Copper Explained

Copper is a chemical element; it has symbol Cu and atomic number 29. It is a soft, malleable, and ductile metal with very high thermal and electrical conductivity. A freshly exposed surface of pure copper has a pinkish-orange color. Copper is used as a conductor of heat and electricity, as a building material, and as a constituent of various metal alloys, such as sterling silver used in jewelry, cupronickel used to make marine hardware and coins, and constantan used in strain gauges and thermocouples for temperature measurement.

Copper is one of the few metals that can occur in nature in a directly usable metallic form (native metals). This led to very early human use in several regions, from . Thousands of years later, it was the first metal to be smelted from sulfide ores, ; the first metal to be cast into a shape in a mold, ; and the first metal to be purposely alloyed with another metal, tin, to create bronze, .[1]

Commonly encountered compounds are copper(II) salts, which often impart blue or green colors to such minerals as azurite, malachite, and turquoise, and have been used widely and historically as pigments.

Copper used in buildings, usually for roofing, oxidizes to form a green patina of compounds called verdigris. Copper is sometimes used in decorative art, both in its elemental metal form and in compounds as pigments. Copper compounds are used as bacteriostatic agents, fungicides, and wood preservatives.

Copper is essential to all living organisms as a trace dietary mineral because it is a key constituent of the respiratory enzyme complex cytochrome c oxidase. In molluscs and crustaceans, copper is a constituent of the blood pigment hemocyanin, replaced by the iron-complexed hemoglobin in fish and other vertebrates. In humans, copper is found mainly in the liver, muscle, and bone.[2] The adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight.[3]

Etymology

In the Roman era, copper was mined principally on Cyprus, the origin of the name of the metal, from aes cyprium (metal of Cyprus), later corrupted to (Latin). (Old English) and copper were derived from this, the later spelling first used around 1530.[4]

Characteristics

Physical

Copper, silver, and gold are in group 11 of the periodic table; these three metals have one s-orbital electron on top of a filled d-electron shell and are characterized by high ductility, and electrical and thermal conductivity. The filled d-shells in these elements contribute little to interatomic interactions, which are dominated by the s-electrons through metallic bonds. Unlike metals with incomplete d-shells, metallic bonds in copper are lacking a covalent character and are relatively weak. This observation explains the low hardness and high ductility of single crystals of copper.[5] At the macroscopic scale, introduction of extended defects to the crystal lattice, such as grain boundaries, hinders flow of the material under applied stress, thereby increasing its hardness. For this reason, copper is usually supplied in a fine-grained polycrystalline form, which has greater strength than monocrystalline forms.[6]

The softness of copper partly explains its high electrical conductivity and high thermal conductivity, second highest (second only to silver) among pure metals at room temperature.[7] This is because the resistivity to electron transport in metals at room temperature originates primarily from scattering of electrons on thermal vibrations of the lattice, which are relatively weak in a soft metal. The maximum possible current density of copper in open air is approximately, above which it begins to heat excessively.[8]

Copper is one of a few metallic elements with a natural color other than gray or silver.[9] Pure copper is orange-red and acquires a reddish tarnish when exposed to air. This is due to the low plasma frequency of the metal, which lies in the red part of the visible spectrum, causing it to absorb the higher-frequency green and blue colors.[10]

As with other metals, if copper is put in contact with another metal in the presence of an electrolyte, galvanic corrosion will occur.[11]

Chemical

Copper does not react with water, but it does slowly react with atmospheric oxygen to form a layer of brown-black copper oxide which, unlike the rust that forms on iron in moist air, protects the underlying metal from further corrosion (passivation). A green layer of verdigris (copper carbonate) can often be seen on old copper structures, such as the roofing of many older buildings[12] and the Statue of Liberty.[13] Copper tarnishes when exposed to some sulfur compounds, with which it reacts to form various copper sulfides.[14]

Isotopes

See main article: Isotopes of copper. There are 29 isotopes of copper. and are stable, with comprising approximately 69% of naturally occurring copper; both have a spin of . The other isotopes are radioactive, with the most stable being with a half-life of 61.83 hours. Seven metastable isomers have been characterized; is the longest-lived with a half-life of 3.8 minutes. Isotopes with a mass number above 64 decay by β, whereas those with a mass number below 64 decay by β+. , which has a half-life of 12.7 hours, decays both ways.[15]

and have significant applications. is used in Cu-PTSM as a radioactive tracer for positron emission tomography.[16]

Occurrence

See also: List of copper ores. Copper is produced in massive stars[17] and is present in the Earth's crust in a proportion of about 50 parts per million (ppm).[18] In nature, copper occurs in a variety of minerals, including native copper, copper sulfides such as chalcopyrite, bornite, digenite, covellite, and chalcocite, copper sulfosalts such as tetrahedite-tennantite, and enargite, copper carbonates such as azurite and malachite, and as copper(I) or copper(II) oxides such as cuprite and tenorite, respectively. The largest mass of elemental copper discovered weighed 420 tonnes and was found in 1857 on the Keweenaw Peninsula in Michigan, US. Native copper is a polycrystal, with the largest single crystal ever described measuring .[19] Copper is the 26th most abundant element in Earth's crust, representing 50 ppm compared with 75 ppm for zinc, and 14 ppm for lead.[20]

Typical background concentrations of copper do not exceed in the atmosphere; in soil; in vegetation; 2 μg/L in freshwater and in seawater.[21]

Production

See also: List of countries by copper production.

Most copper is mined or extracted as copper sulfides from large open pit mines in porphyry copper deposits that contain 0.4 to 1.0% copper. Sites include Chuquicamata, in Chile, Bingham Canyon Mine, in Utah, United States, and El Chino Mine, in New Mexico, United States. According to the British Geological Survey, in 2005, Chile was the top producer of copper with at least one-third of the world share followed by the United States, Indonesia and Peru. Copper can also be recovered through the in-situ leach process. Several sites in the state of Arizona are considered prime candidates for this method.[22] The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries to reach developed world levels of usage.[23] An alternative source of copper for collection currently being researched are polymetallic nodules, which are located at the depths of the Pacific Ocean approximately 3000–6500 meters below sea level. These nodules contain other valuable metals such as cobalt and nickel.[24]

Reserves and prices

Copper has been in use for at least 10,000 years, but more than 95% of all copper ever mined and smelted has been extracted since 1900. As with many natural resources, the total amount of copper on Earth is vast, with around 1014 tons in the top kilometer of Earth's crust, which is about 5 million years' worth at the current rate of extraction. However, only a tiny fraction of these reserves is economically viable with present-day prices and technologies. Estimates of copper reserves available for mining vary from 25 to 60 years, depending on core assumptions such as the growth rate.[25] Recycling is a major source of copper in the modern world.[26]

The price of copper is volatile.[27] After a peak in 2022 the price unexpectedly fell.[28]

Methods

See main article: Copper extraction techniques. The great majority of copper ores are sulfides. Common ores are the sulfides chalcopyrite (CuFeS2), bornite (Cu5FeS4) and, to a lesser extent, covellite (CuS) and chalcocite (Cu2S). These ores occur at the level of <1% Cu. Concentration of the ore is required, which begins with comminution followed by froth flotation. The remaining concentrate is the smelted, which can be described with two simplified equations:[29]

2 Cu2S + 3 O2 → 2 Cu2O + 2 SO2Cuprous oxide reacts with cuprous sulfide to convert to blister copper upon heating

2 Cu2O + Cu2S → 6 Cu + 2 SO2This roasting gives matte copper, roughly 50% Cu by weight, which is purified by electrolysis. Depending on the ore, sometimes other metals are obtained during the electrolysis including platinum and gold.

