Misplaced Pages

#250749

122-489: To supply its mills, Nucor uses electric arc furnaces and continuous casting to melt scrap steel as opposed to blast furnaces to melt iron . In 2023, the company produced and sold approximately 18.5 million tons of steel and recycled 18.4 million tons of scrap. None of Nucor's mills are unionized and the corporate culture is opposed to trade unions . After REO Motor Car Company , founded by Ransom E. Olds , sold its operations and initiated liquidation proceedings,

244-486: A poll tax and literacy test . The 1901 constitution required racial segregation of public schools. By 1903 only 2,980 African Americans were registered in Alabama, although at least 74,000 were literate . This compared to more than 181,000 African Americans eligible to vote in 1900. The numbers dropped even more in later decades. The state legislature passed additional racial segregation laws related to public facilities into

366-431: A base. Care is taken to layer the scrap in the basket to ensure good furnace operation; heavy melt is placed on top of a light layer of protective shred, on top of which is placed more shred. These layers should be present in the furnace after charging. After loading, the basket may pass to a scrap pre-heater, which uses hot furnace off-gases to heat the scrap and recover energy, increasing plant efficiency. The scrap basket

488-431: A capacity of only a few dozen grams. Industrial electric arc furnace temperatures can reach 1,800 °C (3,300 °F), while laboratory units can exceed 3,000 °C (5,400 °F). In electric arc furnaces, the charge material (the material entered into the furnace for heating, not to be confused with electric charge ) is directly exposed to an electric arc, and the current from the electrode terminals passes through

610-403: A continuous, rather than batch, basis. Continuous-process furnaces may also use paste-type, Søderberg electrodes to prevent interruptions from electrode changes. Such a furnace is known as a submerged arc furnace , because the electrode tips are buried in the slag/charge, and arcing occurs through the slag, between the matte and the electrode. The casing and casing fins of the electrode melt

732-650: A few days, it joined the Confederate States of America . The Confederacy's capital was initially at Montgomery. Alabama was heavily involved in the American Civil War . Although comparatively few battles were fought in the state, Alabama contributed about 120,000 soldiers to the war effort. A company of cavalry soldiers from Huntsville, Alabama, joined Nathan Bedford Forrest 's battalion in Hopkinsville, Kentucky . The company wore new uniforms with yellow trim on

854-566: A greater affinity for oxygen. Metals that have a poorer affinity for oxygen than iron, such as nickel and copper , cannot be removed through oxidation and must be controlled through scrap chemistry alone, such as introducing the direct reduced iron and pig iron mentioned earlier. A foaming slag is maintained throughout, and often overflows the furnace to pour out of the slag door into the slag pit. Temperature sampling and chemical sampling take place via automatic lances. Oxygen and carbon can be automatically measured via special probes that dip into

976-643: A group of dissident activist shareholders , noticing the existence of a usable tax loss, successfully challenged the liquidation in a proxy fight in September 1955 and forced REO to take over a tiny nuclear services company called Nuclear Consultants, Inc. in a reverse takeover . The company was renamed "Nuclear Corporation of America Inc." and relocated to offices in the Empire State Building in New York City . The organization's attempt to recast itself as

1098-505: A hideout of Jesse James ; Stephens Gap Cave, in Jackson County , which has a 143-foot pit and two waterfalls and is one of the most photographed wild cave scenes in America; Little River Canyon, near Fort Payne, one of the nation's longest mountaintop rivers; Rickwood Caverns , near Warrior , which has an underground pool, blind cave-fish, and 260-million-year-old limestone formations; and

1220-561: A lawsuit and court order. Beginning in the 1940s, when the courts started taking the first steps to recognize the voting rights of black voters, the Alabama legislature took several counter-steps designed to disfranchise black voters. The legislature passed, and the voters ratified [as these were mostly white voters], a state constitutional amendment that gave local registrars greater latitude to disqualify voter registration applicants. Black citizens in Mobile successfully challenged this amendment as

1342-555: A local aerospace industry. Alabama's economy in the 21st century is based on automotive, finance, tourism, manufacturing, aerospace, mineral extraction, healthcare, education, retail, and technology. The name of the Alabama River and state is derived from the Alabama people , a Muskogean-speaking tribe whose members lived just below the confluence of the Coosa and Tallapoosa rivers on

SECTION 10

#1732856188251

1464-399: A modern shop such a furnace would be expected to produce a quantity of 80 tonnes of liquid steel in approximately 50 minutes from charging with cold scrap to tapping the furnace. In comparison, basic oxygen furnaces can have a capacity of 150–300 tonnes per batch, or "heat", and can produce a heat in 30–40 minutes. Enormous variations exist in furnace design details and operation, depending on

1586-528: A nuclear industry services company was unsuccessful, and it followed the example of other companies in the 1950s and 60s by attempting to become a conglomerate , moving its headquarters to Phoenix, Arizona . It made several acquisitions, including the Vulcraft Corporation, a steel joist manufacturer located in Florence, South Carolina . Vulcraft was founded by Sanborn Chase, who died at an early age, leaving

1708-437: A pattern of hot and cold-spots around the hearth perimeter, with the cold-spots located between the electrodes. Modern furnaces mount oxygen-fuel burners in the sidewall and use them to provide chemical energy to the cold-spots, making the heating of the steel more uniform. Additional chemical energy is provided by injecting oxygen and carbon into the furnace; historically this was done through lances (hollow mild-steel tubes ) in

1830-404: A scrap bay, located next to the melt shop. Scrap generally comes in two main grades: shred ( whitegoods , cars and other objects made of similar light-gauge steel) and heavy melt (large slabs and beams), along with some direct reduced iron (DRI) or pig iron for chemical balance. Some furnaces melt almost 100% DRI. The scrap is loaded into large buckets called baskets, with "clamshell" doors for

