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Monday, March 11, 2019

Conflict resource

From Wikipedia, the free encyclopedia

Four common conflict minerals, clockwise from top left: coltan, cassiterite, gold ore, and wolframite.
 
Conflict resources are natural resources extracted in a conflict zone and sold to perpetuate the fighting. There is both statistical and anecdotal evidence that belligerent accessibility to precious commodities can prolong conflicts (a "resource curse"). The most prominent contemporary example has been the eastern provinces of the Democratic Republic of the Congo (DRC), where various armies, rebel groups, and outside actors have profited from mining while contributing to violence and exploitation during wars in the region. 

The four most commonly mined conflict minerals (known as 3TGs, from their initials) are cassiterite (for tin), wolframite (for tungsten), coltan (for tantalum), and gold ore, which are extracted from the eastern Congo, and passed through a variety of intermediaries before being purchased. These minerals are essential in the manufacture of a variety of devices, including consumer electronics such as mobile phones, laptops, and MP3 players.

The extraction and sale of blood diamonds, also known as "conflict diamonds", is a better-known phenomenon which occurs under virtually identical conditions. Even petroleum can be a conflict resource; ISIS used oil revenue to finance its military and terrorist activities. 

There have been international efforts to reduce trade in conflict resources, which try to reduce incentives to extract and fight over them. For example, in the United States, the 2010 Dodd–Frank Wall Street Reform and Consumer Protection Act required manufacturers to audit their supply chains and report use of conflict minerals. In 2015 a US federal appeals court struck down some aspects of the reporting requirements as a violation of corporations’ freedom of speech, but left others in place.

History

The concept of 'conflict resource', or 'conflict commodity' emerged in the late 1990s, initially in relation to the 'conflict diamonds' that were financing rebellions in Angola and Sierra Leone. (The media often called these 'blood diamonds'.) Then 'conflict timber' financed hostilities in Cambodia and Liberia.

Conventions

The concept was first officially discussed by the UN General Assembly in the context of 'conflict diamonds': The UN Security Council has since referred to conflict resources in several resolutions.

Global Witness has called for an international standardized definition to facilitate a more systematic application of UN resolutions, the prevention of complicity in abuses during hostilities by commercial entities exploiting or trading in conflict resources, and the prosecution of war profiteers suspected of supporting or abetting war criminals."
...natural resources whose systematic exploitation and trade in a context of conflict contribute to, benefit from or result in the commission of serious violations of human rights, violations of international humanitarian law or violations amounting to crimes under international law.
— Global Witness, proposed Definition of conflict resources
Since 1996 the Bonn International Center for Conversion has tracked resource governance and conflict intensity by country. Aside from fossil fuels, metals, diamonds, and timber it tracks the governance of other primary goods that might fund conflicts, including: poppy seeds and talc (Afghanistan), rubber (Côte d'Ivoire), cotton (Zambia), and cocoa (Indonesia).

Conflict minerals

The four most prominent conflict minerals, for example codified in the U.S. Conflict Minerals Law, are:
  • Columbite-tantalite (or coltan, the colloquial African term) is the metal ore from which the element tantalum is extracted. Tantalum is used primarily for the production of tantalum capacitors, particularly for applications requiring high performance, a small compact format and high reliability, from hearing aids and pacemakers, to airbags, GPS, ignition systems and anti-lock braking systems in automobiles, through to laptop computers, mobile phones, video game consoles, video cameras and digital cameras. In its carbide form, tantalum possesses significant hardness and wear resistance properties. As a result, it is used in jet engine/turbine blades, drill bits, end mills and other tools.
  • Cassiterite is the chief ore needed to produce tin, essential for the production of tin cans and the solder on the circuit boards of electronic equipment. Tin is also commonly a component of biocides, fungicides and as tetrabutyl tin/tetraoctyl tin, an intermediate in polyvinyl chloride (PVC) and high performance paint manufacturing.
  • Wolframite is an important source of the element tungsten. Tungsten is a very dense metal and is frequently used for this property, such as in fishing weights, dart tips and golf club heads. Like tantalum carbide, tungsten carbide possesses hardness and wear resistance properties and is frequently used in applications like metalworking tools, drill bits and milling. Smaller amounts are used to substitute lead in "green ammunition". Minimal amounts are used in electronic devices, including the vibration mechanism of cell phones.
  • Gold is used in jewelry, investments, electronics, and dental products. It is also present in some chemical compounds used in certain semiconductor manufacturing processes.
These are sometimes referred to as "the 3T's and gold", 3TG, or even simply the "3T's". Under the US Conflict Minerals Law, additional minerals may be added to this list in the future.

Democratic Republic of the Congo

As of 2010, the conflict resource fueling the world's deadliest war is gold in the Congo. Gold bars are less traceable than diamonds, and gold is abundant in the Kivu conflict region. In any case, no jewellery industry standard exists for verifying gold origination, as it does for diamonds (though jeweler's total outlay on gold is five times that on diamonds). Other conflict minerals being illicitly exported from the Congo include cobalt, tungsten, cassiterite, and coltan (which provides the tantalum for mobile phones, and is also said to be directly sustaining the conflict).

Armed conflict and mineral resource looting by the Congolese National Army and various armed rebel groups, including the Democratic Forces for the Liberation of Rwanda (FDLR) and the National Congress for the Defense of the People (CNDP), a proxy Rwandan militia group, has occurred throughout the late 20th century and the early 21st century. Additionally, the looting of the Congo's natural resources is not limited to domestic actors. During the Congo Wars (First Congo War (1996–1997) and Second Congo War (1998–2003)), Rwanda, Uganda and Burundi particularly profited from the Congo's resources. These governments continued to smuggle resources out of the Congo to this day.

The profits from the sale of these minerals have financed fighting in the Second Congo War and ongoing follow-on conflicts. Control of lucrative mines has also itself become a military objective.

Mines

Mines, in eastern Congo, are often located far from populated areas in remote and dangerous regions. A recent study by International Peace Information Service (IPIS) indicates that armed groups are present at more than 50% of mining sites. At many sites, armed groups illegally tax, extort, and coerce civilians to work. Miners, including children, work up to 48-hour shifts amidst mudslides and tunnel collapses that kill many. The groups are often affiliated with rebel groups, or with the Congolese National Army, but both use rape and violence to control the local population.

