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27-529: Nyby bruk ( Nyby Mill ) is a steel mill and former mill village , today part of Torshälla in Eskilstuna Municipality , Södermanland County , Sweden . Iron working on the lands of present-day Nyby is first mentioned in written sources from the 15th century. Construction started on a canal through Nyby in the late 16th century during the administration of Charles, Duke of Södermanland, Närke and Värmland , later King Charles IX. The canal

54-411: A cold rolling mill at Nyby bruk. Steel mill A steel mill or steelworks is an industrial plant for the manufacture of steel . It may be an integrated steel works carrying out all steps of steelmaking from smelting iron ore to rolled product, but may also be a plant where steel semi-finished casting products are made from molten pig iron or from scrap . Since the invention of

81-709: A rolling mill . Originally the minimill was adapted to production of bar products only, such as concrete reinforcing bar , flats, angles, channels, pipe, and light rails. Since the late 1980s, successful introduction of the direct strip casting process has made minimill production of strip feasible. Often a minimill will be constructed in an area with no other steel production, to take advantage of local markets, resources, or lower-cost labour. Minimill plants may specialize, for example, in making coils of rod for wire-drawing use, or pipe, or in special sections for transportation and agriculture. Capacities of minimills vary: some plants may make as much as 3,000,000 tons per year,

108-412: A factor of 1,000, from more than 3 man-hours per metric ton to just 0.003. By 2000 the basic oxygen furnace accounted for 60% of global steel output. Modern furnaces will take a charge of iron of up to 400 tons and convert it into steel in less than 40 minutes, compared to 10–12 hours in an open hearth furnace . The basic oxygen process developed outside of the traditional "big steel" environment. It

135-483: A few hours, the accumulated liquid iron is tapped from the blast furnace and either cast into pig iron or directed to other vessels for further steel making operations. Historically the Bessemer process was a major advancement in the production of economical steel, but it has now been entirely replaced by other processes such as the basic oxygen furnace . Molten steel is cast into large blocks called blooms . During

162-421: A lance over the molten pig iron inside the converter. Exothermic heat is generated by the oxidation reactions during blowing. The basic oxygen steel-making process is as follows: Earlier converters, with a false bottom that can be detached and repaired, are still in use. Modern converters have a fixed bottom with plugs for argon purging. The energy optimization furnace (EOF) is a BOF variant associated with

189-621: A professor at the Technische Hochschule in Charlottenburg (now Technische Universität Berlin ), returned to Switzerland and accepted a seat on the board of Roll AG , the country's largest steel mill. In 1947 he purchased the first small 2.5-ton experimental converter from the US, and on April 3, 1948 the new converter produced its first steel. The new process could conveniently process large amounts of scrap metal with only

216-434: A regular basis, minimills can follow the market demand for their products easily, operating on 24-hour schedules when demand is high and cutting back production when sales are lower. Basic oxygen furnace Basic oxygen steelmaking ( BOS , BOP , BOF , or OSM ), also known as Linz-Donawitz steelmaking or the oxygen converter process , is a method of primary steelmaking in which carbon-rich molten pig iron

243-707: A small proportion of primary metal necessary. In the summer of 1948, Roll AG and two Austrian state-owned companies, VÖEST and ÖAMG, agreed to commercialize the Durrer process. By June 1949, VÖEST developed an adaptation of Durrer's process, known as the LD (Linz-Donawitz) process. In December 1949, VÖEST and ÖAMG committed to building their first 30-ton oxygen converters. They were put into operation in November 1952 (VÖEST in Linz) and May 1953 (ÖAMG, Donawitz) and temporarily became

270-457: A typical size is in the range 200,000 to 400,000 tons per year, and some old or specialty plants may make as little as 50,000 tons per year of finished product. Nucor Corporation , for example, annually produces around 9,100,000 tons of sheet steel from its four sheet mills, 6,700,000 tons of bar steel from its 10 bar mills and 2,100,000 tons of plate steel from its two plate mills. Since the electric arc furnace can be easily started and stopped on

297-449: 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 fluxes of calcium oxide or dolomite , which are chemical bases , are added to promote the removal of impurities and protect the lining of the converter. The process was invented in 1948 by Swiss engineer Robert Durrer and commercialized in 1952–1953 by

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324-416: Is sometimes used with scrap, to help maintain desired chemistry of the steel, though usually DRI is too expensive to use as the primary raw steelmaking material. A typical mini-mill will have an electric arc furnace for scrap melting, a ladle furnace or vacuum furnace for precision control of chemistry, a strip or billet continuous caster for converting molten steel to solid form, a reheat furnace and

351-640: Is the pollution produced in the manufacture of coke , which is an essential intermediate product in the reduction of iron ore in a blast furnace. Integrated mills may also adopt some of the processes used in mini-mills, such as arc furnaces and direct casting, to reduce production costs. A minimill is traditionally a secondary steel producer; however, Nucor (one of the world's largest steel producers) and Commercial Metals Company (CMC) use minimills exclusively. Usually it obtains most of its iron from scrap steel, recycled from used automobiles and equipment or byproducts of manufacturing. Direct reduced iron (DRI)

378-583: The Bessemer process , steel mills have replaced ironworks , based on puddling or fining methods. New ways to produce steel appeared later: from scrap melted in an electric arc furnace and, more recently, from direct reduced iron processes. In the late 19th and early 20th centuries the world's largest steel mill was the Barrow Hematite Steel Company steelworks located in Barrow-in-Furness , United Kingdom . Today,

