Parts of this article (those related to 2018 tariffs) need to be updated.(November 2018)
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In 2014, the United States was the world’s third-largest producer of raw steel (after China and Japan), and the sixth-largest producer of pig iron. The industry produced 29 million metric tons of pig iron and 88 million tons of steel. Most iron and steel in the United States is now made from iron and steel scrap, rather than iron ore. The United States is also a major importer of iron and steel, as well as iron and steel products.
Employment as of 2014 was 149,000 people employed in iron and steel mills, and 69,000 in foundries. The value of iron and steel produced in 2014 was $113 billion.About 0.3% of the US population is employed by the steel industry.
As of 2015, major steel-makers in the United States included: ArcelorMittal USA, AK Steel, Carpenter Technology, Commercial Metals Company, Nucor, Steel Dynamics, and U.S. Steel.
There are two main types of steel mills. The traditional large integrated steel mill, which reduces metallic iron from ore (iron oxide) and makes it into pig iron and steel, has been steadily declining in importance for decades in the US. The second type, the mini-mill, or specialty steel mill, which produces new steel products by melting steel scrap, now produces the majority of steel in the US.
In 2017, there were 9 operating integrated steel mills in the United States (plus one idled), down from 13 in 2000. Integrated mills produced 31% of the steel produced in the US.
In an integrated steel mill, iron ore is reduced to metallic iron. In the US, this is done in blast furnaces and since 2014 again using direct reduced iron furnaces in Nucor's plant in Louisiana as well as another DRI plant (producing a compactified version of DRI called hot briquetted iron, or HBI) in Texas by Voestalpine. Some of the iron from the blast furnaces is converted to steel; today this is done in basic oxygen furnaces. Iron ore, coke, and flux are fed into the blast furnace and heated. The coke reduces the iron oxide in the ore to metallic iron, and the molten mass separates into slag and iron. Some of the iron from the blast furnace is cooled, and marketed as pig iron; the rest flows into basic oxygen furnaces, where it is converted into steel. Iron and steel scrap may be added to both the blast furnace and the basic iron furnace.
US Steel operates a number of integrated steel mills, including the Gary Works in Gary, Indiana. They also operate the Edgar Thomson Works, which is the iron- and steel-making unit of the Mon Valley Works, which includes three other related plants. The Company operates the Great Lakes Works,and Granite City Works.
ArcelorMittal operates three integrated steel mills: in East Chicago, Indiana, Burns Harbor, Indiana, and Cleveland, Ohio.
AK Steel Corporation has three integrated steel mills, one in Middletown, Ohio, Dearborn, Michigan and the other in Ashland, Kentucky. At present, the Ashland Works is temporarily idled.
Current integrated steel mills in the US
|Name||Location||Owner||Status and Date|
|Gary Works||Gary, Indiana||US Steel||Operating, February 2015|
|Mon Valley Works - Irvin Plant, Edgar Thomson Steel Works||North Braddock, Pennsylvania||US Steel|
|Indiana Harbor Works||East Chicago, Indiana||Cleveland-Cliffs|
|Burns Harbor Works||Burns Harbor, Indiana||Cleveland-Cliffs|
|Middletown Works||Middletown, Ohio||Cleveland-Cliffs|
|Cleveland Works||Cleveland, Ohio||Cleveland-Cliffs|
|Dearborn Works||Dearborn, Michigan||Cleveland-Cliffs||One operating blast furnace ("A") |
Formerly Severstal Dearborn (2004-2014)
Previously Rouge Steel (1989-2004)
Previously Ford Rouge Plant (1910-1989)
|Great Lakes Works||River Rouge and Ecorse, Michigan||US Steel||idled 2019 December|
|Granite City Works||Granite City, Illinois||US Steel||Resumed operation 2018|
|Fairfield Works||Fairfield, Alabama||US Steel||closed permanently 2015 August|
There were about 112 minimills or specialty mills in the US, which in 2013 produced 59% of US total steel production. The specialty mills use iron and steel scrap, rather than iron ore, as feedstock, and melt the scrap in electric furnaces.
Notable Specialty and Mini-Mills in the US
|Name||Location||Owner||Status and Date|
|Brackenridge Works||Brackenridge, Pennsylvania||Allegheny Technologies|
|former Colorado Fuel and Iron plant||Pueblo, Colorado||Oregon Steel Mills||Former integrated mill|
|Evraz Claymont Steel||Claymont, Delaware||Evraz Group||Closed|
|Mississippi Steel||Flowood, Mississippi||Nucor|
|Pennsylvania Steel Company||Steelton, Pennsylvania||ArcelorMittal||Former integrated mill|
The two main inputs into iron- and steel-making are a source of iron and a source of energy. Additional requirements are a fluxing material to remove the impurities, and alloy metals to give particular properties to the metal.
