Magnesia‑Dolomite Brick
Main Chemical Compositions & Categories
Magnesia-Dolomite bricks are composed primarily of MAGNESIUM OXIDE (MgO) and CALCIUM OXIDE (CaO), typically blended from synthetic or natural DBM (MgO) and doloma (CaO – MgO).
| COMPONENT | CONTENT | KEY FEATURE | PRIMARY ADVANTAGE |
| MAGNESIA (MgO) | 50% to 80% | High Refractoriness / Hot Strength | Provides structural stability at peak T |
| DOLOMA (CaO + MgO) | 20% to 50% | High CaO Content | CRITICAL: High chemical affinity for basic slag |
Key Properties and Performance
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
| Slag Resistance | EXCELLENT (to BASIC Slags) | The CaO component quickly saturates the basic slag, creating a stable, high-viscosity interface that slows dissolution. |
| Volume Stability | VERY GOOD | The dense MgO matrix is stabilized by the CaO phase, resisting volume change under load. |
| Hot Strength (TUL) | VERY HIGH | Maintained by the high refractoriness of the MgO and CaO components. |
| Purity | GOOD | Low silica and alumina content minimizes the formation of low-melting-point liquid phases. |
Advantages and Key Characteristics
Magnesia-Dolomite bricks are highly effective basic refractories, particularly valued for their cost-effectiveness and chemical performance in environments saturated with basic slag.
- Superior Slag Satiation: The high content of CaO is highly beneficial when dealing with CaO-saturated slags (common in basic steelmaking). The CaO component in the brick quickly saturates the molten slag, minimizing the chemical potential difference and drastically reducing the rate of refractory dissolution.
- Cost-Effectiveness: Dolomite raw materials are often more abundant and cost-effective than high-purity synthetic magnesia, offering an economic advantage for large-volume applications.
- Non-Wetting to Slag: The presence of the basic oxides minimizes the wettability of the brick surface, inhibiting slag penetration into the brick’s internal structure.
- Structural Stability: The high firing temperature creates a dense product with minimal residual shrinkage, providing good structural integrity at high temperatures.
Typical Industries and Applications
This brick is predominantly used in the ferrous industry and cement production:
- Ferrous Industry (Steel): Working linings and safety linings of Ladle Refining Furnaces (LRFs), Basic Oxygen Furnaces (BOFs), and Electric Arc Furnaces (EAFs), especially where CaO-rich, high-basicity slags are used.
- Cement & Lime: Burning zones of rotary kilns.
Furnace Areas and Service Zones
They are specified for critical containment zones in contact with basic melts:
- STEEL LADLE SLAG LINE: The primary application, maximizing life where CaO-rich slags attack the lining.
- EAF/BOF WALLS AND BOTTOMS: Used as a cost-effective alternative to pure magnesia in specific zones.
- KILN BURNING ZONE: Used where the charge is CaO-rich.
Key Data Sheet Properties to Consider
Selection is based on the CaO content and stability:
- CaO and MgO Content: CRITICAL VALUE. The specific ratio (e.g., 70%, MgO – 30%, CaO) dictates the chemical resistance profile.
- Hydration Resistance: The CaO component is susceptible to hydration (reaction with water/humidity) during storage, which can lead to brick deterioration. Look for data or guarantees on a dense, stabilized product or require special packaging (e.g., plastic wrapping) and installation procedures.
- Bulk Density (BD) and Apparent Porosity (AP): High BD and low AP are essential for resisting slag infiltration and maximizing hot strength.
- SiO2 Content: Must be extremely low, as silica forms low-melting liquid phases with CaO and MgO, which is detrimental to TUL.
Technical Guidance: Magnesia-Dolomite bricks are a powerful solution for basic slag environments. However, due to the high CaO content, they MUST be stored and handled in a dry environment to prevent hydration. The brick should be installed as quickly as possible after receipt and brought up to service temperature to prevent moisture damage.
✨ 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. |
