Nickel
Template:About Template:Good article Template:Pp-semi-indef Template:Use mdy dates Template:Infobox nickel
Nickel is a chemical element; it has symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel is a hard and ductile transition metal. Pure nickel is chemically reactive, but large pieces are slow to react with air under standard conditions because a passivation layer of nickel oxide forms on the surface that prevents further corrosion. Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks,<ref>Template:Cite book</ref><ref>Template:Cite web</ref> and in the interiors of larger nickel–iron meteorites that were not exposed to oxygen when outside Earth's atmosphere.
Meteoric nickel is found in combination with iron, a reflection of the origin of those elements as major end products of supernova nucleosynthesis. An iron–nickel mixture is thought to compose Earth's outer and inner cores.<ref>Template:Cite journal</ref>
Use of nickel (as natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classified as an element in 1751 by Axel Fredrik Cronstedt, who initially mistook the ore for a copper mineral, in the cobalt mines of Los, Hälsingland, Sweden. The element's name comes from a mischievous sprite of German miner mythology, Nickel (similar to Old Nick). Nickel minerals can be green, like copper ores, and were known as kupfernickel – Nickel's copper – because they produced no copper.
Although most nickel in the earth's crust exists as oxides, economically more important nickel ores are sulfides, especially pentlandite. Major production sites include Sulawesi, Indonesia, the Sudbury region, Canada (which is thought to be of meteoric origin), New Caledonia in the Pacific, Western Australia, and Norilsk, Russia.<ref name="ullmann-1"/>
Nickel is one of four elements (the others are iron, cobalt, and gadolinium)<ref name="CoeySkumryev1999">Template:Cite journal</ref> that are ferromagnetic at about room temperature. Alnico permanent magnets based partly on nickel are of intermediate strength between iron-based permanent magnets and rare-earth magnets. The metal is used chiefly in alloys and corrosion-resistant plating.
About 68% of world production is used in stainless steel. A further 10% is used for nickel-based and copper-based alloys, 9% for plating, 7% for alloy steels, 3% in foundries, and 4% in other applications such as in rechargeable batteries,<ref name="Nickel Use In Society">Template:Cite web</ref> including those in electric vehicles (EVs).<ref>Template:Cite web</ref> Nickel is widely used in coins, though nickel-plated objects sometimes provoke nickel allergy. As a compound, nickel has a number of niche chemical manufacturing uses, such as a catalyst for hydrogenation, cathodes for rechargeable batteries, pigments and metal surface treatments.<ref>Template:Cite web</ref> Nickel is an essential nutrient for some microorganisms and plants that have enzymes with nickel as an active site.<ref>Template:Cite journal</ref>
Properties
[edit]Atomic and physical properties
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Nickel is a silvery-white metal with a slight golden tinge that takes a high polish. It is one of only four elements that are ferromagnetic at or near room temperature; the others are iron, cobalt and gadolinium. Its Curie temperature is Template:Convert, meaning that bulk nickel is non-magnetic above this temperature.<ref>Template:Cite book</ref><ref name="CoeySkumryev1999" /> The unit cell of nickel is a face-centered cube; it has lattice parameter of 0.352 nm, giving an atomic radius of 0.124 nm. This crystal structure is stable to pressures of at least 70 GPa. Nickel is hard, malleable and ductile, and has a relatively high electrical and thermal conductivity for transition metals.<ref name="crc" /> The high compressive strength of 34 GPa, predicted for ideal crystals, is never obtained in the real bulk material due to formation and movement of dislocations. However, it has been reached in Ni nanoparticles.<ref>Template:Cite journal</ref>
Electron configuration dispute
[edit]Nickel has two atomic electron configurations, [Ar] 3dTemplate:Sup 4sTemplate:Sup and [Ar] 3dTemplate:Sup 4sTemplate:Sup, which are very close in energy; [Ar] denotes the complete argon core structure. There is some disagreement on which configuration has the lower energy.<ref name="Scerri" /> Chemistry textbooks quote nickel's electron configuration as [Ar] 4sTemplate:Sup 3dTemplate:Sup,<ref>Miessler, G.L. and Tarr, D.A. (1999) Inorganic Chemistry 2nd ed., Prentice–Hall. p. 38. Template:ISBN.</ref> also written [Ar] 3dTemplate:Sup 4sTemplate:Sup.<ref>Petrucci, R.H. et al. (2002) General Chemistry 8th ed., Prentice–Hall. p. 950. Template:ISBN.</ref> This configuration agrees with the Madelung energy ordering rule, which predicts that 4s is filled before 3d. It is supported by the experimental fact that the lowest energy state of the nickel atom is a 3dTemplate:Sup 4sTemplate:Sup energy level, specifically the 3dTemplate:Sup(Template:SupF) 4sTemplate:Sup Template:SupF, J = 4 level.<ref name="JPCRD">Template:Cite web</ref><ref name="NIST">NIST Atomic Spectrum Database Template:Webarchive To read the nickel atom levels, type "Ni 0" or "Ni I" in the Spectrum box and click on Retrieve data.</ref>
