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76-484: Big Rock was Michigan's first nuclear power plant and the nation's fifth. It also produced cobalt-60 for the medical industry from 1971 to 1982. Ground was broken on July 20, 1960. Construction was completed in 29 months at a cost of $ 27.7 million. Its license from the Nuclear Regulatory Commission was issued on August 29, 1962. The reactor first went critical on September 27 and the first electricity

152-852: A passivating oxide film. It is attacked by halogens and sulfur . Heating in oxygen produces Co 3 O 4 which loses oxygen at 900 °C (1,650 °F) to give the monoxide CoO. The metal reacts with fluorine (F 2 ) at 520 K to give CoF 3 ; with chlorine (Cl 2 ), bromine (Br 2 ) and iodine (I 2 ), producing equivalent binary halides . It does not react with hydrogen gas ( H 2 ) or nitrogen gas ( N 2 ) even when heated, but it does react with boron , carbon , phosphorus , arsenic and sulfur. At ordinary temperatures, it reacts slowly with mineral acids , and very slowly with moist, but not dry, air. Common oxidation states of cobalt include +2 and +3, although compounds with oxidation states ranging from −3 to +5 are also known. A common oxidation state for simple compounds

228-401: A radiation therapy unit illegally purchased by a private medical company and subsequently dismantled for lack of personnel to operate it. The radioactive material, Co, ended up in a junkyard, where it was sold to foundries that inadvertently smelted it with other metals and produced about 6,000 tons of contaminated rebar . These were distributed in 17 Mexican states and several cities in

304-417: A relative permeability two-thirds that of iron . Metallic cobalt occurs as two crystallographic structures : hcp and fcc . The ideal transition temperature between the hcp and fcc structures is 450 °C (842 °F), but in practice the energy difference between them is so small that random intergrowth of the two is common. Cobalt is a weakly reducing metal that is protected from oxidation by

380-529: A " salting " element to add to nuclear weapons , to produce a cobalt bomb , an extremely "dirty" weapon which would contaminate large areas with Co nuclear fallout , rendering them uninhabitable. In one design, the tamper of the weapon would be made of Co. When the bomb explodes, neutrons from the nuclear fission would irradiate the cobalt and transmute it to Co. No country is known to have done any serious development of this type of weapon. Co does not occur naturally on Earth in significant amounts, so Co

456-442: A 9–20 year period. On average, these people unknowingly received a radiation dose of 0.4 Sv. Some studies have found that this large group did not suffer a higher incidence of cancer mortality, as the linear no-threshold model would predict, but suffered a lower cancer mortality than the general Taiwan public. These observations support the radiation hormesis model, however other studies have found health impacts that confound

532-701: A Canadian-built CANDU at Embalse Nuclear Power Station . India has a number of CANDU reactors at the Rajasthan Atomic Power Station used for producing Co. India had a capacity of more than 6  MCi of Co production in 2021; this capacity is slated to increase with more CANDU reactors being commissioned at the Rajasthan Atomic Power Station. Heavy-water reactors are particularly well suited for production of Co because of their excellent neutron economy and because their capacity for online refueling allows targets to be inserted into

608-578: A bucket used in mining, frequently mentioned by Agricola, namely the kobel/köbel (Latinized as modulus ). Another theory given by the Etymologisches Wörterbuch derives the term from kōbathium or rather cobathia ( κωβάθια , "arsenic sulfide" ) which occurs as noxious fumes. An etymology from Slavonic kowalti was suggested by Emanuel Merck (1902). W. W. Skeat and J. Berendes construed κόβαλος as "parasite", i.e. as an ore parasitic to nickel , but this explanation

684-411: A distinctive deep blue color to glass , ceramics , inks , paints and varnishes . Cobalt occurs naturally as only one stable isotope , cobalt-59. Cobalt-60 is a commercially important radioisotope, used as a radioactive tracer and for the production of high-energy gamma rays . Cobalt is also used in the petroleum industry as a catalyst when refining crude oil. This is to purge it of sulfur, which