405-522: The Austrian steelmaking company VOEST and ÖAMG . The LD converter, named after the Austrian towns Linz and Donawitz (a district of Leoben ) is a refined version of the Bessemer converter where blowing of air is replaced 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

432-482: The blast furnace grow cold, though some adjustment of the production rate is possible. Integrated mills are large facilities that are typically only economical to build in 2,000,000-ton per year annual capacity and up. Final products made by an integrated plant are usually large structural sections, heavy plate, strip, wire rod, railway rails , and occasionally long products such as bars and pipe . A major environmental hazard associated with integrated steel mills

459-472: The casting process various methods are used, such as addition of aluminum , so that impurities in the steel float to the surface where they can be cut off the finished bloom. Because of the energy cost and structural stress associated with heating and cooling a blast furnace, typically these primary steel making vessels will operate on a continuous production campaign of several years duration. Even during periods of low steel demand, it may not be feasible to let

486-459: The leading edge of the world's steelmaking, causing a surge in steel-related research. Thirty-four thousand businesspeople and engineers visited the VÖEST converter by 1963. The LD process reduced processing time and capital costs per ton of steel, contributing to the competitive advantage of Austrian steel. VÖEST eventually acquired the rights to market the new technology. Errors by the VÖEST and

513-495: The line has been used by the steel mill for freight traffic. The Nyby village remained independent of the neighbouring town of Torshälla until 1952, when the two were merged. Nyby bruk and Nyby-Uddeholm became part of the Avesta group in 1984, after 1992 steel manufacturer Avesta Sheffield . Since 2002 the main production facilities at Nyby bruk are owned by Finnish stainless steel manufacturer Outokumpu . Outokumpu operates

540-698: The molten metal and removing phosphorus impurities. In the Soviet Union, some experimental production of steel using the process was done in 1934, but industrial use was hampered by lack of efficient technology to produce liquid oxygen. In 1939, the Russian physicist Pyotr Kapitsa perfected the design of the centrifugal turboexpander . The process was put to use in 1942–1944. Most turboexpanders in industrial use since then have been based on Kapitsa's design and centrifugal turboexpanders have taken over almost 100% of industrial gas liquefaction, and in particular

567-486: The production of liquid oxygen for steelmaking. Big American steelmakers were late adopters of the new technology. The first oxygen converters in the US were launched at the end of 1954 by McLouth Steel in Trenton, Michigan , which accounted for less than 1% of the national steel market. U.S. Steel and Bethlehem Steel introduced the oxygen process in 1964. By 1970, half of the world's and 80% of Japan's steel output

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594-461: The world's largest steel mill is in Gwangyang , South Korea . An integrated steel mill has all the functions for primary steel production: The principal raw materials for an integrated mill are iron ore, limestone, and coal (or coke). These materials are charged in batches into a blast furnace where the iron compounds in the ore give up excess oxygen and become liquid iron. At intervals of

621-520: The ÖAMG management in licensing their technology made control over its adoption in Japan impossible. By the end of the 1950s, the Austrians lost their competitive edge. In the original LD process, oxygen was blown over the top of the molten iron through the water-cooled nozzle of a vertical lance. In the 1960s, steelmakers introduced bottom-blown converters and developed inert gas blowing for stirring

648-512: Was approximately 2 kilometres long, had three locks and was constructed to circumvent the natural rapids in Torshällaån at Torshälla. However, the canal proved short-lived and gradually fell out of use during the first half of the 17th century due to lack of maintenance, but the stream thus left by the canal provided a natural source of water power. Some traces of the original locks and historical bridges remain along Nybyån. The Nyby Ironworks

675-763: Was developed and refined by a single man, Swiss engineer Robert Durrer , and commercialized by two small steel companies in allied-occupied Austria , which had not yet recovered from the destruction of World War II . In 1856, Henry Bessemer had patented a steelmaking process involving oxygen blowing for decarbonizing molten iron (UK Patent No. 2207). For nearly 100 years commercial quantities of oxygen were not available or were too expensive, and steelmaking used air blowing. During WWII German (Karl Valerian Schwarz), Belgian ( John Miles ) and Swiss ( Durrer and Heinrich Heilbrugge) engineers proposed their versions of oxygen-blown steelmaking, but only Durrer and Heilbrugge brought it to mass-scale production. In 1943, Durrer, formerly

702-429: Was founded in 1829 by Adolf Zethelius on the lands of Nyby manor house west of Torshälla . The ironworks was constructed by Samuel Owen and a new manor house as well as cottages for the workers were built next to the ironworks. A mill village gradually formed around the ironworks. The Norra Södermanlands Järnväg railway was connected to Nyby bruk in 1895. Passenger traffic was discontinued in 1933, after which

729-497: Was produced in oxygen converters. In the last quarter of the 20th century, use of basic oxygen converters for steel production was gradually, partially replaced by the electric arc furnace using scrap steel and iron. In Japan the share of LD process decreased from 80% in 1970 to 70% in 2000; worldwide share of the basic oxygen process stabilized at 60%. Basic oxygen steelmaking is a primary steelmaking process for converting molten pig iron into steel by blowing oxygen through

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