However, each of these two configurations splits into several energy levels due to fine structure,<ref name="JPCRD"/><ref name="NIST" /> and the two sets of energy levels overlap. The average energy of states with [Ar] 3dTemplate:Sup 4sTemplate:Sup is actually lower than the average energy of states with [Ar] 3dTemplate:Sup 4sTemplate:Sup. Therefore, the research literature on atomic calculations quotes the ground state configuration as [Ar] 3dTemplate:Sup 4sTemplate:Sup.<ref name="Scerri">Template:Cite book</ref>
Isotopes
[edit]Template:Main The isotopes of nickel range in atomic weight from 48 u (Template:Chem) to 82 u (Template:Chem).Template:NUBASE2020
Natural nickel is composed of five stable isotopes, Template:Chem, Template:Chem, Template:Chem, Template:Chem and Template:Chem, of which Template:Chem is the most abundant (68.077% natural abundance).Template:NUBASE2020
Nickel-62 has the highest binding energy per nucleon of any nuclide: 8.7946 MeV/nucleon.<ref>Template:Cite journal</ref><ref>Template:Cite web</ref> Its binding energy is greater than both [[iron-56|Template:Chem]] and [[iron-58|Template:Chem]], more abundant nuclides often incorrectly cited as having the highest binding energy.<ref name="aip1995">Template:Cite journal</ref> Though this would seem to predict nickel as the most abundant heavy element in the universe, the high rate of photodisintegration of nickel in stellar interiors causes iron to be by far the most abundant.<ref name="aip1995" />
Nickel-60 is the daughter product of the extinct radionuclide [[iron-60|Template:Chem]] (half-life 2.6 million years). Due to the long half-life of Template:Chem, its persistence in materials in the Solar System may generate observable variations in the isotopic composition of Template:Chem. Therefore, the abundance of Template:Chem in extraterrestrial material may give insight into the origin of the Solar System and its early history.<ref>Template:Cite web</ref>
At least 26 nickel radioisotopes have been characterized; the most stable are Template:Chem with half-life 76,000 years, Template:Chem (100 years), and Template:Chem (6 days). All other radioisotopes have half-lives less than 60 hours and most these have half-lives less than 30 seconds. This element also has one meta state.Template:NUBASE2020
Radioactive nickel-56 is produced by the silicon burning process and later set free in large amounts in type Ia supernovae. The shape of the light curve of these supernovae at intermediate to late-times corresponds to the decay via electron capture of Template:Chem to cobalt-56 and ultimately to iron-56.<ref name="Nucleos">Template:Cite book</ref> Nickel-59 is a long-lived cosmogenic radionuclide; half-life 76,000 years. Template:Chem has found many applications in isotope geology. Template:Chem has been used to date the terrestrial age of meteorites and to determine abundances of extraterrestrial dust in ice and sediment. Nickel-78, with a half-life of 110 milliseconds, is believed an important isotope in supernova nucleosynthesis of elements heavier than iron.<ref>Template:Cite web</ref> Template:SupNi, discovered in 1999, is the most proton-rich heavy element isotope known. With 28 protons and 20 neutrons, Template:SupNi is "doubly magic", as is Template:SupNi with 28 protons and 50 neutrons. Both are therefore unusually stable for nuclei with so large a proton–neutron imbalance.Template:NUBASE2020<ref>Template:Cite magazine</ref>
Nickel-63 is a contaminant found in the support structure of nuclear reactors. It is produced through neutron capture by nickel-62. Small amounts have also been found near nuclear weapon test sites in the South Pacific.<ref>Template:Cite journal</ref>
Occurrence
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Nickel ores are classified as oxides or sulfides. Oxides include laterite, where the principal mineral mixtures are nickeliferous limonite, (Fe,Ni)O(OH), and garnierite (a mixture of various hydrous nickel and nickel-rich silicates).<ref name="Mudd 2010 pp. 9–26">Template:Cite journal</ref> Nickel sulfides commonly exist as solid solutions with iron in minerals such as pentlandite and pyrrhotite with the formula Fe9−xNixS8 and Fe7−xNixS6, respectively. Other common Ni-containing minerals are millerite and the arsenide niccolite.<ref>National Pollutant Inventory – Nickel and compounds Fact Sheet Template:Webarchive. Npi.gov.au. Retrieved on January 9, 2012.</ref><ref>Template:Cite web</ref>
