Nickel is a chemical element with symbol Ni and atomic number 28. It is a silvery-white lustrous metal with a slight golden tinge. Nickel belongs to the transition metals and is hard and ductile. Pure nickel, powdered to maximize the reactive surface area, shows a significant chemical activity, but larger pieces are slow to react with air under standard conditions because an oxide layer forms on the surface and prevents further corrosion (passivation). Even so, pure native nickel is found in Earth's crust only in tiny amounts, usually in ultramafic rocks, 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 inner core.
Use of nickel (as a natural meteoric nickel–iron alloy) has been traced as far back as 3500 BCE. Nickel was first isolated and classified as a chemical 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), who personified the fact that copper-nickel ores resisted refinement into copper. An economically important source of nickel is the iron ore limonite, which often contains 1–2% nickel. Nickel's other important ore minerals include pentlandite and a mixture of Ni-rich natural silicates known as garnierite. Major production sites include the Sudbury region in Canada (which is thought to be of meteoric origin), New Caledonia in the Pacific, and Norilsk in Russia.
Nickel is slowly oxidized by air at room temperature and is considered corrosion-resistant. Historically, it has been used for plating iron and brass, coating chemistry equipment, and manufacturing certain alloys that retain a high silvery polish, such as German silver. About 9% of world nickel production is still used for corrosion-resistant nickel plating. Nickel-plated objects sometimes provoke nickel allergy. Nickel has been widely used in coins, though its rising price has led to some replacement with cheaper metals in recent years.
Nickel is one of four elements (the others are iron, cobalt, and gadolinium) that are ferromagnetic at approximately 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 valuable in modern times chiefly in alloys; about 68% of world production is used in stainless steel. A further 10% is used for nickel-based and copper-based alloys, 7% for alloy steels, 3% in foundries, 9% in plating and 4% in other applications, including the fast-growing battery sector. As a compound, nickel has a number of niche chemical manufacturing uses, such as a catalyst for hydrogenation, cathodes for batteries, pigments and metal surface treatments. Nickel is an essential nutrient for some microorganisms and plants that have enzymes with nickel as an active site.
|Appearance||lustrous, metallic, and silver with a gold tinge|
|Standard atomic weight Ar, std(Ni)||58.6934(4)|
|Nickel in the periodic table|
|Atomic number (Z)||28|
|Element category||transition metal|
|Electron configuration||[Ar] 3d8 4s2 or [Ar] 3d9 4s1|
Electrons per shell
|2, 8, 16, 2 or 2, 8, 17, 1|
|Phase at STP||solid|
|Melting point||1728 K (1455 °C, 2651 °F)|
|Boiling point||3003 K (2730 °C, 4946 °F)|
|Density (near r.t.)||8.908 g/cm3|
|when liquid (at m.p.)||7.81 g/cm3|
|Heat of fusion||17.48 kJ/mol|
|Heat of vaporization||379 kJ/mol|
|Molar heat capacity||26.07 J/(mol·K)|
|Oxidation states||−2, −1, +1, +2, +3, +4, (a mildly basic oxide)|
|Electronegativity||Pauling scale: 1.91|
|Atomic radius||empirical: 124 pm|
|Covalent radius||124±4 pm|
|Van der Waals radius||163 pm|
Spectral lines of nickel
|Crystal structure|| face-centered cubic (fcc)|
|Speed of sound thin rod||4900 m/s (at r.t.)|
|Thermal expansion||13.4 µm/(m·K) (at 25 °C)|
|Thermal conductivity||90.9 W/(m·K)|
|Electrical resistivity||69.3 nΩ·m (at 20 °C)|
|Young's modulus||200 GPa|
|Shear modulus||76 GPa|
|Bulk modulus||180 GPa|
|Vickers hardness||638 MPa|
|Brinell hardness||667–1600 MPa|
|Discovery and first isolation||Axel Fredrik Cronstedt (1751)|
|Main isotopes of nickel|
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 magnetic at or near room temperature, the others being iron, cobalt and gadolinium. Its Curie temperature is 355 °C (671 °F), meaning that bulk nickel is non-magnetic above this temperature. The unit cell of nickel is a face-centered cube with the 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 belongs to the transition metals and is hard and ductile.
The nickel atom has two electron configurations, [Ar] 3d8 4s2 and [Ar] 3d9 4s1, which are very close in energy – the symbol [Ar] refers to the argon-like core structure. There is some disagreement on which configuration has the lowest energy. Chemistry textbooks quote the electron configuration of nickel as [Ar] 4s2 3d8, which can also be written [Ar] 3d8 4s2. 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 3d8 4s2 energy level, specifically the 3d8(3F) 4s2 3F, J = 4 level.
