What are AZS bricks? For engineers, purchasers, and technical personnel in glass manufacturing, metallurgy, and chemical industries, AZS bricks are indispensable high-performance refractory materials—but many still confuse them with ordinary refractory bricks like high-alumina bricks or magnesia-carbon bricks. As a core material designed for extreme high-temperature and corrosion-resistant environments, AZS bricks play a decisive role in extending equipment service life and reducing maintenance costs.
This comprehensive guide will answer all your questions about AZS bricks, covering their definition, core composition, key properties, classification differences (33#, 36#, 41#), typical applications, selection criteria, and procurement guidelines. Whether you’re exploring “what is AZS refractory bricks” for the first time or looking for a detailed comparison of 33# vs 36# AZS bricks for your next project, this article provides authoritative, data-backed insights to support your decision-making.
AZS bricks, also known as Alumina-Zirconia-Silica refractory bricks, are high-purity composite refractory materials composed of three key components: Alumina (Al₂O₃), Zirconia (ZrO₂), and Silica (SiO₂). Unlike single-component refractory bricks, the synergistic effect of these three ingredients endows AZS bricks with exceptional high-temperature resistance, corrosion resistance, and mechanical stability—making them the first choice for harsh industrial environments where ordinary refractories fail.
The abbreviation “AZS” directly derives from the first letters of its main components: Alumina (Al₂O₃), Zirconia (ZrO₂), and Silica (SiO₂). The most common classifications of AZS bricks—33#, 36#, and 41#—are defined by the mass percentage of Zirconia (ZrO₂) in the material. This classification is an industry-wide standard adopted globally, including compliance with ASTM C1671 and ISO 10081 refractory material specifications.
33# AZS Bricks: ZrO₂ content ≈ 33% (typical range: 32-34%). The most cost-effective type among AZS bricks.
36# AZS Bricks: ZrO₂ content ≈ 36% (typical range: 35-37%). Balances performance and cost, widely used in mainstream high-temperature applications.
41# AZS Bricks: ZrO₂ content ≈ 41% (typical range: 40-42%). Premium grade with the highest corrosion resistance and temperature tolerance.
It’s important to note that some manufacturers may use alternative naming conventions, but the ZrO₂ content-based classification (33#, 36#, 41#) remains the most recognized in international trade and industrial applications. When asking “what are AZS bricks made of,” the ZrO₂ content is the primary factor determining their performance level and application scope.
To understand why AZS bricks are irreplaceable in extreme environments, we must first analyze their core composition and corresponding properties. Each component plays a unique role, and their proportional matching directly affects the final performance of AZS refractory bricks.
|
Component |
Typical Content (36# AZS) |
Core Function |
Industrial Value |
|---|---|---|---|
|
Zirconia (ZrO₂) |
36% |
Enhances corrosion resistance (especially against glass melt, slag, and chemical media); improves high-temperature stability. |
Reduces material erosion in glass furnaces and metallurgical equipment, extending brick service life. |
|
Alumina (Al₂O₃) |
48-50% |
Boosts high-temperature mechanical strength, improves sintering density, and enhances thermal shock resistance. |
Prevents brick cracking or spalling due to temperature fluctuations and mechanical impact. |
|
Silica (SiO₂) |
12-14% |
Optimizes sintering performance, reduces production costs, and adjusts material viscosity. |
Balances product performance and cost, ensuring stable production quality. |
|
Impurities (Fe₂O₃, Na₂O, K₂O) |
< 1% |
Minimized to avoid reducing high-temperature performance and corrosion resistance. |
Ensures long-term stability in harsh environments, avoiding premature failure. |
AZS bricks’ superior performance is reflected in five core properties, all verified by strict ASTM and ISO testing standards. These properties make them stand out in high-temperature, high-corrosion scenarios:
Maximum service temperature: 1700-1850℃ (varies by type: 33# ≈ 1700℃, 36# ≈ 1750℃, 41# ≈ 1850℃). Tested per ASTM C1275, AZS bricks show only ≤1.5% volume shrinkage after 100 hours of continuous exposure at 1700℃—far below the industry limit of 3.0%. This ensures structural stability even in long-term high-temperature operation.
ZrO₂, the core component of AZS bricks, forms a dense protective layer when in contact with glass melt, slag, or acidic/alkaline media, preventing penetration and erosion. In glass melt corrosion tests (ASTM C621), 36# AZS bricks show a corrosion loss rate of only 0.8 g/cm² after 72 hours—30-50% lower than high-alumina bricks and magnesia-carbon bricks.
