Fire clay bricks are one of the most essential refractory materials in high-temperature industrial applications. Made from clay rich in alumina (Al₂O₃) and silica (SiO₂), fire clay bricks undergo a strict process of batching, molding, drying, and high-temperature firing. These steps ensure that the bricks have superior heat resistance, chemical stability, and long service life.
At Highland Refractory, we specialize in producing high-quality fire clay bricks and superior clay firebricks, suitable for steel, cement, glass, ceramic, and other industrial furnaces. Whether you are building a new kiln, maintaining a blast furnace, or constructing glass melting equipment, our fire clay bricks provide reliable, cost-effective, and high-performance solutions.
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 bricks are among the most widely used refractory products in industrial furnaces, kilns, and thermal equipment. Known for their balanced performance, excellent thermal stability, and cost-effectiveness, fire clay bricks remain a preferred lining material for many high-temperature applications ranging from iron and steel production to glass manufacturing, cement kilns, and coke ovens.
If you are searching for fire clay bricks for sale, you are likely not just comparing prices—you are evaluating performance reliability, service life, suitability for your furnace conditions, and long-term operating cost.
This page is designed to help engineers, furnace designers, and procurement managers make correct and confident purchasing decisions. It provides:
A clear technical explanation of what fire clay bricks are
Detailed specifications and performance parameters
Grade-based selection guidance for different furnace conditions
Industrial applications with real operating logic
A practical buying guide for industrial refractory clay bricks
Whether you need standard fire clay bricks or customized refractory solutions, this guide will help you choose the right product for your application, not just the lowest-priced option.
Fire clay bricks are aluminosilicate refractory bricks primarily composed of fire clay, a natural refractory raw material containing alumina (Al₂O₃) and silica (SiO₂).
Typical fire clay bricks contain:
Al₂O₃ content: 30%–45%
SiO₂ content: 50%–65%
These bricks are shaped under high pressure and fired at elevated temperatures to achieve the required refractoriness, mechanical strength, and thermal stability.
Fire clay bricks are classified as acidic or weakly acidic refractories, making them especially suitable for environments dominated by acidic slags and gases.
Fire clay bricks are valued for their balanced physical and chemical performance, which makes them suitable for a wide range of furnace applications.
Typical refractoriness: 1580°C – 1750°C
Suitable for medium- to high-temperature furnace zones
RUL typically ranges from 1250°C to 1450°C
Indicates resistance to deformation under mechanical load at high temperatures
Good resistance to temperature fluctuation
Stable crystal structure during long-term service
High cold crushing strength (CCS)
Excellent resistance to mechanical wear and abrasion
Strong resistance to acidic slags and gases
Limited resistance to basic slags (lime-rich environments)
Below is a typical specification table for industrial fire clay bricks. Actual values may vary depending on grade and customization.
| Parameter | Unit | Typical Value |
|---|---|---|
| Al₂O₃ Content | % | 30–45 |
| Bulk Density | g/cm³ | 2.0–2.3 |
| Apparent Porosity | % | ≤26 |
| Cold Crushing Strength | MPa | ≥20 |
| Refractoriness | °C | ≥1580 |
| RUL (0.2 MPa) | °C | ≥1300 |
| Permanent Linear Change | % | ±0.5 |
Not all fire clay bricks perform the same. Selecting the correct grade is critical for achieving optimal furnace performance and service life.
| Grade | Al₂O₃ (%) | Bulk Density | RUL (°C) | Best Application |
|---|---|---|---|---|
| FC-30 | ≥30 | 2.0–2.1 | ≥1250 | Light-duty furnaces |
| FC-35 | ≥35 | 2.1–2.2 | ≥1300 | Glass kilns, coke ovens |
| FC-40 | ≥40 | 2.2–2.3 | ≥1350 | Hot blast stoves |
| FC-42 | ≥42 | 2.25–2.35 | ≥1400 | High-load furnace zones |
If your furnace operates below 1300°C with moderate mechanical load →
FC-30 or FC-35 is typically sufficient.
If your furnace experiences frequent temperature fluctuation or moderate slag attack →
FC-40 offers improved thermal and mechanical stability.
If your furnace wall or dome carries structural load →
Choose FC-42 with higher RUL and lower porosity.
Fire clay bricks are widely used across multiple industries due to their versatility and cost-performance balance.
Hot blast stoves
Reheating furnaces
Ladle backup linings
Coke oven walls
Fire clay bricks perform well in acidic and neutral atmospheres commonly found in these applications.
Regenerator chambers
Glass melting furnace sidewalls
Crown backup linings
Their low iron content and stable structure make them suitable for glass-related applications.
Cement kiln transition zones
Preheater and cooler linings
Lime shaft kilns
Fire clay bricks serve as reliable backup refractories in high-temperature zones.
Tunnel kilns
Roller hearth kilns
Kiln furniture support structures
Coke ovens
Carbon roasters
Waste incinerators
Understanding how fire clay bricks compare to alternatives helps avoid costly selection mistakes.
| Property | Fire Clay Brick | High Alumina Brick | Silica Brick |
|---|---|---|---|
| Al₂O₃ Content | 30–45% | ≥48% | <2% |
| Max Temp | Medium–High | High | Very High |
| Thermal Shock | Good | Moderate | Poor |
| Acid Slag Resistance | Good | Moderate | Excellent |
| Cost | Low–Medium | Medium–High | Medium |
Key takeaway:
Fire clay bricks provide the best cost-to-performance ratio for many medium- and high-temperature industrial furnaces.
High-quality fire clay bricks depend on strict manufacturing control.
High-purity fire clay
Controlled alumina and silica ratio
Low alkali and iron impurities
High-pressure pressing
Controlled firing temperature curve
Uniform sintering for strength and density
Chemical composition analysis
Physical property testing
Dimensional accuracy inspection
In addition to standard rectangular bricks, fire clay bricks can be manufactured in custom shapes, including:
Wedge bricks
Arch bricks
Curved bricks
Special-shaped blocks
Custom shaping reduces mortar joints and improves lining stability.
Export-grade wooden pallets
Moisture-proof packaging
Bulk container or break-bulk shipment
Stable lead times for large projects
Reliable logistics ensure on-time delivery for furnace shutdown schedules.
Yes, fire clay bricks are commonly used as backup linings in steel furnaces and hot blast stoves.
Fire clay bricks are not recommended for strongly basic slag environments.
Service life depends on temperature, load, and slag conditions, but typically ranges from 2–5 years.
Yes, sizes, shapes, and grades can be customized to match furnace design.
Choosing the right fire clay bricks is not just about price. It’s about:
Matching material chemistry to furnace atmosphere
Selecting the correct grade for load and temperature
Ensuring stable long-term operation
Reducing downtime and maintenance cost
High-quality fire clay bricks offer predictable performance, easy installation, and reliable supply, making them a practical choice for industrial users worldwide.
Fire clay bricks remain a cornerstone of industrial refractory linings due to their balanced thermal performance, mechanical strength, and cost efficiency. When correctly selected and properly installed, they provide long-lasting service across a wide range of industrial furnaces and kilns.
If you are looking for fire clay bricks for sale, prioritize not only price but also technical suitability, quality consistency, and supplier reliability. A well-selected fire clay brick solution will protect your furnace, stabilize your process, and reduce overall operating costs.
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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.