However, each of these two configurations splits into several energy levels due to fine structure, and the two sets of energy levels overlap. The average energy of states with configuration [Ar] 3d9 4s1 is actually lower than the average energy of states with configuration [Ar] 3d8 4s2. For this reason, the research literature on atomic calculations quotes the ground state configuration of nickel as [Ar] 3d9 4s1.
Naturally occurring nickel is composed of five stable isotopes; 58
Ni and 64
Ni, with 58
Ni being the most abundant (68.077% natural abundance). Isotopes heavier than 62
Ni cannot be formed by nuclear fusion without losing energy.
Nickel-62 has the highest mean nuclear binding energy per nucleon of any nuclide, at 8.7946 MeV/nucleon. Its binding energy is greater than both 56
Fe and 58
Fe, more abundant elements often incorrectly cited as having the most tightly-bound nuclides. Although this would seem to predict nickel-62 as the most abundant heavy element in the universe, the relatively high rate of photodisintegration of nickel in stellar interiors causes iron to be by far the most abundant.
Stable isotope nickel-60 is the daughter product of the extinct radionuclide 60
Fe, which decays with a half-life of 2.6 million years. Because 60
Fe has such a long half-life, its persistence in materials in the solar system may generate observable variations in the isotopic composition of 60
Ni. Therefore, the abundance of 60
Ni present in extraterrestrial material may provide insight into the origin of the solar system and its early history.
Some 18 nickel radioisotopes have been characterised, the most stable being 59
Ni with a half-life of 76,000 years, 63
Ni with 100 years, and 56
Ni with 6 days. All of the remaining radioactive isotopes have half-lives that are less than 60 hours and the majority of these have half-lives that are less than 30 seconds. This element also has one meta state.
Radioactive nickel-56 is produced by the silicon burning process and later set free in large quantities during 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 nickel-56 to cobalt-56 and ultimately to iron-56. Nickel-59 is a long-lived cosmogenic radionuclide with a half-life of 76,000 years. 59
Ni has found many applications in isotope geology. 59
Ni has been used to date the terrestrial age of meteorites and to determine abundances of extraterrestrial dust in ice and sediment. Nickel-78's half-life was recently measured at 110 milliseconds, and is believed an important isotope in supernova nucleosynthesis of elements heavier than iron. The nuclide 48Ni, discovered in 1999, is the most proton-rich heavy element isotope known. With 28 protons and 20 neutrons 48Ni is "double magic", as is 78
Ni with 28 protons and 50 neutrons. Both are therefore unusually stable for nuclides with so large a proton-neutron imbalance.
On Earth, nickel occurs most often in combination with sulfur and iron in pentlandite, with sulfur in millerite, with arsenic in the mineral nickeline, and with arsenic and sulfur in nickel galena. Nickel is commonly found in iron meteorites as the alloys kamacite and taenite.
The bulk of the nickel is mined from two types of ore deposits. The first is laterite, where the principal ore mineral mixtures are nickeliferous limonite, (Fe,Ni)O(OH), and garnierite (a mixture of various hydrous nickel and nickel-rich silicates). The second is magmatic sulfide deposits, where the principal ore mineral is pentlandite: (Ni,Fe)
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.
On geophysical evidence, most of the nickel on Earth is believed to be in the 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, although impurities (such as cobalt or carbon) may be present, while for taenite the nickel content is between 20% and 65%. Kamacite and taenite are also found in nickel iron meteorites.
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.
Nickel(I) complexes are uncommon, but one example is the tetrahedral complex NiBr(PPh3)3. Many nickel(I) complexes feature Ni-Ni bonding, such as the dark red diamagnetic K
6] prepared by reduction of K
6] with sodium amalgam. This compound is oxidised in water, liberating H
Nickel(II) forms compounds with all common anions, including sulfide, sulfate, carbonate, hydroxide, carboxylates, and halides. Nickel(II) sulfate is produced in large quantities by dissolving nickel metal or oxides in sulfuric acid, forming both a hexa- and heptahydrates useful for electroplating nickel. Common salts of nickel, such as the chloride, nitrate, and sulfate, dissolve in water to give green solutions of the metal aquo complex [Ni(H
The four halides form nickel compounds, which are solids with molecules that feature octahedral Ni centres. Nickel(II) chloride is most common, and its behavior is illustrative of the other halides. Nickel(II) chloride is produced by dissolving nickel or its oxide in hydrochloric acid. It is usually encountered as the green hexahydrate, the formula of which is usually written NiCl2•6H2O. When dissolved in water, this salt forms the metal aquo complex [Ni(H
. Dehydration of NiCl2•6H2O gives the yellow anhydrous NiCl
Some tetracoordinate nickel(II) complexes, e.g. bis(triphenylphosphine)nickel chloride, exist both in tetrahedral and square planar geometries. The tetrahedral complexes are paramagnetic, whereas 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.