1952-584: A significant minority in the state, they had been unable to elect any representatives in most of the at-large jurisdictions. As part of settlement of this case, five Alabama cities and counties, including Chilton County , adopted a system of cumulative voting for election of representatives in multi-seat jurisdictions. This has resulted in more proportional representation for voters. In another form of proportional representation, 23 jurisdictions use limited voting , as in Conecuh County . In 1982, limited voting

2074-582: A slight majority of those disenfranchised by these laws: 600,000 whites vs. 520,000 African Americans. Nearly all Blacks had lost the ability to vote. Despite numerous legal challenges which succeeded in overturning certain provisions, the state legislature would create new ones to maintain disenfranchisement. The exclusion of blacks from the political system persisted until after passage of federal civil rights legislation in 1965 to enforce their constitutional rights as citizens. The rural-dominated Alabama legislature consistently underfunded schools and services for

2196-411: A tonne of scrap steel is 300 kWh (1.09 GJ) (melting point 1,520 °C (2,768 °F)). Therefore, a 300-tonne, 300 MVA EAF will require approximately 132 MWh of energy to melt the steel, and a "power-on time" (the time that steel is being melted with an arc) of approximately 37 minutes. Electric arc steelmaking is only economical where there is plentiful, reliable electricity, with

2318-585: A violation of the Fifteenth Amendment . The legislature also changed the boundaries of Tuskegee to a 28-sided figure designed to fence out blacks from the city limits. The Supreme Court unanimously held that this racial " gerrymandering " violated the Constitution. In 1961,   ... the Alabama legislature also intentionally diluted the effect of the black vote by instituting numbered place requirements for local elections. Industrial development related to

2440-410: A well-developed electrical grid. In many locations, mills operate during off-peak hours when utilities have surplus power generating capacity and the price of electricity is less. This compares very favourably with energy consumption of global steel production by all methods estimated at some 5,555 kWh (20 GJ) per tonne (1 gigajoule is equal to approximately 270 kWh). Scrap metal is delivered to

2562-426: Is iron oxide from steel combusting with the injected oxygen. Later in the heat, carbon (in the form of coke or coal ) is injected into this slag layer, reacting with the iron oxide to form metallic iron and carbon monoxide gas, which then causes the slag to foam , allowing greater thermal efficiency , and better arc stability and electrical efficiency . The slag blanket also covers the arcs, preventing damage to

SECTION 20

#1732856188251

2684-483: Is Alabama's largest metropolitan area and its economic center. Politically, as part of the Deep South , or " Bible Belt ", Alabama is a predominantly conservative state, and is known for its Southern culture . Within Alabama, American football , particularly at the college level, plays a major part of the state's culture. Originally home to many native tribes, present-day Alabama was a Spanish territory beginning in

2806-639: Is a state in the Southeastern region of the United States. It borders Tennessee to the north, Georgia to the east, Florida and the Gulf of Mexico to the south, and Mississippi to the west. Alabama is the 30th largest by area and the 24th-most populous of the 50 U.S. states . Alabama is nicknamed the Yellowhammer State , after the state bird . Alabama is also known as the "Heart of Dixie " and

2928-406: Is called "tapping". Originally, all steelmaking furnaces had a tapping spout closed with refractory that washed out when the furnace was tilted, but often modern furnaces have an eccentric bottom tap-hole (EBT) to reduce inclusion of nitrogen and slag in the liquid steel. These furnaces have a taphole that passes vertically through the hearth and shell, and is set off-centre in the narrow "nose" of

3050-573: Is common in the U.S.; an estimated 26 states have names of Native American origin. Sources disagree on the word's meaning. Some scholars suggest the word comes from the Choctaw alba (meaning 'plants' or 'weeds') and amo (meaning 'to cut', 'to trim', or 'to gather'). The meaning may have been 'clearers of the thicket' or 'herb gatherers', referring to clearing land for cultivation or collecting medicinal plants. The state has numerous place names of Native American origin . An 1842 article in

3172-600: Is filled with sand at the completion of tapping. For a 90-tonne, medium-power furnace, the whole process will usually take about 60–70 minutes from the tapping of one heat to the tapping of the next (the tap-to-tap time). The furnace is completely emptied of steel and slag on a regular basis so that an inspection of the refractories can be made and larger repairs made if necessary. As the refractories are often made from calcined carbonates , they are extremely susceptible to hydration from water, so any suspected leaks from water-cooled components are treated extremely seriously, beyond

3294-626: Is flexibility: while blast furnaces cannot vary their production by much and can remain in operation for years at a time, EAFs can be rapidly started and stopped, allowing the steel mill to vary production according to demand. Although steelmaking arc furnaces generally use scrap steel as their primary feedstock, if hot metal from a blast furnace or direct-reduced iron is available economically, these can also be used as furnace feed. As EAFs require large amounts of electrical power, many companies schedule their operations to take advantage of off-peak electricity pricing . A typical steelmaking arc furnace

3416-420: Is left in the furnace in order to form a "hot heel", which helps preheat the next charge of scrap and accelerate its meltdown. During and after tapping, the furnace is "turned around": the slag door is cleaned of solidified slag, the visible refractories are inspected and water-cooled components checked for leaks, and electrodes are inspected for damage or lengthened through the addition of new segments. The taphole

3538-570: Is mostly mountainous, with the Tennessee River cutting a large valley and creating numerous creeks, streams, rivers, mountains, and lakes. Alabama is bordered by the states of Tennessee to the north, Georgia to the east, Florida to the south, and Mississippi to the west. Alabama has coastline at the Gulf of Mexico, in the extreme southern edge of the state. The state ranges in elevation from sea level at Mobile Bay to more than 2,000 feet (610 m) in

3660-470: Is provided by wall-mounted oxygen-fuel burners. Both processes accelerate scrap meltdown. Supersonic nozzles enable oxygen jets to penetrate foaming slag and reach the liquid bath. An important part of steelmaking is the formation of slag , which floats on the surface of the molten steel. Slag usually consists of metal oxides , and acts as a destination for oxidised impurities, as a thermal blanket (stopping excessive heat loss) and helping to reduce erosion of

