With clay clinker as orthopedic, refractory clay as a binder made of Al2O3 content of 30% ~ 48% refractory products. The pulverized bonded clay is mixed with the fine clinker, and then the granular clinker is prepared into semi-dry mud, which is formed under high pressure and fired at about 1400℃.
Clay bricks are weakly acidic refractory products that can resist the erosion of acidic slag and acidic gas.
1. High temperature resistance
2. Good wear resistance
3. Weakly acidic at high temperatures
4. Strong erosion resistance
5. Good volume stability
6. Low prices
Used for lining blast furnaces, hot blast furnaces, electric furnace roofs, oxygen converters, reverberatory furnaces, and rotary kilns. They are also widely used as regenerative flat furnace checker bricks, plugs for pouring systems, and water mouth bricks, among other applications.
|
Item |
Index |
||||||||
|
Model |
N-1 |
N-2a |
N-2b |
N-3a |
N-3b |
N-4 |
N-5 |
N-6 |
|
|
Refractory temperature（℃≥） |
1750 |
1730 |
1730 |
1710 |
1710 |
1690 |
1670 |
1580 |
|
|
Bulk densityg/cm3 |
2.1 |
-- |
-- |
-- |
-- |
2.0 |
-- |
2.0 |
|
|
Softening temperature under load[0.2MPa*0.6%]≥ |
1400 |
1350 |
-- |
1320 |
-- |
1300 |
-- |
-- |
|
|
Reburning line change rate（%） |
1400℃*2h |
+0.1-0.4 |
+0.1-0.5 |
+0.1-0.5 |
-- |
-- |
-- |
-- |
-- |
|
1400℃*2h |
-- |
-- |
-- |
+0.2-0.5 |
+0.2-0.5 |
+0.2-0.5 |
+0.2-0.5 |
-- |
|
|
Apparent porosity（%≤） |
22 |
26 |
24 |
24 |
26 |
24 |
26 |
28 |
|
|
Normal temperature compressive strength（MPa≥） |
30.0 |
20.0 |
25.0 |
20.0 |
15.0 |
20.0 |
15.0 |
15.0 |
|
Fire clay brick is a widely used refractory brick manufactured from fire clay, a naturally occurring alumino-silicate material with good refractoriness and thermal stability. It is designed to withstand medium to high temperatures, making it suitable for a broad range of industrial furnace and kiln applications.
Compared with high-alumina or specialty refractory bricks, fire clay bricks offer a balanced combination of performance, durability, and cost-efficiency, which is why they remain one of the most commonly used refractory products in industries such as cement, steel, ceramics, petrochemicals, and boilers.
Fire clay bricks are typically used in working linings, backup linings, furnace walls, air ducts, preheaters, and structural refractory zones where extreme temperatures are not the dominant factor but long-term stability and reliability are essential.
The performance of fire clay bricks is determined by their chemical composition, physical structure, and manufacturing process. The most important properties include:
Fire clay bricks generally operate effectively in temperature ranges up to 1400–1500°C, depending on alumina content and formulation. This makes them suitable for many medium-temperature furnace zones and auxiliary refractory linings.
These bricks provide adequate cold crushing strength and load-bearing capacity, allowing them to support structural loads in furnace walls and backup lining systems without deformation.
Fire clay bricks show stable volume behavior under continuous operation and moderate resistance to thermal shock, especially when used in areas with controlled heating and cooling cycles.
They exhibit good resistance to neutral and mildly acidic environments, making them suitable for cement kilns, ceramic kilns, and industrial boilers.
Fire clay bricks are used across many industrial sectors due to their versatility and economic advantages.
In cement plants, fire clay bricks are commonly applied in preheater towers, tertiary air ducts, kiln shell backup linings, and transition zones. These areas require stable thermal insulation and structural integrity rather than extreme refractoriness.
Fire clay bricks are widely used in reheating furnaces, soaking pits, ladle backup linings, and auxiliary furnace zones, where moderate temperatures and long service life are required.
They are often applied in kiln walls, roofs, and flue systems, providing stable support and insulation for ceramic firing processes.
Fire clay bricks are used in boiler linings, waste incinerators, and hot gas ducts, where resistance to thermal cycling and gas erosion is essential.
Selecting the correct fire clay brick is essential for achieving long service life and stable furnace operation.
Different alumina levels correspond to different refractoriness and strength characteristics. Higher alumina fire clay bricks are suitable for higher temperature zones, while standard grades are ideal for backup and structural applications.
Working lining: Requires better thermal stability and abrasion resistance
Backup lining: Focuses on insulation and structural support
Air ducts and flues: Require resistance to gas flow and thermal cycling
Fire clay bricks are not ideal for extreme high-temperature zones, severe chemical corrosion environments, or areas with intense slag attack, where high-alumina, silica, or special refractories may be more appropriate.