Numerous Ni(III) compounds are known, with the first such examples being Nickel(III) trihalophosphines (NiIII(PPh3)X3). Further, Ni(III) forms simple salts with fluoride or oxide ions. Ni(III) can be stabilized by σ-donor ligands such as thiols and phosphines.
Ni(IV) is present in the mixed oxide BaNiO
3, while Ni(III) is present 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. Ni(IV) remains a rare oxidation state of nickel and very few compounds are known to date.
Because the ores of nickel are easily mistaken for ores of silver, understanding of this metal and its use dates to relatively recent times. However, the unintentional use of nickel is ancient, and can be traced back as far as 3500 BCE. Bronzes from what is now Syria have been found to contain as much as 2% nickel. Some ancient Chinese manuscripts suggest that "white copper" (cupronickel, known as baitong) was used there between 1700 and 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. Coins of nickel-copper alloy were minted by the Bactrian kings Agathocles, Euthydemus II and Pantaleon in the 2nd Century BCE, possibly out of the Chinese cupronickel.
In medieval Germany, a red mineral was found in the Erzgebirge (Ore Mountains) that resembled copper ore. However, when miners were unable to extract 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 Kupfernickel from the German Kupfer for copper. This ore is now known to be nickeline, a nickel arsenide. In 1751, Baron Axel Fredrik Cronstedt tried to extract copper from kupfernickel at a cobalt mine in the Swedish village of Los, and instead produced a white metal that he named after the spirit that had given its name to the mineral, nickel. In modern German, Kupfernickel or Kupfer-Nickel designates the alloy cupronickel.
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. The introduction of nickel in steel production in 1889 increased the demand for nickel, and 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, Canada in 1883, in Norilsk-Talnakh, Russia in 1920, and in the Merensky Reef, South Africa in 1924, made large-scale production of nickel possible.
Aside from the aforementioned Bactrian coins, nickel was not a component of coins until the mid-19th century.
99.9% nickel five-cent coins were struck in Canada (the world's largest nickel producer at the time) during non-war years from 1922–1981; the metal content made these coins magnetic. During the wartime period 1942–45, most or all nickel was removed from Canadian and U.S. coins to save it for manufacturing armor. Canada used 99.9% nickel from 1968 in its higher-value coins until 2000.
Coins of nearly pure nickel were first used in 1881 in Switzerland.
Birmingham forged nickel coins in about 1833 for trading in Malaya.
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 1859–1864. 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. Along with the alloy proportion, this term has been used to the present in the United States.
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¢ and 50¢ U.S. coins, and 20p, 50p, £1 and £2 UK coins. Nickel-alloy in 5p and 10p UK coins was replaced with nickel-plated steel began in 2012, causing allergy problems for some people and public controversy.
Around 2 million tonnes of nickel are produced annually worldwide. The Philippines, Indonesia, Russia, Canada and Australia are the world's largest producers of nickel, as reported by the US Geological Survey. The largest deposits of nickel in non-Russian Europe are located in Finland and Greece. Identified land-based resources averaging 1% nickel or greater contain at least 130 million tons of nickel. About 60% is in laterites and 40% is in sulfide deposits. In addition, extensive deep-sea resources of nickel are in manganese crusts and nodules covering large areas of the ocean floor, particularly in the Pacific Ocean.
The one locality in the United States where nickel has been profitably mined is Riddle, Oregon, where several square miles of nickel-bearing garnierite surface deposits are located. The mine closed in 1987. 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. In the first full year of operation, Eagle Mine produced 18,000 tonnes.
|Mine production and reserves (in metric tons)||2016 (estimated)||2015||2014||2013||2012||2011||Reserves|
|World total (rounded)||2,250,000||2,280,000||2,450,000||2,630,000||2,220,000||1,940,000||78,000,000|
Nickel is obtained through extractive metallurgy: it is extracted from the ore by conventional roasting and reduction processes that yield a metal of greater than 75% purity. In many stainless steel applications, 75% pure nickel can be used without further purification, depending on the impurities.
Traditionally, most sulfide ores have been processed using pyrometallurgical techniques to produce a matte for further refining. Recent advances in hydrometallurgical techniques resulted in significantly purer metallic nickel product. Most sulfide deposits have traditionally been processed by concentration through a froth flotation process followed by pyrometallurgical extraction. In hydrometallurgical processes, nickel sulfide ores are concentrated with flotation (differential flotation if Ni/Fe ratio is too low) and then smelted. 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 99%.
A second common refining process is leaching the metal matte into a nickel salt solution, followed by the electro-winning of the nickel from solution by plating it onto a cathode as electrolytic nickel.