Room-temperature compressive strength ≥ 100 MPa; high-temperature (1400℃) compressive strength ≥ 60 MPa (tested per ASTM C191). This high strength resists mechanical impact and structural deformation, making AZS bricks suitable for high-load areas such as glass furnace pool bottoms and metallurgical furnace linings.
Capable of withstanding ≥ 20 cycles of thermal shock (1100℃ water quenching, no visible cracks) per ASTM C1171. This property is critical for equipment with frequent temperature fluctuations, such as shuttle kilns and glass furnace regenerators, avoiding brick damage caused by rapid heating and cooling.
Apparent porosity ≤ 18%; bulk density ≥ 3.6 g/cm³ (tested per ASTM C20). Low porosity reduces the penetration of corrosive media, further enhancing corrosion resistance and extending service life. For example, in glass furnaces, low-porosity AZS bricks reduce glass melt penetration by 40%, significantly lowering maintenance frequency.
These properties collectively explain why AZS bricks are the preferred material for industries requiring “high temperature + corrosion resistance.” For example, in glass manufacturing, where glass melt at 1500-1600℃ is highly corrosive, AZS bricks can extend furnace lining life by 2-3 times compared to ordinary refractory bricks.
The primary difference between 33#, 36#, and 41# AZS bricks lies in their ZrO₂ content, which directly affects their performance, application scope, and cost. Choosing the right type requires balancing “performance requirements” and “cost budget.” Below is a detailed comparison and selection guide:
|
AZS Brick Type |
ZrO₂ Content |
Max Service Temp |
Corrosion Resistance |
Typical Applications |
Relative Cost |
|---|---|---|---|---|---|
|
33# AZS Bricks |
32-34% |
1700℃ |
Medium |
Glass furnace side walls, regenerator chambers, metallurgical furnace auxiliary zones |
100% |
|
36# AZS Bricks |
35-37% |
1750℃ |
High |
Glass furnace pool walls, throat, feeder channels, non-ferrous metal smelting furnaces |
130-150% |
|
41# AZS Bricks |
40-42% |
1850℃ |
Excellent |
Glass furnace melting pool, flow channels, chemical high-temperature corrosion reactors |
200-250% |
33# AZS bricks are the most economical option in the AZS family, suitable for low-to-medium corrosion and temperature environments. They are ideal for non-critical areas of glass furnaces (e.g., side walls, regenerators) and auxiliary zones of metallurgical furnaces where high corrosion resistance is not required. Best for: Purchasers prioritizing cost control with moderate performance needs.
36# AZS bricks balance performance and cost, making them the most widely used type in industrial applications. Their high corrosion resistance and 1750℃ temperature tolerance make them suitable for core areas of glass furnaces (e.g., pool walls, throats) and non-ferrous metal smelting furnaces. Best for: Most glass and metallurgy manufacturers seeking reliable performance without excessive cost.
41# AZS bricks offer the highest ZrO₂ content, corrosion resistance, and temperature tolerance. They are designed for extreme environments such as glass furnace melting pools (where glass melt is most corrosive) and chemical high-temperature reactors. Best for: High-end glass manufacturers (e.g., optical glass, borosilicate glass) and industries with harsh corrosion conditions.
Key Selection Tip: Do not simply choose the lowest-cost 33# AZS bricks or the highest-performance 41# AZS bricks. Match the type to your specific working conditions: focus on ZrO₂ content for corrosion-prone areas, and temperature resistance for high-heat zones. Misselection (e.g., using 33# in a glass furnace pool wall) can reduce service life by 50% and increase maintenance costs.
AZS bricks are primarily used in industries requiring high-temperature resistance (≥1500℃) and corrosion resistance, with the glass manufacturing industry accounting for 70% of global demand. Below are their typical applications, including recommended AZS brick types and value highlights:
Glass furnaces operate at 1500-1650℃, with molten glass (a highly corrosive silicate melt) continuously eroding the furnace lining. AZS bricks are the preferred material for key components due to their excellent resistance to glass melt corrosion.
Melting Pool Walls & Bottoms: The most corrosive area, directly in contact with molten glass. Recommended: 36# (general glass) or 41# (high-end/borosilicate glass). Value: Extends lining life from 12-18 months (ordinary bricks) to 36-48 months, reducing furnace shutdown frequency.
Throat & Feeder Channels: Subject to high-temperature gas erosion and glass melt flow scouring. Recommended: 36# AZS bricks.Value: Reduces material loss by 40%, ensuring stable glass flow and product quality.
