Editing Basic oxygen steelmaking (section)

{{Short description|Steelmaking method}}
[[File:ThyssenKrupp Duisburg 016.jpg|thumb|upright=1.1|Oxygen converter being charged at ThyssenKrupp steel mill in [[Duisburg]] (Germany)]]

'''Basic oxygen steelmaking''' ('''BOS''', '''BOP''', '''BOF''', or '''OSM'''), also known as '''Linz-Donawitz steelmaking''' or the '''oxygen converter process''',<ref name=B50>Brock and Elzinga, p. 50.</ref> is a method of primary [[steelmaking]] in which carbon-rich molten [[pig iron]] is made into [[steel]]. Blowing [[oxygen]] through molten pig iron lowers the carbon content of the [[alloy]] and changes it into [[low-carbon steel]]. The process is known as ''basic'' because [[flux (metallurgy)|flux]]es of [[calcium oxide]] or [[dolomite (rock)|dolomite]], which are chemical ''[[base (chemistry)|bases]]'', are added to promote the removal of impurities and protect the lining of the converter.<ref>{{cite web |url=https://content.steeluniversity.org/simulators/sc13/bos/help/BOS_User_Guide_EN_ver02.pdf |title=Basic Oxygen Steelmaking Simulation User Guide version 2.00 |website=[[steeluniversity.org]] |access-date=2021-04-27 |url-status=live |archive-url=https://web.archive.org/web/20210427223054/https://content.steeluniversity.org/simulators/sc13/bos/help/BOS_User_Guide_EN_ver02.pdf |archive-date=2021-04-27}}</ref>

The process was invented in 1948 by Swiss engineer [[Robert Durrer]] and commercialized in 1952–1953 by the Austrian steelmaking company [[voestalpine|VOEST and ÖAMG]]. The LD converter, named after the [[Austria]]n towns [[Linz]] and Donawitz (a district of [[Leoben]]) is a refined version of the [[Bessemer converter]] which replaces blowing air with blowing oxygen. It reduced capital cost of the plants and smelting time, and increased labor productivity. Between 1920 and 2000, labor requirements in the industry decreased by a factor of 1,000, from more than 3 man-hours per metric ton to just 0.003.<ref name=S99>Smil, p. 99.</ref> By 2000 the basic oxygen furnace accounted for 60% of global steel output.<ref name=S99/>

Modern furnaces will take a charge of iron of up to 400 tons<ref>{{cite web |title=Hot metal and crude steel production |url=http://en.stahl-online.de/index.php/topics/technology/steelmaking/ |website=stahl-online.de |url-status=dead |archive-url=https://web.archive.org/web/20210116171715/https://en.stahl-online.de/index.php/topics/technology/steelmaking/ |archive-date=2021-01-16}}</ref> and convert it into steel in less than 40 minutes, compared to 10–12 hours in an [[open hearth furnace]].