Aside from sulfides, another family of ores are oxides. Approximately 15% of the world's copper supply derives from these oxides. The beneficiation process for oxides involves extraction with sulfuric acid solutions followed by electrolysis. In parallel with the above method for "concentrated" sulfide and oxide ores, copper is recovered from mine tailings and heaps. A variety of methods are used including leaching with sulfuric acid, ammonia, ferric chloride. Biological methods are also used.[29] [30]

A significant source of copper is from recycling. Recycling is facilitated because copper is usually deployed in its metallic state. In 2001, a typical automobile contained 20–30 kg of copper. Recycling usually begins with some melting process using a blast furnace.[29]

A potential source of copper is polymetallic nodules, which have an estimated concentration 1.3%.[31] [32]

Recycling

Like aluminium, copper is recyclable without any loss of quality, both from raw state and from manufactured products.[33] In volume, copper is the third most recycled metal after iron and aluminium.[34] An estimated 80% of all copper ever mined is still in use today.[35] According to the International Resource Panel's Metal Stocks in Society report, the global per capita stock of copper in use in society is 35–55 kg. Much of this is in more-developed countries (140–300 kg per capita) rather than less-developed countries (30–40 kg per capita).

The process of recycling copper is roughly the same as is used to extract copper but requires fewer steps. High-purity scrap copper is melted in a furnace and then reduced and cast into billets and ingots; lower-purity scrap is refined by electroplating in a bath of sulfuric acid.[36]

Environmental impacts

The environmental cost of copper mining was estimated at 3.7 kg CO2eq per kg of copper in 2019.[37] Codelco, a major producer in Chile, reported that in 2020 the company emitted 2.8t CO2eq per ton (2.8 kg CO2eq per kg) of fine copper.[38] Greenhouse gas emissions primarily arise from electricity consumed by the company, especially when sourced from fossil fuels, and from engines required for copper extraction and refinement. Companies that mine land often mismanage waste, rendering the area sterile for life. Additionally, nearby rivers and forests are also negatively impacted. The Philippines is an example of a region where land is overexploited by mining companies.[39]

Copper mining waste in Valea Şesei, Romania, has significantly altered nearby water properties. The water in the affected areas is highly acidic, with a pH range of 2.1–4.9, and shows elevated electrical conductivity levels between 280 and 1561 mS/cm.[40] These changes in water chemistry make the environment inhospitable for fish, essentially rendering the water uninhabitable for aquatic life.

Alloys

See also: List of copper alloys. Numerous copper alloys have been formulated, many with important uses. Brass is an alloy of copper and zinc. Bronze usually refers to copper-tin alloys, but can refer to any alloy of copper such as aluminium bronze. Copper is one of the most important constituents of silver and karat gold solders used in the jewelry industry, modifying the color, hardness and melting point of the resulting alloys.[41] Some lead-free solders consist of tin alloyed with a small proportion of copper and other metals.[42]

The alloy of copper and nickel, called cupronickel, is used in low-denomination coins, often for the outer cladding. The US five-cent coin (currently called a nickel) consists of 75% copper and 25% nickel in homogeneous composition. Prior to the introduction of cupronickel, which was widely adopted by countries in the latter half of the 20th century,[43] alloys of copper and silver were also used, with the United States using an alloy of 90% silver and 10% copper until 1965, when circulating silver was removed from all coins with the exception of the half dollar—these were debased to an alloy of 40% silver and 60% copper between 1965 and 1970.[44] The alloy of 90% copper and 10% nickel, remarkable for its resistance to corrosion, is used for various objects exposed to seawater, though it is vulnerable to the sulfides sometimes found in polluted harbors and estuaries.[45] Alloys of copper with aluminium (about 7%) have a golden color and are used in decorations. Shakudō is a Japanese decorative alloy of copper containing a low percentage of gold, typically 4–10%, that can be patinated to a dark blue or black color.[46]

Compounds

See main article: Copper compounds.

Copper forms a rich variety of compounds, usually with oxidation states +1 and +2, which are often called cuprous and cupric, respectively. Copper compounds promote or catalyse numerous chemical and biological processes.[47]

Binary compounds

As with other elements, the simplest compounds of copper are binary compounds, i.e. those containing only two elements, the principal examples being oxides, sulfides, and halides. Both cuprous and cupric oxides are known. Among the numerous copper sulfides,[48] important examples include copper(I) sulfide and copper monosulfide .

Cuprous halides with fluorine, chlorine, bromine, and iodine are known, as are cupric halides with fluorine, chlorine, and bromine. Attempts to prepare copper(II) iodide yield only copper(I) iodide and iodine.[49]

2 Cu2+ + 4 I → 2 CuI + I2

Coordination chemistry

Copper forms coordination complexes with ligands. In aqueous solution, copper(II) exists as . This complex exhibits the fastest water exchange rate (speed of water ligands attaching and detaching) for any transition metal aquo complex. Adding aqueous sodium hydroxide causes the precipitation of light blue solid copper(II) hydroxide. A simplified equation is:

Cu2+ + 2 OH → Cu(OH)2Aqueous ammonia results in the same precipitate. Upon adding excess ammonia, the precipitate dissolves, forming tetraamminecopper(II):

+ 4 NH3 → + 2 H2O + 2 OHMany other oxyanions form complexes; these include copper(II) acetate, copper(II) nitrate, and copper(II) carbonate. Copper(II) sulfate forms a blue crystalline pentahydrate, the most familiar copper compound in the laboratory. It is used in a fungicide called the Bordeaux mixture.[50]

Polyols, compounds containing more than one alcohol functional group, generally interact with cupric salts. For example, copper salts are used to test for reducing sugars. Specifically, using Benedict's reagent and Fehling's solution the presence of the sugar is signaled by a color change from blue Cu(II) to reddish copper(I) oxide.[51] Schweizer's reagent and related complexes with ethylenediamine and other amines dissolve cellulose.[52] Amino acids such as cystine form very stable chelate complexes with copper(II)[53] [54] [55] including in the form of metal-organic biohybrids (MOBs). Many wet-chemical tests for copper ions exist, one involving potassium ferricyanide, which gives a red-brown precipitate with copper(II) salts.[56]

