Refractories for AOD Furnace

VOD furnace is short for vacuum oxygen decarburization. In other words, the post-furnace refining equipment is used to decarbonize the molten steel by vacuum blowing and oxygen blowing. Since oxygen blowing makes the temperature in the furnace rise above 1700℃ and desulfurization and reduction is needed at last, the alkalinity of slag changes greatly, the steelmaking temperature is high, and the vacuum condition damages the refractory lining greatly. Such harsh service conditions decided VOD lining to use high quality refractory materials, and also decided to lower lining service life, generally only about 20 furnace times.
VOD slag lines are generally made of recombined or pre-reactive magnesia-chrome bricks, while cladding walls are made of low-grade magnesia-chrome bricks. Although magnesia-Chrome brick makes the service life of VOD furnace higher, but its price is higher, resulting in a ton of steel refractory cost higher. Therefore, resource-rich dolomite refractories are commonly used in Europe. Ultra-high temperature magnesia dolomite bricks are used for slag lines, and low-grade magnesia dolomite bricks or non-magnesia dolomite bricks combined with asphalt are used for cladding.