760-554: A hard, lustrous, somewhat brittle, gray metal . Cobalt-based blue pigments ( cobalt blue ) have been used since antiquity for jewelry and paints, and to impart a distinctive blue tint to glass. The color was long thought to be due to the metal bismuth . Miners had long used the name kobold ore ( German for goblin ore ) for some of the blue pigment-producing minerals . They were so named because they were poor in known metals and gave off poisonous arsenic -containing fumes when smelted. In 1735, such ores were found to be reducible to

836-499: A hospital in Tijuana to a radioactive waste storage center was hijacked at a gas station near Mexico City . The truck was soon recovered, but the thieves had removed the source from its shielding. It was found intact in a nearby field. Despite early reports with lurid headlines asserting that the thieves were "likely doomed", the radiation sickness was mild enough that the suspects were quickly released to police custody, and no one

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912-408: A late 18th century writer. Later, Grimms' dictionary (1868) noted the kobalt/kobelt ore was blamed on the mountain spirit ( Bergmännchen  [ de ] ) which was also held responsible for "stealing the silver and putting out an ore that caused poor mining atmosphere ( Wetter ) and other health hazards". Grimms' dictionary entries equated the word "kobel" with "kobold", and listed it as

988-514: A mere variant diminutive , but the latter is defined in it as a household spirit . Whereas some of the more recent commentators prefer to characterize the ore's namesake kobelt (recté kobel ) as a gnome . The early 20th century Oxford English Dictionary (1st edition, 1908) had upheld Grimm's etymology. However, by around the same time in Germany, the alternate etymology not endorsed by Grimm ( kob/kof "house, chamber" + walt "power, ruler")

1064-543: A missile nuclear warhead in the 1970 film Beneath the Planet of the Apes . Cobalt Cobalt is a chemical element ; it has symbol Co and atomic number 27. As with nickel , cobalt is found in the Earth's crust only in a chemically combined form, save for small deposits found in alloys of natural meteoric iron . The free element , produced by reductive smelting , is

1140-509: A new metal (the first discovered since ancient times), which was ultimately named for the kobold . Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as cobaltite (CoAsS). The element is more usually produced as a by-product of copper and nickel mining. The Copperbelt in the Democratic Republic of the Congo (DRC) and Zambia yields most of

1216-414: A period of days at the junkyard. Ten people, including the scrap collectors and workers at the junkyard, were exposed to high levels of radiation and became ill. Three junkyard workers later died of their exposure, which was estimated to be over 6  Gy . Afterward, the source was safely recovered by Thai authorities. In December 2013, a truck carrying a disused 111 TBq Co teletherapy source from

1292-407: A simplified decay scheme of Co and Co. The main β-decay transitions are shown. The probability for population of the middle energy level of 2.1 MeV by β-decay is 0.0022%, with a maximum energy of 665.26 keV. Energy transfers between the three levels generate six different gamma-ray frequencies. In the diagram the two important ones are marked. Internal conversion energies are well below

1368-446: A small number of fuel assemblies. Still, over 40% of all single-use medical devices are sterilized using Co from Bruce nuclear generating station . Exposure to Co is lethal for humans, and can cause death (potentially in less than an hour from acute exposure). After entering a living mammal (such as a human), assuming that the subject does not die shortly after exposure (as may happen in acute exposure incidents), some of

1444-401: A spirit or goblin held superstitiously responsible for it; this spirit is considered equitable to the kobold (a household spirit ) by some, or, categorized as a gnome (mine spirit) by others. Cobalt is a ferromagnetic metal with a specific gravity of 8.9. The Curie temperature is 1,115 °C (2,039 °F) and the magnetic moment is 1.6–1.7 Bohr magnetons per atom . Cobalt has

