Cobalt

What is Cobalt?

Cobalt is an element in chemistry with the atomic number 27 and symbol Co. Except for trace amounts found in alloys of naturally occurring meteoric iron, cobalt is only present in the Earth’s crust in a chemically mixed state, similar to nickel.

The hard, shiny, silvery metal that results after reductive smelting is the free element. Since ancient times, cobalt-based blue pigments, sometimes known as cobalt blue, have been used to make jewelry, paintings, and glass with a unique blue hue.

It was long believed that the metal bismuth was the cause of the hue. For a considerable time, miners referred to certain minerals that produced blue pigment as “kobold ore,” which is German for “goblin ore.”

They were named for this because, when melted, they released toxic vapors including arsenic, and had low concentrations of known metals.

These ores were found to be reducible in 1735 to a new metal (the first found since antiquity), which was eventually given the kobold’s name.

These days, a few metallic-lustered ores, including cobaltite (CoAsS), are specially used to create a certain amount of cobalt. The element is often created as a byproduct of mining for nickel and copper.

Most of the world’s cobalt is produced in the Copperbelt, which is located in Zambia and the Democratic Republic of the Congo (DRC).

Natural Resources Canada estimates that the world produced 116,000 tonnes (114,000 long tons; 128,000 short tons) in 2016, with the DRC alone contributing more than 50% of that total. Lithium-ion batteries and the production of magnetic, wear-resistant, and high-strength alloys are the two main uses for cobalt.

The unique deep blue hue of cobalt blue is imparted to glass, ceramics, inks, paints, and varnishes by the compounds cobalt silicate and cobalt(II) aluminate (CoAl₂O₄).

There is just one stable isotope of cobalt found in nature, cobalt-59. A significant radioisotope for commerce, cobalt-60 is used to produce high-energy gamma rays and as a radioactive tracer.

In the petroleum sector, cobalt is also utilized as a catalyst during the refining of crude oil. This is to rid it of sulfur, which when burned releases a lot of pollutants including acid rain.

The active component of a class of coenzymes known as cobalamin is cobalt. The most well-known of the category, vitamin B12, is necessary for all mammals. Fungi, algae, and bacteria all use cobalt as a micronutrient when it’s in inorganic form.

Characteristics

Cobalt is a refractory 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.

The relative permeability of cobalt is two-thirds that of iron. Metallic chrome appears as two epitaxial structures: the hcp and fcc.

Although there should be a 450 °C (842 °F) transition temperature between the hcp and fcc structures, in reality, there is so little energy difference that random intergrowth of the two is widespread. A passivating oxide coating shields the weakly reducing metal cobalt from oxidation.

Sulfur and halogens are its enemies. When  Co₃O₄ is heated in oxygen, it releases oxygen at 900 °C (1,650 °F), resulting in the monoxide CoO.

The metal interacts with fluorine (F₂) at 520 K to create CoF₃; with chlorine (Cl₂), bromine (Br₂), and iodine (I₂), creating corresponding binary halides.

Even when heated, it does not react with hydrogen gas (H₂) or nitrogen gas (N₂), but it does react with phosphorus, carbon, sulfur, arsenic, and boron. It interacts extremely slowly with wet, but not dry, air and slowly with mineral acids at room temperature.

Compounds

Cobalt is commonly found in the oxidation states +2 and +3, however, it may also be found in compounds with oxidation levels ranging from -3 to +5. For simple compounds, the oxidation state +2 (cobalt(II)) is typical.

In water, these salts combine to create the pink metal aquo complex [Co(H₂O)₆]²⁺. Chloride is added to produce the vividly blue [CoCl₄]²⁻.Cobalt has a strong blue color in both oxidizing and reducing flames in a borax bead flame test.

Oxygen and Chalcogen Compounds

There are many known cobalt oxides. The structure of green cobalt(II) oxide (CoO) is rock salt. When combined with oxygen and water, it easily oxidizes to brown cobalt(III) hydroxide (Co(OH)₃).

CoO oxidizes to blue cobalt(II, III) oxide (Co₃O₄), which has a spinel structure, of around 600–700 °C. It is also known as black cobalt(III) oxide (Co₂O₃).

At low temperatures, cobalt oxides such as CoO (Néel temperature: 291 K) and Co₃O₄ (Néel temperature: 40K), which resembles magnetite (Fe₃O₄₎ and has a combination of +2 and +3 oxidation states, are antiferromagnetic.