Organocopper chemistry

See main article: Organocopper compound. Compounds that contain a carbon-copper bond are known as organocopper compounds. They are very reactive towards oxygen to form copper(I) oxide and have many uses in chemistry. They are synthesized by treating copper(I) compounds with Grignard reagents, terminal alkynes or organolithium reagents;[57] in particular, the last reaction described produces a Gilman reagent. These can undergo substitution with alkyl halides to form coupling products; as such, they are important in the field of organic synthesis. Copper(I) acetylide is highly shock-sensitive but is an intermediate in reactions such as the Cadiot–Chodkiewicz coupling[58] and the Sonogashira coupling.[59] Conjugate addition to enones[60] and carbocupration of alkynes[61] can also be achieved with organocopper compounds. Copper(I) forms a variety of weak complexes with alkenes and carbon monoxide, especially in the presence of amine ligands.[62]

Copper(III) and copper(IV)

Copper(III) is most often found in oxides. A simple example is potassium cuprate, KCuO2, a blue-black solid.[63] The most extensively studied copper(III) compounds are the cuprate superconductors. Yttrium barium copper oxide (YBa2Cu3O7) consists of both Cu(II) and Cu(III) centres. Like oxide, fluoride is a highly basic anion[64] and is known to stabilize metal ions in high oxidation states. Both copper(III) and even copper(IV) fluorides are known, K3CuF6 and Cs2CuF6, respectively.

Some copper proteins form oxo complexes, which, in extensively studied synthetic analog systems, feature copper(III).[65] [66] With tetrapeptides, purple-colored copper(III) complexes are stabilized by the deprotonated amide ligands.[67]

Complexes of copper(III) are also found as intermediates in reactions of organocopper compounds, for example in the Kharasch–Sosnovsky reaction.[68] [69]

History

A timeline of copper illustrates how this metal has advanced human civilization for the past 11,000 years.[70]

Prehistoric

Copper Age

See main article: Copper Age. Copper occurs naturally as native metallic copper and was known to some of the oldest civilizations on record. The history of copper use dates to 9000 BC in the Middle East;[71] a copper pendant was found in northern Iraq that dates to 8700 BC.[72] Evidence suggests that gold and meteoric iron (but not smelted iron) were the only metals used by humans before copper.[73] The history of copper metallurgy is thought to follow this sequence: first, cold working of native copper, then annealing, smelting, and, finally, lost-wax casting. In southeastern Anatolia, all four of these techniques appear more or less simultaneously at the beginning of the Neolithic .[74]

Copper smelting was independently invented in different places. The earliest evidence of lost-wax casting copper comes from an amulet found in Mehrgarh, Pakistan, and is dated to 4000 BC.[75] Investment casting was invented in 4500–4000 BC in Southeast Asia Smelting was probably discovered in China before 2800 BC, in Central America around 600 AD, and in West Africa about the 9th or 10th century AD.[76] Carbon dating has established mining at Alderley Edge in Cheshire, UK, at 2280 to 1890 BC.[77]

Ötzi the Iceman, a male dated from 3300 to 3200 BC, was found with an axe with a copper head 99.7% pure; high levels of arsenic in his hair suggest an involvement in copper smelting.[78] Experience with copper has assisted the development of other metals; in particular, copper smelting likely led to the discovery of iron smelting. Production in the Old Copper Complex in Michigan and Wisconsin is dated between 6500 and 3000 BC.[79] [80] [81] A copper spearpoint found in Wisconsin has been dated to 6500 BC. Copper usage by the indigenous peoples of the Old Copper Complex from the Great Lakes region of North America has been radiometrically dated to as far back as 7500 BC.[82] [83] Indigenous peoples of North America around the Great Lakes may have also been mining copper during this time, making it one of the oldest known examples of copper extraction in the world.[84] There is evidence from prehistoric lead pollution from lakes in Michigan that people in the region began mining copper . Evidence suggests that utilitarian copper objects fell increasingly out of use in the Old Copper Complex of North America during the Bronze Age and a shift towards an increased production of ornamental copper objects occurred.[85]

Bronze Age

See main article: Bronze Age. Natural bronze, a type of copper made from ores rich in silicon, arsenic, and (rarely) tin, came into general use in the Balkans around 5500 BC.[86] Alloying copper with tin to make bronze was first practiced about 4000 years after the discovery of copper smelting, and about 2000 years after "natural bronze" had come into general use.[87] Bronze artifacts from the Vinča culture date to 4500 BC.[88] Sumerian and Egyptian artifacts of copper and bronze alloys date to 3000 BC.[89] Egyptian Blue, or cuprorivaite (calcium copper silicate) is a synthetic pigment that contains copper and started being used in ancient Egypt around 3250 BC.[90] The manufacturing process of Egyptian blue was known to the Romans, but by the fourth century AD the pigment fell out of use and the secret to its manufacturing process became lost. The Romans said the blue pigment was made from copper, silica, lime and natron and was known to them as caeruleum.

The Bronze Age began in Southeastern Europe around 3700–3300 BC, in Northwestern Europe about 2500 BC. It ended with the beginning of the Iron Age, 2000–1000 BC in the Near East, and 600 BC in Northern Europe. The transition between the Neolithic period and the Bronze Age was formerly termed the Chalcolithic period (copper-stone), when copper tools were used with stone tools. The term has gradually fallen out of favor because in some parts of the world, the Chalcolithic and Neolithic are coterminous at both ends. Brass, an alloy of copper and zinc, is of much more recent origin. It was known to the Greeks, but became a significant supplement to bronze during the Roman Empire.

Ancient and post-classical

In Greece, copper was known by the name (χαλκός). It was an important resource for the Romans, Greeks and other ancient peoples. In Roman times, it was known as aes Cyprium, being the generic Latin term for copper alloys and Cyprium from Cyprus, where much copper was mined. The phrase was simplified to cuprum, hence the English copper. Aphrodite (Venus in Rome) represented copper in mythology and alchemy because of its lustrous beauty and its ancient use in producing mirrors; Cyprus, the source of copper, was sacred to the goddess. The seven heavenly bodies known to the ancients were associated with the seven metals known in antiquity, and Venus was assigned to copper, both because of the connection to the goddess and because Venus was the brightest heavenly body after the Sun and Moon and so corresponded to the most lustrous and desirable metal after gold and silver.[91]

Copper was first mined in ancient Britain as early as 2100 BC. Mining at the largest of these mines, the Great Orme, continued into the late Bronze Age. Mining seems to have been largely restricted to supergene ores, which were easier to smelt. The rich copper deposits of Cornwall seem to have been largely untouched, in spite of extensive tin mining in the region, for reasons likely social and political rather than technological.[92]