1520-453: A tank filled with a liquid solution containing boron, a neutron absorber. In the event of a control rod failure during a reactor scram, the LPS system would have drained the boron solution into the core thus halting the nuclear chain reaction. However, during decommissioning when technicians attempted to drain the tank they were unable to do so due to a corroded pipe. Because of its contributions to

1596-449: A transition metal-alkyl complex that is notable for its resistance to β-hydrogen elimination , in accord with Bredt's rule . The cobalt(III) and cobalt(V) complexes [Li(THF) 4 ] [Co(1-norb) 4 ] and [Co(1-norb) 4 ] [BF 4 ] are also known. Co is the only stable cobalt isotope and the only isotope that exists naturally on Earth. Twenty-two radioisotopes have been characterized:

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1672-559: A wide variety of coordination complexes with ammonia and amines, which are called ammine complexes . Examples include [Co(NH 3 ) 6 ] , [Co(NH 3 ) 5 Cl] ( chloropentamminecobalt(III) ), and cis - and trans - [Co(NH 3 ) 4 Cl 2 ] . The corresponding ethylenediamine complexes are also well known. Analogues are known where the halides are replaced by nitrite , hydroxide , carbonate , etc. Alfred Werner worked extensively on these complexes in his Nobel-prize winning work. The robustness of these complexes

1748-528: Is +2 (cobalt(II)). These salts form the pink-colored metal aquo complex [Co(H 2 O) 6 ] in water. Addition of chloride gives the intensely blue [CoCl 4 ] . In a borax bead flame test , cobalt shows deep blue in both oxidizing and reducing flames. Several oxides of cobalt are known. Green cobalt(II) oxide (CoO) has rocksalt structure. It is readily oxidized with water and oxygen to brown cobalt(III) hydroxide (Co(OH) 3 ). At temperatures of 600–700 °C, CoO oxidizes to

1824-451: Is a synthetic radioactive isotope of cobalt with a half-life of 5.2714 years. It is produced artificially in nuclear reactors . Deliberate industrial production depends on neutron activation of bulk samples of the monoisotopic and mononuclidic cobalt isotope Co . Measurable quantities are also produced as a by-product of typical nuclear power plant operation and may be detected externally when leaks occur. In

1900-428: Is achieved within seconds. Test sources, such as those used for school experiments, have an activity of <100 kBq. Devices for nondestructive material testing use sources with activities of 1 TBq and more. The high γ-energies correspond to a significant mass difference between Ni and Co: 0.003  u . This amounts to nearly 20 watts per gram, nearly 30 times larger than that of Pu. The diagram shows

1976-430: Is demonstrated by the optical resolution of tris(ethylenediamine)cobalt(III) ( [Co(en) 3 ] ). Cobalt(II) forms a wide variety of complexes, but mainly with weakly basic ligands. The pink-colored cation hexaaquocobalt(II) [Co(H 2 O) 6 ] is found in several routine cobalt salts such as the nitrate and sulfate. Upon addition of excess chloride, solutions of the hexaaquo complex converts to

2052-443: Is described as an attempted theft, but some of the rods are reportedly still missing. In 1957, Chien-Shiung Wu et al. discovered that β-decay violated parity , implying nature has a handedness. In the Wu experiment , researchers aligned Co nuclei by cooling the source to low temperatures in a magnetic field. Wu's observation was that more β-rays were emitted in the opposite direction to

2128-548: Is faulted for its anachronism since nickel was not discovered until 1751. Cobalt compounds have been used for centuries to impart a rich blue color to glass , glazes , and ceramics . Cobalt has been detected in Egyptian sculpture, Persian jewelry from the third millennium BC, in the ruins of Pompeii , destroyed in 79 AD, and in China, dating from the Tang dynasty (618–907 AD) and

2204-454: Is known to have died from the incident. On 13 September 1999, six people tried to steal Co rods from a chemical plant in the city of Grozny , Chechen Republic. During the theft, the suspects opened the radioactive material container and handled it, resulting in the deaths of three of the suspects and injury of the remaining three. The suspect who held the material directly in his hands died of radiation exposure 30 minutes later. This incident

