Fused Zirconium Corundum Brick, also known as fused cast zirconia–corundum refractory brick, is a premium refractory material specifically engineered for glass melting furnaces and other high-temperature, high-corrosion industrial environments.
Manufactured through an electric arc melting process, this brick combines zirconia (ZrO₂) and alumina (Al₂O₃) in a dense, fully fused microstructure. Compared with sintered refractories, fused zirconium corundum bricks exhibit exceptional resistance to molten glass corrosion, alkali vapor attack, and thermal shock, making them a critical lining material in modern glass production.
（1）Exceptional corrosion resistance against molten glass, slags, and chemical media
（2）High ZrO₂ content (33-41%) for superior high-temperature stability (up to 1800℃ continuous service)
（3）Dense fused cast structure with low porosity (≤3%) and high bulk density (3.6-3.8 g/cm³)
（4）Strong wear resistance to prolong service life in high-traffic industrial applications
（5）Non-toxic and environmentally friendly, compliant with global refractory safety standards
（1）Glass furnace pool walls, feeder channels, and spout linings
（2）Chemical melting reactor linings and molten salt crucible linings
（3）Metallurgical ladle linings and secondary refining furnace components
（4）Special high-temperature furnace linings (ceramic sintering, electronic component annealing)
（5）Tin bath linings for float glass production lines
（6）Corrosion-resistant linings for acid-alkali high-temperature pipelines and valves
| Item | Fused Zirconium Corundum Brick | AZS33 | AZS36 | AZS41 |
| Chemical Composition (%) | Al₂O₃ | ≥50.00 | ≥49.00 | ≥45.00 |
| ZrO₂ | ≥32.50 | ≥35.50 | ≥40.50 | |
| SiO₂ | ≤15.00 | ≤13.50 | ≤12.50 | |
| Na₂O + K₂O | ≤1.30 | ≤1.35 | ≤1.30 | |
| Volume Density (g/cm³) | ≥3.75 | ≥3.85 | ≥4.00 | |
| Apparent Porosity (%) | ≤1.2 | ≤1.0 | ≤1.2 | |
| Cold Crushing Strength (MPa) | ≥200 | ≥200 | ≥200 | |
| Exudation Temperature of Glass Phase (°C) | ≥1400 | ≥1400 | ≥1410 | |
| Bubble Separation Ratio (1300°C × 10h) | (%) | ≤1.2 | ≤1.0 | ≤1.0 |
| Anti-corrosion Rate of Glass Liquid (1500°C × 36h) | (mm/24h) | ≤1.4 | ≤1.3 | ≤1.2 |
| Bulk Density (g/cm³) | Ordinary Casting PT (RN / RC / N) | ≥3.55 | ≥3.55 | ≥3.70 |
| No Shrinking Casting ZWS (RR / EVF / EC / ENC) | ≥3.65 | ≥3.75 | ≥3.85 | |
| Tilt Casting QX (RO) | ≥3.65 | ≥3.75 | ≥3.90 | |
| No Shrinkage Casting WS (RT / VF / EPIC / FVP / DCL) | ≥3.75 | ≥3.80 | ≥3.95 |
Fused Zirconium Corundum Brick, also known as fused cast zirconia–corundum refractory brick, is a premium refractory material specifically engineered for glass melting furnaces and other high-temperature, high-corrosion industrial environments.
Manufactured through an electric arc melting process, this brick combines zirconia (ZrO₂) and alumina (Al₂O₃) in a dense, fully fused microstructure. Compared with sintered refractories, fused zirconium corundum bricks exhibit exceptional resistance to molten glass corrosion, alkali vapor attack, and thermal shock, making them a critical lining material in modern glass production.
This product is widely applied in float glass furnaces, container glass furnaces, forehearths, feeder channels, tank bottoms, and critical transition zones, where long campaign life and stable glass quality are essential.
Fused zirconium corundum brick is a cast refractory produced by melting carefully proportioned raw materials—high-purity alumina, zircon sand, and selected additives—at temperatures above 2000°C in an electric arc furnace.
After complete melting and homogenization, the molten material is cast into molds and slowly cooled, forming a dense, crystalline structure with extremely low porosity.
Fully fused, non-sintered microstructure
Interlocking zirconia and corundum phases
Minimal open porosity
High glass-phase stability
Excellent chemical inertness
This structure is fundamentally different from conventional fired or sintered refractories and is the reason why fused zirconium corundum bricks deliver significantly longer service life in glass-contact zones.
Fused zirconium corundum bricks are available in different grades based on zirconia content, allowing precise material selection according to furnace zone severity.
| Grade | ZrO₂ | Al₂O₃ | SiO₂ | Others |
| ZC33 / AZS33 | ≥33 | Balance | ≤15 | Trace |
| ZC36 / AZS36 | ≥36 | Balance | ≤13 | Trace |
| ZC41 / AZS41 | ≥41 | Balance | ≤12 | Trace |
Higher zirconia content provides stronger corrosion resistance, while lower grades offer cost-effective solutions for moderate environments.