The purest metal is obtained from nickel oxide by the Mond process, which achieves a purity of greater than 99.99%. The process was patented by Ludwig Mond and has been in industrial use since before the beginning of the 20th century. In this process, nickel is reacted with carbon monoxide in the presence of a sulfur catalyst at around 40–80 °C to form nickel carbonyl. Iron gives iron pentacarbonyl, too, but 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.
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, called pellets, are constantly stirred. The carbonyl decomposes and deposits pure nickel onto the nickel 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".
The market price of nickel surged throughout 2006 and the early months of 2007; as of April 5, 2007, the metal was trading at US$52,300/tonne or $1.47/oz. The price subsequently fell dramatically, and as of September 2017, the metal was trading at $11,000/tonne, or $0.31/oz.
The US nickel coin contains 0.04 ounces (1.1 g) 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. However, the United States Mint, in anticipation of 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. Violators can be punished with a fine of up to $10,000 and/or imprisoned for a maximum of five years.
As of September 19, 2013, the melt value of a U.S. nickel (copper and nickel included) is $0.045, which is 90% of the face value.
The global production of nickel is presently used as follows: 68% in stainless steel; 10% in nonferrous alloys; 9% in electroplating; 7% in alloy steel; 3% in foundries; and 4% other uses (including batteries).
Nickel is used in many specific and recognizable industrial and consumer products, including stainless steel, alnico magnets, coinage, rechargeable batteries, electric guitar strings, microphone capsules, plating on plumbing fixtures, 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).
Because it is resistant to corrosion, nickel 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 was replaced by cheaper stainless steel (i.e., iron) alloys, except in the United States and Canada.
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 is capable of fully collecting all six PGE elements from ores, and of partially collecting gold. High-throughput nickel mines may also engage in PGE recovery (primarily platinum and palladium); examples are Norilsk in Russia and the Sudbury Basin in Canada.
Nickel and its alloys are frequently 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.
Nickel is a naturally magnetostrictive material, meaning that, in the presence of a magnetic field, the material undergoes a small change in length. The magnetostriction of nickel is on the order of 50 ppm and is negative, indicating that it contracts.
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, although the hardness is less than those with a cobalt binder.
Around 27% of all nickel production is destined 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.
Although not recognized until the 1970s, nickel is known to play an important role in the biology of some plants, eubacteria, archaebacteria, and fungi. Nickel enzymes such as urease are considered virulence factors in some organisms. Urease catalyzes the hydrolysis of urea to form ammonia and carbamate. The NiFe hydrogenases can catalyze the oxidation of H
2 to form protons and electrons, and can also catalyze the reverse reaction, the reduction of protons to form hydrogen gas. 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. One of the carbon monoxide dehydrogenase enzymes consists of an Fe-Ni-S cluster. Other nickel-bearing enzymes include a rare bacterial class of superoxide dismutase and glyoxalase I enzymes in bacteria and several parasitic eukaryotic trypanosomal parasites (in higher organisms, including yeast and mammals, this enzyme contains divalent Zn2+).
Dietary nickel may affect human health through infections by nickel-dependent bacteria, but it is also possible that nickel is an essential nutrient for bacteria residing in the large intestine, in effect functioning as a prebiotic. The U.S. 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 1000 µg/day as soluble nickel salts. Dietary intake is estimated at 70 to 100 µg/day, with less than 10% absorbed. What is absorbed is excreted in urine. 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.
Nickel released from Siberian Traps volcanic eruptions is suspected of assisting the growth of Methanosarcina, a genus of euryarchaeote archaea that produced methane during the Permian–Triassic extinction event, the biggest extinction event on record.
|GHS signal word||Danger|
|H317, H351, H372, H412|
|P273, P280, P314, P333+313|
The major source of nickel exposure is oral consumption, as nickel is essential to plants. Nickel is found naturally in both food and water, and may be increased by human pollution. For example, nickel-plated faucets may contaminate water and soil; mining and smelting may dump nickel into waste-water; nickel–steel alloy cookware and nickel-pigmented dishes may release nickel into food. The atmosphere 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.
The average daily exposure does not pose a threat to human health. Most of the nickel absorbed every day 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.
Nickel compounds are classified as human carcinogens based on increased respiratory cancer risks observed in epidemiological studies of sulfidic ore refinery workers. This is supported by the positive results of the NTP bioassays with Ni sub-sulfide and Ni oxide in rats and mice. 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. Nickel metal is classified as a suspect carcinogen; there is consistency between the absence of increased respiratory cancer risks in workers predominantly exposed to metallic nickel and the lack of respiratory tumours in a rat lifetime inhalation carcinogenicity study with nickel metal powder. 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. In rat studies, oral ingestion of water-soluble nickel salts can trigger perinatal mortality effects in pregnant animals. Whether these effects are relevant to humans is unclear as epidemiological studies of highly exposed female workers have not shown adverse developmental toxicity effects.