Side Walls & Regenerators: Moderate temperature and corrosion. Recommended: 33# AZS bricks. Value: Balances performance and cost, lowering overall furnace construction costs by 15-20%.
Flow Channels & Spouts: High flow velocity of molten glass causes severe scouring. Recommended: 36# or 41# AZS bricks. Value: Avoids frequent maintenance, improving production efficiency by 10%.
Case Study: A large flat glass manufacturer in Southeast Asia replaced high-alumina bricks with 36# AZS bricks for their furnace pool walls. The result: lining service life increased from 16 months to 42 months, maintenance costs reduced by 58%, and glass defect rates (caused by lining erosion) dropped from 2.3% to 0.8%.
Why Use AZS Bricks in Glass Furnaces?: Ordinary refractory bricks (e.g., high-alumina) are quickly eroded by molten glass, leading to frequent maintenance and unstable product quality. AZS bricks’ ZrO₂ component forms a protective barrier, significantly reducing corrosion and extending service life.
In non-ferrous metal (copper, aluminum, zinc) smelting furnaces, AZS bricks are used in areas exposed to high-temperature slag and metal melt corrosion.
Non-Ferrous Metal Smelting Furnace Linings: Recommended: 36# AZS bricks. Resists corrosion from slag and metal oxides. Value: Extends lining life by 2-3 times compared to magnesia-carbon bricks in acidic slag environments.
Continuous Casting Tundishes: Recommended: 33# or 36# AZS bricks. Withstands thermal shock and molten steel scouring. Value: Improves casting quality and reduces downtime.
AZS bricks are used in high-temperature chemical reactors, incinerators, and acid-base treatment equipment where corrosion and high temperatures coexist.
High-Temperature Corrosion Reactors: Recommended: 41# AZS bricks. Resists corrosion from acidic/alkaline gases and catalysts.Value: Ensures long-term stable operation of reactors, avoiding leakage risks.
Hazardous Waste Incinerators: Recommended: 36# AZS bricks. Withstands 1600-1700℃ incineration temperatures and corrosive ash. Value: Extends incinerator service life and reduces maintenance costs.
Ceramic Industry: Used in high-temperature shuttle kilns and tunnel kilns for firing advanced ceramics. Recommended: 33# or 36# AZS bricks.
Energy Industry: Lining of coal gasification furnaces and biomass combustion boilers. Recommended: 36# AZS bricks.
Selecting the correct AZS bricks requires comprehensive consideration of working conditions, performance requirements, and cost. Follow these four core steps to avoid misselection and maximize investment returns:
Operating Temperature: Measure the maximum and average temperatures of the application area. For ≤1700℃, 33# or 36# is sufficient; for 1700-1850℃, choose 36# or 41#.
Corrosive Medium: Identify the type and concentration of corrosive media (e.g., glass melt, acidic slag, alkaline gas). High-corrosion environments (e.g., glass melt pool walls) require higher ZrO₂ content (36#/41#).
Mechanical Impact & Flow Velocity: High flow velocity (e.g., glass feeder channels) or mechanical impact requires higher strength—36# or 41# AZS bricks are preferred.
Temperature Fluctuation Frequency: Frequent heating/cooling (e.g., shuttle kilns) requires good thermal shock resistance—36# AZS bricks balance performance in this regard.
|
Application Scenario |
Key Working Conditions |
Recommended AZS Type |
|---|---|---|
|
Glass furnace pool wall (ordinary float glass) |
1550-1600℃, high glass melt corrosion |
36# AZS Bricks |
|
Glass furnace pool wall (borosilicate glass) |
1600-1650℃, extreme glass melt corrosion |
41# AZS Bricks |
|
Metallurgical furnace auxiliary zone |
1500-1600℃, medium slag corrosion |
33# AZS Bricks |
|
Chemical high-temperature reactor |
1650-1750℃, acidic gas corrosion |
36#/41# AZS Bricks |
Mistake 1: Prioritizing Cost Over Performance: Using 33# AZS bricks in high-corrosion areas (e.g., glass pool walls) may reduce upfront costs but increases maintenance frequency and downtime costs. Solution: Calculate total cost of ownership (TCO) instead of just purchase price.
Mistake 2: Over-Specifying Performance: Using 41# AZS bricks in low-corrosion areas (e.g., glass furnace side walls) wastes investment. Solution: Match performance to actual needs.
Mistake 3: Ignoring Installation Requirements: AZS bricks require strict installation (e.g., refractory mortar selection, joint thickness). Poor installation can reduce performance by 30%. Solution: Choose suppliers offering on-site installation guidance.