United States law

In April 2009, Senator Sam Brownback (R-KS) introduced the Congo Conflict Minerals Act of 2009 (S. 891) to require electronics companies to verify and disclose their sources of cassiterite, wolframite, and tantalum. This legislation died in committee. However, Brownback added similar language as Section 1502 of the Dodd–Frank Wall Street Reform and Consumer Protection Act, which passed Congress and was signed into law by President Barack Obama on July 21, 2010.

The U.S. Securities and Exchange Commission (SEC) draft regulations to implement the Conflict Mineral Law, published in the Federal Register of December 23, 2010. would have required U.S. and certain foreign companies to report and make public their use of so-called "conflict minerals" from the Democratic Republic of the Congo or adjoining countries in their products. Comments on this proposal were extended until March 2, 2011. The comments on the proposal were reviewable by the public.

One report on the proposal stated the following statistics for the submitted comments:
  • Slightly more than 700 comment letters were submitted to SEC on the proposal;
  • Approximately 65% of those were form letters or basic letters from the general public supporting the rule's intent;
  • The remaining 35% (roughly 270) represent views of businesses, trade/industry associations, the investment/financial community, professional auditing firms, and other relevant governmental entities; and
  • Of those 270 comments, an estimated 200 contained substantive and/or technical comments.
That report also contained what it calls a "preview of the final SEC regulations" synthesized from their detailed research and analysis of a large body of documents, reports and other information on the law, proposed regulation and the current budget/political setting facing the SEC in the current administration. 

The final rule went into effect 13 November 2012.

The SEC rule did not go unnoticed by the international community, including entities seeking to undermine traceability efforts. A report published by a metals trading publication illustrated one DRC ore/mineral flow method that has apparently been devised to thwart detection.

On July 15, 2011, the US State Department issued a statement on the subject. Section 1502(c) of the Law mandates that the State Department work in conjunction with SEC on certain elements of conflict minerals policy development and support.

On October 23, 2012 U.S. State Dept Officials asserted that ultimately, it falls on the U.S. State Dept. to determine when this rule would no longer apply.

In April 2014, the United States Court of Appeals for the District of Columbia Circuit struck down several parts of the SEC Rules as unconstitutional.

Auditing and reporting requirements

US Conflict Minerals Law contains two requirements that are closely connected:
  • independent third party supply chain traceability audits
  • reporting of audit information to the public and SEC.
Even companies not directly regulated by the SEC will be impacted by the audit requirements because they will be pushed down through entire supply chains, including privately held and foreign-owned companies. 

SEC estimated that 1,199 "issuers" (i.e., companies subject to filing other SEC reports) will be required to submit full conflict mineral reports. This estimate was developed by finding the amount of tantalum produced by the DRC in comparison to global production (15% – 20%). The Commission selected the higher figure of 20% and multiplied that by 6,000 (the total number of "issuers" SEC will be required to do initial product/process evaluations). This estimate does not account for the companies who supply materials to the "issuers" (but are not themselves SEC-regulated) but who will almost certainly be required to conduct conflict minerals audits to meet the demands of those customers. Other estimates indicate that the total number of US companies likely impacted may exceed 12,000.

A study of the potential impact of the regulation in early 2011 by the IPC – Association Connecting Electronic Industries trade association. was submitted with the association's comments to the SEC. The study states that the IPC survey respondents had a median of 163 direct suppliers. Applying that number to the SEC's estimated number of impacted issuers results in the possibility of over 195,000 businesses that could be subject to some level of supply chain traceability effort.

Applicability in general

Under the law, companies have to submit an annual conflict minerals report to the SEC if:
  • (a) they are required to file reports with the SEC under the Exchange Act of 1934
  • (b) conflict minerals are necessary to the functionality or production of a product that they manufacture or contract to be manufactured. That statement contains two separate – but critical concepts: the purpose of the conflict mineral in the product/process, and the control that the company exerts over the manufacturing process/specifications.
A company would be deemed to contract an item to be manufactured if it:
  • Exerts any influence over the manufacturing process; or,
  • Offers a generic product under its own brand name or a separate brand name (regardless of whether the company has any influence over the manufacturing process) and the company contracted to have the product manufactured specifically for itself.
This language implied that some retailers who are not manufacturers might be subject to the audit and disclosure requirements.

"Contracting to manufacture" a product requires some actual influence over the manufacturing of process that product, a determination based on facts and circumstances. A company is not to be deemed to have influence over the manufacturing process if it merely:
  • Affixes its brand, marks, logo, or label to a generic product manufactured by a third party.
  • Services, maintains, or repairs a product manufactured by a third party.
  • Specifies or negotiates contractual terms with a manufacturer that do not directly relate to the manufacturing of the product.
The proposed regulations attempted to clarify that tools used in assembly and manufacturing will not trigger the law. The intent was to cover minerals/metals in the final product only. Nothing specifically addresses intermediate chemical processes that use chemicals that contain conflict minerals. Additionally, neither the law nor the proposed regulation established a de minimis quantity or other form of materiality threshold that would preclude the applicability of the auditing/reporting requirements.

Supply chain traceability auditing

The law mandates the use of an "independent private sector auditor" to conduct the audits. SEC has proposed two different standards for the audits: the "reasonable inquiry" and the "due diligence". Should the final rule include this structure, the reasonable inquiry would be the first step to determine if the company can on its own, using reasonable efforts and trustworthy information, make a reliable determination as to the source/origin of its tin, tantalum, tungsten and/or gold. Where companies are unable to make such a determination for any reason, they would then be required to take the next step of the "due diligence", which is the independent private sector audit. 

The statute specified that the audits be "conducted in accordance with standards established by the Comptroller General of the United States, in accordance with rules promulgated by the Commission." This means that the same auditing standards that apply to other SEC auditing requirements will apply to conflict minerals audits  Because of this language, SEC will have little discretion to allow companies to issue self-generated statements or certifications to satisfy the law. 

Third party audits for conflict minerals supply chain traceability began in summer 2010 under the Electronic Industry Citizenship Coalition (EICC), a US-based electronics manufacturing trade association. Under this program, EICC selected three audit firms to conduct the actual audits, with two of the three participating in the pilot audits in 2010. After concluding the pilot, one of the two firms involved in 2010 withdrew from the program specifically in response to the SEC's proposal and to reduce potential legal risks to the audited entities.