In North America, native copper is known to have been extracted from sites on Isle Royale with primitive stone tools between 800 and 1600 AD.[93] Copper annealing was being performed in the North American city of Cahokia around 1000–1300 AD.[94] There are several exquisite copper plates, known as the Mississippian copper plates that have been found in North America in the area around Cahokia dating from this time period (1000–1300 AD). The copper plates were thought to have been manufactured at Cahokia before ending up elsewhere in the Midwest and southeastern United States like the Wulfing cache and Etowah plates.In South America a copper mask dated to 1000 BC found in the Argentinian Andes is the oldest known copper artifact discovered in the Andes.[95] Peru has been considered the origin for early copper metallurgy in pre-Columbian America, but the copper mask from Argentina suggests that the Cajón del Maipo of the southern Andes was another important center for early copper workings in South America. Copper metallurgy was flourishing in South America, particularly in Peru around 1000 AD. Copper burial ornamentals from the 15th century have been uncovered, but the metal's commercial production did not start until the early 20th century.

The cultural role of copper has been important, particularly in currency. Romans in the 6th through 3rd centuries BC used copper lumps as money. At first, the copper itself was valued, but gradually the shape and look of the copper became more important. Julius Caesar had his own coins made from brass, while Octavianus Augustus Caesar's coins were made from Cu-Pb-Sn alloys. With an estimated annual output of around 15,000 t, Roman copper mining and smelting activities reached a scale unsurpassed until the time of the Industrial Revolution; the provinces most intensely mined were those of Hispania, Cyprus and in Central Europe.[96] [97]

The gates of the Temple of Jerusalem used Corinthian bronze treated with depletion gilding. The process was most prevalent in Alexandria, where alchemy is thought to have begun.[98] In ancient India, copper was used in the holistic medical science Ayurveda for surgical instruments and other medical equipment. Ancient Egyptians (~2400 BC) used copper for sterilizing wounds and drinking water, and later to treat headaches, burns, and itching.

Modern

The Great Copper Mountain was a mine in Falun, Sweden, that operated from the 10th century to 1992. It satisfied two-thirds of Europe's copper consumption in the 17th century and helped fund many of Sweden's wars during that time.[99] It was referred to as the nation's treasury; Sweden had a copper backed currency.[100]

Copper is used in roofing, currency, and for photographic technology known as the daguerreotype. Copper was used in Renaissance sculpture, and was used to construct the Statue of Liberty; copper continues to be used in construction of various types. Copper plating and copper sheathing were widely used to protect the under-water hulls of ships, a technique pioneered by the British Admiralty in the 18th century.[101] The Norddeutsche Affinerie in Hamburg was the first modern electroplating plant, starting its production in 1876.[102] The German scientist Gottfried Osann invented powder metallurgy in 1830 while determining the metal's atomic mass; around then it was discovered that the amount and type of alloying element (e.g., tin) to copper would affect bell tones.

During the rise in demand for copper for the Age of Electricity, from the 1880s until the Great Depression of the 1930s, the United States produced one third to half the world's newly mined copper.[103] Major districts included the Keweenaw district of northern Michigan, primarily native copper deposits, which was eclipsed by the vast sulphide deposits of Butte, Montana, in the late 1880s, which itself was eclipsed by porphyry deposits of the Southwest United States, especially at Bingham Canyon, Utah, and Morenci, Arizona. Introduction of open pit steam shovel mining and innovations in smelting, refining, flotation concentration and other processing steps led to mass production. Early in the twentieth century, Arizona ranked first, followed by Montana, then Utah and Michigan.[104]

Flash smelting was developed by Outokumpu in Finland and first applied at Harjavalta in 1949; the energy-efficient process accounts for 50% of the world's primary copper production.[105]

The Intergovernmental Council of Copper Exporting Countries, formed in 1967 by Chile, Peru, Zaire and Zambia, operated in the copper market as OPEC does in oil, though it never achieved the same influence, particularly because the second-largest producer, the United States, was never a member; it was dissolved in 1988.[106]

Applications

See also: Copper in renewable energy. The major applications of copper are electrical wire (60%), roofing and plumbing (20%), and industrial machinery (15%). Copper is used mostly as a pure metal, but when greater hardness is required, it is put into such alloys as brass and bronze (5% of total use). For more than two centuries, copper paint has been used on boat hulls to control the growth of plants and shellfish.[107] A small part of the copper supply is used for nutritional supplements and fungicides in agriculture.[108] Machining of copper is possible, although alloys are preferred for good machinability in creating intricate parts.

Wire and cable

See main article: Copper wire and cable.

Despite competition from other materials, copper remains the preferred electrical conductor in nearly all categories of electrical wiring except overhead electric power transmission where aluminium is often preferred.[109] [110] Copper wire is used in power generation, power transmission, power distribution, telecommunications, electronics circuitry, and countless types of electrical equipment.[111] Electrical wiring is the most important market for the copper industry.[112] This includes structural power wiring, power distribution cable, appliance wire, communications cable, automotive wire and cable, and magnet wire. Roughly half of all copper mined is used for electrical wire and cable conductors.[113] Many electrical devices rely on copper wiring because of its multitude of inherent beneficial properties, such as its high electrical conductivity, tensile strength, ductility, creep (deformation) resistance, corrosion resistance, low thermal expansion, high thermal conductivity, ease of soldering, malleability, and ease of installation.

For a short period from the late 1960s to the late 1970s, copper wiring was replaced by aluminium wiring in many housing construction projects in America. The new wiring was implicated in a number of house fires and the industry returned to copper.[114]

Electronics and related devices

Integrated circuits and printed circuit boards increasingly feature copper in place of aluminium because of its superior electrical conductivity; heat sinks and heat exchangers use copper because of its superior heat dissipation properties. Electromagnets, vacuum tubes, cathode ray tubes, and magnetrons in microwave ovens use copper, as do waveguides for microwave radiation.[115]

Electric motors

Copper's superior conductivity enhances the efficiency of electrical motors.[116] This is important because motors and motor-driven systems account for 43–46% of all global electricity consumption and 69% of all electricity used by industry.[117] Increasing the mass and cross section of copper in a coil increases the efficiency of the motor. Copper motor rotors, a new technology designed for motor applications where energy savings are prime design objectives,[118] [119] are enabling general-purpose induction motors to meet and exceed National Electrical Manufacturers Association (NEMA) premium efficiency standards.[120]

Architecture

See main article: Copper in architecture. Copper has been used since ancient times as a durable, corrosion resistant, and weatherproof architectural material.[121] [122] [123] [124] Roofs, flashings, rain gutters, downspouts, domes, spires, vaults, and doors have been made from copper for hundreds or thousands of years. Copper's architectural use has been expanded in modern times to include interior and exterior wall cladding, building expansion joints, radio frequency shielding, and antimicrobial and decorative indoor products such as attractive handrails, bathroom fixtures, and counter tops. Some of copper's other important benefits as an architectural material include low thermal movement, light weight, lightning protection, and recyclability.