The two main cobalt chalcogenides are cobalt(III) sulfide (Co₂S₃) and the black cobalt(II) sulfide, CoS₂, which take on a structure resembling pyrite.

Halides

Cobalt(II) fluoride (CoF₂, pink), cobalt(II) chloride (CoCl₂, blue), cobalt(II) bromide (CoBr₂, green), and cobalt(II) iodide (CoI₂, blue-black) are the four dihalides of cobalt(II) that are known.

There are two types of these halides: hydrated and anhydrous. The hydrate is red, whereas the anhydrous dichloride is blue.

The reaction Co³⁺+ e⁻ → Co²⁺ has a reduction potential of +1.92 V, which is higher than the potential of +1.36 V for chlorine to chloride.

Chlorine and cobalt(II) chloride would therefore be produced spontaneously from cobalt(III) chloride.

One of the few simple stable cobalt(III) compounds is cobalt(III) fluoride due to its high reduction potential of +2.87 V for fluorine to fluoride. Water and cobalt(III) fluoride, which are both utilized in fluorination processes, reacts violently.

Coordination Compounds

As with all metals, molecular compounds, and polyatomic ions of cobalt are categorized as coordination complexes, that is, molecules or ions that include cobalt coupled to one or more ligands. These might consist of any number of combinations of ions and molecules, including:

1As in the cation hexaaquocobalt(II) [Co(H₂O)₆]²⁺, which is waterH₂O.
In solid cobalt sulfate CoSO₄·(H₂O)_x, where x = 6 or 7, as well as in theiraqueous solutions, this pink complex is the main cation.
2 similar to cis-diaquotetraamminecobalt(III) ammonia NH₃.[Co(NH₃)₄(H₂O)₂]³⁺ 2 In iohexol [Co(Co(NH₃)₄(HO)₂)₃]⁶⁻in [Co(NO₂)₄(NH₃)₂]⁻ (Errmann’s salt anion), as well as in [Co(NH₃)₅(CO₃)⁻

3 carbonate  [CO₃]²⁻, similar to triscarbonatocobaltate(III) [Co(CO₃)₃]³⁻ in green
4 Nitrate [NO₂]⁻, similar to [Co(NO₂)₄(NH₃)₂]⁻.
5 hydroxide [HO]⁻ , as in hexol.
6 as in tetrachloridocobaltate(II)  CoCl₄]²⁻, chloride [Cl]^–.
7 [HCO₃]⁻ bicarbonate, as in[Co(CO₃)₂(HCO₃)(H₂O)]³⁻.
8 oxalate [C₂O₄]²⁻ , as in trisoxalatocobaltate(III) [Co(C₂O₄)³⁻_3].

These linked groups alter the stability of oxidation states of the cobalt atoms, according to general laws of electronegativity and of the hardness– softness.

For example, Co³⁺ compounds prefer to contain ammine ligands. Tris(triphenylphosphine)cobalt(I) chloride ((P(C₆H₅)₃)₃CoCl).  is an example of a phosphine ligand that often has the softer Co²⁺ and Co³⁺ due to phosphorus’s tendency to be softer than nitrogen.

Co⁴⁺ and Co⁵⁺ derivatives, such as potassium percobaltate (K₃CoO₄) and cesium hexafluorocobaltate(IV) (Cs₂CoF₆), can be stabilized by the more electronegative (and harder) oxide and fluoride.

Alfred Werner, a coordination chemistry pioneer who won the Nobel Prize, experimented with molecules with the empirical formula [Co(NH₃)₆]³⁺.

The isomer cobalt(III) hexamine chloride was one of the ones identified. Six ammine orthogonal ligands and three chloride counteranions coordinate a central cobalt atom in this coordination complex, which is a typical Werner-type complex.

Using chelating ethylenediamine ligands in lieu of ammonia provides tris(ethylenediamine)cobalt(III) ([Co(en)₃]³⁺), which was one of the first coordination complexes to be resolved into optical isomers.

Both left- and right-handed versions of a “three-bladed propeller” of the complex exist. Werner originally isolated this compound as needle-like crystals that were yellow-gold in color.

Organometallic Compounds

A structural analog of ferrocene, cobalt replaces iron in cobaltocene. Compared to ferrocene, cobaltocene is far more susceptible to oxidation.

In carbonylation and hydrosilylation processes, cobalt carbonyl (Co₂(CO)₈) acts as a catalyst. The only vitamin that has a metal atom in it is vitamin B₁₂ (see below), is an organometallic substance that may be found in nature.