Neither the law nor the proposed regulations provide guidance on what will be considered an acceptable audit scope or process, preferring to allow companies the flexibility meeting the requirement in a manner that is responsive to their own individual business and supply chain. At the same time, the law contains a provision that preserves the government's rights to deem any report, audit or other due diligence processes as being unreliable, and in such cases, the report shall not satisfy the requirements of the regulations, further emphasizing the need for such audits to conform to established SEC auditing standards. Comments on the proposed regulation pointed out that, should SEC not specify an applicable audit standard, it cannot also be silent or ambiguous on the auditor standards as well, or the Commission will violate the plain language of the Law mandating "standards established by the Comptroller General of the United States". It is generally expected that SEC will provide specificity on both the audit standard and the auditor standard. SEC's proposal attempted to clarify its position on auditor requirements.

The Organisation for Economic Co-operation and Development (OECD) published its Guidance on conflict minerals supply chain traceability. This guidance is gaining much momentum as "the" standard within US policy. However, a recent critical analysis of the standard in comparison to existing US auditing standards under SEC highlighted a number of significant inconsistencies and conflict with relevant US standards. Companies subject to the US law who implement the OECD Guidance without regard for the SEC auditing standards may face legal compliance risks.

Reporting and disclosure

Companies subject to the SEC reporting requirement would be required to disclose whether the minerals used in their products originated in the DRC or adjoining countries (as defined above). The law mandates that this reporting be submitted/made available annually. Many comments to the proposed regulation asked SEC to clarify whether the report must be "furnished"—meaning it is made available to SEC but not directly incorporated within the company's formal financial report—or "submitted"—meaning the report is directly incorporated into the financial report. At first glance, this may appear to be a minor point; however, this difference is very important in determining the audit/auditor standards and related liabilities.

If it is determined that none of the minerals originated in the DRC or adjoining countries, the report must include a statement to that effect and provide an explanation of the country of origin analysis that was used to arrive at the ultimate conclusion. On the other hand, if conflict minerals originating in the DRC or adjoining countries were used (or if it is not possible to determine the country of origin of the conflict minerals used), companies would be required to state as such in the annual report. In either case, companies would also be required to make this information public by posting their annual conflict minerals report on their websites, and providing the SEC with the internet addresses where the reports may be found. Further, the proposed regulations would require companies to maintain records relating to the country of origin of conflict minerals used in their products.

Media outlets have reported that many companies required to file Specialized Disclosure Reports to the U.S. Securities and Exchange Commission (SEC) and any necessary conflict minerals reports for 2013 under the SEC’s conflict minerals rule are struggling to meet the June 2, 2014 report filing deadline. Many impacted companies were hoping for clarification regarding filing requirements, from the United States Court of Appeals for the District of Columbia Circuit from a lawsuit filed by the National Association of Manufacturers. The appellate court’s ruling left the necessary conflict minerals reporting requirements largely intact and it has been suggested that impacted companies should review the SEC’s Division of Corporation Finance’s response to the court’s ruling which provides guidance regarding the effect of the appellate court’s ruling.

On August 18, 2015 the divided D.C. Circuit Court again held the SEC's conflict materials rule violates the First Amendment. Senior Circuit Judge A. Raymond Randolph, joined by Senior Circuit Judge David B. Sentelle, weighed if the required disclosures were effective and uncontroversial. Citing news reports and a Congressional hearing, the court decided the policy was ineffective. The court next found the required label was controversial because it "is a metaphor that conveys moral responsibility for the Congo war." As such, the court struck down the conflict materials rule’s disclosure requirements as a violation of corporations’ freedom of speech. Circuit Judge Sri Srinivasan dissented, writing that the required disclosures were not controversial because they were truthful.

Criticism of the law

The law has been criticised for not addressing the root causes of the conflict, leaving to the Congolese government the responsibility for providing an environment in which companies can practice due diligence and legitimately purchase the minerals they need, when the reality is that mechanisms for transparency do not exist. The effect has been to halt legitimate mining ventures that provided livelihoods for people, reducing the Congo's legal exports of tantalum by 90%.

An investigation by the U.S. Government Accountability Office (GAO) found that most companies were unable to determine the source of their conflict minerals.

Technology manufacturers criticized a law which required them to label a product as not "DRC Conflict Free" as compelled speech, and in violation of the First Amendment.

Proposed law in Europe

The European Parliament passed legislation in 2015; negotiations are currently underway among member states as to specific wording details.

On 16 June 2016 the European Parliament confirmed that "mandatory due diligence" would be required for "all but the smallest EU firms importing tin, tungsten, tantalum, gold and their ores".

On May 17, 2017 the EU passed Regulation (EU) 2017/821 of the Parliament and of the Council on the supply chain due diligence obligations for importers of tin, tantalum, tungsten, their ores, and gold from conflict-affected and high risk areas. The regulation will take effect in January 2021, and will directly apply to companies that import 3TG metals into the EU, no matter where they originate.

On August 10, 2018 The European Commission published their non-binding guidelines for the identification of conflict-affected and high-risk areas and other supply chain risks under Regulation (EU) 2017/821 of the European Parliament and of the Council.

Conflict resources in supply chains

Increases in business process outsourcing to globally dispersed production facilities means that social problems and human rights violations are no longer only an organization matter, but also often occur in companies’ supply chains, and challenge for supply chain managers. Besides the harm conflict minerals do where they are produced, human rights violations also raise an enormous risk to corporate reputations. Consumers, mass media and employees expect companies to behave responsibly and have become intolerant of those who don't. 

Consequently, firms that are located downstream in the supply chain and that are more visible to stakeholders are particularly threatened by social supply chain problems. The recent debate concerning conflict minerals illustrates the importance of social and human rights issues in supply chain management practice as well as the emerging need to react to social conflicts. Conflict minerals are processed in many different components throughout various industries and hence have a high overall impact on business. 

Initiatives like the Dodd–Frank Wall Street Reform and Consumer Protection Act or the OECD Due Diligence Guidance for Responsible Supply Chains of Minerals from Conflict-Affected and High-Risk Areas demand that supply chain managers verify purchased goods as ‘‘conflict-free’’ or implement measures to better manage any inability to do so.

