basic oxygen process


basic oxygen process
a high-speed method of steelmaking in which oxygen of high purity is blown through an oxygen lance at high velocity onto the surface of a bath containing steel scrap and molten pig iron within a vessel with a basic lining (basic oxygen furnace).

* * *

Steelmaking method in which pure oxygen is blown through a long, movable lance into a bath of molten blast-furnace iron and scrap, in a steel furnace with a refractory lining called a converter.

The oxygen initiates a series of heat-releasing reactions, including the oxidation of such impurities as silicon, carbon, phosphorus, and manganese; carbon dioxide is released, and the oxidation products of the other impurities form molten slag that floats on the molten steel. The advantages of using pure oxygen instead of air in refining iron into steel were recognized as early as the 1850s (see Bessemer process), but the process could not be commercialized until the late 1940s, when cheap, high-purity oxygen became available. Within 40 years it had replaced the open-hearth process and was producing more than half of all steel worldwide. Commercial advantages include high production rates, less labour, and steel with a low nitrogen content.

* * *

 a steelmaking method in which pure oxygen is blown into a bath of molten blast-furnace iron and scrap. The oxygen initiates a series of intensively exothermic (heat-releasing) reactions, including the oxidation of such impurities as carbon, silicon, phosphorus, and manganese.

      The advantages of using pure oxygen instead of air in refining pig iron (iron processing) into steel were recognized as early as 1855 by Henry Bessemer, but the process could not be brought to commercial fruition until the 20th century, when large tonnages of cheap, high-purity oxygen became available. Commercial advantages include high production rates, less labour, and steel with a low nitrogen content. Development of the BOP was initiated in Switzerland by Robert Durrer in the late 1940s. After experimenting with a 2.5-ton pilot unit, Durrer worked with engineers at the Voest company at Linz, Austria, who set up a commercially operating 35-ton converter in 1952. A second unit began operation within a year at Donawitz, also in Austria. Consequently, the BOP was first known as the LD (Linz-Donawitz) process. Within 40 years, virtually all of the steel in Japan and more than half of the steel worldwide was produced by the BOP.

      A typical top-blown basic oxygen furnace is a vertical cylindrical vessel with a closed bottom and an open upper cone through which a water-cooled oxygen lance can be raised and lowered. The vessel is lined with a refractory such as magnesite and is mounted on trunnions so that it can be tilted for charging and also for tapping liquid steel. A charge typically consisting of 70–75 percent molten blast-furnace iron (containing approximately 4 percent carbon), 25–30 percent scrap metal, and lime and other fluxes is fed into the furnace. The lance is lowered into the vessel, and oxygen is injected into the bath at supersonic velocities with flow rates that can exceed 800 cubic m (28,000 cubic feet) per minute. The duration of the oxygen “blow,” normally close to 20 minutes, is varied to reduce the carbon in the steel to the required level. The steel is then tapped into a ladle at temperatures close to 1,600° C (2,900° F), and appropriate ferroalloys and deoxidizers are added to meet the required steel composition. “Heats” of steel, ranging in size from 30 to 360 tons, can be produced in 30 to 45 minutes.

      Another, though less common, oxygen steelmaking system is a bottom-blown process known as the Q-BOP (quick-quiet BOP) in North America and the OBM (from the German, Oxygen bodenblasen Maxhuette, or “oxygen bottom-blowing furnace”) in Europe. In this system, oxygen is injected with lime through nozzles, or tuyeres, located in the bottom of the vessel. The tuyeres consist of two concentric tubes: oxygen and lime are introduced through the inner tube, and a hydrocarbon such as natural gas is injected through the outer annulus. The endothermic (heat-absorbing) decomposition of the hydrocarbon near the molten bath cools the tuyeres and protects the adjacent refractory. Yet another variation, which has found wide application in top-blown furnaces, is the injection of inert gases into the molten bath through permeable blocks in the bottom of the vessel for the purpose of enhancing chemical reactions.

* * *


Universalium. 2010.

Look at other dictionaries:

  • basic-oxygen process — basic( oxygen) process noun A steelmaking process in which oxygen is blown at high pressure through molten pig iron • • • Main Entry: ↑basic …   Useful english dictionary

  • basic(-oxygen) process — noun A steelmaking process in which oxygen is blown at high pressure through molten pig iron ● basic …   Useful english dictionary

  • basic oxygen process — n. a process for refining steel in which oxygen is blown into the molten iron …   English World dictionary

  • basic oxygen process — a high speed method of steelmaking in which oxygen of high purity is blown through an oxygen lance at high velocity onto the surface of a bath containing steel scrap and molten pig iron within a vessel with a basic lining (basic oxygen furnace) …   Useful english dictionary

  • basic oxygen process — noun a steel making process in which carbon and other impurities are burned away from iron by a jet of oxygen in a retort lined with a basic refractory …   English new terms dictionary

  • Basic oxygen steelmaking — ( BOS, BOF, Linz Donawitz Verfahren, LD converter ) is a method of steelmaking in which carbon rich molten iron is made into steel. The process is an improvement over the historically important Bessemer process. The LD converter is named after… …   Wikipedia

  • Basic oxygen furnace — A basic oxygen furnace, also known as an LD converter , is the place within an integrated steel mill where molten iron from the blast furnace is changed into liquid steel. LD is short for Linz Donawitz, the names of the two towns in Austria, near …   Wikipedia

  • basic process — noun : a process (as in steelmaking) carried on in a furnace lined with basic material (as magnesite, dolomite, lime, or iron oxide) and under a slag that is dominantly basic opposed to acid process; compare bessemer process * * * basic( oxygen)… …   Useful english dictionary

  • basic — /bay sik/, adj. 1. of, pertaining to, or forming a base; fundamental: a basic principle; the basic ingredient. 2. Chem. a. pertaining to, of the nature of, or containing a base. b. not having all of the hydroxyls of the base replaced by the acid… …   Universalium

  • process — processual /pro sesh ooh euhl/ or, esp. Brit, /proh /, adj. /pros es/; esp. Brit. /proh ses/, n., pl. processes /pros es iz, euh siz, euh seez / or, esp. Brit., /proh ses , proh seuh /, v., adj. n. 1. a systematic series of actions directed to… …   Universalium


Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”

We are using cookies for the best presentation of our site. Continuing to use this site, you agree with this.