Identified land-based resources throughout the world averaging 1% nickel or greater comprise at least 130 million tons of nickel (about the double of known reserves). About 60% is in laterites and 40% in sulfide deposits.<ref name="USGSCS2019">Template:Cite web</ref>
On geophysical evidence, most of the nickel on Earth is believed to be in Earth's outer and inner cores. Kamacite and taenite are naturally occurring alloys of iron and nickel. For kamacite, the alloy is usually in the proportion of 90:10 to 95:5, though impurities (such as cobalt or carbon) may be present. Taenite is 20% to 65% nickel. Kamacite and taenite are also found in nickel iron meteorites.<ref>Template:Cite journal</ref>
Nickel is commonly found in iron meteorites as the alloys kamacite and taenite. Nickel in meteorites was first detected in 1799 by Joseph-Louis Proust, a French chemist who then worked in Spain. Proust analyzed samples of the meteorite from Campo del Cielo (Argentina), which had been obtained in 1783 by Miguel Rubín de Celis, discovering the presence in them of nickel (about 10%) along with iron.<ref>Template:Cite book</ref>
Compounds
[edit]Template:Main The most common oxidation state of nickel is +2, but compounds of Template:Chem2, Template:Chem2, and Template:Chem2 are well known, and the exotic oxidation states Template:Chem2 and Template:Chem2 have been characterized.<ref name="Greenwood">Template:Greenwood&Earnshaw2nd</ref>Template:Clear
Nickel(0)
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Nickel tetracarbonyl Template:Chem2), discovered by Ludwig Mond,<ref name="MondNa">Template:Cite journal</ref> is a volatile, highly toxic liquid at room temperature. On heating, the complex decomposes back to nickel and carbon monoxide:
This behavior is exploited in the Mond process for purifying nickel, as described above. The related nickel(0) complex bis(cyclooctadiene)nickel(0) is a useful catalyst in organonickel chemistry because the cyclooctadiene (or cod) ligands are easily displaced.Template:Clear
Nickel(I)
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Nickel(I) complexes are uncommon, but one example is the tetrahedral complex Template:Chem2. Many nickel(I) complexes have Ni–Ni bonding, such as the dark red diamagnetic Template:Chem2 prepared by reduction of Template:Chem2 with sodium amalgam. This compound is oxidized in water, liberating Template:Chem2.<ref name="InorgChemH">Template:Housecroft3rd</ref>
It is thought that the nickel(I) oxidation state is important to nickel-containing enzymes, such as [NiFe]-hydrogenase, which catalyzes the reversible reduction of protons to Template:Chem2.<ref name="Housecroft 4th">Template:Housecroft4th</ref>Template:Clear
Nickel(II)
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Nickel(II) forms compounds with all common anions, including sulfide, sulfate, carbonate, hydroxide, carboxylates, and halides. Nickel(II) sulfate is produced in large amounts by dissolving nickel metal or oxides in sulfuric acid, forming both a hexa- and heptahydrate<ref name=NiCmpds>Lascelles, Keith; Morgan, Lindsay G.; Nicholls, David and Beyersmann, Detmar (2019) "Nickel Compounds" in Ullmann's Encyclopedia of Industrial Chemistry. Wiley-VCH, Weinheim. Template:Doi</ref> useful for electroplating nickel. Common salts of nickel, such as chloride, nitrate, and sulfate, dissolve in water to give green solutions of the metal aquo complex Template:Chem2.<ref>Template:Cite web</ref>
The four halides form nickel compounds, which are solids with molecules with octahedral Ni centres. Nickel(II) chloride is most common, and its behavior is illustrative of the other halides. Nickel(II) chloride is made by dissolving nickel or its oxide in hydrochloric acid. It is usually found as the green hexahydrate, whose formula is usually written Template:Chem2. When dissolved in water, this salt forms the metal aquo complex Template:Chem2. Dehydration of Template:Chem2 gives yellow anhydrous Template:Chem2.<ref>Template:Cite web</ref>
Some tetracoordinate nickel(II) complexes, e.g. bis(triphenylphosphine)nickel chloride, exist both in tetrahedral and square planar geometries. The tetrahedral complexes are paramagnetic; the square planar complexes are diamagnetic. In having properties of magnetic equilibrium and formation of octahedral complexes, they contrast with the divalent complexes of the heavier group 10 metals, palladium(II) and platinum(II), which form only square-planar geometry.<ref name="Greenwood" />
Nickelocene has an electron count of 20. Many chemical reactions of nickelocene tend to yield 18-electron products.<ref>Template:Cite book</ref>
Nickel(III) and (IV)
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Many Ni(III) compounds are known. Ni(III) forms simple salts with fluoride<ref name = "Ni(III)F">Template:Cite journal</ref> or oxide ions. Ni(III) can be stabilized by σ-donor ligands such as thiols and organophosphines.<ref name="InorgChemH" />