Raw materials used in US iron and steel production, 2012
|Iron ore||46,900,000||Iron source|
|Iron and steel scrap||104,100,000||Iron source|
|Source: US Geological Survey, Minerals Yearbooks, 2012 and 2013.|
Two-thirds of the iron and steel produced in the US is made from recycled scrap, rather than from iron ore. In 2014, 81 million mt of iron and steel were produced from scrap.Most steel from scrap is produced using electric arc furnaces.
Coke is used to reduce iron ore (made up of iron oxides) to metallic iron.
Flux is added to the furnace charge (iron ore, pig iron, or scrap) to lower the melting point, and draw unwanted impurities into the slag. The most common flux is lime. Other fluxes include dolomite, soda ash, and fluorspar.
Other metals are commonly added to steel to produce alloy steels of various types. Common alloy metals are manganese, nickel, molybdenum, chromium, and vanadium. Stainless steel commonly contains a minimum of 10.5% chromium, and may also contain significant amounts of nickel or molybdenum.
Slag, a byproduct of iron and steel-making composed primarily of highly impure glass, would normally be a waste product. However, it is in demand as an aggregate in concrete, asphalt paving, and construction fill. In 2014, the industry produced and marketed about 16.0 million mt of slag, worth an estimated $270 million.
The United States has been a major importer of steel and steel mill products since the 1960s. In 2014, the US exported 11 million tons of steel products, and imported 39 million tons. Net imports were 17 percent of consumption.
The US iron and steel industry has paralleled the industry in other countries in technological developments. In the 1800s, the US switched from charcoal to coke in ore smelting, adopted the Bessemer process, and saw the rise of very large integrated steel mills. In the 20th century, the US industry successively adopted the open hearth process, then the basic oxygen furnace. Since the American industry peaked in the 1940s and 1950s, the US industry has shifted to small mini-mills and specialty mills, using iron and steel scrap as feedstock, rather than iron ore.
Smelting is a process of applying heat to ore in order to extract a base metal. It is a form of extractive metallurgy. It is used to extract many metals from their ores, including silver, iron, copper, and other base metals. Smelting uses heat and a chemical reducing agent to decompose the ore, driving off other elements as gases or slag and leaving the metal base behind. The reducing agent is commonly a fossil fuel source of carbon, such as coke—or, in earlier times, charcoal. The oxygen in the ore binds to carbon at high temperatures due to the lower potential energy of the bonds in carbon dioxide. Smelting most prominently takes place in a blast furnace to produce pig iron, which is converted into steel.
Wrought iron is an iron alloy with a very low carbon content in contrast to that of cast iron. It is a semi-fused mass of iron with fibrous slag inclusions, which gives it a "grain" resembling wood that is visible when it is etched or bent to the point of failure. Wrought iron is tough, malleable, ductile, corrosion resistant, and easily welded.
Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, or deep purple to rusty red. The iron is usually found in the form of magnetite (Fe
4, 72.4% Fe), hematite (Fe
3, 69.9% Fe), goethite (FeO(OH), 62.9% Fe), limonite (FeO(OH)·n(H2O), 55% Fe) or siderite (FeCO3, 48.2% Fe).
Steelmaking is the process of producing steel from iron ore and/or scrap. In steelmaking, impurities such as nitrogen, silicon, phosphorus, sulfur and excess carbon are removed from the sourced iron, and alloying elements such as manganese, nickel, chromium, carbon and vanadium are added to produce different grades of steel. Limiting dissolved gases such as nitrogen and oxygen and entrained impurities in the steel is also important to ensure the quality of the products cast from the liquid steel.
Slag is the glass-like by-product left over after a desired metal has been separated from its raw ore. Slag is usually a mixture of metal oxides and silicon dioxide. However, slags can contain metal sulfides and elemental metals. While slags are generally used to remove waste in metal smelting, they can also serve other purposes, such as assisting in the temperature control of the smelting, and minimizing any re-oxidation of the final liquid metal product before the molten metal is removed from the furnace and used to make solid metal. In some smelting processes, such as ilmenite smelting to produce titanium dioxide, the slag is the valuable product instead of the metal.
A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. Blast refers to the combustion air being "forced" or supplied above atmospheric pressure.
Nucor Corporation is a producer of steel and related products based in Charlotte, North Carolina. It is the largest steel producer in the United States, as well as the largest "mini-mill" steelmaker. It is also the biggest recycler of scrap in North America.
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.
An electric arc furnace (EAF) is a furnace that heats charged material by means of an electric arc.