2280-400: Is low and easily shielded; however, the gamma-ray emission lines have energies around 1.3 MeV, and are highly penetrating. The physical properties of cobalt such as resistance to bulk oxidation and low solubility in water give some advantages in safety in the case of a containment breach over some other gamma sources such as caesium-137 . The main uses for Co are: Cobalt has been discussed as

2356-460: Is much more sensitive to oxidation than ferrocene. Cobalt carbonyl ( Co 2 (CO) 8 ) is a catalyst in carbonylation and hydrosilylation reactions. Vitamin B 12 (see below ) is an organometallic compound found in nature and is the only vitamin that contains a metal atom. An example of an alkylcobalt complex in the otherwise uncommon +4 oxidation state of cobalt is the homoleptic complex tetrakis(1-norbornyl)cobalt(IV) (Co(1-norb) 4 ),

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2432-541: Is not found on Earth's surface because of its tendency to react with oxygen in the atmosphere. Small amounts of cobalt compounds are found in most rocks, soils, plants, and animals. In the ocean cobalt typically reacts with chlorine. In nature, cobalt is frequently associated with nickel . Both are characteristic components of meteoric iron , though cobalt is much less abundant in iron meteorites than nickel. As with nickel, cobalt in meteoric iron alloys may have been well enough protected from oxygen and moisture to remain as

2508-459: Is obtained by reducing the cobalt by-products of nickel and copper mining and smelting . Since cobalt is generally produced as a by-product, the supply of cobalt depends to a great extent on the economic feasibility of copper and nickel mining in a given market. Demand for cobalt was projected to grow 6% in 2017. Primary cobalt deposits are rare, such as those occurring in hydrothermal deposits , associated with ultramafic rocks , typified by

2584-419: Is one of the few simple stable cobalt(III) compounds. Cobalt(III) fluoride, which is used in some fluorination reactions, reacts vigorously with water. The inventory of complexes is very large. Starting with higher oxidation states, complexes of Co(IV) and Co(V) are rare. Examples are found in caesium hexafluorocobaltate(IV) (Cs 2 CoF 6 ) and potassium percobaltate (K 3 CoO 4 ). Cobalt(III) forms

2660-534: Is reduced to metal by the aluminothermic reaction or reduction with carbon in a blast furnace . The United States Geological Survey estimates world reserves of cobalt at 7,100,000 metric tons. The Democratic Republic of the Congo (DRC) currently produces 63% of the world's cobalt. This market share may reach 73% by 2025 if planned expansions by mining producers like Glencore Plc take place as expected. Bloomberg New Energy Finance has estimated that by 2030, global demand for cobalt could be 47 times more than it

2736-399: Is related to the decay energy and time. For Co it is equal to 0.35  mSv /(GBq h) at one meter from the source. This allows calculation of the equivalent dose , which depends on distance and activity. For example, 2.8 GBq or 60 μg of Co, generates a dose of 1 mSv at 1 meter away, within an hour. The swallowing of Co reduces the distance to a few millimeters, and the same dose

2812-528: Is synthesized by bombarding a Co target with a slow neutron source. Californium-252 , moderated through water, can be used for this purpose, as can the neutron flux in a nuclear reactor . The CANDU reactors can be used to activate Co, by substituting the control rods with cobalt rods. In the United States, as of 2010, it is being produced in a boiling water reactor at Hope Creek Nuclear Generating Station . The cobalt targets are substituted here for

2888-463: Is very polluting when burned and causes acid rain. Cobalt is the active center of a group of coenzymes called cobalamins . Vitamin B 12 , the best-known example of the type, is an essential vitamin for all animals. Cobalt in inorganic form is also a micronutrient for bacteria , algae , and fungi . The name cobalt derives from a type of ore considered a nuisance by 16th century German silver miners, which in turn may have been named from

