Dead-Burned Magnesia (DBM)
Main Chemical Compositions & Categories
Magnesia bricks are composed predominantly of crystalline MAGNESIUM OXIDE (MgO), which is derived from natural magnesite or sea/brine magnesia that has been Dead Burned (sintered at very high temperatures, 1750°C or higher) to achieve maximum density and inertness.
| CATEGORY | MgO CONTENT | BONDING/MATRIX | PRIMARY ADVANTAGE |
| STANDARD DBM | 90% to 95% | Ceramic (High-Fired) | Excellent slag resistance, high refractoriness |
| HIGH-PURITY DBM | 98% to 99% | Ceramic (High-Fired) | Maximum hot strength and creep resistance |
| MgO-CARBON | 60% to 90% MgO | Resin/Carbon | Enhanced thermal shock and non-wetting |
Key Properties and Performance
| PROPERTY | TYPICAL PERFORMANCE | MECHANISM OF ADVANTAGE |
| Slag Resistance | EXCELLENT (to BASIC Slags) | MgO is chemically stable in CaO– and MgO-saturated melts, forming solid solution layers. |
| Refractoriness | EXTREMELY HIGH | MgO has a melting point of 2800°C, ensuring stability at maximum steelmaking temperatures. |
| Thermal Shock | POOR (Standard DBM) | High thermal expansion and poor elasticity make standard DBM prone to spalling upon rapid temperature changes. |
| Creep in Compression (CISC) | VERY LOW (High Purity) | The dense, high-purity structure resists deformation under load at high temperatures. |
Advantages and Key Characteristics
Magnesia bricks are the backbone of basic steelmaking and refining due to their unique chemical profile and high-temperature performance.
- Superior Basic Slag Resistance: MgO $ is chemically inert to the basic slags CaO) typical of steelmaking. Corrosion is minimized by forming a benign solid solution rather than rapid dissolution.
- Structural Stability: The high dead-burn temperature and purity ensure a dense product with minimal residual shrinkage and excellent load-bearing capacity at peak operating temperatures.
- Alkali and Fe2O3 Resistance: Magnesia offers better resistance to the corrosive effects of iron oxide and alkali vapors than most alumino-silicate refractories.
Typical Industries and Applications
DBM is essential for all metallurgical processes involving high-temperature, basic melts:
- Ferrous Industry (Steel): Working and permanent linings of Electric Arc Furnaces (EAFs), Basic Oxygen Furnaces (BOFs), and Ladle Refining Furnaces (LRFs).11
- Cement & Lime: Burning zones of rotary cement and lime kilns, where the charge is rich in CaO.
- Non-Ferrous Industry: Converters and refining vessels handling basic copper or nickel slags.
Furnace Areas and Service Zones
They are specified for all contact zones with basic slag and high radiant heat:
- EAF/BOF/LRF: Hot spots, slag lines, and walls. Often the MgO-C variant is used here for superior thermal shock resistance.
- KILN BURNING ZONE: Used as the working lining where the highest material temperature and chemical reactivity occur.
- LADLE FREEBOARD: The area above the slag line subject to fumes and radiant heat.
Key Data Sheet Properties to Consider
Selection criteria focus heavily on purity and density:
- MgO Content: CRITICAL VALUE. Must be verified (e.g., 95% or 98%) as purity directly correlates with refractoriness and creep resistance.
- B2O3 and SiO2 Content: Must be minimized. These impurities form low-melting silicate/borate phases that severely limit hot strength and accelerate creep.
- Bulk Density (BD) and Apparent Porosity (AP): High BD (e.g., > 3.0 g/cm3) and low AP are essential to prevent slag penetration.
- TUL and CISC: Must be exceptionally high to confirm suitability for structural use in high-temperature steel furnaces.
Technical Guidance: Standard Magnesia Bricks should NEVER be used in areas subject to severe thermal cycling or rapid cool-down unless the brick is stabilized with a carbon bond (MgO–C) or other enhancing phases like Spinel (MgO-Al2O3). Use DBM when chemical resistance to basic slag and structural integrity at the highest operating temperature are the absolute priorities.
✨ 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. |