The homoleptic complex tetrakis(1-norbornyl)cobalt(IV) (Co(1-norb)₄), a transition metal-alkyl complex noted for its resistance to ß-hydrogen elimination, according to Bredt’s rule, is an example of an alkylcobalt complex in the otherwise unusual +4 oxidation state of cobalt.

It is also known that the cobalt(III) and cobalt(V) complexes are [Li(THF)₄]⁺[Co(1-norb)
₄]⁻ and [Co(1-norb)₄]⁺ [BF₄]⁻.

Isotopes

The only naturally occurring cobalt isotope on Earth is ⁵⁹Co, which is also the sole stable isotope. Twenty-two radioisotopes have been identified; the most stable, ⁶⁰Co, has a half-life of 5.2714 years; ⁵⁷Co and ⁵⁶Co have half-lives of 271.8 days, 77.27 days, and 70.86 days, respectively.

The half-lives of the other radioactive cobalt isotopes are all less than 18 hours, and typically less than 1 second.

This element also has 4 meta-states, all of which have half-lives of less than 15 minutes. The atomic weights of the cobalt isotopes range from 50u(⁵⁰Co) to 73u(⁷³Co).

The predominant decay mechanism for isotopes with atomic mass unit values less than that of the only stable isotope, ⁵⁹Co, is electron capture whereas the primary mode of decay in isotopes with atomic mass larger than 59 atomic mass units is beta decay.

Elements 26 (iron) and 28 (nickel) isotopes are the main decay products below and above ⁵⁹Co, respectively.

History

For millennia, cobalt compounds have been utilized to give glass, glazes, and ceramics a deep blue hue.

Evidence of cobalt has been found in Egyptian artwork, Persian jewelry from the third millennium BC, the 79 AD ruins of Pompeii, and artifacts from the Tang (618–907 AD) and Ming (1368–1644) dynasties in China.

Glass has been colored with cobalt since the Bronze Age. An ingot of blue glass, cast in the fourteenth century BC, was discovered during the excavation of the Uluburun shipwreck.

Copper, iron, or cobalt were the colors used to tint Egyptian blue glass. The earliest known examples of cobalt-colored glass date back to Egypt’s eighteenth dynasty (1550–1292 BC). It is unknown where the Egyptians obtained the cobalt they used.

The German word “kobalt,” which means “goblin” in folklore, is where the name “cobalt” originates. Miners called the ore “goblin.”

Instead of producing copper or silver, the initial attempts to process such ores produced only powder (cobalt(II) oxide).

Since arsenic is a constant component of primary cobalt ores, smelting the ore converted the arsenic to the very poisonous and volatile arsenic oxide, further elevating the mineral’s reputation.

The term “cobalt” was used by Paracelsus, Georgius Agricola, and Basil Valentine to describe these silicates.

Cobalt was discovered about 1735 by the Swedish scientist Georg Brandt (1694–1768), who also demonstrated that it was a different element from bismuth and other conventional metals. It was dubbed a “semi-metal” by Brandt.

He demonstrated that the blue hue in glass, which was previously thought to be caused by the bismuth present in cobalt-containing compounds, was really caused by cobalt metal complexes.

Since the prehistoric era, cobalt has been the first metal to be found. There are no recognized discoverers for any of the other known metals, including iron, copper, silver, gold, zinc, mercury, tin, lead, and bismuth.

The Norwegian Blaafarvevaerket produced a large portion of the world’s supply of cobalt blue (a pigment formed of cobalt compounds and alumina) and smalt (powdered cobalt glass used as a pigment in ceramics and painting) throughout the 1800s.

In the sixteenth century, Norway, Sweden, Saxony, and Hungary were home to the first smalt mines. The mining of cobalt in Europe began to diminish in 1864 after cobalt ore was discovered in New Caledonia.

After ore reserves were found in Ontario, Canada, in 1904, and even bigger quantities were found in mining activities once again changed in 1914 in the Congo’s Katanga Province.

The Shaba War began in 1978, almost completely shutting down Katanga Province’s copper mines. Because cobalt is a scarce metal and the pigment is extremely hazardous, the dispute had less of an effect on the global cobalt economy than anticipated.

Additionally, the industry had already developed efficient methods for recovering cobalt products. The industry was able to switch to substitutes devoid of cobalt in certain instances.Cobalt-60 was discovered by Glenn T.

Seaborg and John Livingood in 1938. This isotope is well known for being utilized in the 1950s at Columbia University to demonstrate parity violation in radioactive beta decay.