3782-571: Is significantly lower than the conventional production route via blast furnaces and the basic oxygen furnace, which produces 2.9 tons CO2 per ton of steel produced. Although the modern electric arc furnace is a highly efficient recycler of steel scrap , operation of an arc furnace shop can have adverse environmental effects. Much of the capital cost of a new installation will be devoted to systems intended to reduce these effects, which include: Since EAF steelmaking mainly use recycled materials like scrap iron and scrap steel, as their composition varies

Nucor - Misplaced Pages Continue

3904-422: Is the highest efficiency cooling method. A spray cooling piece of equipment can be relined almost endlessly. Equipment that lasts 20 years is the norm. While a tubular leak is immediately noticed in an operating furnace due to the pressure loss alarms on the panels, at this time there exists no immediate way of detecting a very small volume spray cooling leak. These typically hide behind slag coverage and can hydrate

4026-495: Is the source of steel for a mini-mill, which may make bars or strip product. Mini-mills can be sited relatively near the markets for steel products, so the transport requirements are less than for an integrated mill, which would commonly be sited near a harbor for better access to shipping. Depending on the proportions of steel scrap, DRI and pig iron used, electric arc furnace steelmaking can result in carbon dioxide emissions as low as 0.6 tons CO 2 per ton of steel produced, which

4148-456: Is then taken to the melt shop, the roof is swung off the furnace, and the furnace is charged with scrap from the basket. Charging is one of the more dangerous operations for the EAF operators. A lot of potential energy is released by the tonnes of falling metal; any liquid metal in the furnace is often displaced upwards and outwards by the solid scrap, and the grease and dust on the scrap is ignited if

4270-521: Is today southern Clarke County , northernmost Mobile County , and most of Washington County . What are now Baldwin and Mobile counties became part of Spanish West Florida in 1783, part of the independent Republic of West Florida in 1810, and finally part of the Mississippi Territory in 1812. Most of what is now the northern two-thirds of Alabama was known as the Yazoo lands beginning during

4392-411: Is too conductive to form an effective heat-generating resistance. Amateurs have constructed a variety of arc furnaces, often based on electric arc welding kits contained by silica blocks or flower pots. Though crude, these simple furnaces can melt a wide range of materials, create calcium carbide , and more. Smaller arc furnaces may be adequately cooled by circulation of air over structural elements of

4514-457: Is used, as well as less electrical harmonics and other similar problems. The size of DC arc furnaces is limited by the current carrying capacity of available electrodes, and the maximum allowable voltage. Maintenance of the conductive furnace hearth is a bottleneck in extended operation of a DC arc furnace. In a steel plant, a ladle furnace (LF) is used to maintain the temperature of liquid steel during processing after tapping from EAF or to change

4636-621: The Blaine Amendment , prohibiting public money from being used to finance religious-affiliated schools. The same year, legislation was approved that called for racially segregated schools. Railroad passenger cars were segregated in 1891. The new 1901 Constitution of Alabama included provisions for voter registration that effectively disenfranchised large portions of the population, including nearly all African Americans and Native Americans, and tens of thousands of poor European Americans, through making voter registration difficult, requiring

4758-536: The Jacksonville Republican proposed it meant 'Here We Rest'. This notion was popularized in the 1850s through the writings of Alexander Beaufort Meek . Experts in the Muskogean languages have not found any evidence to support such a translation. Indigenous peoples of varying cultures lived in the area for thousands of years before the advent of European colonization. Trade with the northeastern tribes by

4880-644: The Montgomery bus boycott (1955–1956), Freedom Rides in 1961, and 1965 Selma to Montgomery marches. These contributed to Congressional passage and enactment of the Civil Rights Act of 1964 and Voting Rights Act of 1965 by the U.S. Congress. Legal segregation ended in the states in 1964, but Jim Crow customs often continued until specifically challenged in court. According to The New York Times , by 2017, many of Alabama's African Americans were living in Alabama's cities such as Birmingham and Montgomery. Also,

5002-499: The Muskogee tribes developed distinct cultures and languages. The Spanish were the first Europeans to reach Alabama during their exploration of North America in the 16th century. The expedition of Hernando de Soto passed through Mabila and other parts of the state in 1540. More than 160 years later, the French founded the region's first European settlement at Old Mobile in 1702. The city

Nucor - Misplaced Pages Continue

5124-709: The Natchez Trace Parkway , the Selma To Montgomery National Historic Trail , and the Trail of Tears National Historic Trail . Natural wonders include the "Natural Bridge" rock, the longest natural bridge east of the Rockies , just south of Haleyville ; Cathedral Caverns , in Marshall County , named for its cathedral-like appearance, which features one of the largest cave entrances and one of

5246-709: The Ohio River began during the Burial Mound Period (1000   BCE – 700   CE) and continued until European contact . The agrarian Mississippian culture covered most of the state from 1000 to 1600 CE, with one of its major centers built at what is now the Moundville Archaeological Site in Moundville, Alabama . This is the second-largest complex of the classic Middle Mississippian era, after Cahokia in present-day Illinois , which

5368-589: The Upper South brought slaves with them as the cotton plantations in Alabama expanded. The economy of the central Black Belt (named for its dark, productive soil) was built around large cotton plantations whose owners' wealth grew mainly from slave labor. The area also drew many poor, disenfranchised people who became subsistence farmers . Alabama had an estimated population of under 10,000 people in 1810, but it increased to more than 300,000 people by 1830. Most Native American tribes were completely removed from

5490-623: The Walls of Jericho canyon, on the Alabama–Tennessee border. A 5-mile (8 km)-wide meteorite impact crater is located in Elmore County , just north of Montgomery. This is the Wetumpka crater , the site of "Alabama's greatest natural disaster". A 1,000-foot (300 m)-wide meteorite hit the area about 80 million years ago. The hills just east of downtown Wetumpka showcase the eroded remains of