A bloomery is a type of furnace once used widely for smelting iron from its oxides. The bloomery was the earliest form of smelter capable of smelting iron. Bloomeries produce a porous mass of iron and slag called a bloom. The mix of slag and iron in the bloom, termed sponge iron, is usually consolidated and further forged into wrought iron. Blast furnaces, which produce pig iron, have largely superseded bloomeries.
Ferroalloy refers to various alloys of iron with a high proportion of one or more other elements such as manganese (Mn), aluminium (Al), or silicon (Si). They are used in the production of steels and alloys. The alloys impart distinctive qualities to steel and cast iron or serve important functions during production and are, therefore, closely associated with the iron and steel industry, the leading consumer of ferroalloys. The leading producers of ferroalloys in 2014 were China, South Africa, India, Russia and Kazakhstan, which accounted for 84% of the world production. World production of ferroalloys was estimated as 52.8 million tonnes in 2015.
An ironworks or iron works is an industrial plant where iron is smelted and where heavy iron and steel products are made. The term is both singular and plural, i.e. the singular of ironworks is ironworks.
Direct reduced iron (DRI), also called sponge iron, is produced from the direct reduction of iron ore into iron by a reducing gas or elemental carbon produced from natural gas or coal. Many ores are suitable for direct reduction.
A finery forge is a forge used to produce wrought iron from pig iron by decarburization in a process called "fining" which involved liquifying cast iron in a fining hearth and removing carbon from the molten cast iron through oxidation. Finery forges were used as early as the 3rd century BC in China. The finery forge process was replaced by the puddling process and the roller mill, both developed by Henry Cort in 1783–4, but not becoming widespread until after 1800.
Cornwall Iron Furnace is a designated National Historic Landmark that is administered by the Pennsylvania Historical and Museum Commission in Cornwall, Lebanon County, Pennsylvania in the United States. The furnace was a leading Pennsylvania iron producer from 1742 until it was shut down in 1883. The furnaces, support buildings and surrounding community have been preserved as a historical site and museum, providing a glimpse into Lebanon County's industrial past. The site is the only intact charcoal-burning iron blast furnace in its original plantation in the western hemisphere. Established by Peter Grubb in 1742, Cornwall Furnace was operated during the Revolution by his sons Curtis and Peter Jr. who were major arms providers to George Washington. Robert Coleman acquired Cornwall Furnace after the Revolution and became Pennsylvania's first millionaire. Ownership of the furnace and its surroundings was transferred to the Commonwealth of Pennsylvania in 1932.
A cupola or cupola furnace is a melting device used in foundries that can be used to melt cast iron, Ni-resist iron and some bronzes. The cupola can be made almost any practical size. The size of a cupola is expressed in diameters and can range from 1.5 to 13 feet. The overall shape is cylindrical and the equipment is arranged vertically, usually supported by four legs. The overall look is similar to a large smokestack.
Plants for the production of lead are generally referred to as lead smelters. Primary lead production begins with sintering. Concentrated lead ore is fed into a sintering machine with iron, silica, limestone fluxes, coke, soda ash, pyrite, zinc, caustics or pollution control particulates. Smelting uses suitable reducing substances that will combine with those oxidizing elements to free the metal. Reduction is the final, high-temperature step in smelting. It is here that the oxide becomes the elemental metal. A reducing environment pulls the final oxygen atoms from the raw metal.
The US iron and steel industry has paralleled the industry in other countries in technological developments. In the 1800s, the US switched from charcoal to coke in ore smelting, adopted the Bessemer process, and saw the rise of very large integrated steel mills. In the 20th century, the US industry successively adopted the open hearth furnace, then the basic oxygen steelmaking process. Since the American industry peaked in the 1940s and 1950s, the US industry has shifted to small mini-mills and specialty mills, using iron and steel scrap as feedstock, rather than iron ore.
The iron and steel industries are among the most important industries in India. India replaces Japan as second top steel producer in January,2019. As per worldsteel, India's crude steel production in 2018 was at 106.5 MT, 4.9% increase from 101.5 MT in 2017, means that India has replaced Japan as world second largest steel production country. Japan produced 104.3 MT in year 2018, decrease of 0.3% compared to year 2017. Industry produced 82.68 million tons of total finished steel and 9.7 million tons of raw iron. Most iron and steel in India is produced from the iron ore.
The Lithgow Blast Furnace is a heritage-listed former blast furnace and now park and visitor attraction at Inch Street, Lithgow, City of Lithgow, New South Wales, Australia. It was built from 1906 to 1907 by William Sandford Limited. It is also known as Eskbank Ironworks Blast Furnace site; Industrial Archaeological Site. The property is owned by Lithgow City Council. It was added to the New South Wales State Heritage Register on 2 April 1999.