Ni(III) occurs in nickel oxide hydroxide, which is used as the cathode in many rechargeable batteries, including nickel–cadmium, nickel–iron, nickel–hydrogen, and nickel–metal hydride, and used by certain manufacturers in Li-ion batteries.<ref>Template:Cite news</ref>
Ni(IV) remains a rare oxidation state and very few compounds are known. Ni(IV) occurs in the mixed oxide Template:Chem2.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref name="NiIV Science">Template:Cite journal</ref><ref name="NiIV dap">Template:Cite journal</ref>
Nickel(VI)
[edit]As of 2024, hexavalent nickel is known in the form of crystalline Ni(BeCp)6. Notably it is not octahedral, instead adopting C3v geometry.<ref>Template:Cite journal</ref>
History
[edit]Unintentional use of nickel can be traced back as far as 3500 BCE.<ref>Template:Cite journal</ref> Bronzes from what is now Syria have been found to contain as much as 2% nickel.<ref>Template:Cite bookTemplate:Pn</ref> Some ancient Chinese manuscripts suggest that "white copper" (cupronickel, known as baitong) was used there in 1700–1400 BCE. This Paktong white copper was exported to Britain as early as the 17th century, but the nickel content of this alloy was not discovered until 1822.<ref name="McNeil">Template:Cite book</ref> Coins of nickel-copper alloy were minted by Bactrian kings Agathocles, Euthydemus II, and Pantaleon in the 2nd century BCE, possibly out of the Chinese cupronickel.<ref>Needham, Joseph; Wang, Ling; Lu, Gwei-Djen; Tsien, Tsuen-hsuin; Kuhn, Dieter and Golas, Peter J. (1974) Science and civilisation in China Template:Webarchive. Cambridge University Press. Template:ISBN, pp. 237–250.</ref>
In medieval Germany, a metallic yellow mineral was found in the Ore Mountains that resembled copper ore. But when miners were unable to get any copper from it, they blamed a mischievous sprite of German mythology, Nickel (similar to Old Nick), for besetting the copper. They called this ore Template:Lang from German Template:Lang 'copper'.<ref>Chambers Twentieth Century Dictionary, p888, W&R Chambers Ltd., 1977.</ref><ref name="JEC-I">Template:Cite journal</ref><ref name="JEC-II">Template:Cite journal</ref><ref name="JEC-III">Template:Cite journal</ref> This ore is now known as the mineral nickeline (formerly niccolite<ref>Fleisher, Michael and Mandarino, Joel. Glossary of Mineral Species. Tucson, Arizona: Mineralogical Record, 7th ed. 1995.</ref>), a nickel arsenide. In 1751, Baron Axel Fredrik Cronstedt tried to extract copper from kupfernickel at a cobalt mine in the village of Los, Sweden, and instead produced a white metal that he named nickel after the spirit that had given its name to the mineral.<ref>Template:Cite journal</ref> In modern German, Kupfernickel or Kupfer-Nickel designates the alloy cupronickel.<ref name="crc">Template:Cite book</ref>
Originally, the only source for nickel was the rare Kupfernickel. Beginning in 1824, nickel was obtained as a byproduct of cobalt blue production. The first large-scale smelting of nickel began in Norway in 1848 from nickel-rich pyrrhotite.<ref>Template:Cite web</ref> The introduction of nickel in steel production in 1889 increased the demand for nickel; the nickel deposits of New Caledonia, discovered in 1865, provided most of the world's supply between 1875 and 1915. The discovery of the large deposits in the Sudbury Basin in Canada in 1883, in Norilsk-Talnakh in Russia in 1920, and in the Merensky Reef in South Africa in 1924 made large-scale nickel production possible.<ref name="McNeil" />
Coinage
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Aside from the aforementioned Bactrian coins, nickel was not a component of coins until the mid-19th century.<ref name="toxmetal">Template:Cite web</ref>
Canada
[edit]99.9% nickel five-cent coins were struck in Canada (the world's largest nickel producer at the time) during non-war years from 1922 to 1981; the metal content made these coins magnetic.<ref>Template:Cite web</ref> During the war years 1942–1945, most or all nickel was removed from Canadian and US coins to save it for making armor.<ref name="JEC-I" /> Canada used 99.9% nickel from 1968 in its higher-value coins until 2000.<ref>Template:Cite journal</ref>
Switzerland
[edit]Coins of nearly pure nickel were first used in 1881 in Switzerland.<ref name="anna" />
United Kingdom
[edit]Birmingham forged nickel coins in Template:Circa for trading in Malaysia.<ref>Template:Cite web</ref>
United States
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Template:See also
In the United States, the term "nickel" or "nick" originally applied to the copper-nickel Flying Eagle cent, which replaced copper with 12% nickel 1857–58, then the Indian Head cent of the same alloy from 1859 to 1864. Still later, in 1865, the term designated the three-cent nickel, with nickel increased to 25%. In 1866, the five-cent shield nickel (25% nickel, 75% copper) appropriated the designation, which has been used ever since for the subsequent 5-cent pieces. This alloy proportion is not ferromagnetic.