5612-1071: The northeast , to Mount Cheaha at 2,413 ft (735 m). Alabama's land consists of 22 million acres (89,000 km ) of forest or 67% of the state's total land area. Suburban Baldwin County , along the Gulf Coast, is the largest county in the state in both land area and water area. Areas in Alabama administered by the National Park Service include Horseshoe Bend National Military Park near Alexander City ; Little River Canyon National Preserve near Fort Payne ; Russell Cave National Monument in Bridgeport ; Tuskegee Airmen National Historic Site in Tuskegee; and Tuskegee Institute National Historic Site near Tuskegee. Additionally, Alabama has four National Forests : Conecuh , Talladega , Tuskegee , and William B. Bankhead . Alabama also contains

5734-405: The refractory lining. For a furnace with basic refractories, which includes most carbon steel -producing furnaces, the usual slag formers are calcium oxide (CaO, in the form of burnt lime ) and magnesium oxide (MgO, in the form of dolomite and magnesite ). These slag formers are either charged with the scrap, or blown into the furnace during meltdown. Another major component of EAF slag

5856-423: The "Cotton State". The state has diverse geography, with the north dominated by the mountainous Tennessee Valley and the south by Mobile Bay , a historically significant port. Alabama's capital is Montgomery , and its largest city by population and area is Huntsville . Its oldest city is Mobile , founded by French colonists ( Alabama Creoles ) in 1702 as the capital of French Louisiana . Greater Birmingham

5978-405: The "Magic City". By 1920, Birmingham was the 36th-largest city in the United States. Heavy industry and mining were the basis of its economy. Its residents were under-represented for decades in the state legislature, which refused to redistrict after each decennial census according to population changes, as it was required by the state constitution. This did not change until the late 1960s following

6100-404: The 1950s: jails were segregated in 1911; hospitals in 1915; toilets, hotels, and restaurants in 1928; and bus stop waiting rooms in 1945. While the planter class had persuaded poor whites to vote for this legislative effort to suppress black voting, the new restrictions resulted in their disenfranchisement as well, due mostly to the imposition of a cumulative poll tax. By 1941, whites constituted

6222-493: The Alabama Territory on March 3, 1817. St. Stephens , now abandoned, served as the territorial capital from 1817 to 1819. Alabama was admitted as the 22nd state on December 14, 1819, with Congress selecting Huntsville as the site for the first Constitutional Convention . From July   5 to August 2, 1819, delegates met to prepare the new state constitution. Huntsville served as temporary capital from 1819 to 1820, when

SECTION 50

#1732856188251

6344-519: The Alabama legislature." In the United States Supreme Court cases of Baker v. Carr (1962) and Reynolds v. Sims (1964), the court ruled that the principle of " one man, one vote " needed to be the basis of both houses of state legislatures, and that their districts had to be based on population rather than geographic counties. African Americans continued to press in the 1950s and 1960s to end disenfranchisement and segregation in

6466-636: The Black Belt region across central Alabama "is home to largely poor counties that are predominantly African-American. These counties include Dallas, Lowndes , Marengo and Perry ." In 1972, for the first time since 1901, the legislature completed the congressional redistricting based on the decennial census. This benefited the urban areas that had developed, as well as all in the population who had been underrepresented for more than sixty years. Other changes were made to implement representative state house and senate districts. Alabama has made some changes since

6588-671: The British colonial period. It was claimed by the Province of Georgia from 1767 onwards. Following the Revolutionary War, it remained a part of Georgia, although heavily disputed. With the exception of the area around Mobile and the Yazoo lands, what is now the lower one-third of Alabama was made part of the Mississippi Territory when it was organized in 1798. The Yazoo lands were added to

6710-536: The Eastern US, the companies that followed them into mini-mill operations concentrated on local markets for long products, where the EAF allowed the plants to vary production according to local demand. This pattern was followed globally, with EAF steel production primarily used for long products, while integrated mills, using blast furnaces and basic oxygen furnaces , cornered the markets for "flat products"— sheet steel and heavier steel plate. In 1987, Nucor expanded into

6832-554: The Knight of Elvas and Rodrigo Ranjel wrote Alibamu and Limamu , respectively, in transliterations of the term. As early as 1702, the French called the tribe the Alibamon , with French maps identifying the river as Rivière des Alibamons . Other spellings of the name have included Alibamu , Alabamo , Albama , Alebamon , Alibama , Alibamou , Alabamu , and Allibamou . The use of state names derived from Native American languages

6954-585: The Mississippian peoples; it is one of the primary means by which their religion is understood. Among the historical tribes of Native American people living in present-day Alabama at the time of European contact were the Cherokee , an Iroquoian language people; and the Muskogean-speaking Alabama ( Alibamu ), Chickasaw , Choctaw , Creek, and Koasati . While part of the same large language family,

7076-548: The United States with 52,419 square miles (135,760 km ) of total area: 3.2% of the area is water, making Alabama 23rd in the amount of surface water, also giving it the second-largest inland waterway system in the United States. About three-fifths of the land area is part of the Gulf Coastal Plain , a gentle plain with a general descent towards the Mississippi River and the Gulf of Mexico. The North Alabama region

7198-644: The alloy composition. The ladle is used for the first purpose when there is a delay later in the steelmaking process. The ladle furnace consists of a refractory roof, a heating system, and, when applicable, a provision for injecting argon gas into the bottom of the melt for stirring. Unlike a scrap melting furnace, a ladle furnace does not have a tilting or scrap-charging mechanism. Electric arc furnaces are also used for production of calcium carbide , ferroalloys , and other non-ferrous alloys , and for production of phosphorus . Furnaces for these services are physically different from steel-making furnaces and may operate on