Following World War II, the US conducted cobalt prospecting in order to ensure that there would be an adequate supply of cobalt ore for military purposes—as the Germans had been doing.

High-purity cobalt was in great demand for gas turbine and jet engine applications. Near Blackbird Canyon in Idaho, there was a sufficient amount of the ore discovered. At the location, Calera Mining Company began production.

Since cobalt is a necessary component of materials used in superalloys, catalysts, and rechargeable batteries, demand for the metal has increased even more in the twenty-first century.

In a future powered by renewable energy and reliant on batteries, it has been suggested that cobalt will be one of the primary targets of geopolitical rivalry; however, this viewpoint has also come under fire for undervaluing the influence of financial incentives for increased production.

Occurrence

The r-process in supernovae produces cobalt in its stable state. It makes up 0.0029% of the crust of the Earth. The native metal, free cobalt, is not present on Earth’s surface due to its propensity to react with atmospheric oxygen.

The majority of rocks, soils, plants, and animals contain trace levels of cobalt compounds. Typically, cobalt interacts with chlorine in the ocean.

On Earth, pure cobalt in native metal form is unknown, with the exception of recent deliveries in meteoric iron.

Nickel and cobalt are commonly found together in nature. Both are typical components of meteoric iron, however, cobalt is significantly less plentiful in iron meteorites than a nickel.

Similar to nickel, cobalt in meteoric iron alloys could have had adequate protection from moisture and oxygen to stay in its free but alloyed state.

Copper and nickel minerals have compounds containing cobalt. It is the principal metallic element that forms combinations with arsenic and sulfur in the sulfidic minerals skutterudite (CoAs₃), safflorite (CoAs₂), glaucodot ((Co,Fe)AsS), and cobaltite (CoAsS).

Cattierite, a mineral that resembles pyrite, is found in the copper deposits of Katanga Province with vaesite.

When it enters the atmosphere, weathering begins; the sulfide minerals oxidize and generate pink erythrite (“cobalt glance”:  Co₃(AsO₄)₂·8H₂O)  and spherocobaltite (CoCO₃).

Tobacco smoke contains cobalt as well. Heavy metals such as cobalt are easily taken up by the tobacco plant and stored in its leaves. These are then inhaled when smoking tobacco.

In the Ocean

Cobalt is a trace metal involved in photosynthesis and nitrogen fixation observed in most ocean basins and is a limiting micronutrient for phytoplankton and cyanobacteria.

The upper ocean has low quantities of dissolved cobalt because only cyanobacteria and a few archaea can produce the Co-containing compound cobalamin.

Co shares a hybrid profile with Mn and Fe, whereby phytoplankton absorbs the element through photosynthesis in the upper ocean and scavenging in the deep ocean.

However, the majority of scavenging is restricted by intricate organic ligands. Rivers and land runoff are major sources of cobalt for many ocean bodies, with hydrothermal vents also contributing part of the element.

Cobalt sources in the deep ocean are located atop seamounts, which can range in size from big to tiny. Over millions of years, ocean currents sweep the ocean bottom to remove material, allowing the sediment to develop into ferromanganese crusts.

While there hasn’t been much mapping of the seabed, preliminary research suggests that the Clarion Clipperton Zone—which is receiving more attention—is home to a significant portion of these cobalt-rich crusts.

Interest for deep-sea mining enterprises due to the mineral-rich environment within its area. Though extremely little, anthropogenic input is a non-natural source of contribution.

Reservoirs with low dissolved oxygen concentrations are the main factors controlling the quantities of dissolved cobalt (dCo) throughout seas.

Although the intricate metabolic cycling of cobalt in the ocean is still poorly understood, patterns of increased concentrations have been seen in low-oxygen regions, such as the Southern Atlantic Ocean’s Oxygen Minimum Zone (OMZ). When cobalt concentrations are high, marine ecosystems are thought to be hazardous.

Production

Although cobaltite, erythrite, glaucodot, and skutterudite are the primary ores of cobalt (see above), the majority of cobalt is produced by smelting and mining cobalt by-products from nickel and copper.

Since cobalt is often generated as a by-product, the viability of copper and nickel mining in a particular market has a significant impact on the availability of cobalt. Cobalt demand was expected to increase by 6% in 2017.

Rare primary cobalt deposits can be found in hydrothermal deposits linked to ultramafic rocks, like in the Bou-Azzer region of Morocco.

These sites only mine cobalt ores, but at a lesser concentration, necessitating additional downstream processing in order to extract cobalt.