Minerals mined in Eastern Congo pass through the hands of numerous middlemen as they are shipped out of Congo, through neighboring countries such as Rwanda or Burundi, to East Asian processing plants. Because of this, the US Conflict Minerals Law applies to materials originating (or claimed to originate) from the DRC as well as the nine adjoining countries: Angola, Burundi, Central African Republic, Congo Republic, Rwanda, South Sudan, Zimbabwe, Uganda, and Zambia.

Firms have begun to apply governance mechanisms to avoid adverse effects of conflict mineral sourcing. However, the mere transfer of responsibilities upstream in the supply chain apparently will not stop the trade with conflict minerals, notably due to two reasons:
  • On the one hand, globalization has created governance gaps in a sense that companies are able to abuse human rights without being sanctioned by independent third parties. This gap results in a non-allocation of responsibility that makes the problem of human rights abuses and social conflicts within dispersed supply chains very likely to endure, particularly without collaborative approaches to remedy these deficiencies.
  • On the other hand, conflict minerals usually originate from globally diverse deposits and are difficult to track within components and manufactured products. This is the case because they are mixed with minerals of different origin and added to metal alloys. Consequently, although the share of these minerals in single end products may be negligible, they are prevalent in numerous products and commodities. Together, these circumstances leave downstream firms nearly incapable of detecting risks associated with conflict minerals. Hence, the topic of conflict minerals becomes one of supply chain management rather than of individual companies’ legal or compliance divisions alone. What is needed is effective and supply-chain wide-mechanisms of traceability and due diligence that allow firms to take individual and collective responsibility as parts of supply chains.
In the context of mineral supply chains, due diligence represents a holistic concept that aims at providing a chain of custody tracking from mine to export at country level, regional tracking of mineral flows through the creation of a database on their purchases, independent audits on all actors in the supply chain, and a monitoring of the whole mineral chain by a mineral chain auditor. In this sense, due diligence transcends conventional risk management approaches that usually focus on the prevention of direct impacts on the core business activities of companies. Moreover, due diligence focuses on a maximum of transparency as an end itself while risk management is always directed towards the end of averting direct damages. However, besides the Dodd–Frank Wall Street Reform and Consumer Protection Act and the OECD Guidance, there is still a gap in due diligence practices as international norms are just emerging. Studies found that the motivation for supply chain due diligence as well as expected outcomes of these processes vary among firms. Furthermore, different barriers, drivers, and implementation patterns of supply chain due diligence have been identified in scholarly research.

Organizations and activists involved

A number of organizations and celebrities working to find solutions and raise awareness of conflict minerals. These include:
Moreover, FairPhone Foundation raises awareness of conflict minerals in the mobile industry and is a company which tries to produce a smart phone with 'fair' conditions along the supply chain. Various industry and trade associations are also monitoring developments in conflict minerals laws and traceability frameworks. Some of these represent electronics, retailers, jewelry, mining, electronics components, and general manufacturing sectors. One organization – ITRI (a UK-based international non-profit organization representing the tin industry and sponsored/supported by its members, principally miners and smelters.) had spearheaded efforts for the development and implementation of a "bag and tag" scheme at the mine as a key element of credible traceability. The program and related efforts were initially not likely to extend beyond the pilot phase due to a variety of implementation and funding problems that occurred. In the end however, the device did enter the market.

In late March 2011, the UK government launched an informational section on its Foreign & Commonwealth Office website dedicated to conflict minerals. This information resource is intended to assist British companies in understanding the issues and, specifically, the US requirements. 

On Jan 6th 2014, the semiconductor giant Intel announced that it would distance itself from conflict minerals. As a result, all Intel microprocessors henceforth will be conflict-free.

Commercial reporting solutions

Manufacturers and supply chain partners needing to comply with the ever-increasing reporting regulations have a few commercial options available. 

A major research report from November 2012 by the Southern Africa Resource Watch revealed that gold miners in the east of the Democratic Republic of Congo were being exploited by corrupt government officials, bureaucrats and security personnel, who all demand illegal tax, fees and levies from the miners without delivering any services in return. Despite the alleged gold rush in regions of the country, none of the population and workforce is benefiting from this highly lucrative industry.

Cobalt

From Wikipedia, the free encyclopedia

Cobalt,  27Co
cobalt chips
Cobalt
Appearancehard lustrous bluish gray metal
Standard atomic weight Ar, std(Co)58.933194(3)
Cobalt in the periodic table
Hydrogen
Helium
Lithium Beryllium
Boron Carbon Nitrogen Oxygen Fluorine Neon
Sodium Magnesium
Aluminium Silicon Phosphorus Sulfur Chlorine Argon
Potassium Calcium Scandium
Titanium Vanadium Chromium Manganese Iron Cobalt Nickel Copper Zinc Gallium Germanium Arsenic Selenium Bromine Krypton
Rubidium Strontium Yttrium

Zirconium Niobium Molybdenum Technetium Ruthenium Rhodium Palladium Silver Cadmium Indium Tin Antimony Tellurium Iodine Xenon
Caesium Barium Lanthanum Cerium Praseodymium Neodymium Promethium Samarium Europium Gadolinium Terbium Dysprosium Holmium Erbium Thulium Ytterbium Lutetium Hafnium Tantalum Tungsten Rhenium Osmium Iridium Platinum Gold Mercury (element) Thallium Lead Bismuth Polonium Astatine Radon
Francium Radium Actinium Thorium Protactinium Uranium Neptunium Plutonium Americium Curium Berkelium Californium Einsteinium Fermium Mendelevium Nobelium Lawrencium Rutherfordium Dubnium Seaborgium Bohrium Hassium Meitnerium Darmstadtium Roentgenium Copernicium Nihonium Flerovium Moscovium Livermorium Tennessine Oganesson