7320-615: The arc type. The first successful and operational furnace was invented by James Burgess Readman in Edinburgh , Scotland, in 1888 and patented in 1889. This was specifically for the creation of phosphorus . Further electric arc furnaces were developed by Paul Héroult , of France , with a commercial plant established in the United States in 1907. The Sanderson brothers formed The Sanderson Brothers Steel Co. in Syracuse, New York, installing

7442-411: The arcs. Once the electrodes have reached the heavy melt at the base of the furnace and the arcs are shielded by the scrap, the voltage can be increased and the electrodes raised slightly, lengthening the arcs and increasing power to the melt. This enables a molten pool to form more rapidly, reducing tap-to-tap times. Oxygen is blown into the scrap, combusting or cutting the steel, and extra chemical heat

SECTION 60

#1732856188251

7564-601: The area, such as Georgia and Florida. In 2001, Alabama Supreme Court chief justice Roy Moore installed a statue of the Ten Commandments in the capitol in Montgomery. In 2002, the 11th US Circuit Court ordered the statue removed, but Moore refused to follow the court order, which led to protests around the capitol in favor of keeping the monument. The monument was removed in August 2003. A few natural disasters have occurred in

7686-612: The bath. The Girod furnace is similar to the Héroult furnace . While EAFs were widely used in World War II for production of alloy steels, it was only later that electric steelmaking began to expand. The low capital cost for a mini-mill —around US$ 140–200 per ton of annual installed capacity, compared with US$ 1,000 per ton of annual installed capacity for an integrated steel mill —allowed mills to be quickly established in war-ravaged Europe, and also allowed them to successfully compete with

7808-504: The big United States steelmakers, such as Bethlehem Steel and U.S. Steel , for low-cost, carbon steel "long products" ( structural steel , rod and bar, wire , and fasteners ) in the U.S. market. When Nucor —now one of the largest steel producers in the US — entered the market for long steel products in 1969, they used a mini-mill with an EAF as its steelmaking furnace, soon followed by other manufacturers. While Nucor expanded rapidly in

7930-402: The bus tubes or arms with the transformer located adjacent to the furnace. The transformer is installed in a vault and is cooled by pump-circulated transformer oil, with the oil being cooled by water via heat exchangers. The furnace is built on a tilting platform so that the liquid steel can be poured into another vessel for transport. The operation of tilting the furnace to pour molten steel

8052-461: The charge and by the radiant energy evolved by the arc. The electric arc temperature reaches around 3,000 °C (5,400 °F), thus causing the lower sections of the electrodes to glow incandescently when in operation. The electrodes are automatically raised and lowered by a positioning system, which may use either electric winch hoists or hydraulic cylinders . The regulating system maintains approximately constant current and power input during

8174-472: The charge material. Arc furnaces differ from induction furnaces , in which the charge is heated instead by eddy currents . In the 19th century, a number of people had employed an electric arc to melt iron . Sir Humphry Davy conducted an experimental demonstration in 1810; welding was investigated by Pepys in 1815; Pinchon attempted to create an electrothermic furnace in 1853; and, in 1878–79, Sir William Siemens took out patents for electric furnaces of

8296-630: The company moved its headquarters to Charlotte, North Carolina to be closer to its main Vulcraft plant in South Carolina. In 1968, unable to get favorable steel prices from American manufacturers and unhappy with the imported steel available at the time, Iverson, a metallurgist by training, extended Nucor vertically into steelmaking by building its first steel bar mill in Darlington, South Carolina . The company purchased an electric arc furnace , which

8418-510: The company opened its building products division. In 1989, Nucor opened a facility in Crawfordsville, Indiana , the first mini mill in the world to produce flat rolled steel using thin-slab technology. In March 2000, a joint venture, owned 47.5% by Nucor, 47.5% by BlueScope , and 5% by IHI Corporation was formed to license Castrip technology. This technology allowed for continuous casting of sheet steel directly from molten steel without

8540-689: The company signed an agreement with ExxonMobil for carbon capture and storage of up to 800,000 metric tons from its direct reduced iron plant in Convent, Louisiana . The plant had been criticized for its emissions. Electric arc furnace An electric arc furnace ( EAF ) is a furnace that heats material by means of an electric arc . Industrial arc furnaces range in size from small units of approximately one-tonne capacity (used in foundries for producing cast iron products) up to about 400-tonne units used for secondary steelmaking . Arc furnaces used in research laboratories and by dentists may have

8662-475: The company to his widow. Nuclear purchased Vulcraft from Chase's widow in 1962 and hired F. Kenneth Iverson as general manager . In March 1965, the company again filed for bankruptcy. Iverson, head of the only profitable division, took over as head of the company due to lack of interest in the job from others. Iverson reorganized Nucor around its only profitable business, the steel fabricator Vulcraft. All other businesses were either sold or liquidated. In 1966,

8784-530: The construction costs. The fund required the local community and state to raise matching funds to pay the rest. Black residents effectively taxed themselves twice, by raising additional monies to supply matching funds for such schools, which were built in many rural areas. They often donated land and labor as well. Beginning in 1913, the first 80 Rosenwald Schools were built in Alabama for African American children. A total of 387 schools, seven teachers' houses, and several vocational buildings were completed by 1937 in

8906-438: The demands of World War II brought a level of prosperity to the state not seen since before the civil war. Rural workers poured into the largest cities in the state for better jobs and a higher standard of living. One example of this massive influx of workers occurred in Mobile. Between 1940 and 1943, more than 89,000 people moved into the city to work for war-related industries. Cotton and other cash crops faded in importance as

9028-513: The disenfranchised African Americans, but it did not relieve them of paying taxes. Partially as a response to chronic underfunding of education for African Americans in the South, the Rosenwald Fund began funding the construction of what came to be known as Rosenwald Schools . In Alabama, these schools were designed, and the construction partially financed with Rosenwald funds, which paid one-third of