2964-640: The Co is excreted in feces . The rest is taken up by tissues, mainly the liver , kidneys , and bones , where the prolonged exposure to gamma radiation can cause cancer. Over time, the absorbed cobalt is eliminated in urine. Cobalt is found in steel . Uncontrolled disposal of Co in scrap metal is responsible for the radioactivity in some iron products. Circa 1983, construction was finished of 1700 apartments in Taiwan which were built with steel contaminated with cobalt-60. About 10,000 people occupied these buildings during

3040-507: The Congo in 1914, mining operations shifted again. When the Shaba conflict started in 1978, the copper mines of Katanga Province nearly stopped production. The impact on the world cobalt economy from this conflict was smaller than expected: cobalt is a rare metal, the pigment is highly toxic, and the industry had already established effective ways for recycling cobalt materials. In some cases, industry

3116-552: The Ming dynasty (1368–1644 AD). Cobalt has been used to color glass since the Bronze Age . The excavation of the Uluburun shipwreck yielded an ingot of blue glass, cast during the 14th century BC. Blue glass from Egypt was either colored with copper, iron, or cobalt. The oldest cobalt-colored glass is from the eighteenth dynasty of Egypt (1550–1292 BC). The source for the cobalt

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3192-753: The Bay Shore RBS group at the Bay Shore RBS Site . At 6:33 PM, after completing three successful electronic bombings, the Bay Shore RBS crew lost contact with the B-52C flight crew. Witnesses observed a fireball falling from the sky with a large associated loud explosion as the B-52C impacted the water at Little Traverse Bay , 5 miles north of the Big Rock Point Nuclear Power Plant. All nine on board were lost. This became known as 1971 B-52C Lake Michigan crash . Cobalt-60 Cobalt-60 ( Co)

3268-547: The Bou-Azzer district of Morocco . At such locations, cobalt ores are mined exclusively, albeit at a lower concentration, and thus require more downstream processing for cobalt extraction. Several methods exist to separate cobalt from copper and nickel, depending on the concentration of cobalt and the exact composition of the used ore. One method is froth flotation , in which surfactants bind to ore components, leading to an enrichment of cobalt ores. Subsequent roasting converts

3344-472: The Egyptians used is not known. The word cobalt is derived from the 16th century German " kobelt ", a type of ore, as aforementioned. The first attempts to smelt those ores for copper or silver failed, yielding simply powder (cobalt(II) oxide) instead. Because the primary ores of cobalt always contain arsenic, smelting the ore oxidized the arsenic into the highly toxic and volatile arsenic oxide , adding to

3420-526: The US. High purity cobalt was highly sought after for its use in jet engines and gas turbines. An adequate supply of the ore was found in Idaho near Blackbird canyon . Calera Mining Company started production at the site. Cobalt demand has further accelerated in the 21st century as an essential constituent of materials used in rechargeable batteries, superalloys, and catalysts. It has been argued that cobalt will be one of

3496-543: The United States. It is estimated that 4,000 people were exposed to radiation as a result of this incident. In the Samut Prakan radiation accident in 2000, a disused radiotherapy head containing a Co source was stored at an unsecured location in Bangkok , Thailand and then accidentally sold to scrap collectors. Unaware of the danger, a junkyard employee dismantled the head and extracted the source, which remained unprotected for

3572-407: The anhydrous dichloride is blue, the hydrate is red. The reduction potential for the reaction Co + e → Co is +1.92 V, beyond that for chlorine to chloride, +1.36 V. Consequently, cobalt(III) chloride would spontaneously reduce to cobalt(II) chloride and chlorine. Because the reduction potential for fluorine to fluoride is so high, +2.87 V, cobalt(III) fluoride