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/m3 per 8-hour workday, excluding nickel carbonyl. The National Institute for Occupational Safety and Health (NIOSH) specifies the recommended exposure limit (REL) of 0.015 mg/m3 per 8-hour workday. At 10 mg/m3, nickel is immediately dangerous to life and health. Nickel carbonyl [Ni(CO)
4] 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.
Sensitized individuals may show a skin contact allergy to nickel known as a contact dermatitis. Highly sensitized individuals may also react to foods with high nickel content. Sensitivity to nickel may also be present in patients with pompholyx. Nickel is the top confirmed contact allergen worldwide, partly due to its use in jewelry for pierced ears. Nickel allergies affecting pierced ears are often marked by itchy, red skin. Many earrings are now made without nickel or low-release nickel 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 was far in excess of those standards. This is believed to be the result of a galvanic reaction. Nickel was voted Allergen of the Year in 2008 by the American Contact Dermatitis Society. 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."
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.
.... That spike in nickel allowed methanogens to take off.
The Buffalo nickel or Indian Head nickel is a copper-nickel five-cent piece that was struck by the United States Mint from 1913 to 1938. It was designed by sculptor James Earle Fraser.
As part of a drive to beautify the coinage, five denominations of US coins had received new designs between 1907 and 1909. In 1911, Taft administration officials decided to replace Charles E. Barber's Liberty Head design for the nickel, and commissioned Fraser to do the work. They were impressed by Fraser's designs showing a Native American and an American bison. The designs were approved in 1912, but were delayed several months because of objections from the Hobbs Manufacturing Company, which made mechanisms to detect slugs in nickel-operated machines. The company was not satisfied by changes made in the coin by Fraser, and in February 1913, Treasury Secretary Franklin MacVeagh decided to issue the coins despite the objections.
Despite attempts by the Mint to adjust the design, the coins proved to strike indistinctly, and to be subject to wear—the dates were easily worn away in circulation. In 1938, after the expiration of the minimum 25-year period during which the design could not be replaced without congressional authorization, it was replaced by the Jefferson nickel, designed by Felix Schlag. Fraser's design is admired today, and has been used on commemorative coins and the gold American Buffalo series.Cupronickel
Cupronickel (also known as copper-nickel) is an alloy of copper that contains nickel and strengthening elements, such as iron and manganese. Despite its high copper content, cupronickel is silver in colour.
Due to the specific properties of nickel and copper alloys, they are applied in various domains of
industry e.g. coin and medal minting, armaments manufacture, desalination materials, marine engineering, and extensively
used in the chemical, petrochemical and electrical industries.Cupronickel is highly resistant to corrosion in seawater. For this reason, it is used for piping, heat exchangers and condensers in seawater systems, marine hardware, and sometimes for the propellers, crankshafts and hulls of premium tugboats, fishing boats and other working boats.
Another common use of cupronickel is in silver-coloured modern-circulated coins. A typical mix is 75% copper, 25% nickel (a proportion of 3:1), and a trace amount of manganese. In the past, true silver coins were debased with cupronickel.Group 10 element
Group 10, numbered by current IUPAC style, is the group of chemical elements in the periodic table that consists of nickel (Ni), palladium (Pd), platinum (Pt), and perhaps also the chemically uncharacterized darmstadtium (Ds). All are d-block transition metals. All known isotopes of darmstadtium are radioactive with short half-lives, and are not known to occur in nature; only minute quantities have been synthesized in laboratories.
Like other groups, the members of this group show patterns in electron configuration, especially in the outermost shells, although for this group they are particularly weak, with palladium being an exceptional case. The relativistic stabilization of the 7s orbital is the explanation to the predicted electron configuration of darmstadtium, which, unusually for this group, conforms to that predicted by the Aufbau principle.Iron meteorite
Iron meteorites are meteorites that consist overwhelmingly of an iron–nickel alloy known as meteoric iron that usually consists of two mineral phases: kamacite and taenite. Iron meteorites originate from cores of planetesimals.The iron found in iron meteorites was one of the earliest sources of usable iron available to humans, before the development of smelting that signaled the beginning of the Iron Age.Isotopes of nickel
Naturally occurring nickel (28Ni) is composed of five stable isotopes; 58Ni, 60Ni, 61Ni, 62Ni and 64Ni with 58Ni being the most abundant (68.077% natural abundance). 26 radioisotopes have been characterised with the most stable being 59Ni with a half-life of 76,000 years, 63Ni with a half-life of 100.1 years, and 56Ni with a half-life of 6.077 days. All of the remaining radioactive isotopes have half-lives that are less than 60 hours and the majority of these have half-lives that are less than 30 seconds. This element also has 1 meta state.Jefferson nickel
The Jefferson nickel has been the five-cent coin struck by the United States Mint since 1938, when it replaced the Buffalo nickel. From 1938 until 2004, the copper-nickel coin's obverse featured a profile depiction of founding father and third U.S. President Thomas Jefferson by artist Felix Schlag; the obverse design used in 2005 was also in profile, though by Joe Fitzgerald. Since 2006 Jefferson's portrayal, newly designed by Jamie Franki, faces forward. The coin's reverse is still the Schlag original, although in 2004 and 2005 the piece bore commemorative designs.