9150-459: The early decades of the 20th century as part of the Great Migration out of the South. Reflecting this emigration, the population growth rate in Alabama (see "historical populations" table below) dropped by nearly half from 1910 to 1920. At the same time, many rural people migrated to the city of Birmingham to work in new industrial jobs. Birmingham experienced such rapid growth it was called

9272-424: The egg-shaped hearth. It is filled with refractory sand, such as olivine , when it is closed off. Modern plants may have two shells with a single set of electrodes that can be transferred between the two; one shell preheats scrap while the other shell is utilised for meltdown. Other DC-based furnaces have a similar arrangement, but have electrodes for each shell and one set of electronics. AC furnaces usually exhibit

9394-435: The electrode paste through electrical current passing through the electrode casing and heat from the furnace. A steelmaking arc furnace, by comparison, arcs in the open. The key is the electrical resistance , which is what generates the heat required: the resistance in a steelmaking furnace is the atmosphere, while in a submerged-arc furnace, the slag (or charge) supplies the resistance. The liquid metal formed in either furnace

9516-561: The emission of toxic chemicals into the air, water, and soil in Alabama , Arkansas , Indiana , Nebraska , South Carolina , Texas , and Utah . The settlement was "the largest and most comprehensive environmental settlement ever with a steel manufacturer." In 2016, the company unsuccessfully filed a lawsuit to block the Environmental Protection Agency from adopting a plan to control visible pollution in Arkansas . In 2023,

9638-623: The end product and local conditions, as well as ongoing research to improve furnace efficiency. The largest scrap-only furnace (in terms of tapping weight and transformer rating) is a DC furnace operated by Tokyo Steel in Japan, with a tap weight of 420 tonnes and fed by eight 32 MVA transformers for 256 MVA total power. To produce a ton of steel in an electric arc furnace requires approximately 400 kilowatt-hours (1.44 gigajoules ) per short ton or about 440 kWh (1.6 GJ) per tonne . The theoretical minimum amount of energy required to melt

9760-435: The first electric arc furnace in the U.S. This furnace is now on display at Station Square, Pittsburgh, Pennsylvania. Initially "electric steel" produced by an electric arc furnace was a specialty product for such uses as machine tools and spring steel . Arc furnaces were also used to prepare calcium carbide for use in carbide lamps . The Stassano electric furnace is an arc type furnace that usually rotates to mix

9882-445: The flat products market, still using the EAF production method. An electric arc furnace used for steelmaking consists of a refractory -lined vessel, usually water-cooled in larger sizes, covered with a retractable roof, and through which one or more graphite electrodes enter the furnace. The furnace is primarily split into three sections: The hearth may be hemispherical in shape, or in an eccentric bottom tapping furnace (see below),

10004-617: The freedmen and Republicans. These groups included The Ku Klux Klan , the Pale Faces, Knights of the White Camellia , Red Shirts , and the White League . Reconstruction in Alabama ended in 1874, when the Democrats regained control of the legislature and governor's office through an election dominated by fraud and violence. They wrote another constitution in 1875, and the legislature passed

10126-442: The furnace is hot, resulting in a fireball erupting. In some twin-shell furnaces, the scrap is charged into the second shell while the first is being melted down, and pre-heated with off-gas from the active shell. Other operations are continuous charging—pre-heating scrap on a conveyor belt, which then discharges the scrap into the furnace proper, or charging the scrap from a shaft set above the furnace, with off-gases directed through

10248-545: The furnace roof and sidewalls from radiant heat. Once the initial scrap charge has been melted down, another bucket of scrap can be charged into the furnace, although EAF development is moving towards single-charge designs. The scrap-charging and meltdown process can be repeated as many times as necessary to reach the required heat weight - the number of charges is dependent on the density of scrap; lower-density scrap means more charges. After all scrap charges have completely melted, refining operations take place to check and correct

10370-435: The furnace, or are fixed to the raised platform. A typical alternating current furnace is powered by a three-phase electrical supply , and therefore has three electrodes. Electrodes are round in section, and typically in segments with threaded couplings, so that as the electrodes wear, new segments can be added. The arc forms between the charged material and the electrode; the charge is heated both by current passing through

10492-417: The hearth has the shape of a halved egg. In modern meltshops, the furnace is often raised off the ground floor, so that ladles and slag pots can easily be maneuvered under either end of the furnace. Separate from the furnace structure is the electrode support and electrical system, and the tilting platform on which the furnace rests. Two configurations are possible: the electrode supports and the roof tilt with

10614-417: The immediate concern of potential steam explosions . Excessive refractory wear can lead to breakouts, where the liquid metal and slag penetrate the refractory and furnace shell and escape into the surrounding areas. The use of EAFs allows steel to be made from a 100% scrap metal feedstock. This greatly reduces the energy required to make steel when compared with primary steelmaking from ores. Another benefit

10736-401: The ladle. For some special steel grades, including stainless steel, the slag is poured into the ladle as well, to be treated at the ladle furnace to recover valuable alloying elements. During tapping some alloy additions are introduced into the metal stream, and more fluxes such as lime are added on top of the ladle to begin building a new slag layer. Often, a few tonnes of liquid steel and slag

10858-554: The largest stalagmites in the world; Ecor Rouge, in Fairhope , the highest coastline point between Maine and Mexico; DeSoto Caverns , in Childersburg , the first officially recorded cave in the United States; Noccalula Falls , in Gadsden , which has a 90-foot waterfall; Dismals Canyon , near Phil Campbell , which is home to two waterfalls and six natural bridges and is said to have been

10980-536: The late 19th century up until the 1960s. High-profile events such as the Selma to Montgomery marches made the state a major focal point of the civil rights movement in the 1950s and 1960s. During and after World War II , Alabama grew as the state's economy diversified with new industries. In 1960, the establishment of NASA 's Marshall Space Flight Center in Huntsville helped boost Alabama's economic growth by developing