3648-527: The atmosphere, weathering occurs; the sulfide minerals oxidize and form pink erythrite ("cobalt glance": Co 3 (AsO 4 ) 2 ·8H 2 O ) and spherocobaltite (CoCO 3 ). Cobalt is also a constituent of tobacco smoke . The tobacco plant readily absorbs and accumulates heavy metals like cobalt from the surrounding soil in its leaves. These are subsequently inhaled during tobacco smoking . The main ores of cobalt are cobaltite , erythrite , glaucodot and skutterudite (see above), but most cobalt

3724-414: The black cobalt(II) sulfides , CoS 2 ( pyrite structure), Co 2 S 3 ( spinel structure ), and CoS ( nickel arsenide structure). Four dihalides of cobalt(II) are known: cobalt(II) fluoride (CoF 2 , pink), cobalt(II) chloride (CoCl 2 , blue), cobalt(II) bromide (CoBr 2 , green), cobalt(II) iodide (CoI 2 , blue-black). These halides exist in anhydrous and hydrated forms. Whereas

3800-428: The blue cobalt(II,III) oxide (Co 3 O 4 ), which has a spinel structure . Black cobalt(III) oxide (Co 2 O 3 ) is also known. Cobalt oxides are antiferromagnetic at low temperature : CoO ( Néel temperature 291 K) and Co 3 O 4 (Néel temperature: 40 K), which is analogous to magnetite (Fe 3 O 4 ), with a mixture of +2 and +3 oxidation states. The principal chalcogenides of cobalt are

3876-475: The cobalt ore may have got its name from "a type of mine spirit/demon" ( daemon metallicus ) while stating that this is "apparently" the kobold. Joseph William Mellor (1935) also stated that cobalt may derive from kobalos ( κόβαλος ), though other theories had been suggested. Several alternative etymologies that have been suggested, which may not involve a spirit (kobel or kobold) at all. Karl Müller-Fraureuth conjectured that kobelt derived from Kübel ,

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3952-465: The deep blue CoCl 2− 4 , which is tetrahedral. Softer ligands like triphenylphosphine form complexes with Co(II) and Co(I), examples being bis- and tris(triphenylphosphine)cobalt(I) chloride, CoCl 2 (PPh 3 ) 2 and CoCl(PPh 3 ) 3 . These Co(I) and Co(II) complexes represent a link to the organometallic complexes described below. Cobaltocene is a structural analog to ferrocene , with cobalt in place of iron. Cobaltocene

4028-448: The free (but alloyed) metal. Cobalt in compound form occurs in copper and nickel minerals. It is the major metallic component that combines with sulfur and arsenic in the sulfidic cobaltite (CoAsS), safflorite (CoAs 2 ), glaucodot ( (Co,Fe)AsS ), and skutterudite (CoAs 3 ) minerals. The mineral cattierite is similar to pyrite and occurs together with vaesite in the copper deposits of Katanga Province . When it reaches

4104-479: The global cobalt production. World production in 2016 was 116,000 tonnes (114,000 long tons; 128,000 short tons) (according to Natural Resources Canada ), and the DRC alone accounted for more than 50%. Cobalt is primarily used in lithium-ion batteries , and in the manufacture of magnetic , wear-resistant and high-strength alloys . The compounds cobalt silicate and cobalt(II) aluminate (CoAl 2 O 4 , cobalt blue) give

4180-406: The latter case (in the absence of added cobalt ) the incidentally produced Co is largely the result of multiple stages of neutron activation of iron isotopes in the reactor's steel structures via the creation of its Co precursor. The simplest case of the latter would result from the activation of Fe . Co undergoes beta decay to

4256-428: The main energy levels. Co is a nuclear isomer of Co with a half-life of 10.467 minutes. It decays by internal transition to Co, emitting 58.6 keV gamma rays, or with a low probability (0.22%) by β-decay into Ni. The main advantage of Co is that it is a high-intensity gamma-ray emitter with a relatively long half-life, 5.27 years, compared to other gamma ray sources of similar intensity. The β-decay energy