The metal's distinctive natural green patina has long been coveted by architects and designers. The final patina is a particularly durable layer that is highly resistant to atmospheric corrosion, thereby protecting the underlying metal against further weathering.[125] [126] [127] It can be a mixture of carbonate and sulfate compounds in various amounts, depending upon environmental conditions such as sulfur-containing acid rain.[128] [129] [130] [131] Architectural copper and its alloys can also be 'finished' to take on a particular look, feel, or color. Finishes include mechanical surface treatments, chemical coloring, and coatings.[132]

Copper has excellent brazing and soldering properties and can be welded; the best results are obtained with gas metal arc welding.[133]

Antibiofouling

See main article: Copper alloys in aquaculture and Copper sheathing. Copper is biostatic, meaning bacteria and many other forms of life will not grow on it. For this reason it has long been used to line parts of ships to protect against barnacles and mussels. It was originally used pure, but has since been superseded by Muntz metal and copper-based paint. Similarly, as discussed in copper alloys in aquaculture, copper alloys have become important netting materials in the aquaculture industry because they are antimicrobial and prevent biofouling, even in extreme conditions[134] and have strong structural and corrosion-resistant[135] properties in marine environments.

Antimicrobial

See main article: Antimicrobial properties of copper and Antimicrobial copper-alloy touch surfaces.

Copper-alloy touch surfaces have natural properties that destroy a wide range of microorganisms (e.g., E. coli O157:H7, methicillin-resistant Staphylococcus aureus (MRSA), Staphylococcus, Clostridium difficile, influenza A virus, adenovirus, SARS-CoV-2, and fungi).[136] [137] Indians have been using copper vessels since ancient times for storing water, even before modern science realized its antimicrobial properties.[138] Some copper alloys were proven to kill more than 99.9% of disease-causing bacteria within just two hours when cleaned regularly.[139] The United States Environmental Protection Agency (EPA) has approved the registrations of these copper alloys as "antimicrobial materials with public health benefits"; that approval allows manufacturers to make legal claims to the public health benefits of products made of registered alloys. In addition, the EPA has approved a long list of antimicrobial copper products made from these alloys, such as bedrails, handrails, over-bed tables, sinks, faucets, door knobs, toilet hardware, computer keyboards, health club equipment, and shopping cart handles. Copper doorknobs are used by hospitals to reduce the transfer of disease, and Legionnaires' disease is suppressed by copper tubing in plumbing systems.[140] Antimicrobial copper alloy products are now being installed in healthcare facilities in the U.K., Ireland, Japan, Korea, France, Denmark, and Brazil, as well as being called for in the US,[141] and in the subway transit system in Santiago, Chile, where copper–zinc alloy handrails were installed in some 30 stations between 2011 and 2014.[142] [143] [144] Textile fibers can be blended with copper to create antimicrobial protective fabrics.[145]

Copper demand

Total world production in 2023 is expected to be almost 23 million metric tons.[146] Copper demand is increasing due to the ongoing energy transition to electricity.[147] China accounts for over half the demand.[148]

For some purposes, other metals can substitute, aluminium wire was substituted in many applications, but improper design resulted in fire hazards.[149] The safety issues have since been solved by use of larger sizes of aluminium wire (#8AWG and up), and properly designed aluminium wiring is still being installed in place of copper. For example, the Airbus A380 uses aluminum wire in place of copper wire for electrical power transmission.[150]

Speculative investing

Copper may be used as a speculative investment due to the predicted increase in use from worldwide infrastructure growth, and the important role it has in producing wind turbines, solar panels, and other renewable energy sources.[151] [152] Another reason predicted demand increases is the fact that electric cars contain an average of 3.6 times as much copper as conventional cars, although the effect of electric cars on copper demand is debated.[153] [154] Some people invest in copper through copper mining stocks, ETFs, and futures. Others store physical copper in the form of copper bars or rounds although these tend to carry a higher premium in comparison to precious metals.[155] Those who want to avoid the premiums of copper bullion alternatively store old copper wire, copper tubing or American pennies made before 1982.[156]

Folk medicine

Copper is commonly used in jewelry, and according to some folklore, copper bracelets relieve arthritis symptoms.[157] In one trial for osteoarthritis and one trial for rheumatoid arthritis, no differences were found between copper bracelet and control (non-copper) bracelet.[158] [159] No evidence shows that copper can be absorbed through the skin. If it were, it might lead to copper poisoning.[160]

Degradation

Chromobacterium violaceum and Pseudomonas fluorescens can both mobilize solid copper as a cyanide compound.[161] The ericoid mycorrhizal fungi associated with Calluna, Erica and Vaccinium can grow in metalliferous soils containing copper. The ectomycorrhizal fungus Suillus luteus protects young pine trees from copper toxicity. A sample of the fungus Aspergillus niger was found growing from gold mining solution and was found to contain cyano complexes of such metals as gold, silver, copper, iron, and zinc. The fungus also plays a role in the solubilization of heavy metal sulfides.[162]

Biological role

See main article: Copper in biology.

Biochemistry

Copper proteins have diverse roles in biological electron transport and oxygen transportation, processes that exploit the easy interconversion of Cu(I) and Cu(II).[163] Copper is essential in the aerobic respiration of all eukaryotes. In mitochondria, it is found in cytochrome c oxidase, which is the last protein in oxidative phosphorylation. Cytochrome c oxidase is the protein that binds the O2 between a copper and an iron; the protein transfers 8 electrons to the O2 molecule to reduce it to two molecules of water. Copper is also found in many superoxide dismutases, proteins that catalyze the decomposition of superoxides by converting it (by disproportionation) to oxygen and hydrogen peroxide:

The protein hemocyanin is the oxygen carrier in most mollusks and some arthropods such as the horseshoe crab (Limulus polyphemus).[164] Because hemocyanin is blue, these organisms have blue blood rather than the red blood of iron-based hemoglobin. Structurally related to hemocyanin are the laccases and tyrosinases. Instead of reversibly binding oxygen, these proteins hydroxylate substrates, illustrated by their role in the formation of lacquers.[165] The biological role for copper commenced with the appearance of oxygen in Earth's atmosphere.[166] Several copper proteins, such as the "blue copper proteins", do not interact directly with substrates; hence they are not enzymes. These proteins relay electrons by the process called electron transfer.