11102-430: The late 20th century and has used new types of voting to increase representation. In the 1980s, an omnibus redistricting case, Dillard v. Crenshaw County , challenged the at-large voting for representative seats of 180 Alabama jurisdictions, including counties and school boards. At-large voting had diluted the votes of any minority in a county, as the majority tended to take all seats. Despite African Americans making up

11224-426: The melting of the charge, even though scrap may move under the electrodes as it melts. The mast arms holding the electrodes can either carry heavy busbars (which may be hollow water-cooled copper pipes carrying current to the electrode clamps) or be "hot arms", where the whole arm carries the current, increasing efficiency. Hot arms can be made from copper-clad steel or aluminium . Large water-cooled cables connect

11346-587: The need for heavy, expensive, and energy-consuming rollers. In 2000, Nucor agreed to spend $ 98 million, including $ 85 million for new air pollution control equipment, $ 4 million to monitor and reduce pollution in communities near its plants, and a $ 9 million civil fine to resolve allegations by the United States Department of Justice and the United States Environmental Protection Agency that it had not adequately controlled

11468-431: The quality of power for other customers; flicker and harmonic distortion are common power system side-effects of arc furnace operation. For steelmaking, direct current (DC) arc furnaces are used, with a single electrode in the roof and the current return through a conductive bottom lining or conductive pins in the base. The advantage of DC is lower electrode consumption per ton of steel produced, since only one electrode

11590-472: The refractory in the hearth, leading to a break out of molten metal or in the worst case a steam explosion. A plasma arc furnace (PAF) uses plasma torches instead of graphite electrodes. Each of these torches has a casing with a nozzle and axial tubing for feeding a plasma-forming gas (either nitrogen or argon) and a burnable cylindrical graphite electrode within the tubing. Such furnaces can be called plasma arc melt (PAM) furnaces; they are used extensively in

11712-404: The resulting EAF slag and EAF dust can be toxic. EAF dust is collected by air pollution control equipment. It is called collected dust and usually contains heavy metals, such as zinc, lead and dioxins, etc. It is categorized as hazardous industrial waste and disposal is regulated. Because of the very dynamic quality of the arc furnace load, power systems may require technical measures to maintain

11834-617: The seat of government moved to Cahaba in Dallas County . Cahaba , now a ghost town , was the first permanent state capital from 1820 to 1825. The Alabama Fever land rush was underway when the state was admitted to the Union, with settlers and land speculators pouring into the state to take advantage of fertile land suitable for cotton cultivation. Part of the frontier in the 1820s and 1830s, its constitution provided for universal suffrage for white men. Southeastern planters and traders from

11956-451: The shaft. Other furnaces can be charged with hot (molten) metal from other operations. After charging, the roof is swung back over the furnace and meltdown commences. The electrodes are lowered onto the scrap, an arc is struck and the electrodes are then set to bore into the layer of shred at the top of the furnace. Lower voltages are selected for this first part of the operation to protect the roof and walls from excessive heat and damage from

12078-419: The shell and roof, but larger installations require intensive forced cooling to maintain the structure within safe operating limits. The furnace shell and roof may be cooled either by water circulated through pipes which form a panel, or by water sprayed on the panel elements. Tubular panels may be replaced when they become cracked or reach their thermal stress life cycle. Spray cooling is the most economical and

12200-490: The sixteenth century until the French acquired it in the early eighteenth century. The British won the territory in 1763 until losing it in the American Revolutionary War . Spain held Mobile as part of Spanish West Florida until 1813. In December 1819, Alabama was recognized as a state. During the antebellum period, Alabama was a major producer of cotton , and widely used African American slave labor . In 1861,

12322-400: The slag door, but now this is mainly done through wall-mounted injection units that combine the oxygen-fuel burners and the oxygen or carbon injection systems into one unit. A mid-sized modern steelmaking furnace would have a transformer rated about 60,000,000 volt-amperes (60 MVA), with a secondary voltage between 400 and 900 volts and a secondary current in excess of 44,000 amperes. In

12444-610: The sleeves, collar and coattails. This led to them being greeted with "Yellowhammer", and the name later was applied to all Alabama troops in the Confederate Army. Alabama's slaves were freed by the 13th Amendment in 1865. Alabama was under military rule from the end of the war in May 1865 until its official restoration to the Union in 1868. From 1867 to 1874, with most white citizens barred temporarily from voting and freedmen enfranchised, many African Americans emerged as political leaders in

12566-414: The state developed a manufacturing and service base. Despite massive population changes in the state from 1901 to 1961, the rural-dominated legislature refused to reapportion House and Senate seats based on population, as required by the state constitution to follow the results of decennial censuses. They held on to old representation to maintain political and economic power in agricultural areas. One result

12688-454: The state in the twenty-first century. In 2004, Hurricane Ivan , a category 3 storm upon landfall, struck the state and caused over $ 18 billion of damage. It was among the most destructive storms to strike the state in its modern history. A super outbreak of 62 tornadoes hit the state in April 2011 and killed 238 people, devastating many communities. Alabama is the thirtieth-largest state in

12810-505: The state seceded from the United States to become part of the Confederate States of America , with Montgomery acting as its first capital, and rejoined the Union in 1868. Following the American Civil War , Alabama would suffer decades of economic hardship, in part due to agriculture and a few cash crops being the main driver of the state's economy. Similar to other former slave states, Alabamian legislators employed Jim Crow laws from

12932-457: The state through the civil rights movement, including legal challenges. In 1954, the U.S. Supreme Court ruled in Brown v. Board of Education that public schools had to be desegregated , but Alabama was slow to comply. During the 1960s, under Governor George Wallace , Alabama resisted compliance with federal demands for desegregation. The civil rights movement had notable events in Alabama, including

13054-610: The state within a few years of the passage of the Indian Removal Act by Congress in 1830. From 1826 to 1846, Tuscaloosa served as Alabama's capital. On January 30, 1846, the Alabama legislature announced it had voted to move the capital city from Tuscaloosa to Montgomery. The first legislative session in the new capital met in December 1847. A new capitol building was erected under the direction of Stephen Decatur Button of Philadelphia . The first structure burned down in 1849, but