Co

Rh
ironcobaltnickel
Atomic number (Z)27
Groupgroup 9
Periodperiod 4
Blockd-block
Element category  transition metal
Electron configuration[Ar] 3d7 4s2
Electrons per shell
2, 8, 15, 2
Physical properties
Phase at STPsolid
Melting point1768 K ​(1495 °C, ​2723 °F)
Boiling point3200 K ​(2927 °C, ​5301 °F)
Density (near r.t.)8.90 g/cm3
when liquid (at m.p.)8.86 g/cm3
Heat of fusion16.06 kJ/mol
Heat of vaporization377 kJ/mol
Molar heat capacity24.81 J/(mol·K)
Vapor pressure
P (Pa) 1 10 100 1 k 10 k 100 k
at T (K) 1790 1960 2165 2423 2755 3198
Atomic properties
Oxidation states−3, −1, +1, +2, +3, +4, +5 (an amphoteric oxide)
ElectronegativityPauling scale: 1.88
Ionization energies
  • 1st: 760.4 kJ/mol
  • 2nd: 1648 kJ/mol
  • 3rd: 3232 kJ/mol
Atomic radiusempirical: 125 pm
Covalent radiusLow spin: 126±3 pm
High spin: 150±7 pm
Color lines in a spectral range
Spectral lines of cobalt
Other properties
Natural occurrenceprimordial
Crystal structurehexagonal close-packed (hcp)
Hexagonal close packed crystal structure for cobalt
Speed of sound thin rod4720 m/s (at 20 °C)
Thermal expansion13.0 µm/(m·K) (at 25 °C)
Thermal conductivity100 W/(m·K)
Electrical resistivity62.4 nΩ·m (at 20 °C)
Magnetic orderingferromagnetic
Young's modulus209 GPa
Shear modulus75 GPa
Bulk modulus180 GPa
Poisson ratio0.31
Mohs hardness5.0
Vickers hardness1043 MPa
Brinell hardness470–3000 MPa
CAS Number7440-48-4
History
Discovery and first isolationGeorg Brandt (1735)
Main isotopes of cobalt
Iso­tope Abun­dance Half-life (t1/2) Decay mode Pro­duct
56Co syn 77.27 d ε 56Fe
57Co syn 271.79 d ε 57Fe
58Co syn 70.86 d ε 58Fe
59Co 100% stable
60Co syn 5.2714 y β, γ 60Ni

Cobalt is a chemical element with symbol Co and atomic number 27. Like nickel, cobalt is found in the Earth's crust only in chemically combined form, save for small deposits found in alloys of natural meteoric iron. The free element, produced by reductive smelting, is a hard, lustrous, silver-gray metal.

Cobalt-based blue pigments (cobalt blue) have been used since ancient times for jewelry and paints, and to impart a distinctive blue tint to glass, but the color was later thought by alchemists to be due to the known 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 poisonous arsenic-containing fumes when smelted. In 1735, such ores were found to be reducible to a new metal (the first discovered since ancient times), and this was ultimately named for the kobold.

Today, some cobalt is produced specifically from one of a number of metallic-lustered ores, such as for example cobaltite (CoAsS). The element is however more usually produced as a by-product of copper and nickel mining. The copper belt in the Democratic Republic of the Congo (DRC) and Zambia yields most of the global cobalt production. The DRC alone accounted for more than 50% of world production in 2016 (123,000 tonnes), according to Natural Resources Canada.

Cobalt is primarily used in the manufacture of magnetic, wear-resistant and high-strength alloys. The compounds cobalt silicate and cobalt(II) aluminate (CoAl2O4, cobalt blue) give 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 the active center of a group of coenzymes called cobalamins. vitamin B12, 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.

Characteristics

a sample of pure cobolt
A block of electrolytically refined cobalt (99.9% purity) cut from a large plate
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 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 a passivating oxide film. It is attacked by halogens and sulfur. Heating in oxygen produces Co3O4 which loses oxygen at 900 °C (1,650 °F) to give the monoxide CoO. The metal reacts with fluorine (F2) at 520 K to give CoF3; with chlorine (Cl2), bromine (Br2) and iodine (I2), producing equivalent binary halides. It does not react with hydrogen gas (H2) or nitrogen gas (N2) even when heated, but it does react with boron, carbon, phosphorus, arsenic and sulfur.[12] At ordinary temperatures, it reacts slowly with mineral acids, and very slowly with moist, but not with dry, air.

Compounds

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 is +2 (cobalt(II)). These salts form the pink-colored metal aquo complex [Co(H2O)6]2+ in water. Addition of chloride gives the intensely blue [CoCl
4
]2−
. In a borax bead flame test, cobalt shows deep blue in both oxidizing and reducing flames.

Oxygen and chalcogen compounds

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 the blue cobalt(II,III) oxide (Co3O4), which has a spinel structure. Black cobalt(III) oxide (Co2O3) is also known.[14] Cobalt oxides are antiferromagnetic at low temperature: CoO (Néel temperature 291 K) and Co3O4 (Néel temperature: 40 K), which is analogous to magnetite (Fe3O4), with a mixture of +2 and +3 oxidation states.

The principal chalcogenides of cobalt include the black cobalt(II) sulfides, CoS2, which adopts a pyrite-like structure, and cobalt(III) sulfide (Co2S3).

Halides

purple pile of power of Cobalt(II)-chloride-hexahydrate
Cobalt(II) chloride hexahydrate
Four dihalides of cobalt(II) are known: cobalt(II) fluoride (CoF2, pink), cobalt(II) chloride (CoCl2, blue), cobalt(II) bromide (CoBr2, green), cobalt(II) iodide (CoI2, blue-black). These halides exist in anhydrous and hydrated forms. Whereas the anhydrous dichloride is blue, the hydrate is red.

The reduction potential for the reaction Co3+ + eCo2+ is +1.92 V, beyond that for chlorine to chloride, +1.36 V. Consequently, cobalt(III) and chloride would result in the cobalt(III) being reduced to cobalt(II). Because the reduction potential for fluorine to fluoride is so high, +2.87 V, cobalt(III) fluoride is one of the few simple stable cobalt(III) compounds. Cobalt(III) fluoride, which is used in some fluorination reactions, reacts vigorously with water.

Coordination compounds

As for all metals, molecular compounds and polyatomic ions of cobalt are classified as coordination complexes, that is, molecules or ions that contain cobalt linked to several ligands. The principles of electronegativity and hardness–softness of a series of ligands can be used to explain the usual oxidation state of cobalt. For example, Co+3 complexes tend to have ammine ligands. Because phosphorus is softer than nitrogen, phosphine ligands tend to feature the softer Co2+ and Co+, an example being tris(triphenylphosphine)cobalt(I) chloride ((P(C6H5)3)3CoCl). The more electronegative (and harder) oxide and fluoride can stabilize Co4+ and Co5+ derivatives, e.g. caesium hexafluorocobaltate (Cs2CoF6) and potassium percobaltate (K3CoO4).