A unique tetranuclear copper center has been found in nitrous-oxide reductase.[167]

Chemical compounds which were developed for treatment of Wilson's disease have been investigated for use in cancer therapy.[168]

Nutrition

Copper is an essential trace element in plants and animals, but not all microorganisms. The human body contains copper at a level of about 1.4 to 2.1 mg per kg of body mass.[169]

Absorption

Copper is absorbed in the gut, then transported to the liver bound to albumin.[170] After processing in the liver, copper is distributed to other tissues in a second phase, which involves the protein ceruloplasmin, carrying the majority of copper in blood. Ceruloplasmin also carries the copper that is excreted in milk, and is particularly well-absorbed as a copper source.[171] Copper in the body normally undergoes enterohepatic circulation (about 5 mg a day, vs. about 1 mg per day absorbed in the diet and excreted from the body), and the body is able to excrete some excess copper, if needed, via bile, which carries some copper out of the liver that is not then reabsorbed by the intestine.[172] [173]

Dietary recommendations

The U.S. Institute of Medicine (IOM) updated the estimated average requirements (EARs) and recommended dietary allowances (RDAs) for copper in 2001. If there is not sufficient information to establish EARs and RDAs, an estimate designated Adequate Intake (AI) is used instead. The AIs for copper are: 200 μg of copper for 0–6-month-old males and females, and 220 μg of copper for 7–12-month-old males and females. For both sexes, the RDAs for copper are: 340 μg of copper for 1–3 years old, 440 μg of copper for 4–8 years old, 700 μg of copper for 9–13 years old, 890 μg of copper for 14–18 years old and 900 μg of copper for ages 19 years and older. For pregnancy, 1,000 μg. For lactation, 1,300 μg.[174] As for safety, the IOM also sets tolerable upper intake levels (ULs) for vitamins and minerals when evidence is sufficient. In the case of copper, the UL is set at 10 mg/day. Collectively the EARs, RDAs, AIs and ULs are referred to as Dietary Reference Intakes.[175]

The European Food Safety Authority (EFSA) refers to the collective set of information as Dietary Reference Values, with Population Reference Intake (PRI) instead of RDA, and Average Requirement instead of EAR. AI and UL are defined the same as in the United States. For women and men ages 18 and older, the AIs are set at 1.3 and 1.6 mg/day, respectively. AIs for pregnancy and lactation is 1.5 mg/day. For children ages 1–17 years, the AIs increase with age from 0.7 to 1.3 mg/day. These AIs are higher than the U.S. RDAs.[176] The European Food Safety Authority reviewed the same safety question and set its UL at 5 mg/day, which is half the U.S. value.

For U.S. food and dietary supplement labeling purposes, the amount in a serving is expressed as a percent of Daily Value (%DV). For copper labeling purposes, 100% of the Daily Value was 2.0 mg, but, it was revised to 0.9 mg to bring it into agreement with the RDA.[177] [178] A table of the old and new adult daily values is provided at Reference Daily Intake.

Deficiency

Because of its role in facilitating iron uptake, copper deficiency can produce anemia-like symptoms, neutropenia, bone abnormalities, hypopigmentation, impaired growth, increased incidence of infections, osteoporosis, hyperthyroidism, and abnormalities in glucose and cholesterol metabolism. Conversely, Wilson's disease causes an accumulation of copper in body tissues.

Severe deficiency can be found by testing for low plasma or serum copper levels, low ceruloplasmin, and low red blood cell superoxide dismutase levels; these are not sensitive to marginal copper status. The "cytochrome c oxidase activity of leucocytes and platelets" has been stated as another factor in deficiency, but the results have not been confirmed by replication.[179]

Toxicity

See main article: Copper toxicity.

Gram quantities of various copper salts have been taken in suicide attempts and produced acute copper toxicity in humans, possibly due to redox cycling and the generation of reactive oxygen species that damage DNA.[180] [181] Corresponding amounts of copper salts (30 mg/kg) are toxic in animals.[182] A minimum dietary value for healthy growth in rabbits has been reported to be at least 3 ppm in the diet.[183] However, higher concentrations of copper (100 ppm, 200 ppm, or 500 ppm) in the diet of rabbits may favorably influence feed conversion efficiency, growth rates, and carcass dressing percentages.[184]

Chronic copper toxicity does not normally occur in humans because of transport systems that regulate absorption and excretion. Autosomal recessive mutations in copper transport proteins can disable these systems, leading to Wilson's disease with copper accumulation and cirrhosis of the liver in persons who have inherited two defective genes.

Elevated copper levels have also been linked to worsening symptoms of Alzheimer's disease.[185] [186]

Human exposure

In the US, the Occupational Safety and Health Administration (OSHA) has designated a permissible exposure limit (PEL) for copper dust and fumes in the workplace as a time-weighted average (TWA) of 1 mg/m3. The National Institute for Occupational Safety and Health (NIOSH) has set a recommended exposure limit (REL) of 1 mg/m3, time-weighted average. The IDLH (immediately dangerous to life and health) value is 100 mg/m3.

Copper is a constituent of tobacco smoke.[187] [188] The tobacco plant readily absorbs and accumulates heavy metals, such as copper from the surrounding soil into its leaves. These are readily absorbed into the user's body following smoke inhalation.[189] The health implications are not clear.[190]