13176-513: The state, particularly Huntsville, benefited from the opening of the George C. Marshall Space Flight Center in 1960, a major facility in the development of the Saturn rocket program and the space shuttle. Technology and manufacturing industries, such as automobile assembly, replaced some the state's older industries in the late twentieth century, but the state's economy and growth lagged behind other states in

13298-684: The state. Alabama was represented in Congress during this period by three African-American congressmen: Jeremiah Haralson , Benjamin S. Turner , and James T. Rapier . Following the war, the state remained chiefly agricultural, with an economy tied to cotton. During Reconstruction, state legislators ratified a new state constitution in 1868 which created the state's first public school system and expanded women's rights. Legislators funded numerous public road and railroad projects, although these were plagued with allegations of fraud and misappropriation . Organized insurgent , resistance groups tried to suppress

13420-476: The state. Several of the surviving school buildings in the state are now listed on the National Register of Historic Places . Continued racial discrimination and lynchings , agricultural depression, and the failure of the cotton crops due to boll weevil infestation led tens of thousands of African Americans from rural Alabama and other states to seek opportunities in northern and midwestern cities during

13542-410: The steel chemistry and superheat the melt above its freezing temperature in preparation for tapping. More slag formers are introduced and more oxygen is blown into the bath, burning out impurities such as silicon , sulfur , phosphorus , aluminium , manganese , and calcium , and removing their oxides to the slag. Removal of carbon takes place after these elements have burnt out first, as they have

13664-443: The steel, but for all other elements, a "chill" sample — a small, solidified sample of the steel — is analysed on an arc-emission spectrometer . Once the temperature and chemistry are correct, the steel is tapped out into a preheated ladle through tilting the furnace. For plain-carbon steel furnaces, as soon as slag is detected during tapping the furnace is rapidly tilted back towards the deslagging side, minimising slag carryover into

13786-707: The surrender of the Spanish garrison at Mobile to U.S. forces on April 13, 1813. Thomas Bassett, a loyalist to the British monarchy during the Revolutionary era, was one of the earliest white settlers in the state outside Mobile. He settled in the Tombigbee District during the early 1770s. The district's boundaries were roughly limited to the area within a few miles of the Tombigbee River and included portions of what

13908-568: The territory in 1804, following the Yazoo land scandal . Spain kept a claim on its former Spanish West Florida territory in what would become the coastal counties until the Adams–Onís Treaty officially ceded it to the U.S. in 1819. Before Mississippi's admission to statehood on December 10, 1817, the more sparsely settled eastern half of the territory was separated and named the Alabama Territory . The United States Congress created

14030-752: The titanium-melting industry and similar specialty metal industries. Vacuum arc remelting (VAR) is a secondary remelting process for vacuum refining and manufacturing of ingots with improved chemical and mechanical homogeneity. In critical military and commercial aerospace applications, material engineers commonly specify VIM-VAR steels. VIM means vacuum induction melted and VAR means vacuum arc remelted. VIM-VAR steels become bearings for jet engines, rotor shafts for military helicopters, flap actuators for fighter jets, gears in jet or helicopter transmissions, mounts or fasteners for jet engines, jet tail hooks and other demanding applications. Alabama Alabama ( / ˌ æ l ə ˈ b æ m ə / AL -ə- BAM -ə )

14152-473: The upper reaches of the river. In the Alabama language , the word for a person of Alabama lineage is Albaamo (or variously Albaama or Albàamo in different dialects; the plural form is Albaamaha ). The word's spelling varies significantly among historical sources. The first usage appears in three accounts of the Hernando de Soto expedition of 1540: Garcilaso de la Vega used Alibamo , while

14274-415: Was far cheaper than the traditional steel blast furnace , with a $ 6 million loan secured by all of the company's assets. Production delays and staffing problems resulted in losses, but earnings soared in 1971 and 1972. In 1972, the company, recognizing that it was now misnamed, adopted its current title, Nucor Corporation. That year, it became a public company via an initial public offering . In 1988,

14396-528: Was first tested in Conecuh County. Together use of these systems has increased the number of African Americans and women being elected to local offices, resulting in governments that are more representative of their citizens. Beginning in the 1960s, the state's economy shifted away from its traditional lumber, steel, and textile industries because of increased foreign competition. Steel jobs, for instance, declined from 46,314 in 1950 to 14,185 in 2011. However,

14518-502: Was moved to the current site of Mobile in 1711. This area was claimed by the French from 1702 to 1763 as part of La Louisiane . After the French lost to the British in the Seven Years' War , it became part of British West Florida from 1763 to 1783. After the U.S. victory in the American Revolutionary War , the territory was divided between the United States and Spain. The latter retained control of this western territory from 1783 until

14640-490: Was rebuilt on the same site in 1851. This second capitol building in Montgomery remains to the present day. It was designed by Barachias Holt of Exeter, Maine . By 1860, the population had increased to 964,201 people, of which nearly half, 435,080, were enslaved African Americans, and 2,690 were free people of color . On January 11, 1861, Alabama declared its secession from the Union . After remaining an independent republic for

14762-413: Was that Jefferson County , containing Birmingham's industrial and economic powerhouse, contributed more than one-third of all tax revenue to the state, but did not receive a proportional amount in services. Urban interests were consistently underrepresented in the legislature. A 1960 study noted that because of rural domination, "a minority of about 25% of the total state population is in majority control of

14884-527: Was the center of the culture. Analysis of artifacts from archaeological excavations at Moundville were the basis of scholars' formulating the characteristics of the Southeastern Ceremonial Complex (SECC). Contrary to popular belief, the SECC appears to have no direct links to Mesoamerican culture but developed independently. The Ceremonial Complex represents a major component of the religion of

#250749