Alfred Werner, a Nobel-prize winning pioneer in coordination chemistry, worked with compounds of empirical formula [Co(NH3)6]3+. One of the isomers determined was cobalt(III) hexammine chloride. This coordination complex, a typical Werner-type complex, consists of a central cobalt atom coordinated by six ammine orthogonal ligands and three chloride counteranions. Using chelating ethylenediamine ligands in place of ammonia gives tris(ethylenediamine)cobalt(III) ([Co(en)3]3+), which was one of the first coordination complexes to be resolved into optical isomers. The complex exists in the right- and left-handed forms of a "three-bladed propeller". This complex was first isolated by Werner as yellow-gold needle-like crystals.

Organometallic compounds

Structure of tetrakis(1-norbornyl)cobalt(IV)

Cobaltocene is a structural analog to ferrocene, with cobalt in place of iron. Cobaltocene is much more sensitive to oxidation than ferrocene. Cobalt carbonyl (Co2(CO)8) is a catalyst in carbonylation and hydrosilylation reactions. Vitamin B12 (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), a transition metal-alkyl complex that is notable for its stability to β-hydrogen elimination. The cobalt(III) and cobalt(V) complexes [Li(THF)4]+[Co(1-norb)4] and [Co(1-norb)4]+[BF4] are also known.

Isotopes

59Co is the only stable cobalt isotope and the only isotope that exists naturally on Earth. Twenty-two radioisotopes have been characterized; the most stable, 60Co has a half-life of 5.2714 years, and 57Co has a half-life of 271.8 days, 56Co a half-life of 77.27 days, and 58Co 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 (50Co) to 73 u (73Co). The primary decay mode for isotopes with atomic mass unit values less than that of the most abundant stable isotope, 59Co, 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 59Co are element 26 (iron) isotopes; above that the decay products are element 28 (nickel) isotopes.

History

cobalt blue Chinese porcelain
Early Chinese blue and white porcelain, manufactured c. 1335
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 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 the Egyptians used is not known.

The word cobalt is derived from the German kobalt, from kobold meaning "goblin", a superstitious term used for the ore of cobalt by miners. The first attempts to smelt those ores for copper or nickel 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 the notoriety of the ore.

Swedish chemist Georg Brandt (1694–1768) is credited with discovering cobalt circa 1735, showing it to be a previously unknown element, different from bismuth and other traditional metals. Brandt called it a new "semi-metal". He showed that compounds of cobalt metal were 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 other 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 dye made with cobalt compounds and alumina) and smalt (cobalt glass powdered for use for pigment purposes in ceramics and painting) 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 the Congo in 1914, the 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 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 the U.S. border. An adequate supply of the ore was found in Idaho near Blackbird canyon in the side of a mountain. The firm Calera Mining Company started production at the site.

Occurrence

The stable form of cobalt is produced in supernovas through the r-process. It comprises 0.0029% of the Earth's crust. Free cobalt (the native metal) is not found on Earth because of the oxygen in the atmosphere and the chlorine in the ocean. Both are abundant enough in the upper layers of the Earth's crust to prevent native metal cobalt from forming. Except as recently delivered in meteoric iron, pure cobalt in native metal form is unknown on Earth. The element has a medium abundance but natural compounds of cobalt are numerous and small amounts of cobalt compounds are found in most rocks, soils, plants, and animals. 

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 the free (but alloyed) metal, though neither element is seen in that form in the ancient terrestrial crust.

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 (CoAs2), glaucodot ((Co,Fe)AsS), and skutterudite (CoAs3) minerals. The mineral cattierite is similar to pyrite and occurs together with vaesite in the copper deposits of Katanga Province. When it reaches the atmosphere, weathering occurs; the sulfide minerals oxidize and form pink erythrite ("cobalt glance": Co3(AsO4)2·8H2O) and spherocobaltite (CoCO3).

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.

Production

cobolt ore specimen
Cobalt ore
cobolt production in 1000 of tons by year
World production trend

The main ores of cobalt are cobaltite, erythrite, glaucodot and skutterudite (see above), but most cobalt 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.

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 different ore components, leading to an enrichment of cobalt ores. Subsequent roasting converts 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 (Co3O4). This oxide is reduced to metal by the aluminothermic reaction or reduction with carbon in a blast furnace.

Cobalt extraction

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. But by 2030, global demand could be 47 times more than it was in 2017, Bloomberg New Energy Finance has estimated.

Changes that Congo made to mining laws in 2002 attracted new investments in Congolese copper and cobalt projects. Glencore's Mutanda mine shipped 24,500 tons of cobalt last year, 40% of Congo DRC’s output and nearly a quarter of global production. Glencore’s Katanga Mining project is resuming as well and should produce 300,000 tons of copper and 20,000 tons of cobalt by 2019, according to Glencore.

Democratic Republic of the Congo

In 2005, the top producer of cobalt was the copper deposits in the Democratic Republic of the Congo's Katanga Province. Formerly Shaba province, the area had almost 40% of global reserves, reported the British Geological Survey in 2009. By 2015, Democratic Republic of the Congo (DRC) supplied 60% of world cobalt production, 32,000 tons at $20,000 to $26,000 per ton. Recent growth in production could at least partly be due to how low mining production fell during DRC Congo's very violent civil wars in the early 2000s, or to the changes the country made to its Mining Code in 2002 to encourage foreign and multinational investment and which did bring in a number of investors, including Glencore

Artisanal mining supplied 10% to 25% of the DRC production. Some 100,000 cobalt miners in Congo DRC use hand tools to dig hundreds of feet, with little planning and fewer safety measures, say workers and government and NGO officials, as well as Washington Post reporters' observations on visits to isolated mines. The lack of safety precautions frequently causes injuries or death. Mining pollutes the vicinity and exposes local wildlife and indigenous communities to toxic metals thought to cause birth defects and breathing difficulties, according to health officials.

Human rights activists have alleged, and investigative journalism reported confirmation, that child labor is used in mining cobalt from African artisanal mines. This revelation prompted cell phone maker Apple Inc., on March 3, 2017, to stop buying ore from suppliers such as Zhejiang Huayou Cobalt who source from artisanal mines in the DRC, and begin using only suppliers that are verified to meet its workplace standards.