4332-443: The main objects of geopolitical competition in a world running on renewable energy and dependent on batteries, but this perspective has also been criticised for underestimating the power of economic incentives for expanded production. The stable form of cobalt is produced in supernovae through the r-process . It comprises 0.0029% of the Earth's crust . Except as recently delivered in meteoric iron, free cobalt (the native metal )

4408-586: The most stable, Co , has a half-life of 5.2714 years; Co has a half-life of 271.8 days; Co has a half-life of 77.27 days; and Co has a half-life of 70.86 days. All the other radioactive isotopes of cobalt have half-lives shorter than 18 hours, and in most cases shorter than 1 second. This element also has 4 meta states , all of which have half-lives shorter than 15 minutes. The isotopes of cobalt range in atomic weight from 50 u ( Co) to 73 u ( Co). The primary decay mode for isotopes with atomic mass unit values less than that of

4484-474: The notoriety of the ore. Paracelsus , Georgius Agricola , and Basil Valentine all referred to such silicates as "cobalt". Swedish chemist Georg Brandt (1694–1768) is credited with discovering cobalt c.  1735 , showing it to be a previously unknown element, distinct from bismuth and other traditional metals. Brandt called it a new "semi-metal", naming it for the mineral from which he had extracted it. He showed that compounds of cobalt metal were

4560-472: The nuclear and medical industries, the American Nuclear Society named Big Rock Point a Nuclear Historic Landmark. The 235,000-pound (107,000 kg) reactor vessel was removed on August 25, 2003 and shipped to Barnwell, South Carolina on October 7, 2003. All of Big Rock Point's 500-acre (200 ha) area has been torn down. Other than eight spent fuel casks , there are no signs that the site

4636-536: The nuclear spin. This asymmetry violates parity conservation . Argentina, Canada, India and Russia are the largest suppliers of Co in the world. Both Argentina and Canada have (as of 2022) an all- heavy-water reactor fleet for power generation. Canada has CANDU in numerous locations throughout Ontario as well as Point Lepreau Nuclear Generating Station in New Brunswick, while Argentina has two German-supplied heavy water reactors at Atucha nuclear power plant and

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4712-417: The only stable isotope, Co, is electron capture and the primary mode of decay in isotopes with atomic mass greater than 59 atomic mass units is beta decay . The primary decay products below Co are element 26 ( iron ) isotopes; above that the decay products are element 28 (nickel) isotopes. Many different stories about the origin of the word "cobalt" have been proposed. In one version the element cobalt

4788-430: The ores to cobalt sulfate , and the copper and the iron are oxidized to the oxide. Leaching with water extracts the sulfate together with the arsenates . The residues are further leached with sulfuric acid , yielding a solution of copper sulfate. Cobalt can also be leached from the slag of copper smelting. The products of the above-mentioned processes are transformed into the cobalt oxide (Co 3 O 4 ). This oxide

4864-400: The reactor core and removed after a predetermined time without the need for cold shutdown . Also, the heavy water used as a moderator is commonly held at lower temperatures than is the coolant in light water reactors , allowing for a lower speed of neutrons, which increases the neutron cross section and decreases the rate of unwanted (n,2n) "knockout" reactions. Co is the material encasing

4940-604: The results . In August 2012, Petco recalled several models of steel pet food bowls after US Customs and Border Protection determined that they were emitting low levels of radiation, which was determined to be from Co that had contaminated the steel. In May 2013, a batch of metal-studded belts sold by online retailer ASOS were confiscated and held in a US radioactive storage facility after testing positive for Co. A radioactive contamination incident occurred in 1984 in Ciudad Juárez , Chihuahua , Mexico , originating from

5016-546: The source of the blue color in glass, which previously had been attributed to the bismuth found with cobalt. Cobalt became the first metal to be discovered since the pre-historical period. All previously known metals (iron, copper, silver, gold, zinc, mercury, tin, lead and bismuth) had no recorded discoverers. During the 19th century, a significant part of the world's production of cobalt blue (a pigment made with cobalt compounds and alumina) and smalt ( cobalt glass powdered for use for pigment purposes in ceramics and painting)

