What is the difference between magnesia carbon fire bricks and alumina magnesia carbon bricks?

The only difference between magnesia carbon bricks and aluminum magnesia carbon bricks is “aluminum”, but their furnace locations are different. Although both are alkaline refractory bricks, their characteristics and applications are significantly different.

Core ingredients and performance differences

The most fundamental difference between the two lies in their chemical composition.

Magnesia carbon fire bricks are mainly composed of high-purity magnesia (MgO) and graphite (C). This makes it extremely resistant to alkaline slag attack and excels in handling high-alkalinity slag.

Alumina-magnesia-carbon refractory bricks are made by adding alumina (Al₂O₃) raw materials to this material. This adjustment in composition directly leads to differences in performance. The aluminum oxide reacts with magnesium oxide at high temperatures to form a spinel phase, which significantly improves the structural strength and spalling resistance of the material. At the same time, its antioxidant properties have also been improved.

Application characteristics of magnesia carbon fire bricks

Due to its excellent slag corrosion resistance, this brick is usually used in areas with the most demanding working environments. For example, in areas such as the furnace cap and slag line of the converter, magnesia carbon bricks are the preferred material. Its performance is often better than traditional dolomite bricks.

In comparison, aluminum-magnesium-carbon bricks have better structural stability. It is more suitable for equipment such as ladles and refining furnaces where temperature changes frequently and high requirements are placed on material integrity.

However, the oxidation resistance of magnesia carbon bricks is relatively weak. Therefore, care should be taken to control the atmosphere in the furnace during use to slow down the oxidation loss of the carbon matrix.

In short, the two types of bricks have their own advantages and should be selected according to specific working conditions. Therefore, working with a refractory brick supplier who can provide professional advice is an important guarantee to ensure the longevity of the equipment.