See also

Further reading

External links

Notes and References

  1. 612. 978-0-85229-553-3. 25228234.
  2. Web site: Johnson, MD PhD . Larry E. . Copper . Merck Manual Home Health Handbook . Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc. . 2008 . 7 April 2013 . 7 March 2016 . https://web.archive.org/web/20160307024751/http://www.merckmanuals.com/home/disorders_of_nutrition/minerals/copper.html . dead .
  3. Web site: Copper in human health.
  4. Web site: Copper. Merriam-Webster Dictionary. 2018. 22 August 2018.
  5. Book: George L. . Trigg. Edmund H. . Immergut. Encyclopedia of Applied Physics. 2 May 2011. 1992. VCH . 978-3-527-28126-8. 267–272. 4: Combustion to Diamagnetism.
  6. Book: Smith . William F.. Hashemi . Javad. amp . Foundations of Materials Science and Engineering. 223. McGraw-Hill Professional. 2003. 978-0-07-292194-6.
  7. Book: Hammond, C. R.. The Elements, in Handbook of Chemistry and Physics. 81st. CRC Press. 978-0-8493-0485-9. 2004.
  8. Book: Resistance Welding Manufacturing Alliance . Resistance Welding Manual. 2003. Resistance Welding Manufacturing Alliance. 978-0-9624382-0-2. 4th. 18–12.
  9. Book: Chambers. William. Chambers. Robert. Chambers's Information for the People. W. & R. Chambers. 1884. L. 312. 5th. 978-0-665-46912-1.
  10. Web site: Ramachandran . Harishankar . Why is Copper Red? . . 27 December 2022 . 14 March 2007.
  11. Web site: Galvanic Corrosion. Corrosion Doctors. 29 April 2011.
  12. Book: Cultural Heritage Conservation and Environmental Impact Assessment by Non-Destructive Testing and Micro-Analysis. Grieken. Rene van. Janssens. Koen. 2005. CRC Press. 978-0-203-97078-2. 197. en.
  13. Web site: Copper.org: Education: Statue of Liberty: Reclothing the First Lady of Metals – Repair Concerns. Copper.org. 11 April 2011.
  14. Rickett. B. I.. Payer. J. H.. Composition of Copper Tarnish Products Formed in Moist Air with Trace Levels of Pollutant Gas: Hydrogen Sulfide and Sulfur Dioxide/Hydrogen Sulfide. Journal of the Electrochemical Society. 1995. 142. 11. 3723–3728. 10.1149/1.2048404. 1995JElS..142.3723R.
  15. Web site: Interactive Chart of Nuclides . National Nuclear Data Center . 8 April 2011 . 25 August 2013 . https://web.archive.org/web/20130825141152/http://www.nndc.bnl.gov/chart/reCenter.jsp?z=29&n=35 . dead .
  16. Okazawad . Hidehiko . Yonekura . Yoshiharu . Fujibayashi . Yasuhisa . Nishizawa . Sadahiko . Magata . Yasuhiro . Ishizu . Koichi . Tanaka . Fumiko . Tsuchida . Tatsuro . Tamaki . Nagara . Konishi . Junji . 1994 . Clinical Application and Quantitative Evaluation of Generator-Produced Copper-62-PTSM as a Brain Perfusion Tracer for PET . Journal of Nuclear Medicine . 35 . 12 . 1910–1915 . 7989968 .
  17. Romano. Donatella. Matteucci. Fransesca. Contrasting copper evolution in ω Centauri and the Milky Way. Monthly Notices of the Royal Astronomical Society: Letters. 2007. 378. 1. L59–L63. 10.1111/j.1745-3933.2007.00320.x. free . 2007MNRAS.378L..59R. astro-ph/0703760. 14595800.
  18. Book: Emsley, John. Nature's building blocks: an A–Z guide to the elements. registration. 2 May 2011. 2003. Oxford University Press. 978-0-19-850340-8. 121–125.
  19. The largest crystals. American Mineralogist. 66. 885. 1981. Rickwood . P. C..
  20. Book: Emsley, John. Nature's building blocks: an A–Z guide to the elements. registration. 2 May 2011. 2003. Oxford University Press. 978-0-19-850340-8. 124, 231, 449, 503.
  21. Book: Rieuwerts, John. The Elements of Environmental Pollution. Earthscan Routledge. 2015. 978-0-415-85919-6. London and New York. 207. 886492996.
  22. Web site: Randazzo . Ryan . A new method to harvest copper . Azcentral.com . 19 June 2011 . 25 April 2014 . 21 February 2023 . https://web.archive.org/web/20230221101426/https://help.azcentral.com/ . dead .
  23. Metal stocks and sustainability. Proceedings of the National Academy of Sciences . 2006. 103. 5. 1209–1214. R.B.. Gordon. M.. Bertram. T.E.. Graedel. 10.1073/pnas.0509498103. 1360560. 16432205. 2006PNAS..103.1209G. free .
  24. Book: Beaudoin . Yannick C. . Baker . Elaine . Deep Sea Minerals: Manganese Nodules, a physical, biological, environmental and technical review . December 2013 . Secretariat of the Pacific Community . 978-82-7701-119-6 . 7–18 . 8 February 2021.
  25. Book: Brown, Lester. Plan B 2.0: Rescuing a Planet Under Stress and a Civilization in Trouble. New York: W.W. Norton. 2006. 109. 978-0-393-32831-8. registration.
  26. News: Leonard . Andrew . Peak copper? . 8 March 2022 . Salon . 3 March 2006 . en.
  27. Schmitz. Christopher. The Rise of Big Business in the World, Copper Industry 1870–1930. Economic History Review. 1986. 39. 2. 3. 392–410. 2596347. 10.1111/j.1468-0289.1986.tb00411.x.
  28. News: Copper is unexpectedly getting cheaper . The Economist . 2023-12-19 . 0013-0613.
  29. Book: 10.1002/14356007.a07_471 . Copper . Ullmann's Encyclopedia of Industrial Chemistry . 2001 . Lossin . Adalbert . 9783527303854 .
  30. Watling . H.R. . The bioleaching of sulphide minerals with emphasis on copper sulphides – A review . Hydrometallurgy . 2006 . 84 . 1 . 81–108 . 10.1016/j.hydromet.2006.05.001 . 2006HydMe..84...81W . dead . https://web.archive.org/web/20110818131019/http://infolib.hua.edu.vn/Fulltext/ChuyenDe/ChuyenDe07/CDe53/59.pdf . 18 August 2011.
  31. Su . Kun . Ma . Xiaodong . Parianos . John . Zhao . Baojun . Thermodynamic and Experimental Study on Efficient Extraction of Valuable Metals from Polymetallic Nodules . Minerals . 2020 . 10 . 4 . 360 . 10.3390/min10040360 . 2020Mine...10..360S . free .
  32. Web site: International Seabed Authority . Polymetallic Nodules . International Seabed Authority . 8 February 2021 . 23 October 2021 . https://web.archive.org/web/20211023145629/https://isa.org.jm/files/files/documents/eng7.pdf . dead .
  33. Book: The Role of Ecological Chemistry in Pollution Research and Sustainable Development. Bahadir. Ali Mufit. Duca. Gheorghe. 2009. Springer. 978-90-481-2903-4. en.
  34. Book: Green, Dan. The Periodic Table in Minutes. 2016. Quercus. 978-1-68144-329-4. en.
  35. Web site: International Copper Association. 22 July 2009. 5 March 2012. https://web.archive.org/web/20120305203937/http://www.copperinfo.com/environment/recycling.html. dead.
