Refractory Mortar (High Alumina)
Main Chemical Compositions & Categories
High Alumina Mortars consist of fine-ground, calcined Alumina or Bauxite aggregate and a binding system. They are classified based on their setting mechanism, as their composition (high Al2O3) dictates that they can’t rely on plastic clay alone.
| BINDER TYPE | SETTING MECHANISM | PRIMARY ADVANTAGE |
| Air-Setting (AS) | Chemical bond (e.g., phosphates, silicates) reacts with air/humidity. | Develops moderate ambient strength for handling before firing. |
| Heat-Setting (HS) | Relies on the formation of a ceramic bond at high temperatures. | Provides the highest refractoriness and purity. |
| Hydraulic (CAC) | Calcium Aluminate Cement (CAC) reacts with water. | Rapid, high ambient strength, but may slightly lower MST. |
| VARIANT | Al2O3 Content | TYPICAL MST |
| High Duty | 70% to 80% | ~1750°C to 1800°C |
| Premium | 85% to 90%+ | ~ 1850°C+ |
Key Properties and Performance
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
| Refractoriness | EXTREMELY HIGH | High $Al2O3 purity ensures minimal fluxing and maximum melting point. |
| Hot Strength | EXCELLENT | The ceramic bond formed at high temperatures provides strength comparable to the brick itself. |
| Chemical Compatibility | EXCELLENT (Neutral) | Matches the chemical nature of high-alumina bricks, preventing localized chemical attack at the joint. |
| Shrinkage/Volume Change | LOW | Formulated for low Permanent Linear Change (PLC) to maintain tight, stable joints. |
Advantages and Key Characteristics
High Alumina Mortars are essential for constructing high-integrity linings in the most demanding hot zones of industrial furnaces, ensuring the weakest part of the structure—the joint—meets the same performance standards as the brick.
- Joint Integrity at High Heat: The primary benefit is ensuring the mortar joint does not shrink, soften, or fail at temperatures where low-alumina mortars would begin to melt or flux. This maintains the structural load-bearing capacity and gas-tightness of the entire lining.
- Chemical Resistance: Matching the high Al2O3 content of the brick prevents localized chemical attack. Using a lower-purity mortar would introduce fluxing agents (Fe2O3, SiO2, CaO) that would be preferentially attacked by slag or process gases.
- Minimizing Joint Volume: High Alumina Mortars are typically used to create a thin, uniform joint (often $1.5 mm to 3 mm), which minimizes the overall volume of mortar needed and maximizes the volume of the high-performance brick.
- Structural Stability: The mortar prevents the brick from shifting or spalling during thermal cycling by distributing stresses evenly across the brick faces and maintaining a tight seal.
Typical Industries and Applications
This mortar is critical in the highest temperature sectors of various industries:
- Ferrous Industry (Steel): Joining high-alumina/Mullite ladle linings, blast furnace stoves, and high-heat reheating furnace linings.
- Glass Industry: Crowns, checker supports, and certain burner port assemblies where high Al2O3.
- Ceramics & Kilns: Joining bricks in high-temperature zones of intermittent and continuous kilns, particularly those firing advanced ceramics.
Furnace Areas and Service Zones
They are specified for structural, high-temperature, and chemical-wear areas:
- HOT FACE WORKING LINING: The outer layer of the refractory structure directly exposed to heat and process materials.
- STRUCTURAL SUPPORTS: Used to join load-bearing piers and sections where high RUL is required.
- CRITICAL GAS SEALING: Used to ensure the hot face is gas-tight and to prevent air or process gas leakage.
Key Data Sheet Properties to Consider
Selection criteria focus on refractoriness, workability, and chemical compatibility:
- Al2O3 Content: CRITICAL VALUE. Must be checked to match or exceed the Al2O3 content of the brick being laid (70% to 90%).
- Maximum Service Temperature (MST): Must be confirmed to exceed the furnace operating temperature (typically 1750°C+).
- Bonding Type: Verify if it is Heat-Setting (HS) or Air-Setting (AS), as this dictates the application procedure and drying time.
- Water Requirement and Workability: Must be controllable to ensure the mortar is easily placed and the joint thickness is maintained.
Technical Guidance: For Heat-Setting (HS) mortars, initial mechanical strength is low; the lining must be supported and heated to a high temperature to develop its permanent ceramic bond. For Air-Setting (AS) and Hydraulic (CAC) mortars, a dry-out schedule is necessary to remove moisture before the final ceramic bond is formed. Always use the thinnest joint possible for maximum performance.
✨ Customization Services
We offer product customization services, allowing you to tailor the appearance, dimensions, or specific markings of items like refractory shapes or bricks. This includes options for incorporating specific geometric requirements to ensure seamless integration into your process systems.
🔬 Sampling for Testing & Validation
Free product samples are available for thorough testing and validation. This allows you to confirm the quality, compatibility, and performance of our materials—such as specific bricks, castables, or raw materials—before committing to a full order.