Mistake 4: Neglecting Quality Certification: Purchasing uncertified AZS bricks may lead to inconsistent performance. Solution: Require ASTM/ISO certification and third-party test reports.
To further clarify AZS bricks’ unique value, here’s a comparison with common refractory bricks:
|
Refractory Brick Type |
High-Temp Resistance |
Corrosion Resistance |
Typical Applications |
Relative Cost |
|
AZS Bricks (36#) |
High (1750℃) |
High |
Glass furnaces, high-corrosion areas |
100% |
|
High-Alumina Bricks |
Medium (1600℃) |
Medium |
Industrial boilers, low-corrosion kilns |
40-50% |
|
Magnesia-Carbon Bricks |
High (1800℃) |
Medium (alkaline slag) |
Steelmaking converters, alkaline furnaces |
80-90% |
|
Silica Bricks |
High (1750℃) |
Low (alkaline corrosion) |
Coke ovens, acidic environments |
60-70% |
After understanding the properties, types, applications, and selection of AZS bricks, many professionals still have practical questions about procurement and daily use. Below are answers to the most frequently asked questions (FAQs) about AZS bricks, followed by a detailed procurement guide to help you streamline the purchasing process and choose a reliable supplier.
Q: What are AZS bricks made of? A: AZS bricks, or Alumina-Zirconia-Silica refractory bricks, are composed of three core components: Alumina (Al₂O₃, 48-50% in 36# AZS), Zirconia (ZrO₂, 32-42% depending on type), and Silica (SiO₂, 12-14%). Impurities (Fe₂O₃, Na₂O, K₂O) are controlled below 1% to ensure high-temperature performance and corrosion resistance.
Q: How long do AZS bricks last in glass furnaces? A: Service life varies by type and application area. 33# AZS bricks for side walls last 18-24 months; 36# AZS bricks for pool walls last 36-48 months; 41# AZS bricks for melting pools (high-end glass furnaces) can last 48-60 months. This is 2-3 times longer than ordinary high-alumina bricks.
Q: What is the MOQ for AZS bricks? A: For standard 33#, 36#, and 41# AZS bricks, the minimum order quantity (MOQ) is usually 10 tons. For custom-sized or special-grade AZS bricks, the MOQ may be 20 tons. Many suppliers offer flexible MOQ for long-term cooperative customers.
Q: What is the delivery time for AZS bricks? A: Standard orders (10-50 tons) have a delivery time of 15-25 working days; large orders (50+ tons) take 25-40 working days; custom orders may take 30-50 working days, depending on production complexity and raw material inventory.
Q: How to store AZS bricks properly? A: Store AZS bricks in a dry, well-ventilated warehouse to avoid moisture. Stack them neatly on pallets, away from walls and ground (use wooden pads to prevent dampness). Avoid direct sunlight and extreme temperature changes, which may affect brick density and performance.
Q: What is the difference between 33# and 36# AZS bricks? A: The core difference is ZrO₂ content: 33# has ~33% ZrO₂, 36# has ~36%. 36# offers higher corrosion resistance and maximum service temperature (1750℃ vs 1700℃ for 33#). 33# is cost-effective for low-corrosion areas, while 36# is suitable for core areas like glass furnace pool walls.
For industrial purchasers, choosing high-quality AZS bricks and reliable suppliers is crucial to ensuring production stability and reducing total cost of ownership. Here are core procurement factors and supplier selection criteria:
|
Procurement Item |
Key Details |
|
MOQ |
Standard: 10 tons; Custom: 20 tons (negotiable for long-term cooperation) |
|
Packaging |
Standard: Wooden pallets + waterproof plastic film; Custom packaging available for sea freight (fumigation-free pallets) |
|
Payment Terms |
T/T: 30% advance payment, 70% balance before delivery; L/C at sight acceptable for large orders (≥100 tons) |
|
Delivery Time |
15-40 working days (varies by order quantity and customization requirements) |
|
Quality Assurance |
ASTM/ISO certification, third-party test reports, 12-month warranty for quality-related issues |
Quality Certification: Prioritize suppliers with ASTM C1671, ISO 10081 certifications, and independent third-party test reports (e.g., SGS, BV) to ensure product consistency.
Production Capacity: Choose suppliers with annual production capacity ≥ 5000 tons, equipped with advanced production lines (e.g., automatic batching, high-temperature sintering kilns) to meet large-order and urgent needs.
