frequent heating and cooling requires materials with excellent thermal shock resistance.

Cost-Effectiveness: While ensuring performance, reasonably control costs and select the appropriate manufacturer and model.

5. Refractory Brick Manufacturers and Pricing

Currently, the price of refractory bricks on the market depends primarily on the material and specifications. Generally, clay bricks range from 600 to 900 yuan per ton, high-alumina bricks from 1,500 to 3,000 yuan per ton, and fused zirconium-corundum bricks can cost over 10,000 yuan per ton.

When purchasing, it is recommended that users prioritize refractory brick manufacturers with ISO certification and comprehensive test reports. This not only ensures quality but also provides professional selection and technical support.

Conclusion

Refractory bricks are an essential material for high-temperature industries. With the continuous advancement of industrial technology, the variety and performance of refractory bricks are also continuously improving. Whether it's a metallurgical furnace, a glass kiln, or a cement rotary kiln, choosing the right refractory brick type can effectively extend equipment life, improve production efficiency, and reduce energy consumption.