💡 Expertise in Refractory Solutions
Leverage our deep expertise to receive detailed, application-specific refractory solutions. We move beyond just selling products by providing comprehensive plans that encompass material selection, installation guidance, and performance optimization to maximize the lifespan and efficiency of your high-temperature processes.
Rabatec products are exclusively manufactured in facilities that have achieved rigorous ISO certifications across Quality (ISO 9001), Environmental Management, and Occupational Health & Safety. This commitment ensures every product, from refractory bricks to specialized equipment, meets the highest global benchmarks for performance, sustainability, and workplace safety.
📦 Logistics Excellence: Shipping, Packaging, and Marking
Minimizing Risk: We manage all logistics to minimize handling touchpoints and transit shock. Our carriers are pre-vetted for their experience in transporting heavy, fragile, and sensitive industrial materials.
Traceability: Every shipment includes comprehensive documentation and tracking information, providing end-to-end visibility and ensuring precise delivery coordination for your site.
Protection is Paramount: Our packaging strictly follows industry standards to prevent damage, corner chipping, and moisture absorption—especially critical for materials like Basic Refractory Bricks and Refractory Mortars & Mixes.
Robust Palletization: Products are secured on fumigated, high-strength export pallets (e.g., 1100x950mm or similar sturdy dimensions) using heavy-duty strapping and durable protective wrapping (polyethylene sheeting, cardboard, etc.) to withstand long-distance travel and multiple loadings.
Moisture Control: Sensitive materials are protected with appropriate sealing and, where necessary, desiccants or moisture-vapor proof enclosures to maintain the product's integrity until installation.
Clear Identification: All outer packaging is clearly marked on multiple sides with large, legible text for immediate identification and safe handling.
Full Traceability: Markings include all essential data points: Product Name, Quality Grade, Batch Number, Quantity, Net/Gross Weight, Order Number, and the Final Destination/Construction Area. This ensures every pallet can be accounted for and correctly staged upon arrival.
Safety & Compliance: We adhere to all regulatory requirements for marking, labeling, and placarding—especially for any items classified as Dangerous Goods—to ensure full compliance with international and domestic transport regulations.
❓ Frequently Asked Questions (FAQ)
Question | Elaborated Answer |
Q: What is the Refractoriness Under Load (RUL) of your refractories? | A: Refractoriness Under Load (RUL) is a critical property that defines the maximum temperature our materials can withstand while under compressive stress before deforming (softening). Since we offer a wide range of materials—from Alumina-Silicate Bricks to high-performance Silicon Carbide Bricks—the RUL varies significantly. For specific product data, please refer to the product data sheet or submit a quote request for the material you are interested in. |
Q: Where are the Rabatec refractories and materials produced? | A: Our products are primarily sourced from specialized manufacturing plants in China. Crucially, these facilities have all undergone rigorous audits and achieved comprehensive ISO certifications (Quality, Environment, and Safety), ensuring that production adheres to the highest global standards for consistency and performance. |
Q: What refractory materials does the company offer? | A: We supply a comprehensive portfolio of advanced refractory solutions, including: Shaped Products: Alumina & Silica Bricks, Basic & Specialized Bricks (e.g., Magnesia), SiC & Structural Ceramics, and Precast Shapes. Monolithic Products: Refractory Castables, Mixes & Mortars. Insulation: Insulation Fibre and High-Performance Insulation Products. |
Q: How should I choose the appropriate refractory material for my application? | A: Selecting the correct refractory is paramount to process efficiency. The choice depends on three key factors: 1. Operating Environment: Maximum process temperature and thermal cycling (shock). 2. Chemical Attack: Type of slag, molten metal, or corrosive gas being handled (acidic, neutral, or basic). 3. Mechanical Stress: Abrasion, erosion, and static load requirements. We recommend utilizing our detailed refractory solutions service to consult with our engineers for an optimized, application-specific recommendation. |
Q: Which monolithic material should I choose when patching an existing lining? | A: For patching and minor repairs, the ideal monolithic material depends on the parent lining material, the patching depth, and the need for a rapid return to service. Common choices include: Refractory Mortars & Mixes (for minor joints/surfaces) or Plastic Refractories (for areas requiring physical compaction). Always choose a patch material chemically compatible with the existing lining to ensure proper bonding and service life. |
Q: Can I receive product samples before placing a major order? | A: Yes. We gladly provide product samples for your internal testing and validation purposes. This ensures you can confirm the quality, composition, and fit of the material—such as our Refractory Castables or Alumina-Silicate Bricks—in your specific operational environment before committing to a bulk purchase. |
Q: Do you provide certifications to verify material quality? | A: Absolutely. We provide product-related inspection certificates and quality assurance documentation upon request. This verifies that your order has passed all internal quality control checks and meets the required material specifications and industry standards. |
Q: What measures are taken for product protection during transport? | A: We ensure quick, reliable transport by using robust, industrial packaging that strictly follows industry standards. This includes high-strength palletization, heavy-duty strapping, and weather-resistant wrapping to protect fragile items like bricks and mixes from corner chipping, mechanical damage, and moisture during transit. |
