Magnesia chrome bricks are core refractory materials in critical components of steelmaking converters. With periclase and magnesia-chrome spinel as the main crystalline phases, they possess excellent high-temperature stability, slag erosion resistance, and thermal shock resistance, making them suitable for extreme conditions in converters exceeding 1600℃. They are widely used in critical areas with severe erosion, playing a vital role in extending converter life and ensuring stable production.
The core application areas of magnesia chrome bricks are concentrated in vulnerable areas such as the slag line and trunnion zone. These areas are constantly at the interface of molten steel, slag, and furnace gas, and are significantly affected by high-FeO slag erosion, high-temperature scouring, and sudden temperature changes. By optimizing the Cr₂O₃ content (typically 15%-25%), magnesia chrome bricks form a dense protective layer, effectively blocking slag penetration, reducing chemical erosion and mechanical wear, and improving thermal shock resistance by more than three times compared to ordinary magnesia bricks.
During use, the appropriate type should be selected based on the operating conditions. Direct bonding of magnesia chrome bricks offers high cost-effectiveness and is suitable for the molten pool zone. Furthermore, magnesia-chrome bricks offer superior slag resistance, making them suitable for demanding applications such as slag lines and trunnions. During installation, brick joints must be strictly controlled to ≤2mm, using a specialized high-temperature adhesive and a scientifically designed furnace drying curve to prevent cracking due to thermal stress.
It is important to note that magnesia chrome bricks may generate toxic hexavalent chromium in high-temperature alkaline environments, requiring proper environmental treatment. Simultaneously, it is necessary to control the composition of the converter’s final slag, strengthen operational procedures, reduce temperature fluctuations and slag erosion, and fully leverage their performance advantages. Currently, although chromium-free alternatives are gradually being promoted, high-performance magnesia chrome bricks remain a crucial and irreplaceable material under the harsh conditions of converter operations. Their proper use can significantly reduce refractory material consumption per ton of steel.