Customization Capability: Opt for suppliers that offer custom-sized, custom-composition AZS bricks to fit special equipment (e.g., non-standard glass furnace components).
Technical Support: Prefer suppliers providing on-site installation guidance, performance testing, and after-sales maintenance advice to avoid issues caused by improper use.
Raw Material Control: Reliable suppliers source high-purity raw materials (e.g., ZrO₂ ≥ 99.5%, Al₂O₃ ≥ 99%) and have strict raw material inspection processes to ensure product quality from the source.
Industrial Bulk Procurement: Negotiate MOQ, delivery time, and payment terms with suppliers; request sample testing before placing large orders; sign long-term cooperation agreements to secure stable supply and preferential prices.
Small-Batch/Custom Procurement: Clearly communicate customization requirements (size, composition, performance parameters); confirm production cycle and cost in advance; choose suppliers with rich customization experience to avoid rework.
Emergency Procurement: Prioritize suppliers with sufficient inventory of standard AZS bricks; confirm logistics channels (e.g., express, air freight) to ensure timely delivery and minimize production downtime.
Whether you’re in the glass manufacturing, metallurgy, or chemical industry, choosing the right AZS bricks is key to improving equipment efficiency and reducing maintenance costs. We offer high-quality 33#, 36#, 41# AZS bricks with ASTM/ISO certification, custom solutions, and professional technical support. Take the next step with our layered services tailored to your needs:
Download our AZS Bricks Complete Guide (including detailed performance parameters, selection tables, and application cases) to deepen your understanding of AZS bricks.
Action: Click to download the guide →
Request free AZS brick samples and technical datasheets to test performance and compatibility with your equipment.
Action: Apply for free samples →
Get a custom quote based on your specific needs (type, quantity, customization requirements). We offer competitive prices and flexible terms.
Highland Refractory, a trusted supplier of premium AZS Refractory Brick, offers high-performance AZS Brick—engineered from zirconia-alumina-silica (ZrO₂-Al₂O₃-SiO₂) composites for extreme high-temperature and corrosive environments. Our product line includes AZS 33 brick (33% ZrO₂ content), AZS 36 brick (36% ZrO₂), and AZS 41 brick (41% ZrO₂), each designed to withstand continuous operating temperatures up to 1800℃ with exceptional thermal shock resistance and corrosion resistance against molten glass, slags, and acids.
ASTM-Certified | Custom Sizes | 12-Month Warranty | Factory Direct Supply ① Cement Kiln: Extend Lining Life to 12-18 Months ② Steel Kiln: Withstand 1800℃ High Temp & Slag Corrosion ③ Ceramic/Glass Kiln: Excellent Thermal Shock Resistance ④ High Purity Raw Materials (Al₂O₃/MgO ≥92%) ⑤ Factory Direct Price (Save 20-30% Intermediate Costs) Tailored solutions for cement rotary kilns, steel blast furnaces, ceramic shuttle kilns, and glass melting furnaces—your reliable partner for kiln lining durability and efficiency.
High-Temp Resistant (Up to 1800℉) | Fast Heating & Heat Retention | Easy Installation ① Heavy-Duty for Commercial Pizza Shops (High-Frequency Use) ② Heat Retention (Reduce Energy Cost by 20%) ③ ASTM-Certified (Reliable Quality) Whether you’re building a DIY backyard pizza oven or upgrading a commercial wood-fired one, the right fire brick is key to authentic Italian-style crispy crusts. Explore our tailored solutions for home and commercial needs.
Clay/High Alumina/Silica/Magnesia Fire Bricks | Factory Direct Price | Custom Quote Available ① Price Range: $50-$500/ton (varies by material & specifications) ② Key Cost Factors: Material Purity, Size Tolerance, Order Quantity ③ Factory Direct Supply: Save 20-30% on Intermediate Costs
JM28 Insulation Brick, made of high-quality raw materials, is a top-tier thermal insulation solution designed to offer exceptional performance in high-temperature environments. Known for its outstanding thermal insulation properties, JM28 is ideal for use in furnaces, kilns, boilers, and other high-temperature industrial applications. With its excellent insulating qualities, low thermal conductivity, and robust physical properties, JM28 Insulation Brick provides significant benefits to industries aiming to improve energy efficiency, reduce operational costs, and increase the lifespan of high-temperature equipment. In this product description, we will explore the key features, benefits, technical specifications, and ideal applications of JM28 Insulation Brick. Whether you’re in steel manufacturing, cement production, or any other high-heat industry, JM28 is designed to meet your thermal insulation needs.
