How to solve the corrosion problem of refractory fire bricks

In high-temperature environments such as industrial kilns, metallurgical furnaces, and boilers, refractory bricks are core materials ensuring stable equipment operation. Their corrosion resistance directly determines the service life of the kiln and production safety. However, factors such as chemical erosion, physical scouring, and thermal shock under high-temperature environments often lead to corrosion problems in refractory fire bricks. Such as peeling, cracking, and pulverization. This not only increases maintenance costs but may also cause production interruptions.

This article will analyze the root causes of corrosion, provide targeted solutions.That further introduce the corrosion resistance characteristics of various refractory brick materials to help companies respond accurately.

The Core Causes of Refractory Brick Corrosion: Identifying the Root Cause is Prerequisite

Refractory fire brick corrosion is the result of multiple factors acting together: Chemical erosion is the primary cause. At high temperatures, molten metal, slag, and acidic/alkaline flue gases (such as SO₂ and Cl₂) in the kiln react with the brick body, generating low-melting-point compounds, leading to a porous structure.

High-speed flowing furnace gases and materials cause physical erosion of the brick body, damaging the surface protection; thermal shock damage caused by sudden temperature rises and falls creates microcracks, allowing corrosive media to penetrate.

Furthermore, improper selection of refractory bricks, excessively large brick joints during construction, and inadequate curing can also exacerbate the corrosion risk.

Five Practical Solutions for Refractory Brick Corrosion, Providing Comprehensive Protection

1. Precise Material Selection to Meet Operating Conditions

Select materials based on the type of corrosive medium: For scenarios with severe molten metal and slag corrosion, prioritize corundum refractory fire bricks (Al₂O₃ content ≥90%). For acidic flue gas conditions, recommend silica or mullite refractory bricks; for alkaline slag environments, magnesia or magnesia-alumina spinel refractory bricks are suitable, enhancing corrosion resistance from the source.

2. Optimize Brick Structure and Construction Quality

Use high-density, low-porosity refractory fire bricks (porosity ≤18%) to reduce medium penetration; control brick joints to ≤2mm during construction, using highly corrosion-resistant mortar to prevent brick joints from becoming corrosion entry points; strictly adhere to furnace curing specifications to avoid thermal shock damage.

3. Control the operating environment and reduce corrosion causes

Optimize the combustion process to reduce harmful gas emissions; regularly clean slag and ash to prevent prolonged adhesion of molten material; rationally control the furnace temperature to prevent overheating and subsequent degradation of brick performance.

4. Regular inspection and localized repair

Use infrared thermography, ultrasonic testing, and other technologies to inspect for corrosion. When problems such as spalling and cracks are found, promptly repair or replace damaged bricks with refractory castable to prevent the spread of corrosion.

5. Provide auxiliary protective measures

Add protective linings or flow guiding devices to key areas such as the furnace opening and flue to reduce erosion; install insulation layers to reduce temperature fluctuations and mitigate thermal shock damage.

Other High-Quality Refractory Bricks, Each with Its Own Corrosion Resistance Advantages

Besides traditional refractory bricks, specialty bricks offer superior performance under specific working conditions: silicon nitride-bonded silicon carbide bricks are resistant to high temperatures and erosion, suitable for highly corrosive environments such as waste incinerators, with a lifespan 3-5 times longer than ordinary bricks;

Zircon refractory fire bricks resist molten metal and acidic slag erosion, making them suitable for glass kilns; corundum-mullite composite bricks offer balanced acid and alkali resistance, suitable for multi-medium environments such as boilers and hot blast stoves.

Refractory brick corrosion directly impacts production efficiency and safety; indiscriminate repairs only increase costs. We have years of experience in the research and application of high-temperature refractory materials. Providing a full-process service from material selection and customized production to construction and maintenance, adapting to various working conditions.

If your equipment is facing corrosion problems or needs optimization of refractory fire material solutions, please feel free to contact us! Our professional technical team will provide you with free working condition analysis and customized solutions, making high-temperature operations safer and more efficient!