Basic steelmaking

Develop a simplified process flow sheet for the basic steelmaking process. Indicate on the schematic where and what types of air emissions take place. 

L-D [Linz, Austria and either Dusenverfahren (nozzle process), or Donawitz, the other Austrian town where it was developed] A basic steelmaking process in which oxygen is used instead of air to remove most of the carbon from the molten pig iron. Developed in Austria by the Vereinigte Osterreichisch Eisen und Stahlwerke of Linz, and Osterreichisch Alpine of Donawitz, in the 1930s and 40s commercialized in 1952, and now widely adopted. The furnace is essentially a Bessemer converter, modified with a water-cooled oxygen injector. See also Bessemer. 

Most ferrous scrap is recycled in steelmaking processes by melting the scrap in either a basic oxygen or an electric arc furnace. However, a significant market exists for cast-iron products, which are also made by melting ferrous scrap. In 1991, world production of cast irons was estimated at nearly 3.9 X 10 t at over 14,000 iron foundries (15). 

Basic Oyygen Steelmaking. New Technology Emerges Proceedings of the Conference, Metallurgical Society of London, 1979. Contaias papers on refractories for conventional and new bottom-blown vessels. 

Pig iron and iron and steel scrap are the sources of iron for steelmaking in basic-oxygen furnaces. Electric furnaces have rehed on iron and steel scrap, although newer iron sources such as direct-reduced iron (DRI), iron carbide, and even pig iron are becoming both desirable and available (see Iron bydirectreduction). In basic-oxygen furnaces, the pig iron is used in the molten state as obtained from the blast furnace in this form, pig iron is referred to as hot metal. 

In oxygen steelmaking, 99.5% pure oxygen gas is mixed with hot metal, causiag the oxidation of the excess carbon and siHcon ia the hot metal and thereby produciag steel. In the United States, this process is called the basic-oxygen process (BOP) (4,9,10). The first U.S. commercial iastallation began operation in 1955. 

Fig. 4. Sketch of a basic-oxygen steelmaking furnace, where an oxygen lance is iaserted through the mouth of the furnace (1).

G. Derge, ed., Basic Open-Hearth Steelmaking, 3rd ed., AIME, Warrendale, Pa., 1964. 

Secondary Emissions from Basic Oxygen Process Steelmaking Facilities for Which Construction Commenced after January 20, 1983 Sewage Treatment Plants Primary Copper Smelters Primary Zinc Smelters... 

Basic oxygen furnaces (BOFs) have largely replaced open hearth furnaces for steelmaking. A water-cooled oxygen lance is used to blow high-purity oxygen into the molten metal bath. This causes violent agitation and rapid oxidation of the carbon, impurities, and some of the iron. The reaction is exothermic, and an entire heat cycle requires only 30-50 min. The atmospheric emissions from the BOF process are listed in Table 30-16. 

The BOS (Basic Oxygen Steelmaking) process is the major modem process for making bulk steels. Apart from special quality steels (such as stainless steel), all flat products, and long products over a certain size, are rolled from steel made by the BOS process. 

Increasingly today, steels after they have been tapped (poured) from the furnace undergo a further stage of processing called secondary steelmaking before the steel is cast. This applies to both the basic oxygen process route and to the electric arc furnace route. 

Basic Open Hearth A version of the Open Hearth process for steelmaking in which the hearth is made from calcined dolomite (calcium and magnesium oxides). The sulfur and phosphorus impurities in the raw materials are converted to basic slag, which is separated from the molten steel. First operated in 1882 at Alexandrovsky, near St. Petersburg, Russia, and at Le Creusot, France. It was the major steelmaking process in the world in the first half of the 20th century. See Thomas. 

Bertrand Thiel A variation of the Basic Open Hearth steelmaking process, suitable for ores rich in silicon and phosphorus. Two hearths are used by varying the quantities of hme added to each it is possible to concentrate most of the silicon and phosphoms in the slag from the first. Developed by E. Bertrand and O. Thiel at Kladno, Bohemia, in 1894 subsequently adopted at Hoesch, Germany (hence the alternative name for the process). 

Duplex (1) An integrated steelmaking process in which iron is converted to steel in a Bessemer furnace with a basic lining, and the molten product is transferred to a basic lined arc furnace in which the remaining impurities are oxidized. Developed in Germany and widely used there and elsewhere around 1900. 

Steelmaking dust, recycling, 21 361-362 Steelmaking processes acid or basic, 23 250 addition agents in, 23 262-263 early, 23 248-249 electric furnace, 23 251-255 energy needed for, 23 253 heat balance in, 23 257 oxygen, 23 255-260... 

Steel production Steelmaking can be performed according to two main routes, to which reference can be made as based on the basic oxygen converter and the electric steel process, respectively. The basic oxygen converter... 

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