Скачать или смотреть How are magnesia carbon bricks for electric arc furnaces used in steelmaking produced ?

Magnesia-carbon (MgO-C) bricks play a crucial role in the refractory lining of electric arc furnaces (EAFs), which are widely used in steelmaking.

1. Primary Function

Magnesia-carbon bricks are basic refractories made from fused or sintered magnesia and flake graphite, bonded with resin or pitch. Their main role in EAFs is to protect the furnace structure and maintain thermal efficiency during high-temperature steelmaking processes.

2. Key Roles in Electric Arc Furnaces

Working Lining for High-Temperature Zones

MgO-C bricks are typically used in the slag line, hot spots, sidewalls, and the furnace hearth—areas subjected to extreme thermal and mechanical stress.

Thermal Shock Resistance

Electric arc furnaces experience rapid temperature fluctuations (from cold charge to molten steel temperatures). The graphite in MgO-C bricks gives excellent thermal shock resistance, preventing cracking or spalling.

Corrosion and Slag Resistance

Steelmaking slags are highly basic and aggressive, especially in oxidizing conditions. MgO provides basicity compatibility, reducing chemical attack by the slag.

Oxidation Resistance and Protection

Carbon in the brick improves slag non-wettability, reducing slag penetration. However, since carbon can oxidize at high temperatures, anti-oxidants (e.g., aluminum, silicon, magnesium powders) are added to enhance oxidation resistance.

Energy Efficiency

The graphite phase improves thermal conductivity, reducing heat loss and helping maintain energy efficiency in the EAF.

Mechanical Strength

They withstand mechanical impact from scrap charging, oxygen lancing, and electrode movement.

3. Advantages for EAF Operations

Longer Service Life due to combined resistance to thermal shock and slag corrosion.

Reduced Refractory Consumption because of higher durability compared to traditional magnesia bricks.

Lower Maintenance and Downtime, improving furnace productivity.

Flexibility for High-Power Furnaces, which operate at higher energy inputs.

4. Typical Areas of Application in EAF

Slag Line and Sidewalls – Most severe wear zone due to slag attack and thermal cycling.

Hot Spots – Areas around the electrodes with intense arc heating.

Upper and Lower Sidewalls – To resist mechanical and thermal stress.

Working Lining of the Furnace – Protecting the shell and maintaining operational stability.

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