Deadburned magnesia (DBM), also called dead burned magnesia or sintered magnesia,remains one of the most important raw materials in the refractory industry. With increasing demand for longer furnace service life, higher corrosion resistance, and stable thermal performance, DBM continues to dominate the basic refractory market . But what makes this material so essential for steelmaking, cement kilns, non-ferrous metallurgy, and various high-temperature processes?
1. What Is Deadburned Magnesia?
DBM is produced by calcining natural magnesite at 1800–2000°C in rotary kilns, shaft kilns, or vertical furnaces. The extreme firing temperature removes CO₂ completely and forms a dense structure of large periclase (MgO) crystals.
Compared with caustic calcined magnesia (CCM), DBM exhibits:
Very low chemical reactivity
High resistance to basic slags
Low porosity
Excellent structural stability at high temperatures
These features make dead burned magnesia the foundation for basic refractories used in steel, cement, and glass industries.
2. DBM Microstructure: Why Low Reactivity Matters
Deadburned magnesia is known as "dead burned" because the high-temperature firing process:Eliminates free lime
Stabilizes periclase grains
Minimizes hydration tendency
Reduces expansion defects
This microstructure is critical in avoiding:Cracking,Spalling,Hydration-related disintegration, Premature refractory failure
In contrast, reactive CCM cannot withstand the same thermal and chemical stresses.
3. Why Deadburned Magnesia Is Essential for Refractories
(1) Excellent Slag Resistance
DBM is the most effective raw material for resisting:
Steel ladle basic slag
Cement kiln dust and clinker
High-alkali and iron-rich furnace atmospheres
Its dense periclase structure slows slag penetration, improving refractory longevity.
(2) High-Temperature Mechanical Strength
DBM maintains integrity above 1700°C, making it ideal for:Rotary kiln burning zones,Converter linings,Electric arc furnace (EAF) slag lines,Steel ladle working linings
Even under rapid temperature changes, DBM refractories demonstrate exceptional durability.
(3) Strong Thermal Shock Resistance (When Combined with Spinel or Carbon)
While pure DBM has moderate thermal shock resistance, it performs exceptionally well in composite systems such as:Magnesia-chrome bricks,Magnesia-carbon bricks,Magnesia-spinel bricks
This makes DBM indispensable in steel and non-ferrous metallurgy.
(4) Compatibility with Additives
Dead burned magnesia blends efficiently with: Fused magnesia,Zirconia,Chrome ore,Alumina, Graphite
This flexibility allows engineers to tailor refractory formulations for specific furnace conditions.
4. Applications of Deadburned Magnesia Across Industries
Steelmaking Industry (Largest Consumer), Basic Oxygen Furnace (BOF), Electric Arc Furnace (EAF),Ladle working lining,Tundish gunning materials, EAF bottom and slag zone repair;
The steel sector consumes more DBM than any other industry, especially high-purity DBM 97%.
Cement Industry
Rotary kilns require refractories that can withstand alkali attack and clinker abrasion. DBM 90–95% is widely used in:Burning zone bricks,Transition zone linings,Pre-calciner equipment
Non-Ferrous Metallurgy
DBM offers excellent corrosion resistance in: Nickel and copper converters,Ferroalloy furnaces,High-alkali smelting environments
Glass and Lime Industries
DBM is used in:Regenerator checkers,Melting zone refractories,Lime kiln cooling zone linings,Its stability helps maintain furnace temperature uniformity and energy efficiency.
5. Comparison: Deadburned Magnesia vs. Fused Magnesia
| Property | DBM | FM |
|---|---|---|
| Purity | 90–97% MgO | 97–99% MgO |
| Density | Medium–high | Very high |
| Slag resistance | Excellent | Superior |
| Thermal shock | Good | Moderate |
| Price | Lower | Higher |
| Applications | General refractory bricks & castables | Severe corrosion zones |
Choose DBM for cost-effective high-performance refractories.
Choose FM for extremely harsh conditions.
6. Global DBM Market Trends in 2025
Several factors affect DBM pricing and supply:
Mining restrictions in China (world's largest producer)
Energy and calcination costs
Ocean freight rates
Environmental requirements for magnesite processing
7. How to Choose a Reliable DBM Supplier?
When sourcing DBM, consider:
Stable MgO purity (±0.2%),Low CaO/SiO₂ impurities;Uniform grain size;Consistent kiln firing temperature; COA + TDS availability; Strong packaging for export
Choosing the right partner ensures stable refractory production and fewer furnace failures.
Deadburned magnesia continues to be the dominant raw material for basic refractories due to its:High-temperature stability,Resistance to slag penetration,Compatibility with additives,Cost-effectiveness.
As industries pursue energy savings and longer furnace campaigns, the importance of high-quality DBM will only grow.