Depending on the cobalt concentration and the precise makeup of the ore being utilized, there are a number of ways to separate cobalt from copper and nickel. Froth flotation is one technique that enriches cobalt ores by binding surfactants to ore constituents.

The ores are roasted again to produce cobalt sulfate, while the iron and copper oxidize to their oxide forms. The sulfate and arsenate are extracted by leaching with water.

Sulfuric acid is added to the residues and further leached, producing a copper sulfate solution. After smelting copper, cobalt may also be extracted from the slag.

Cobalt oxide (Co₃O₄) is produced from the byproducts of the aforementioned procedures. In a blast furnace, the aluminothermic process or reduction with carbon turns this oxide into metal.

Extraction

Global cobalt deposits are estimated by the US Geological Survey to be 7,100,000 metric tons. Presently, 63% of the cobalt produced worldwide is produced in the Democratic Republic of the Congo (DRC).

If anticipated expansions by mining companies like Glencore Plc go as planned, their market share might reach 73% by 2025.

According to estimates from Bloomberg New Energy Finance, there may be a 47-fold increase in cobalt consumption worldwide by 2030 compared to 2017.

2002 mining legislation changes in the Democratic Republic of the Congo brought in fresh funding for copper and cobalt operations there. 24,500 tons of cobalt were exported from Glencore’s Mutanda Mine in 2016, accounting for 40% of the country’s total output and over 25% of the world’s production.

Glencore shut down Mutanda for two years in late 2019 because of oversupply. By 2019, 300,000 tons of copper and 20,000 tons of cobalt should be produced by Glencore’s resumption of its Katanga Mining project.

Democratic Republic of The Congo

The copper resources in the Katanga Province of the Democratic Republic of the Congo were the world’s leading producer of cobalt in 2005.

According to the British Geological Survey, the region, which was once Shaba province, contained about 40% of the world’s deposits in 2009.

Approximately 17–40% of the DRC’s output came from artisanal mining. There are perhaps 100,000 cobalt miners in the Democratic Republic of the Congo (DRC) who dig hundreds of feet with hand tools, little planning, and few safety precautions.

This information comes from government and NGO officials, workers, and The Washington Post reporters who visited remote mines.

Injury or death from neglecting safety procedures occurs often. Health experts claim that birth deformities and respiratory issues may result from the hazardous metals that miners expose local animals and indigenous inhabitants to, as well as pollution in the surrounding area.

Cobalt is mined from African artisanal mines using child labor. Investigative journalism reporting has validated what human rights advocates have pointed out. Following this disclosure, the manufacturer of cell phones, Apple Inc.

Decided on March 3, 2017, to only use suppliers that have been confirmed to adhere to its workplace standards and to cease purchasing ore from vendors like Zhejiang Huayou Cobalt, which sources from artisanal miners in the Democratic Republic of the Congo.

The European Union (EU) and major automakers (OEMs) are pushing for sustainable, ethical, and supply chain traceability in the sourcing and manufacturing of cobalt internationally.

In accordance with OECD guidelines, mining firms are implementing ESG measures and demonstrating zero to low carbon footprint operations in the lithium-ion battery supply chain.

Major mining corporations as well as artisanal and small-scale mining firms (ASM) are already participating in these programs.

Supply networks for automakers and battery manufacturers: Tesla, VW, BMW, BASF, and Glencore are involved in a number of projects, including the Cobalt for Development research and the Responsible Cobalt Initiative.

In 2018 BMW Group in conjunction with BASF, Samsung SDI, and Samsung Electronics have launched a pilot project in the DRC over one pilot mine, to enhance conditions and address difficulties for artisanal miners and their neighbors.

In the past, the region’s political and ethnic dynamics have resulted in violent outbursts, years of military war, and population displacement.

The First and Second Congo Wars’ fighters had perverse incentives to continue fighting because of the instability in the cobalt price, which also made them richer.

The fighters’ military objectives, which often included genocide, were financed in part by their access to diamond mines and other valuable resources.

While DR Congo has in the 2010s not recently been invaded by neighboring armed forces, some of the richest mineral reserves adjoin areas where Tutsis and Hutus still routinely conflict, instability persists although on a reduced scale and refugees still escape outbreaks of violence.

In 2007, a single Chinese business, Congo DongFang International Mining, received cobalt mined from small-scale artisanal mining initiatives in the Congo.