The political and ethnic dynamics of the region have in the past caused horrific outbreaks of violence and years of armed conflict and displaced populations. This instability affected the price of cobalt and also created perverse incentives for the combatants in the First and Second Congo Wars to prolong the fighting, since access to diamond mines and other valuable resources helped to finance their military goals—which frequently amounted to genocide—and also enriched the fighters themselves. While DR Congo has in the 2010s not recently been invaded by neighboring military forces, some of the richest mineral deposits adjoin areas where Tutsis and Hutus still frequently clash, unrest continues although on a smaller scale and refugees still flee outbreaks of violence.

Cobalt extracted from small Congolese artisanal mining endeavors in 2007 supplied a single Chinese company, Congo DongFang International Mining. A subsidiary of Zhejiang Huayou Cobalt, one of the world’s largest cobalt producers, Congo DongFang supplied cobalt to some of the world’s largest battery manufacturers, who produced batteries for ubiquitous products like the Apple iPhones. Corporate pieties about an ethical supply chain were thus met with some incredulity. A number of observers have called for tech corporations and other manufacturers to avoid sourcing conflict metals in Central Africa at all rather than risk enabling the financial exploitation, human rights abuses like kidnappings for unfree labor, environmental devastation and the human toll of violence, poverty and toxic conditions. 

The Mukondo Mountain project, operated by the Central African Mining and Exploration Company (CAMEC) in Katanga Province, may be the richest cobalt reserve in the world. It produced an estimated one third of the total global coval production in 2008. In July 2009, CAMEC announced a long-term agreement to deliver its entire annual production of cobalt concentrate from Mukondo Mountain to Zhejiang Galico Cobalt & Nickel Materials of China.

In February 2018, global asset management firm AllianceBernstein defined the DRC as economically "the Saudi Arabia of the electric vehicle age," due to its cobalt resources, as essential to the lithium-ion batteries that drive electric vehicles.

On March 9, 2018, President Joseph Kabila updated the 2002 mining code, increasing royalty charges and declaring cobalt and coltan "strategic metals".

Canada

In 2017, some exploration companies were planning to survey old silver and cobalt mines in the area of Cobalt, Ontario where significant deposits are believed to lie. The mayor of Cobalt stated that the people of Cobalt welcomed new mining endeavours and pointed out that the local work force is peaceful and English-speaking, and good infrastructure would allow much easier sourcing of spare parts for the equipment or other supplies than were to be found in conflict-zones.

Applications

Cobalt has been used in production of high-performance alloys. It can also be used to make rechargeable batteries, and the advent of electric vehicles and their success with consumers probably has a great deal to do with the DRC's soaring production. Other important factors were the 2002 Mining Code, which encouraged investment by foreign and transnational corporations such as Glencore, and the end of the First and Second Congo Wars.

Alloys

Cobalt-based superalloys have historically consumed most of the cobalt produced. The temperature stability of these alloys makes them suitable for turbine blades for gas turbines and aircraft jet engines, although nickel-based single-crystal alloys surpass them in performance. Cobalt-based alloys are also corrosion- and wear-resistant, making them, like titanium, useful for making orthopedic implants that don't wear down over time. The development of wear-resistant cobalt alloys started in the first decade of the 20th century with the stellite alloys, containing chromium with varying quantities of tungsten and carbon. Alloys with chromium and tungsten carbides are very hard and wear-resistant. Special cobalt-chromium-molybdenum alloys like Vitallium are used for prosthetic parts (hip and knee replacements). Cobalt alloys are also used for dental prosthetics as a useful substitute for nickel, which may be allergenic. Some high-speed steels also contain cobalt for increased heat and wear resistance. The special alloys of aluminium, nickel, cobalt and iron, known as Alnico, and of samarium and cobalt (samarium-cobalt magnet) are used in permanent magnets. It is also alloyed with 95% platinum for jewelry, yielding an alloy suitable for fine casting, which is also slightly magnetic.

Batteries

Lithium cobalt oxide (LiCoO2) is widely used in lithium-ion battery cathodes. The material is composed of cobalt oxide layers with the lithium intercalated. During discharge, the lithium is released as lithium ions. Nickel-cadmium (NiCd) and nickel metal hydride (NiMH) batteries also include cobalt to improve the oxidation of nickel in the battery. Transparency Market Research estimated the global lithium-ion battery market at $30 billion in 2015 and predicted an increase to over US$75 billion by 2024.

Although in 2018 most cobalt in batteries was used in a mobile device, a more recent application for cobalt is rechargeable batteries for electric cars. This industry has increased five-fold in its demand for cobalt, which makes it urgent to find new raw materials in more stable areas of the world. Demand is expected to continue or increase as the prevalence of electric vehicles increases. Exploration in 2016–2017 included the area around Cobalt, Ontario, an area where many silver mines ceased operation decades ago.

Since child and slave labor have been repeatedly reported in cobalt mining, primarily in the artisanal mines of DR Congo, tech companies seeking an ethical supply chain have faced shortages of 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.

Catalysts

Several cobalt compounds are oxidation catalysts. Cobalt acetate is used to convert xylene to terephthalic acid, the precursor of the bulk polymer polyethylene terephthalate. Typical catalysts are the cobalt carboxylates (known as cobalt soaps). They are also used in paints, varnishes, and inks as "drying agents" through the oxidation of drying oils. The same carboxylates are used to improve the adhesion between steel and rubber in steel-belted radial tires. In addition they are used as accelerators in polyester resin systems. 

Cobalt-based catalysts are used in reactions involving carbon monoxide. Cobalt is also a catalyst in the Fischer–Tropsch process for the hydrogenation of carbon monoxide into liquid fuels. Hydroformylation of alkenes often uses cobalt octacarbonyl as a catalyst, although it is often replaced by more efficient iridium- and rhodium-based catalysts, e.g. the Cativa process.

The hydrodesulfurization of petroleum uses a catalyst derived from cobalt and molybdenum. This process helps to clean petroleum of sulfur impurities that interfere with the refining of liquid fuels.