First struck in 1913, the Buffalo nickel had long been difficult to coin, and after it completed the 25-year term during which it could only be replaced by Congress, the Mint moved quickly to replace it with a new design. The Mint conducted a design competition in early 1938, requiring that Jefferson be depicted on the obverse, and Jefferson's house Monticello on the reverse. Schlag won the competition, but was required to submit an entirely new reverse and make other changes before the new piece went into production in October 1938.
As nickel was a strategic war material during World War II, nickels coined from 1942 to 1945 were struck in a copper-silver-manganese alloy which would not require adjustment to vending machines. They bear a large mint mark above the depiction of Monticello on the reverse. In 2004 and 2005, the nickel saw new designs as part of the Westward Journey nickel series, and since 2006 has borne Schlag's reverse and Franki's obverse.Molten-salt battery
Molten-salt batteries (including liquid-metal batteries) are a class of battery that uses molten salts as an electrolyte and offers both a high energy density and a high power density. Traditional "use once" thermal batteries can be stored in their solid state at room temperature for long periods of time before being activated by heating. Rechargeable liquid-metal batteries are used for electric vehicles and potentially also for grid energy storage, to balance out intermittent renewable power sources such as solar panels and wind turbines.New York, Chicago and St. Louis Railroad
The New York, Chicago and St. Louis Railroad (reporting mark NKP), abbreviated NYC&St.L, was a railroad that operated in the mid-central United States. Commonly referred to as the Nickel Plate Road, the railroad served a large area, including trackage in the states of New York, Pennsylvania, Ohio, Indiana, Illinois and Missouri. Its primary connections included Buffalo, Chicago, Cincinnati, Cleveland, Indianapolis, St. Louis, and Toledo.
The Nickel Plate Railroad was constructed in 1881 along the South Shore of the Great Lakes connecting Buffalo and Chicago to compete with the Lake Shore and Michigan Southern Railway. In 1964 the Nickel Plate Road and several other mid-western carriers were merged into the larger Norfolk and Western Railway (N&W). The goal of the N&W expansion was to form a more competitive and successful system serving 14 states and the Canadian province of Ontario on more than 7,000 miles (11,000 km) of railroad. The profitable N&W was itself combined with the Southern Railway, another profitable carrier, to form Norfolk Southern Corporation (NS) in 1982.
At the end of 1960 NKP operated 2,170 miles (3,490 km) of road on 4,009 miles (6,452 km) of track, not including the 25 miles (40 km) of Lorain & West Virginia. That year it reported 9758 million net ton-miles of revenue freight and 41 million passenger-miles.
The Nickel Plate Historical and Technical Society works to preserve the memory of the Nickel Plate Road.Nickel (United States coin)
A nickel, in American usage, is a five-cent coin struck by the United States Mint. Composed of 75% copper and 25% nickel, the piece has been issued since 1866. Its diameter is .835 inches (21.21 mm) and its thickness is .077 inches (1.95 mm). Due to inflation, the purchasing power of the nickel continues to drop and currently the coin represents less than 1% of the federal hourly minimum wage. In 2015, over 1.5 billion nickels were produced at the Philadelphia and Denver mints.
The silver half dime, equal to five cents, had been issued since the 1790s. The American Civil War caused economic hardship, driving gold and silver from circulation; in response, in place of low-value coins, the government at first issued paper currency. In 1865, Congress abolished the five-cent fractional currency note after Spencer M. Clark, head of the Currency Bureau (today the Bureau of Engraving and Printing), placed his own portrait on the denomination. After the successful introduction of two-cent and three-cent pieces without precious metal, Congress also authorized a five-cent piece consisting of base metal; the Mint began striking this version in 1866.
The initial design of the Shield nickel was struck from 1866 until 1883, then was replaced by the Liberty Head nickel. The Buffalo nickel was introduced in 1913 as part of a drive to increase the beauty of American coinage; in 1938, the Jefferson nickel followed. In 2004 and 2005, special designs in honor of the bicentennial of the Lewis and Clark Expedition were issued. In 2006, the Mint reverted to using Jefferson nickel designer Felix Schlag's original reverse (or "tails" side), although a new obverse, by Jamie Franki, was substituted. As of the end of FY 2013, it cost more than nine cents to produce a nickel; the Mint is exploring the possibility of reducing cost by using less expensive metals.Nickel Creek
Nickel Creek (formerly known as the Nickel Creek Band) is an American Americana music group consisting of Chris Thile (mandolin), and siblings Sara Watkins (fiddle) and Sean Watkins (guitar). Formed in 1989 in Southern California, they released six albums between 1993 and 2006. The band broke out in 2000 with a platinum-selling self-titled album produced by Alison Krauss, earning a number of Grammy and CMA nominations.