A division of one of the biggest cobalt producers in the world, Zhejiang Huayou Cobalt, Congo DongFang provided cobalt to some of the biggest battery companies in the world, who made batteries for widely used items like Apple iPhones.

Following up on allegations of labor breaches and environmental issues, LG Chem conducted an OECD-mandated audit of Congo DongFang.

Every supplier that LG Chem inspects is required to adhere to a code of conduct. LG Chem also manufactures battery components for automakers.

Perhaps the world’s richest cobalt resource is found at the Mukondo Mountain project in Katanga Province, run by the Central African Mining and Exploration Company (CAMEC). In 2008, it contributed almost one-third of the world’s total cobalt output.

A long-term arrangement was announced by CAMEC in July 2009 to provide Zhejiang Galico Cobalt & Nickel Materials of China with all of Mukondo Mountain’s yearly production of cobalt concentrate.

Due to its cobalt deposits, which are necessary for the lithium-ion batteries that power electric cars, the Democratic Republic of the Congo was dubbed as “the Saudi Arabia of the electric vehicle age” by global asset management firm AllianceBernstein in February 2018.

President Joseph Kabila revised the 2002 mining legislation on March 9, 2018, designating cobalt and coltan as “strategic metals” and raising royalty fees. On December 4, 2018, the 2002 mining code was essentially changed.

A historic lawsuit against Apple, Tesla, Dell, Microsoft, and Google parent Alphabet for “knowingly benefiting from and aiding and abetting the cruel and brutal use of young children” in cobalt mining was launched in December 2019 by the human rights organization International Rights Advocates. The aforementioned firms refuted any involvement in child labor.

Canada

It was planned by a few exploratory firms in 2017 to examine abandoned silver and cobalt mines in the Cobalt, Ontario, region, where large resources are thought to be located.

Cuba

Canada’s Sherritt International processes cobalt ores in nickel deposits from the Moa mines in Cuba, and the island has numerous more mines in Mayarí, Camagüey, and Pinar del Rio.

Sherit International’s sustained investments in Cuban nickel and cobalt production, together with the acquisition of mining rights for 17–20 years, ranked the communist nation third in the world in terms of cobalt deposits in 2019, just ahead of Canada.

Indonesia

As a byproduct of mining nickel, Indonesia started producing cobalt in 2021, albeit in lower proportions. Indonesia emerged as the second-largest cobalt producer globally by 2022, and according to Benchmark Mineral Intelligence, its output will account for 20% of global cobalt production by 2030.

Applications

2016 saw the utilization of 116,000 tonnes, or 128,000 short tons, of cobalt. Cobalt has been utilized in the manufacturing of alloys with superior performance. Certain rechargeable batteries also used it.

Alloys

In the past, superalloys based on cobalt have mostly absorbed the metal’s production. These alloys are useful for turbine blades in gas turbines and aircraft jet engines because of their temperature stability.

Nevertheless, single-crystal alloys based on nickel perform better than these alloys. Like titanium, cobalt-based alloys are resistant to wear and corrosion, which makes them valuable for orthopedic implant applications where long-term durability is required.

With the invention of satellite alloys in the first ten years of the 1900s, which combined chromium with various amounts of tungsten and carbon, wear-resistant cobalt alloys were first developed.

Chromium and tungsten carbide alloys are incredibly durable and resistant to wear. Particular chromium-cobaltKnee and hip replacements are examples of prosthetic components made of molybdenum alloys like Vitallium.

In dental prostheses, cobalt alloys are also utilized as a helpful replacement for nickel, which has the potential to cause allergies.

Cobalt is another ingredient added to some high-speed steels to improve heat and wear resistance. Permanent magnets are made of specific alloys of samarium and cobalt (samarium–cobalt magnet) and aluminum, nickel, cobalt, and iron (Alnico).

In jewelry, it is also alloyed with 95% platinum to create a slightly magnetic alloy that is appropriate for precise casting.

Batteries

Lithium-ion battery cathodes frequently include lithium cobalt oxide (LiCoO₂). Layers of cobalt oxide with intercalated lithium make up the substance.

Lithium is discharged as lithium ions during discharge, or when it is not actively being charged. Cobalt is also added to nickel-cadmium (NiCd) and nickel metal hydride (NiMH) batteries to enhance nickel oxidation within the battery.

The global market for lithium-ion batteries was valued at $30 billion by Transparency Market Research in 2015, and it is expected to reach over US$75 billion by 2024.