Pigments and coloring

shelf with blue glass vessels
Cobalt blue glass
blue glass bottle with neck
Cobalt-colored glass
Before the 19th century, cobalt was predominantly used as a pigment. It has been used since the Middle Ages to make smalt, a blue-colored glass. Smalt is produced by melting a mixture of roasted mineral smaltite, quartz and potassium carbonate, which yields a dark blue silicate glass, which is finely ground after the production. Smalt was widely used to color glass and as pigment for paintings. In 1780, Sven Rinman discovered cobalt green, and in 1802 Louis Jacques Thénard discovered cobalt blue. Cobalt pigments such as cobalt blue (cobalt aluminate), cerulean blue (cobalt(II) stannate), various hues of cobalt green (a mixture of cobalt(II) oxide and zinc oxide), and cobalt violet (cobalt phosphate) are used as artist's pigments because of their superior chromatic stability. Aureolin (cobalt yellow) is now largely replaced by more lightfast yellow pigments.

Radioisotopes

Cobalt-60 (Co-60 or 60Co) is useful as a gamma-ray source because they can be produced in predictable quantity and high activity by bombarding cobalt with neutrons. It produces gamma rays with energies of 1.17 and 1.33 MeV.

Cobalt is used in external beam radiotherapy, sterilization of medical supplies and medical waste, radiation treatment of foods for sterilization (cold pasteurization), industrial radiography (e.g. weld integrity radiographs), density measurements (e.g. concrete density measurements), and tank fill height switches. The metal has the unfortunate property of producing a fine dust, causing problems with radiation protection. Cobalt from radiotherapy machines has been a serious hazard when not discarded properly, and one of the worst radiation contamination accidents in North America occurred in 1984, when a discarded radiotherapy unit containing cobalt-60 was mistakenly disassembled in a junkyard in Juarez, Mexico.

Cobalt-60 has a radioactive half-life of 5.27 years. Loss of potency requires periodic replacement of the source in radiotherapy and is one reason why cobalt machines have been largely replaced by linear accelerators in modern radiation therapy. Cobalt-57 (Co-57 or 57Co) is a cobalt radioisotope most often used in medical tests, as a radiolabel for vitamin B12 uptake, and for the Schilling test. Cobalt-57 is used as a source in Mössbauer spectroscopy and is one of several possible sources in X-ray fluorescence devices.

Nuclear weapon designs could intentionally incorporate 59Co, some of which would be activated in a nuclear explosion to produce 60Co. The 60Co, dispersed as nuclear fallout, is sometimes called a cobalt bomb.

Other uses

Biological role

chemical diagram of cobalamin molecule
two cobalt-deficient sheep facing away from camera
Cobalt-deficient sheep

Cobalt is essential to the metabolism of all animals. It is a key constituent of cobalamin, also known as vitamin B12, the primary biological reservoir of cobalt as an ultratrace element. Bacteria in the stomachs of ruminant animals convert cobalt salts into vitamin B12, a compound which can only be produced by bacteria or archaea. A minimal presence of cobalt in soils therefore markedly improves the health of grazing animals, and an uptake of 0.20 mg/kg a day is recommended because they have no other source of vitamin B12.
In the early 20th century, during the development of farming on the North Island Volcanic Plateau of New Zealand, cattle suffered from what was termed "bush sickness". It was discovered that the volcanic soils lacked the cobalt salts essential for the cattle food chain.
The "coast disease" of sheep in the Ninety Mile Desert of the Southeast of South Australia in the 1930s was found to originate in nutritional deficiencies of trace elements cobalt and copper. The cobalt deficiency was overcome by the development of "cobalt bullets", dense pellets of cobalt oxide mixed with clay given orally for lodging in the animal's rumen.
Proteins based on cobalamin use corrin to hold the cobalt. Coenzyme B12 features a reactive C-Co bond that participates in the reactions. In humans, B12 has two types of alkyl ligand: methyl and adenosyl. MeB12 promotes methyl (−CH3) group transfers. The adenosyl version of B12 catalyzes rearrangements in which a hydrogen atom is directly transferred between two adjacent atoms with concomitant exchange of the second substituent, X, which may be a carbon atom with substituents, an oxygen atom of an alcohol, or an amine. Methylmalonyl coenzyme A mutase (MUT) converts MMl-CoA to Su-CoA, an important step in the extraction of energy from proteins and fats.
Although far less common than other metalloproteins (e.g. those of zinc and iron), other cobaltoproteins are known besides B12. These proteins include methionine aminopeptidase 2, an enzyme that occurs in humans and other mammals that does not use the corrin ring of B12, but binds cobalt directly. Another non-corrin cobalt enzyme is nitrile hydratase, an enzyme in bacteria that metabolizes nitriles.

Precautions

Cobalt
Hazards
GHS pictograms The health hazard pictogram in the Globally Harmonized System of Classification and Labelling of Chemicals (GHS)
GHS signal word Danger
H317, H334, H413
P261, P280, P342+311
NFPA 704
Flammability code 0: Will not burn. E.g., waterHealth code 2: Intense or continued but not chronic exposure could cause temporary incapacitation or possible residual injury. E.g., chloroformReactivity code 0: Normally stable, even under fire exposure conditions, and is not reactive with water. E.g., liquid nitrogenSpecial hazards (white): no codeNFPA 704 four-colored diamond
0
2
0

Cobalt is an essential element for life in minute amounts. The LD50 value for soluble cobalt salts has been estimated to be between 150 and 500 mg/kg.[114] In the US, the Occupational Safety and Health Administration (OSHA) has designated a permissible exposure limit (PEL) in the workplace as a time-weighted average (TWA) of 0.1 mg/m3. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 0.05 mg/m3, time-weighted average. The IDLH (immediately dangerous to life and health) value is 20 mg/m3.
However, chronic cobalt ingestion has caused serious health problems at doses far less than the lethal dose. In 1966, the addition of cobalt compounds to stabilize beer foam in Canada led to a peculiar form of toxin-induced cardiomyopathy, which came to be known as beer drinker's cardiomyopathy.
It causes respiratory problems when inhaled. It also causes skin problems when touched; after nickel and chromium, cobalt is a major cause of contact dermatitis. These risks are faced by cobalt miners.
Cobalt can be effectively absorbed by charred pigs' bones; however, this process is inhibited by copper and zinc, which have greater affinities to bone char.

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