Their fourth album won a 2003 Grammy Award for Best Contemporary Folk Album. Following a fifth studio album and a compilation album, the band announced an indefinite hiatus at the conclusion of their 2007 Farewell (For Now) Tour. Following numerous solo projects from the band members, Nickel Creek reformed in 2014 with announcement of a new album and subsequent tour.Nickel Plate Provincial Park
Nickel Plate Provincial Park is a provincial park in British Columbia, Canada. Formerly known as Clearwater Park, it is located in the Similkameen District at the northeast corner of Nickel Plate Lake.The park has recreational activities including hiking, fishing, paddling, canoeing and kayaking as well as winter recreation.Nickel defense
In American football, a nickel defense (also known as a 4–2–5 or 3–3–5) is any defensive alignment that uses five defensive backs, of whom the fifth is known as a nickelback. The original and most common form of the nickel defense features four down linemen and two linebackers. Because the traditional 4–2 form preserves the defense's ability to stop an opponent's running game, it has remained more popular than its variants, to the extent that even when another formation technically falls within the "nickel" definition, coaches and analysts will refer to it by a more specific designation (e.g., "3–3–5" for a lineup of three down linemen and three linebackers) that conveys more information with equal or greater conciseness.
The nickel defense originated as an innovation of Philadelphia Eagles defensive coach Jerry Williams in 1960 as a measure to defend against star tight end Mike Ditka of the Chicago Bears. The Nickel defense was later used by then Chicago Bears assistant George Allen, who came up with the name "nickel" and later marketed the idea as his own. The nickel defense was popularized by head coach Don Shula and defensive coordinator Bill Arnsparger of the Miami Dolphins in the 1970s and is now commonly employed in obvious passing situations or against a team that frequently uses three wide receiver sets on offense.
In college football, TCU is known to use a nickel defense as its base set, typically playing three safeties and two linebackers. Current Horned Frogs coach Gary Patterson installed the nickel partly out of necessity upon finding that larger and more prominent programs, most notably those of the large public universities in Texas, were able to "recruit away" most of the large athletes who would otherwise be available to the TCU program. As it turned out, the nickel proved to be a very good set against the spread offenses proliferating throughout college football in the early 21st century.A common defensive front adjustment for 3–4 teams to accommodate the nickel backfield involves putting the two outside linebackers into a three-point stance shading the offensive tackles (i.e. a 5 technique). To complete the adjustment, the 3–4 defensive ends are moved to face or shade the offensive guards. The nose tackle is removed for a defensive back. The purpose of this is to leave the four best pass rushers on the field in a long yardage situation. This is not the only adjustment that can be made. Bill Arnsparger would often remove linebackers from a 3–4 to create nickel and dime sets, replacing them with defensive backs.Nickel silver
Nickel silver, Maillechort, German silver, Argentan, new silver, nickel brass, albata, alpacca, is a copper alloy with nickel and often zinc. The usual formulation is 60% copper, 20% nickel and 20% zinc. Nickel silver is named due to its silvery appearance, but it contains no elemental silver unless plated. The name "German silver" refers to its development by 19th-century German metalworkers from the Chinese alloy known as paktong (白銅) (cupronickel). All modern, commercially important nickel silvers (such as those standardized under ASTM B122) contain significant amounts of zinc, and are sometimes considered a subset of brass.Nickel–Strunz classification
Nickel–Strunz classification is a scheme for categorizing minerals based upon their chemical composition, introduced by German mineralogist Karl Hugo Strunz (24 February 1910 – 19 April 2006) in his Mineralogische Tabellen (1941). The 4th and the 5th edition was also edited by Christel Tennyson (1966). It was followed by A.S. Povarennykh with a modified classification (1966 in Russian, 1972 in English).
As curator of the Mineralogical Museum of Friedrich-Wilhelms-Universität (now known as the Humboldt University of Berlin), Strunz had been tasked with sorting the museum's geological collection according to crystal-chemical properties. His book Mineralogical Tables, has been through a number of modifications; the most recent edition, published in 2001, is the ninth (Mineralogical Tables by Hugo Strunz and Ernest H. Nickel (31 August 1925 – 18 July 2009)). James A. Ferraiolo was responsible for it at Mindat.org. The IMA/CNMNC supports the Nickel–Strunz database.Nickel–cadmium battery
The nickel–cadmium battery (NiCd battery or NiCad battery) is a type of rechargeable battery using nickel oxide hydroxide and metallic cadmium as electrodes. The abbreviation NiCd is derived from the chemical symbols of nickel (Ni) and cadmium (Cd): the abbreviation NiCad is a registered trademark of SAFT Corporation, although this brand name is commonly used to describe all Ni–Cd batteries.