Rechargeable batteries for electric automobiles are a relatively recent usage for cobalt, despite the fact that mobile devices accounted for the majority of cobalt in batteries in 2018 electric vehicles become more commonplace, demand is predicted to either remain unchanged or grow.

The region near Cobalt, Ontario, where several silver mines have closed for many years, was explored in 2016–2017.

For a battery capacity of 46.3 GWh, cobalt for electric cars jumped 81% from the first half of 2018 to 7,200 tons in the first half of 2019.

Technology businesses looking to establish an ethical supply chain have encountered difficulties as a result of frequent reports of child and slave labor in cobalt mining, particularly in the artisanal mines of the Democratic Republic of the Congo. this raw material and the price of cobalt metal reached a nine-year high in October 2017, more than US$30 a pound, versus US$10 in late 2015.

In 2019, the price reduced to a more usual $15 due to overstock. In response to the problems. The Fair Cobalt Alliance (FCA), which strives to eliminate the use of child labor and improve working conditions in DR Congo’s cobalt mining and processing industry, was created in response to the artisanal cobalt mining industry.

Zhejiang Huayou Cobalt, Sono Motors, Fairphone, Glencore, the Responsible Cobalt Initiative, and Tesla, Inc. are among the members of FCA.

The European Union is investigating the feasibility of doing away with the need for cobalt in the manufacturing of lithium-ion batteries.

As of August 2020, battery manufacturers have included the cobalt-free lithium iron phosphate cathode to the battery packs of electric automobiles like the Tesla Model 3 and have progressively decreased the cathode cobalt concentration from 1/3 (NMC 111) to 1/5 (NMC 442) to the current 1/10 (NMC 811).

Tesla revealed their intentions to produce their own battery cells devoid of cobalt in September 2020. With 52% of installed capacity, lithium iron phosphate batteries formally overtook ternary cobalt batteries in 2021. Analysts predict that by 2024, its market share will surpass 60%.

Catalysts

Oxidation catalysts include a number of cobalt compounds. Cobalt acetate is used to convert xylene to terephthalic acid, the precursor of the bulk polymer polyethylene terephthalate. Cobalt carboxylates, also referred to as cobalt soaps, are common catalysts.

By oxidizing drying oils, they are also utilized as “drying agents” in paints, varnishes, and inks. However, toxicity concerns are phasing out their use.

In steel-belted radial tires, the same carboxylates are employed to increase the adherence between steel and rubber. Furthermore, they serve as accelerators in systems using polyester resin.

Carbon monoxide-related processes are catalyzed by cobalt. In the Fischer-Tropsch process, which converts carbon monoxide into liquid fuels, cobalt is also a catalyst. Cobalt octacarbonyl is frequently used as a catalyst in the hydroformylation of alkenes.

Petroleum is hydrodesulfurized using a catalyst made of molybdenum and cobalt. This procedure aids in the removal of sulfur impurities from petroleum that obstruct the refining of liquid fuels.

Pigments and coloring

Prior to the 1800s, cobalt was mostly utilized as a coloring material. Since the Middle Ages, it has been utilized to create blue glass known as smalt.

A dark blue silicate glass called smalt is created by melting a combination of roasted mineral smaltite, quartz, and potassium carbonate. The resulting material is then finely crushed. Smalt was frequently used as a pigment in artworks and to color glass.

Cobalt green was discovered by Sven Rinman in 1780, and Louis Jacques Thénard in 1802.blue cobalt. Because of their exceptional chromatic stability.

cobalt pigments like cobalt violet (cobalt phosphate), cerulean blue (cobalt(II) stannate), and several shades of cobalt green (cobalt(II) oxide and zinc oxide) are employed as artist’s pigments.

Radioisotopes

Cobalt-60, often known as ⁶⁰Co, is a valuable source of gamma rays due to its high activity and ability to be created in predictable quantities by neutron bombardment of cobalt. 1.17 and 1.33 MeV gamma rays are produced by it.

Cobalt is used in industrial radiography (e.g., weld integrity radiographs), density measurements (e.g., concrete density measurements), tank fill height switches, sterilization of medical waste and supplies, and radiation treatment of foods for sterilization (cold pasteurization).

Unfortunately, the metal produces a thin dust that makes radiation shielding problematic. When a radiotherapy unit containing cobalt-60 is improperly disassembled at a junkyard in Juarez, Mexico, it might pose a major risk of radioactive contamination.

This was the case in 1984, one of the worst radiation contamination incidents in North America. The radioactive half-life of cobalt-60 is 5.27 years.