The US nickel coin contains Template:Convert of nickel, which at the April 2007 price was worth 6.5 cents, along with 3.75 grams of copper worth about 3 cents, with a total metal value of more than 9 cents. Since the face value of a nickel is 5 cents, this made it an attractive target for melting by people wanting to sell the metals at a profit. The United States Mint, anticipating this practice, implemented new interim rules on December 14, 2006, subject to public comment for 30 days, which criminalized the melting and export of cents and nickels.<ref>United States Mint Moves to Limit Exportation & Melting of Coins Template:Webarchive, The United States Mint, press release, December 14, 2006</ref> Violators can be punished with a fine of up to $10,000 and/or a maximum of five years in prison.<ref>Template:Cite web</ref> As of February 19, 2025, the melt value of a US nickel (copper and nickel included) is $0.054 (108% of the face value).<ref>Template:Cite web</ref>
Current use
[edit]In the 21st century, the high price of nickel has led to some replacement of the metal in coins around the world. Coins still made with nickel alloys include one- and two-euro coins, 5¢, 10¢, 25¢, 50¢, and $1 U.S. coins,<ref>Template:Cite web</ref> and 20p, 50p, £1, and £2 UK coins. From 2012 on the nickel-alloy used for 5p and 10p UK coins was replaced with nickel-plated steel. This ignited a public controversy regarding the problems of people with nickel allergy.<ref name="anna">Template:Cite news</ref>
World production
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An estimated 3.7 million tonnes (t) of nickel per year are mined worldwide; Indonesia (2,200,000 t), the Philippines (330,000 t), Russia (210,000 t), Canada (190,000 t), China (120,000 t), and Australia (110,000 t) are the largest producers as of 2024.<ref>Template:Cite web</ref> The largest nickel deposits in non-Russian Europe are in Finland and Greece. Identified land-based sources averaging at least 1% nickel contain at least 130 million tonnes of nickel. About 60% is in laterites and 40% is in sulfide deposits. Also, extensive nickel sources are found in the depths of the Pacific Ocean, especially in an area called the Clarion Clipperton Zone in the form of polymetallic nodules peppering the seafloor at 3.5–6 km below sea level.<ref name="usgs1">Template:Cite web</ref><ref>Template:Cite web</ref> These nodules are composed of numerous rare-earth metals and are estimated to be 1.7% nickel.<ref>Template:Cite book</ref> With advances in science and engineering, regulation is currently being set in place by the International Seabed Authority to ensure that these nodules are collected in an environmentally conscientious manner while adhering to the United Nations Sustainable Development Goals.<ref>Template:Cite web</ref>
The one place in the United States where nickel has been profitably mined is Riddle, Oregon, with several square miles of nickel-bearing garnierite surface deposits. The mine closed in 1987.<ref>Template:Cite journal</ref><ref>Template:Cite web</ref> The Eagle mine project is a new nickel mine in Michigan's Upper Peninsula. Construction was completed in 2013, and operations began in the third quarter of 2014.<ref name="eagle">Template:Cite web</ref> In the first full year of operation, the Eagle Mine produced 18,000 t.<ref name="eagle" /> The Eagle mine produced 17,000 tons of nickel concentrate in 2023.<ref>Template:Cite web</ref> Other projects in the region include the Marquette County nickel project, which received $145 million in funding from the federal government in 2024,<ref>Template:Cite web</ref> investments in work at the Boulderdash and Roland mines,<ref>Template:Cite web</ref> and the development of a third zone, the Keel zone, at The Eagle mine.<ref>Template:Cite web</ref>
Production
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Nickel is obtained through extractive metallurgy: it is extracted from ore by conventional roasting and reduction processes that yield metal of greater than 75% purity. In many stainless steel applications, 75% pure nickel can be used without further purification, depending on impurities.<ref name=NiCmpds/>
Traditionally, most sulfide ores are processed using pyrometallurgical techniques to produce a matte for further refining. Hydrometallurgical techniques are also used. Most sulfide deposits have traditionally been processed by concentration through a froth flotation process followed by pyrometallurgical extraction. The nickel matte is further processed with the Sherritt-Gordon process. First, copper is removed by adding hydrogen sulfide, leaving a concentrate of cobalt and nickel. Then, solvent extraction is used to separate the cobalt and nickel, with the final nickel content greater than 86%.<ref>Template:Cite journal</ref>
A second common refining process is leaching the metal matte into a nickel salt solution, followed by electrowinning the nickel from solution by plating it onto a cathode as electrolytic nickel.<ref name="ASM" />
Mond process
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Template:Main The purest metal is obtained from nickel oxide by the Mond process, which gives a purity of over 99.99%. The process was patented by Ludwig Mond and has been in industrial use since before the beginning of the 20th century.<ref>Template:Cite journal</ref> In this process, nickel is treated with carbon monoxide in the presence of a sulfur catalyst at around 40–80 °C to form nickel carbonyl. In a similar reaction with iron, iron pentacarbonyl can form, though this reaction is slow. If necessary, the nickel may be separated by distillation. Dicobalt octacarbonyl is also formed in nickel distillation as a by-product, but it decomposes to tetracobalt dodecacarbonyl at the reaction temperature to give a non-volatile solid.<ref name="ullmann-1">Template:Ullmann</ref>