5092-448: The stable isotope nickel-60 ( Ni ). The activated cobalt nucleus emits two gamma rays with energies of 1.17 and 1.33 MeV , hence the overall equation of the nuclear reaction (activation and decay) is: 27 Co + n → 27 Co → 28 Ni + e + 2 γ Given its half-life, the radioactive activity of a gram of Co is close to 42  TBq (1,100  Ci ). The absorbed dose constant

5168-408: The time was Georgius Agricola . He was also the oft-quoted authority on the mine spirits called " kobel " (Latinized as cobalus or pl. cobali ) in a separate work. Agricola did not make an connection between the similarly named ore and spirit. However, a causal connection (ore blamed on "kobel") was made by a contemporary, and a word origin connection (word "formed" from cobalus ) made by

5244-425: Was scrammed for the last time at 10:33 a.m. EDT on August 29, 1997, 35 years to the day after its license had been issued. The last fuel was removed from the core on September 20. Decontamination was completed in 1999. During the decommissioning process it was discovered that a backup safety system at the plant had been inoperable for at least the previous 14 years. The Liquid Poison System (LPS) consisted of

5320-524: Was a military base for the United States Air Force Strategic Air Command Detachment 6 known as Bay Shore Radar Bombing Score (RBS) Group. Low altitude flights were performed by B-52Cs to simulate deadly bombing missions. On January 7, 1971, a B52C (Using radio call sign ‘Hiram 16’) from the bombing group at Westover Air Force Base near Springfield, Massachusetts took off to perform radar bomb scoring in tandem with

5396-481: Was able to change to cobalt-free alternatives. In 1938, John Livingood and Glenn T. Seaborg discovered the radioisotope cobalt-60 . This isotope was famously used at Columbia University in the 1950s to establish parity violation in radioactive beta decay . After World War II, the US wanted to guarantee the supply of cobalt ore for military uses (as the Germans had been doing) and prospected for cobalt within

5472-546: Was being proposed as more convincing. Somewhat later, Paul Kretschmer (1928) explained that while this "house ruler" etymology was the proper one that backed the original meaning of kobold as household spirit, a corruption later occurred introducing the idea of "mine demon" to it. The present edition of the Etymologisches Wörterbuch (25th ed., 2012) under "kobold" lists the latter, not Grimm's etymology, but still persists, under its entry for "kobalt", that while

5548-737: Was carried out at the Norwegian Blaafarveværket . The first mines for the production of smalt in the 16th century were located in Norway, Sweden, Saxony and Hungary. With the discovery of cobalt ore in New Caledonia in 1864, the mining of cobalt in Europe declined. With the discovery of ore deposits in Ontario , Canada, in 1904 and the discovery of even larger deposits in the Katanga Province in

5624-449: Was generated on December 8, 1962. A promotional video for the plant featured then GE spokesman Ronald Reagan . Consumers Energy had previously announced that Big Rock Point's operating license would not be renewed when it expired on May 31, 2000. However, economics proved in January 1997 that it was not feasible to keep Big Rock Point running to the license's expiration date. The reactor

5700-499: Was home to a nuclear power plant. Decommissioning costs totaled $ 390,000,000. In July 2006, the state of Michigan announced it was considering buying the site, which features a mile of Lake Michigan shoreline, for a possible state park. As part of the sale of Consumers' Palisades Nuclear Plant , the new owner Entergy accepted the responsibility for a basketball court size piece of property at Big Rock containing that plant's eight casks of spent fuel. Located near Big Rock Point

5776-443: Was named after " kobelt ", the name which 16th century German silver miners had given to a nuisance type of ore which occurred that was corrosive and issued poisonous gas. Although such ores had been used for blue pigmentation since antiquity, the Germans at that time did not have the technology to smelt the ore into metal (cf. § History below). The authority on such kobelt ore (Latinized as cobaltum or cadmia ) at

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