In current radiation treatment, linear accelerators have mostly supplanted cobalt machines because of potency loss, which necessitates frequent source replacement.

The cobalt radioisotope cobalt-57 (Co-57 or ⁵⁷Co) is most frequently employed in medical diagnostic procedures, such as the Schilling test, and as a radiolabel for vitamin B₁₂ absorption.

Cobalt-57 is one of numerous potential sources in X-ray fluorescence devices are utilized as a source in Mössbauer spectroscopy.

It is possible that ⁵⁹Co, some of which would be triggered in a nuclear explosion to make ⁶⁰Co, would be purposefully included in nuclear weapon designs. Sometimes referred to as a cobalt bomb, the ⁶⁰Co is spread via radioactive fallout.

Other uses

• Because of its glossy finish, oxidation resistance, and hardness, cobalt is utilized in electroplating.
• It serves as a foundation priming coat for porcelain enamels as well.

Biological role

All creatures need cobalt for proper metabolism. It is an essential component of cobalamin, or vitamin B₁₂, which is the main biological source of cobalt as an ultra-trace element.

Cobalt salts are converted by bacteria in the stomachs of ruminant animals into vitamin B₁₂, an entity that can only be made by bacteria or archaea.

Hence, grazing animals benefit greatly from even a small amount of cobalt in their soils; an intake of 0.20 mg/kg per day is advised since these animals lack access to any other source of vitamin B12. Cobalamin-based proteins bind cobalt with corrin.

A reactive C-Co bond is a characteristic of Coenzyme B₁₂ that takes part in the processes. Methyl and adenosyl are the two forms of alkyl ligands found in human B₁₂. Methyl (−CH3) group transfers are encouraged by MeB₁₂.

When two neighboring atoms get a direct transfer of a hydrogen atom, the second substituent, X—which might be an amine, an oxygen atom from an alcohol, or a carbon atom with substituents—is simultaneously exchanged.

This type of rearrangement is catalyzed by the adenosyl form of B₁₂. Methylmalonyl coenzyme A mutase (MUT) transforms MMl-CoA to Su-CoA, a crucial step in the extraction of energy from proteins and lipids.

Other cobalt proteins besides B₁₂ are known, albeit they are significantly less prevalent than other metalloproteins (such as those of zinc and iron).

Among these proteins is methionine aminopeptidase 2, an enzyme found in humans and other animals that binds cobalt directly instead of via the corrin ring of vitamin B₁₂.

Nitrile hydratase is an additional non-corrin cobalt enzyme found in bacteria that breaks down nitriles.

Cobalt Deficiency

All of a person’s cobalt needs are satisfied by consuming vitamin B₁₂, which contains cobalt. Inorganic cobalt has a purpose for sheep and cattle, since they produce vitamin B₁₂ in their rumens through indigenous bacteria.

Cattle were afflicted with “bush sickness” in the early 1900s when farming was developed on New Zealand’s North Island Volcanic Plateau.

The absence of cobalt salts in the volcanic soils was found. necessary for the cattle food chain. It was discovered that dietary deficits of trace metals cobalt and copper were the root cause of the “coast disease” that struck sheep in the 1930s in the Southeast of South Australia’s Ninety Mile Desert.

The creation of “cobalt bullets,” which are thick pellets of cobalt oxide combined with clay that is fed orally to animals to lodge in their rumen, helped to solve the cobalt shortage.

Health Issues

Soluble cobalt salts have been shown to have an LD₅₀ value of 150–500 mg/kg. The US has a time-weighted average (TWA) of 0.1 mg/m³, which is the acceptable exposure limit (PEL) set by the Occupational Safety and Health Administration (OSHA).

The recommended exposure limit (REL), as established by the National Institute for Occupational Safety and Health (NIOSH), is 0.05 mg/m³, a time-weighted average.

Twenty mg/m³ is the IDLH (immediately dangerous to life and health) standard. Even at far lower levels than the fatal one, persistent cobalt consumption has been linked to significant health issues.

Beer drinker’s cardiomyopathy is the name given to a unique type of toxin-induced cardiomyopathy that was first seen in 1966 when cobalt compounds were added to beer in Canada to stabilize the froth.

Furthermore, according to the International Agency for Research on Cancer (IARC) Monographs, cobalt metal is suspected of causing cancer (i.e., probably carcinogenic, IARC Group 2B). Inhaled, it causes respiratory issues.

When handled, it also results in skin issues; cobalt is a prominent cause of contact dermatitis, ranking third behind nickel and chromium.

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