Nickel is obtained from nickel carbonyl by one of two processes. It may be passed through a large chamber at high temperatures in which tens of thousands of nickel spheres (pellets) are constantly stirred. The carbonyl decomposes and deposits pure nickel onto the spheres. In the alternate process, nickel carbonyl is decomposed in a smaller chamber at 230 °C to create a fine nickel powder. The byproduct carbon monoxide is recirculated and reused. The highly pure nickel product is known as "carbonyl nickel".<ref>Template:Cite book</ref>
Market value
[edit]The market price of nickel surged throughout 2006 and the early months of 2007; Template:As of, the metal was trading at US$52,300/tonne or $1.47/oz.<ref name="LME">Template:Cite web</ref> The price later fell dramatically; Template:As of, the metal was trading at $11,000/tonne, or $0.31/oz.<ref>Template:Cite web</ref> During the 2022 Russian invasion of Ukraine, worries about sanctions on Russian nickel exports triggered a short squeeze, causing the price of nickel to quadruple in just two days, reaching US$100,000 per tonne.<ref>Template:Cite news</ref><ref>Template:Cite news</ref> The London Metal Exchange cancelled contracts worth $3.9 billion and suspended nickel trading for over a week.<ref>Template:Cite news</ref> Analyst Andy Home argued that such price shocks are exacerbated by the purity requirements imposed by metal markets: only Grade I (99.8% pure) metal can be used as a commodity on the exchanges, but most of the world's supply is either in ferro-nickel alloys or lower-grade purities.<ref>Template:Cite news</ref> In 2024, the average nickel price is estimated by the London Metal Exchange (LME) to be $15,328 per metric ton, 7.7% less than it was in 2023. At the end of 2024, the price reached its lowest levels since 2020.<ref>Template:Cite web</ref>
Applications
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Global use of nickel is currently 68% in stainless steel, 10% in nonferrous alloys, 9% electroplating, 7% alloy steel, 3% foundries, and 4% other (including batteries).<ref name="Nickel Use In Society" />
Nickel is used in many recognizable industrial and consumer products, including stainless steel, alnico magnets, coinage, rechargeable batteries (e.g. nickel–iron), electric guitar strings, microphone capsules, plating on plumbing fixtures,<ref>Template:Cite book</ref> and special alloys such as permalloy, elinvar, and invar. It is used for plating and as a green tint in glass. Nickel is preeminently an alloy metal, and its chief use is in nickel steels and nickel cast irons, in which it typically increases the tensile strength, toughness, and elastic limit. It is widely used in many other alloys, including nickel brasses and bronzes and alloys with copper, chromium, aluminium, lead, cobalt, silver, and gold (Inconel, Incoloy, Monel, Nimonic).<ref name="ASM">Template:Cite book</ref>
Nickel is traditionally used for Kris production in Southeastern Asia.
Because nickel is resistant to corrosion, it was occasionally used as a substitute for decorative silver. Nickel was also occasionally used in some countries after 1859 as a cheap coinage metal (see above), but in the later years of the 20th century, it was replaced by cheaper stainless steel (i.e., iron) alloys, except in the United States and Canada.<ref name="toxmetal"/>
Nickel is an excellent alloying agent for certain precious metals and is used in the fire assay as a collector of platinum group elements (PGE). As such, nickel can fully collect all six PGEs from ores, and can partially collect gold. High-throughput nickel mines may also do PGE recovery (mainly platinum and palladium); examples are Norilsk, Russia and the Sudbury Basin, Canada.<ref>Template:Cite book</ref>
Nickel foam or nickel mesh is used in gas diffusion electrodes for alkaline fuel cells.<ref>Template:Cite book</ref><ref>Template:Cite web</ref>
Nickel and its alloys are often used as catalysts for hydrogenation reactions. Raney nickel, a finely divided nickel-aluminium alloy, is one common form, though related catalysts are also used, including Raney-type catalysts.<ref>Template:Cite journal</ref>
Nickel is naturally magnetostrictive: in the presence of a magnetic field, the material undergoes a small change in length.<ref>Magnetostrictive Materials Overview. University of California, Los Angeles.</ref><ref>Template:Cite book</ref> The magnetostriction of nickel is on the order of 50 ppm and is negative, indicating that it contracts.<ref>Template:Cite journal</ref>
Nickel is used as a binder in the cemented tungsten carbide or hardmetal industry and used in proportions of 6% to 12% by weight. Nickel makes the tungsten carbide magnetic and adds corrosion-resistance to the cemented parts, though the hardness is less than those with cobalt binder.<ref>Template:Cite journal</ref>
Template:Chem, with a half-life of 100.1 years, is useful in krytron devices as a beta particle (high-speed electron) emitter to make ionization by the keep-alive electrode more reliable.<ref>Template:Cite web</ref> It is being investigated as a power source for betavoltaic batteries.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>
Around 27% of all nickel production is used for engineering, 10% for building and construction, 14% for tubular products, 20% for metal goods, 14% for transport, 11% for electronic goods, and 5% for other uses.<ref name="Nickel Use In Society" />
In 2025, QuesTek Innovations and Stoke Space developed a nickel-based superalloy for additive manufacturing and extreme high-pressure, high-temperature oxygen environments. Its characteristics allow the material to be used for fully reusable spacecraft launch systems, it can withstand the full-flow staged combustion rocket engine Zenith.<ref>Template:Cite web</ref><ref>Template:Cite web</ref>
Raney nickel is widely used for hydrogenation of unsaturated oils to make margarine, and substandard margarine and leftover oil may contain nickel as a contaminant. Forte et al. found that type 2 diabetic patients have 0.89 ng/mL of Ni in the blood relative to 0.77 ng/mL in control subjects.<ref>Template:Cite journal</ref>
Nickel titanium is an alloy of roughly equal atomic percentages of its constituent metals which exhibits two closely related and unique properties: the shape memory effect and superelasticity.