Compared with conventional refractory bricks, fused zirconium corundum bricks exhibit superior physical performance under extreme operating conditions.
Bulk Density: ≥3.4 g/cm³
Apparent Porosity: ≤1.0%
Cold Crushing Strength: ≥350 MPa
Refractoriness: >1790°C
Thermal Shock Resistance: Excellent
Glass Corrosion Resistance: Outstanding
Low porosity and high density significantly reduce molten glass penetration and chemical erosion.
Molten glass aggressively attacks refractory linings, dissolving components and contaminating the melt. The high zirconia phase in fused zirconium corundum bricks forms a chemical barrier, dramatically slowing corrosion rates.
This makes the brick especially suitable for:
Tank bottoms
Sidewalls in contact with glass melt
Throat and doghouse areas
The fully fused microstructure contains almost no open pores, preventing molten glass from penetrating into the brick body. This reduces:
Structural weakening
Glass contamination
Risk of blistering and spalling
Glass furnaces experience frequent temperature fluctuations during start-up, shutdown, and production adjustments. Fused zirconium corundum bricks maintain structural integrity under thermal cycling, reducing cracking and premature failure.
Thanks to their resistance to corrosion, erosion, and thermal stress, fused zirconium corundum bricks often extend furnace service life by 2–3 times compared with traditional high-alumina refractories.
The tank bottom endures constant exposure to molten glass and static pressure. High-zirconia fused bricks (ZC41 / AZS41) are preferred to maximize corrosion resistance and structural stability.
Sidewalls experience combined chemical corrosion and thermal gradients. ZC36 or ZC41 grades are commonly used depending on glass composition and operating temperature.
These zones suffer from high glass flow velocity and chemical attack. Fused zirconium corundum bricks minimize erosion and extend maintenance intervals.
In these areas, stable glass temperature and purity are critical. ZC33 or ZC36 grades provide a balanced solution between performance and cost.
| Aspect | Zirconium Corundum | High Alumina Brick |
| Corrosion Resistance | Excellent | Moderate |
| Porosity | Very Low | Higher |
| Furnace Life | Long | Shorter |
| Glass Quality Impact | Minimal | Higher contamination risk |
Fire clay bricks are unsuitable for direct glass contact due to low refractoriness and poor corrosion resistance.
Magnesia bricks offer high refractoriness but are chemically incompatible with many glass compositions and can cause severe contamination.
| Furnace Zone | Recommended Grade |
| Tank Bottom | ZC41 / AZS41 |
| Sidewall (High Corrosion) | ZC36–ZC41 |
| Sidewall (Moderate) | ZC36 |
| Forehearth / Feeder | ZC33–ZC36 |
| Regenerator Checker | Based on alkali level |
Proper grade selection avoids over-specification and reduces total refractory cost.
Our fused zirconium corundum bricks are produced under strict quality control systems:
High-purity raw material selection
Electric arc melting with precise temperature control
Controlled casting and annealing
Dimensional machining for tight tolerances
Batch chemical and physical testing
Each batch undergoes inspection to ensure consistent performance in demanding industrial conditions.
Correct installation is essential to maximize refractory performance. We provide:
Installation drawings and layout optimization
Expansion joint and mortar recommendations
On-site technical guidance (if required)
Furnace zone material optimization support
Although fused zirconium corundum bricks have a higher initial cost than conventional refractories, their total lifecycle cost is significantly lower due to:
Extended furnace campaigns
Reduced maintenance downtime
Lower replacement frequency
Improved glass yield and quality
In many cases, the cost difference is recovered within one extended production cycle.
Q1: Is fused zirconium corundum brick the same as AZS brick?
A: Yes. Zirconium corundum brick is commonly referred to as fused cast AZS brick, classified by zirconia content (AZS33, AZS36, AZS41).
Q2: Can it be used outside glass furnaces?
A: Yes. It is also suitable for high-corrosion zones in non-ferrous metallurgy and chemical furnaces, but its primary application is glass melting.
Q3: How do I choose the right grade?
A: Selection depends on furnace zone, glass composition, temperature, and corrosion severity. Technical consultation is recommended.
Proven performance in glass furnace applications
Stable quality and consistent batch control
Custom shapes and dimensions available
Competitive pricing compared with European brands
Engineering-level technical support
If you are planning a furnace rebuild or refractory upgrade, our technical team can help you select the optimal fused zirconium corundum brick grade for your application.
👉 Contact us now to receive technical datasheets, application recommendations, and a competitive quotation.
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