Basic Oxygen Furnace
Where molten iron from the blast furnace is changed into liquid steel.
Consisting of two 180-ton vessels, the basic oxygen furnace can produce up to 160,000 tons of steel a month in a wide variety of carbon, alloy and high-strength chemistries. When the molten iron arrives at the BOF via rail, it is poured into a ladle and desulfurized in preparation for charging.
The BOF generally operates on a charge of 75-percent hot metal and 25-percent scrap. The scrap is loaded into a vessel via crane, and then the molten iron is poured into the vessel. A water-cooled oxygen lance is lowered into the vessel, and high-purity oxygen is blown into the top of the metal at a speed of 16,000 cubic feet a minute. The oxygen combines with carbon and other elements to reduce impurities in the molten metal and converts the metal into clean, high-quality liquid steel. The steel is tapped into a ladle and sent on to the ladle metallurgy facility.
In April 2007, Severstal Warren commissioned a second baghouse at the BOF that is further reducing environmental emissions. The $29.3-million investment also is enhancing production efficiency.