Iron and steel industry in the United States

In 2014, the Iron and steel industry in 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 a major importer of iron and steel, and 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.[1]

As of 2015, major steel-makers in the United States included: AK Steel, Carpenter Technology, Commercial Metals Company, and Nucor, Steel Dynamics, and U.S. Steel.[2]

Steel mills

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.

Integrated steel mills

In 2014, there were 11 operating integrated steel mills in the United States, 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. The direct-reduction method of producing iron from ore has not been used in the US since 2012. 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.[3]

ArcelorMittal operates three integrated steel mills: in East Chicago, Indiana, Burns Harbor, Indiana, and Cleveland, Ohio.[4]

Current integrated steel mills in the US

Name Location Owner Status and Date
Gary Works Gary, Indiana US Steel Operating, February 2015[5]
Mon Valley Works - Irvin Plant, Edgar Thomson Steel Works North Braddock, Pennsylvania US Steel
East Chicago Tin East Chicago, Indiana US Steel
Midwest Plant Portage, Indiana US Steel
Rouge Steel Dearborn, Michigan AK Steel Holding
Fairfield Works Fairfield, Alabama US Steel Plan to convert to electric arc furnace, February 2015.[5]
Granite City Works Granite City, Illinois US Steel
Indiana Harbor Works East Chicago, Indiana ArcelorMittal
Burns Harbor Works Burns Harbor, Indiana ArcelorMittal
Cleveland Works Cleveland, Ohio ArcelorMittal

Specialty steel mills / minimills

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

Raw materials

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

Input metric tons Purpose
Iron ore 46,900,000 Iron source
Iron and steel scrap 104,100,000 Iron source
Coke 9,490,000 Reducing agent
Lime 5,730,000 Flux
Fluorspar 47,800 Flux
Manganese 382,000 Alloy
Chromium 251,000 Alloy
Nickel 194,000 Alloy
Molybdenum 11,800 Alloy
Vanadium 2,500 Alloy
Tungsten 123 Alloy
Source: US Geological Survey, Minerals Yearbooks, 2012 and 2013.[6]

Iron ore

Iron and steel scrap

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.[7] Most steel from scrap is produced using electric arc furnaces.

Coke

Coke is used to reduce iron ore (made up of iron oxides) to metallic iron.

Flux

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.

Alloy metals

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

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 mt of slag, worth an estimated $270 million.[8]

International trade

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.[9] As of 2012, the largest sources of net steel imports to the US were, in descending order, the European Union, Brazil, South Korea, Japan, and Russia.[10]

History of US iron- and steel-making

Graph of US iron and steel production, 1900-2014, data from USGS

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.

References

  1. Iron and Steel, Mineral Commodities Summaries.
  2. US Department of Commerce, [ Steel industry executive summary], June 2015.
  3. US Steel Corp., Facilities, accessed 1 August 2015.
  4. 2014 ArelorMittal USA Factbook.
  5. 1 2 "US Steel closes Gary Works coke plant," Chicago Tribune, 26 Feb. 2015.
  6. US Geological Survey, Minerals Yearbook, 2012 and 2013.
  7. Michael D. Fenton, Iron and steel scrap, US Geological Survey, Mineral Commodity Summary 2015, Jan. 2015.
  8. Hendrik G. van Oss, Iron and Steel Slag, US Geological Survey, Mineral Commodity Summaries, Jan. 2015.
  9. US Geological Survey, , 2015.
  10. Iron and Steel US Geological Survey, Minerals Yearbook 2012.

External links

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