Requirements for refractory fire bricks for different kiln types

Refractory fire bricks serve as a “protective barrier” for industrial kilns, directly impacting their service life, operational efficiency, and production safety.

Different kiln types exhibit significant differences in their working environment, temperature profiles, and media characteristics, leading to varying requirements for the material, structure, and performance of refractory fire bricks. The following analysis, focusing on mainstream kiln types, breaks down their core requirements.

High-Temperature Industrial Kilns: Temperature Resistance and Thermal Shock Resistance are Key

1. Cement Rotary Kiln

Operating temperatures are consistently maintained at 1400-1600℃, with intense material erosion and severe alkali metal corrosion. Fire bricks must possess high refractoriness (≥1750℃), excellent abrasion resistance, and resistance to the penetration and corrosion of alkali compounds.

Magnesium-chrome bricks and high-alumina bricks are the mainstream choices, with special fire bricks requiring even stronger corrosion resistance in critical areas.

2. Glass Kiln

Melting temperatures reach 1500-1650℃, with continuous erosion from the flowing molten glass and the presence of corrosive media such as sulfates and fluorides. The core requirements are good high-temperature stability and strong resistance to molten glass erosion. Simultaneously, good volumetric stability is necessary to prevent brick deformation from affecting glass quality.

Electrominated zirconia-corundum bricks and α-β alumina bricks, due to their outstanding erosion resistance, have become the preferred choice for key parts of glass kilns.

Metallurgical Furnaces: Meeting Both Erosion Resistance and Strength Standards

1. Blast Furnace

The furnace body experiences significant temperature differences (500-1500℃) across different areas. The hearth and bottom are subjected to high-temperature erosion and static pressure from molten iron and slag. High-temperature strength, strong resistance to molten iron penetration, and moderate thermal conductivity are required for the refractory fire bricks.

Carbon bricks and silicon carbide bricks, with their excellent erosion resistance and structural stability, are widely used in key parts of blast furnaces.

2. Converter

A core piece of steelmaking equipment, the furnace temperature reaches 1600-1700℃, facing severe scouring and oxidative corrosion from molten steel and slag, and experiencing frequent temperature fluctuations during the smelting process. Fire bricks must possess extremely strong resistance to slag erosion, good thermal shock resistance, and high-temperature wear resistance, while also being resistant to spalling to prevent brick detachment from affecting smelting safety.

Magnesium-carbon bricks and magnesia-dolomite bricks are the core choices for converter bricks due to their high-temperature resistance and corrosion resistance.

Chemical and Building Materials Kilns: Corrosion Resistance is the Core Requirement

1. Chemical Reaction Kilns

These kilns often handle acidic and alkaline media, operating in complex environments with large temperature fluctuations (800-1400℃). The core requirement for fire bricks is strong chemical corrosion resistance, able to withstand the erosion of acid and alkali media, while also possessing a certain degree of thermal shock resistance and mechanical strength.

Silicon carbide bricks and acid-resistant bricks are suitable for this type of kiln due to their good chemical stability.

2. Ceramic Kilns

Firing temperatures are between 1200-1400℃, with a predominantly oxidizing atmosphere. This requires fire bricks with good volume stability, uniform thermal conductivity, and no contamination of the ceramic body.

High-alumina bricks and silica bricks, due to their pure material and stable high-temperature performance, are ideal choices for ceramic kilns.

Choosing the right refractory bricks ensures efficient kiln operation.

The operating characteristics of different kiln types determine the selection of refractory fire bricks. Choosing the right refractory bricks can significantly reduce kiln maintenance costs and improve production efficiency.

We have been deeply involved in the refractory materials field for many years and can provide customized fire brick selection solutions and high-quality products based on your kiln parameters and operating conditions, providing comprehensive support from material research and development to on-site installation.

If you are struggling with fire brick selection for your kiln or need to optimize your existing fire brick usage, please feel free to contact us. Let’s work together to create a safe, efficient, and long-lasting kiln operating environment!