Understanding the differences between fire clay bricks and high-alumina bricks helps optimize refractory cost and performance.
Fire Clay Brick:
Lower cost
Suitable for medium-temperature zones
Widely used for backup linings and structural areas
High Alumina Brick:
Higher refractoriness
Better slag and corrosion resistance
Used in high-temperature and severe working zones
In many furnace designs, fire clay bricks and high-alumina bricks are used together, with fire clay bricks providing cost-effective support in non-critical zones.
The quality of fire clay bricks depends heavily on controlled manufacturing processes.
High-quality fire clay with controlled chemical composition is selected to ensure consistent refractoriness and thermal performance.
Raw materials are crushed, graded, and mixed according to precise formulations to achieve uniform particle distribution.
Bricks are shaped using high-pressure presses to ensure accurate dimensions and consistent density.
Bricks are dried and fired in high-temperature kilns under controlled conditions to achieve optimal strength, volume stability, and durability.
The service life of fire clay bricks varies depending on application and operating conditions.
Under normal operating conditions, fire clay bricks can last several years in cement kilns, boilers, and industrial furnaces when properly selected and installed.
Operating temperature
Thermal shock frequency
Chemical exposure
Installation quality
Furnace design and maintenance practices
Correct selection and proper installation significantly extend service life and reduce maintenance costs.
Fire clay bricks supplied by Highland Refractory are packed using export-grade packaging, including wooden pallets and protective wrapping to prevent damage during transportation.
With extensive experience supplying refractory products to Europe, Southeast Asia, the Middle East, and the Americas, we ensure reliable delivery schedules and safe transportation for international projects.
What temperature can fire clay bricks withstand?
Fire clay bricks typically withstand temperatures up to 1400–1500°C, depending on grade.
How long do fire clay bricks last?
Service life depends on application conditions but can reach several years under stable operating environments.
Are fire clay bricks cost-effective?
Yes, they offer excellent cost-performance balance for medium-temperature applications.
Can fire clay bricks be used with castables or ceramic fiber?
Yes, they are often combined with castables and fiber materials in layered refractory designs.
Founded in 1990, Highland Refractory is a professional manufacturer of refractory bricks and monolithic refractories, serving global industrial customers with customized solutions, strict quality control, and reliable delivery.
If you are looking for fire clay bricks for cement kilns, steel furnaces, boilers, or industrial kilns, our technical team is ready to assist you with product selection and project support.
📩 Contact us today to receive technical recommendations and competitive quotations.
Fire clay bricks can typically withstand continuous operating temperatures between 1500°C and 1750°C, depending on alumina content and manufacturing quality. They are suitable for many industrial furnaces operating at moderate to high temperatures.
No. Fire clay bricks contain lower alumina content than high alumina bricks. While both belong to the alumino-silicate family, high alumina bricks offer higher refractoriness and better performance in more demanding thermal environments.
Yes. Fire clay bricks are commonly used in cement kilns, especially in transition zones and areas where temperatures and chemical attack are moderate. They provide a cost-effective solution for non-critical kiln sections.
Fire clay bricks offer good thermal shock resistance for many industrial applications. They can tolerate reasonable temperature fluctuations, although extreme thermal cycling may require higher-grade refractories.
Fire clay bricks can be used in auxiliary and non-slag contact zones of steel furnaces. For areas exposed to basic slag, magnesia or high alumina bricks are generally more suitable.
Fire clay bricks perform well in neutral and mildly acidic environments. They are not recommended for direct contact with highly basic slags or aggressive chemical melts.
Service life depends on operating conditions, installation quality, and maintenance. In stable environments, fire clay bricks can provide long and reliable service.
Fire clay bricks offer higher mechanical strength and durability than insulating bricks but lower insulation efficiency. They are often used together in layered furnace designs.
Fire clay bricks are relatively stable in humid environments and less sensitive to moisture compared with magnesia bricks, making storage and handling easier.
Fire clay bricks are widely used in cement, steel, glass, ceramics, petrochemical processing, and power generation industries.
Fire clay bricks are installed using compatible refractory mortars with controlled joint thickness and expansion allowances to accommodate thermal movement.
Their balanced performance, availability, cost-effectiveness, and proven reliability make fire clay bricks a continued choice for many industrial furnace applications.
Mullite lightweight insulation brick is a high-quality insulation material.
Low creep clay bricks have a low creep rate in high temperature environments and can maintain good shape and dimensional stability for a long time.
Silicon carbide plates are mainly composed of silicon carbide (SiC) as the aggregate (with a content usually ≥ 80%).
High alumina fine powder is a powder material with alumina (Al2O3) as the main component.
Clay powder is a powdery material with clay minerals as the main component.
Refractory cement, also known as aluminate cement, is a fire-resistant hydraulic cementitious material.