Biological role
[edit]It was not recognized until the 1970s, but nickel is known to play an important role in the biology of some plants, bacteria, archaea, and fungi.<ref name="Sigel">Template:Cite book</ref><ref name="Sydor">Template:Cite book</ref><ref>Template:Cite book</ref> Nickel enzymes such as urease are considered virulence factors in some organisms.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> Urease catalyzes hydrolysis of urea to form ammonia and carbamate.<ref name="Sydor" /><ref name="Sigel" /> NiFe hydrogenases can catalyze oxidation of Template:Chem2 to form protons and electrons; and also the reverse reaction, the reduction of protons to form hydrogen gas.<ref name="Sydor" /><ref name="Sigel" /> A nickel-tetrapyrrole coenzyme, cofactor F430, is present in methyl coenzyme M reductase, which can catalyze the formation of methane, or the reverse reaction, in methanogenic archaea (in +1 oxidation state).<ref> Template:Cite book </ref> One of the carbon monoxide dehydrogenase enzymes consists of an Fe-Ni-S cluster.<ref> Template:Cite book</ref> Other nickel-bearing enzymes include a rare bacterial class of superoxide dismutase<ref>Template:Cite journal</ref> and glyoxalase I enzymes in bacteria and several eukaryotic trypanosomal parasites<ref>Template:Cite journal</ref> (in other organisms, including yeast and mammals, this enzyme contains divalent Template:Chem2).<ref name="aronsson_1978">Template:Cite journal</ref><ref name="ridderstroem_1996">Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite journal</ref><ref>Template:Cite book</ref>
Dietary nickel may affect human health through infections by nickel-dependent bacteria, but nickel may also be an essential nutrient for bacteria living in the large intestine, in effect functioning as a prebiotic.<ref>Template:Cite book</ref> The US Institute of Medicine has not confirmed that nickel is an essential nutrient for humans, so neither a Recommended Dietary Allowance (RDA) nor an Adequate Intake have been established. The tolerable upper intake level of dietary nickel is 1 mg/day as soluble nickel salts. Estimated dietary intake is 70 to 100 μg/day; less than 10% is absorbed. What is absorbed is excreted in urine.<ref>Nickel. IN: Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Copper Template:Webarchive. National Academy Press. 2001, PP. 521–529.</ref> Relatively large amounts of nickel – comparable to the estimated average ingestion above – leach into food cooked in stainless steel. For example, the amount of nickel leached after 10 cooking cycles into one serving of tomato sauce averages 88 μg.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>
Nickel released from Siberian Traps volcanic eruptions is suspected of helping the growth of Methanosarcina, a genus of euryarchaeote archaea that produced methane in the Permian–Triassic extinction event, the biggest known mass extinction.<ref> Template:Cite web</ref>
Toxicity
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The major source of nickel exposure is oral consumption, as nickel is essential to plants.<ref>Template:Cite journal</ref> Typical background concentrations of nickel do not exceed 20 ng/mTemplate:Sup in air, 100 mg/kg in soil, 10 mg/kg in vegetation, 10 μg/L in freshwater and 1 μg/L in seawater.<ref>Template:Cite book</ref> Environmental concentrations may be increased by human pollution. For example, nickel-plated faucets may contaminate water and soil; mining and smelting may dump nickel into wastewater; nickel–steel alloy cookware and nickel-pigmented dishes may release nickel into food. Air may be polluted by nickel ore refining and fossil fuel combustion. Humans may absorb nickel directly from tobacco smoke and skin contact with jewelry, shampoos, detergents, and coins. A less common form of chronic exposure is through hemodialysis as traces of nickel ions may be absorbed into the plasma from the chelating action of albumin.Template:Citation needed
The average daily exposure is not a threat to human health. Most nickel absorbed by humans is removed by the kidneys and passed out of the body through urine or is eliminated through the gastrointestinal tract without being absorbed. Nickel is not a cumulative poison, but larger doses or chronic inhalation exposure may be toxic, even carcinogenic, and constitute an occupational hazard.<ref>Template:Cite book</ref>
Nickel compounds are classified as human carcinogens<ref name="Nickel and nickel compounds">IARC (2012). "Nickel and nickel compounds" Template:Webarchive in IARC Monogr Eval Carcinog Risks Hum. Volume 100C. pp. 169–218.</ref><ref name="Reg 1272/2008">Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008 on Classification, Labelling and Packaging of Substances and Mixtures, Amending and Repealing Directives 67/548/EEC and 1999/45/EC and amending Regulation (EC) No 1907/2006 [OJ L 353, 31.12.2008, p. 1]. Annex VI Template:Webarchive. Accessed July 13, 2017.</ref><ref name="GHS">Globally Harmonised System of Classification and Labelling of Chemicals (GHS) Template:Webarchive, 5th ed., United Nations, New York and Geneva, 2013.</ref><ref name="Carcinogens">National Toxicology Program. (2016). "Report on Carcinogens" Template:Webarchive, 14th ed. Research Triangle Park, NC: U.S. Department of Health and Human Services, Public Health Service.</ref> based on increased respiratory cancer risks observed in epidemiological studies of sulfidic ore refinery workers.