Wet-cell nickel-cadmium batteries were invented in 1899. Among rechargeable battery technologies, NiCd rapidly lost market share in the 1990s, to NiMH and Li-ion batteries; market share dropped by 80%. A NiCd battery has a terminal voltage during discharge of around 1.2 volts which decreases little until nearly the end of discharge. NiCd batteries are made in a wide range of sizes and capacities, from portable sealed types interchangeable with carbon-zinc dry cells, to large ventilated cells used for standby power and motive power. Compared with other types of rechargeable cells they offer good cycle life and performance at low temperatures with a fair capacity but their significant advantage is the ability to deliver practically their full rated capacity at high discharge rates (discharging in one hour or less). However, the materials are more costly than that of the lead–acid battery, and the cells have high self-discharge rates.
Sealed NiCd cells were at one time widely used in portable power tools, photography equipment, flashlights, emergency lighting, hobby R/C, and portable electronic devices. The superior capacity of the Nickel-metal hydride batteries, and more recently their lower cost, has largely supplanted their use. Further, the environmental impact of the disposal of the toxic metal cadmium has contributed considerably to the reduction in their use. Within the European Union, NiCd batteries can now only be supplied for replacement purposes or for certain types of new equipment such as medical devices.Larger ventilated wet cell NiCd batteries are used in emergency lighting, standby power, and uninterruptible power supplies and other applications.Nickel–metal hydride battery
A nickel metal hydride battery, abbreviated NiMH or Ni–MH, is a type of rechargeable battery. The chemical reaction at the positive electrode is similar to that of the nickel–cadmium cell (NiCd), with both using nickel oxide hydroxide (NiOOH). However, the negative electrodes use a hydrogen-absorbing alloy instead of cadmium. A NiMH battery can have two to three times the capacity of an equivalent size NiCd, and its energy density can approach that of a lithium-ion battery.Norilsk
Norilsk (Russian: Нори́льск, IPA: [nɐˈrʲilʲsk]) is an industrial city in Krasnoyarsk Krai, Russia, located above the Arctic Circle, east of the Yenisei River and south of the western Taymyr Peninsula. It has a permanent population of 175,000. With temporary inhabitants included, its population reaches 220,000.
It is the world's northernmost city with more than 100,000 inhabitants and the second-largest city (after Murmansk) inside the Arctic Circle. Norilsk and Yakutsk are the only large cities in the continuous permafrost zone.Plating
Plating is a surface covering in which a metal is deposited on a conductive surface. Plating has been done for hundreds of years; it is also critical for modern technology. Plating is used to decorate objects, for corrosion inhibition, to improve solderability, to harden, to improve wearability, to reduce friction, to improve paint adhesion, to alter conductivity, to improve IR reflectivity, for radiation shielding, and for other purposes. Jewelry typically uses plating to give a silver or gold finish.
Thin-film deposition has plated objects as small as an atom, therefore plating finds uses in nanotechnology.
There are several plating methods, and many variations. In one method, a solid surface is covered with a metal sheet, and then heat and pressure are applied to fuse them (a version of this is Sheffield plate). Other plating techniques include electroplating, vapor deposition under vacuum and sputter deposition. Recently, plating often refers to using liquids. Metallizing refers to coating metal on non-metallic objects.Stainless steel
In metallurgy, stainless steel, also known as inox steel or inox from French inoxydable (inoxidizable), is a steel alloy, with highest percentage contents of iron, chromium, and nickel, with a minimum of 10.5% chromium content by mass and a maximum of 1.2% carbon by mass.Stainless steels are most notable for their corrosion resistance, which increases with increasing chromium content. Additions of molybdenum increase corrosion resistance in reducing acids and against pitting attack in chloride solutions. Thus, there are numerous grades of stainless steel with varying chromium and molybdenum contents to suit the environment the alloy must endure. Stainless steel's resistance to corrosion and staining, low maintenance, and familiar luster make it an ideal material for many applications where both the strength of steel and corrosion resistance are required.
Stainless steels are rolled into sheets, plates, bars, wire, and tubing to be used in: cookware, cutlery, surgical instruments, major appliances; construction material in large buildings, such as the Chrysler Building; industrial equipment (for example, in paper mills, chemical plants, water treatment); and storage tanks and tankers for chemicals and food products (for example, chemical tankers and road tankers). Stainless steel's corrosion resistance, the ease with which it can be steam cleaned and sterilized, and no need for surface coatings has also influenced its use in commercial kitchens and food processing plants.