<ref name="Nickel Carcinogenesis in Man">Template:Cite journal</ref> This is supported by the positive results of the NTP bioassays with Ni sub-sulfide and Ni oxide in rats and mice.<ref name="Studies of Nickel Subsulfide">Template:Cite journal</ref><ref>Template:Cite journal</ref> The human and animal data consistently indicate a lack of carcinogenicity via the oral route of exposure and limit the carcinogenicity of nickel compounds to respiratory tumours after inhalation.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref> Nickel metal is classified as a suspect carcinogen;<ref name="Nickel and nickel compounds" /><ref name="Reg 1272/2008" /><ref name="GHS" /> there is consistency between the absence of increased respiratory cancer risks in workers predominantly exposed to metallic nickel<ref name="Nickel Carcinogenesis in Man" /> and the lack of respiratory tumours in a rat lifetime inhalation carcinogenicity study with nickel metal powder.<ref name="Inhalation carcinogenicity">Template:Cite journal</ref> In the rodent inhalation studies with various nickel compounds and nickel metal, increased lung inflammations with and without bronchial lymph node hyperplasia or fibrosis were observed.<ref name="Carcinogens" /><ref name="Studies of Nickel Subsulfide" /><ref name="Inhalation carcinogenicity" /><ref>Template:Cite journal</ref> In rat studies, oral ingestion of water-soluble nickel salts can trigger perinatal mortality in pregnant animals.<ref>Springborn Laboratories Inc. (2000). "An Oral (Gavage) Two-generation Reproduction Toxicity Study in Sprague-Dawley Rats with Nickel Sulfate Hexahydrate." Final Report. Springborn Laboratories Inc., Spencerville. SLI Study No. 3472.4.</ref> Whether these effects are relevant to humans is unclear as epidemiological studies of highly exposed female workers have not shown adverse developmental toxicity effects.<ref>Template:Cite journal</ref>
People can be exposed to nickel in the workplace by inhalation, ingestion, and contact with skin or eye. The Occupational Safety and Health Administration (OSHA) has set the legal limit (permissible exposure limit) for the workplace at 1 mg/mTemplate:Sup per 8-hour workday, excluding nickel carbonyl. The National Institute for Occupational Safety and Health (NIOSH) sets the recommended exposure limit (REL) at 0.015 mg/mTemplate:Sup per 8-hour workday. At 10 mg/mTemplate:Sup, nickel is immediately dangerous to life and health.<ref>Template:Cite web</ref> Nickel carbonyl Template:Chem2 is an extremely toxic gas. The toxicity of metal carbonyls is a function of both the toxicity of the metal and the off-gassing of carbon monoxide from the carbonyl functional groups; nickel carbonyl is also explosive in air.<ref>Template:Cite book</ref><ref>Template:Cite journal</ref>
Sensitized persons may show a skin contact allergy to nickel known as a contact dermatitis. Highly sensitized persons may also react to foods with high nickel content.<ref name="aad" /> Patients with pompholyx may also be sensitive to nickel. Nickel is the top confirmed contact allergen worldwide, partly due to its use in jewelry for pierced ears.<ref>Template:Cite journal</ref> Nickel allergies affecting pierced ears are often marked by itchy, red skin. Many earrings are now made without nickel or with low-release nickel<ref>Dermal Exposure: Nickel Alloys Template:Webarchive Nickel Producers Environmental Research Association (NiPERA), accessed 2016 Feb.11</ref> to address this problem. The amount allowed in products that contact human skin is now regulated by the European Union. In 2002, researchers found that the nickel released by 1 and 2 euro coins, far exceeded those standards. This is believed to be due to a galvanic reaction.<ref>Template:Cite journal</ref> Nickel was voted Allergen of the Year in 2008 by the American Contact Dermatitis Society.<ref>Template:Cite web</ref> In August 2015, the American Academy of Dermatology adopted a position statement on the safety of nickel: "Estimates suggest that contact dermatitis, which includes nickel sensitization, accounts for approximately $1.918 billion and affects nearly 72.29 million people."<ref name="aad">Position Statement on Nickel Sensitivity Template:Webarchive. American Academy of Dermatology(August 22, 2015)</ref>
Reports show that both the nickel-induced activation of hypoxia-inducible factor (HIF-1) and the up-regulation of hypoxia-inducible genes are caused by depletion of intracellular ascorbate. The addition of ascorbate to the culture medium increased the intracellular ascorbate level and reversed both the metal-induced stabilization of HIF-1- and HIF-1α-dependent gene expression.<ref>Template:Cite journal</ref><ref>Template:Cite journal</ref>
References
[edit]External links
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- Nickel video from the Periodic Videos series (University of Nottingham)
- Nickel entry (last reviewed October 30, 2019) in the NIOSH Pocket Guide to Chemical Hazards published by the CDC's National Institute for Occupational Safety and Health
- Toxicological Profile for Nickel (draft for public comment) (PDF) (August 2023) – 422-page report from the United States Department of Health and Human Services, Public Health Service, Agency for Toxic Substances and Disease Registry
- The metal that brought you cheap flights, BBC News (2015)
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