  36. http://www.copper.org/publications/newsletters/innovations/1998/06/recycle_overview.html "Overview of Recycled Copper" Copper.org
  37. Web site: Les opportunités du recyclage du cuivre de haute pureté . WeeeCycling . 2021-05-17 . fr . Opportunities for recycling high purity copper.
  38. Web site: Annual Memory 2020. 109 . Codelco .
  39. Web site: Philippines: attention, terrain miné . Amnesty International . fr . Philippines: attention, mined land . 2016-11-09.
  40. Rzymski . Piotr . Klimaszyk . Piotr . Marszelewski . Włodzimierz . Borowiak . Dariusz . Mleczek . Mirosław . Nowiński . Kamil . Pius . Bożena . Niedzielski . Przemysław . Poniedziałek . Barbara . 2017-07-25 . The chemistry and toxicity of discharge waters from copper mine tailing impoundment in the valley of the Apuseni Mountains in Romania . Environmental Science and Pollution Research International . 24 . 26. 21445–21458 . 10.1007/s11356-017-9782-y . 28744684 . 5579155 . 2017ESPR...2421445R .
  41. Web site: Gold Jewellery Alloys . 6 June 2009 . World Gold Council . dead . https://web.archive.org/web/20090414151414/http://www.utilisegold.com/jewellery_technology/colours/colour_alloys . 14 April 2009.
  42. http://www.balverzinn.com/downloads/Solder_Sn97Cu3.pdf Balver Zinn Solder Sn97Cu3
  43. Web site: Deane . D. V. . Modern Coinage Systems . British Numismatic Society . 1 July 2019.
  44. Web site: What is 90% Silver? . American Precious Metals Exchange (APMEX) . 1 July 2019 . 28 July 2020 . https://web.archive.org/web/20200728210159/https://www.apmex.com/education/bullion/what-is-90-percent-silver-junk-silver . dead .
  45. Book: Corrosion Tests and Standards. ASTM International. 368. en. 2005.
  46. Oguchi. Hachiro. 1983. Japanese Shakudō: its history, properties and production from gold-containing alloys. Gold Bulletin. 16. 4. 125–132. 10.1007/BF03214636. free.
  47. Trammell . Rachel . Rajabimoghadam . Khashayar . Garcia-Bosch . Isaac . Copper-Promoted Functionalization of Organic Molecules: from Biologically Relevant Cu/O2 Model Systems to Organometallic Transformations. Chemical Reviews . 119 . 4 . 2954–3031 . 30 January 2019 . 10.1021/acs.chemrev.8b00368. 30698952 . 6571019 .
  48. Book: A. F. . Wells . Structural Inorganic Chemistry . 5th . 1984 . Oxford University Press . 978-0-19-965763-6 . 1142–1145 .
  49. Book: Holleman . A.F. . Wiberg . N. . Inorganic Chemistry . 2001 . Academic Press . San Diego . 978-0-12-352651-9.
  50. Book: https://books.google.com/books?id=cItuoO9zSjkC&pg=PA623. 623. Nonsystematic (Contact) Fungicides. Ullmann's Agrochemicals. 978-3-527-31604-5. Wiley-Vch. 2 April 2007. Wiley .
  51. Ralph L. Shriner, Christine K.F. Hermann, Terence C. Morrill, David Y. Curtin, Reynold C. Fuson "The Systematic Identification of Organic Compounds" 8th edition, J. Wiley, Hoboken.
  52. Saalwächter . Kay . Burchard . Walther . Klüfers . Peter . Kettenbach . G. . Mayer . Peter . Klemm . Dieter . Dugarmaa . Saran . 2000 . Cellulose Solutions in Water Containing Metal Complexes . Macromolecules . 33 . 11. 4094–4107 . 10.1021/ma991893m . 2000MaMol..33.4094S . 10.1.1.951.5219 .
  53. Deodhar, S., Huckaby, J., Delahoussaye, M. and DeCoster, M.A., 2014, August. High-aspect ratio bio-metallic nanocomposites for cellular interactions. In IOP Conference Series: Materials Science and Engineering (Vol. 64, No. 1, p. 012014). https://iopscience.iop.org/article/10.1088/1757-899X/64/1/012014/meta.
  54. Kelly, K.C., Wasserman, J.R., Deodhar, S., Huckaby, J. and DeCoster, M.A., 2015. Generation of scalable, metallic high-aspect ratio nanocomposites in a biological liquid medium. Journal of Visualized Experiments, (101), p.e52901. https://www.jove.com/t/52901/generation-scalable-metallic-high-aspect-ratio-nanocomposites.
  55. Karan, A., Darder, M., Kansakar, U., Norcross, Z. and DeCoster, M.A., 2018. Integration of a Copper-Containing Biohybrid (CuHARS) with Cellulose for Subsequent Degradation and Biomedical Control. International journal of environmental research and public health, 15(5), p.844. https://www.mdpi.com/1660-4601/15/5/844
  56. Web site: 2018-04-03 . Characteristic Reactions of Copper Ions (Cu²⁺) . 2024-05-27 . Chemistry LibreTexts . en.
  57. "Modern Organocopper Chemistry" Norbert Krause, Ed., Wiley-VCH, Weinheim, 2002. .
  58. Berná. José. Goldup. Stephen. Lee. Ai-Lan. Leigh. David. Symes. Mark. Teobaldi. Gilberto. Zerbetto. Fransesco. Cadiot–Chodkiewicz Active Template Synthesis of Rotaxanes and Switchable Molecular Shuttles with Weak Intercomponent Interactions. Angewandte Chemie. 26 May 2008. 120. 23. 4464–4468. 10.1002/ange.200800891. 2008AngCh.120.4464B.
  59. The Sonogashira Reaction: A Booming Methodology in Synthetic Organic Chemistry. Rafael Chinchilla. Carmen Nájera. amp. Chemical Reviews. 2007. 107. 3. 874–922. 10.1021/cr050992x. 17305399.
  60. 1986 . An Addition of an Ethylcopper Complex to 1-Octyne: (E)-5-Ethyl-1,4-Undecadiene . . 64 . 1 . 10.15227/orgsyn.064.0001 . dead . https://web.archive.org/web/20120619005340/http://www.orgsyn.org/orgsyn/pdfs/CV7P0236.pdf . 19 June 2012.
  61. Kharasch . M.S. . Tawney . P.O. . 1941. Factors Determining the Course and Mechanisms of Grignard Reactions. II. The Effect of Metallic Compounds on the Reaction between Isophorone and Methylmagnesium Bromide . Journal of the American Chemical Society . 63 . 9 . 2308–2316 . 10.1021/ja01854a005.
  62. Imai . Sadako . Fujisawa . Kiyoshi . Kobayashi . Takako . Shirasawa . Nobuhiko . Fujii . Hiroshi . Yoshimura . Tetsuhiko . Kitajima . Nobumasa . Moro-oka . Yoshihiko . 63Cu NMR Study of Copper(I) Carbonyl Complexes with Various Hydrotris(pyrazolyl)borates: Correlation between 63Cu Chemical Shifts and CO Stretching Vibrations. Inorganic Chemistry . 1998. 37. 3066–3070. 10.1021/ic970138r. 12.
  63. Book: Potassium Cuprate (III). Handbook of Preparative Inorganic Chemistry. 2nd. G. Brauer. Academic Press. 1963. NY. 1. 1015.
  64. Schwesinger, Reinhard . Link, Reinhard . Wenzl, Peter . Kossek, Sebastian . Anhydrous phosphazenium fluorides as sources for extremely reactive fluoride ions in solution. 10.1002/chem.200500838. 2006. Chemistry: A European Journal. 12. 2. 438–45 . 16196062.
  65. Mirica . Liviu M. . Ottenwaelder . Xavier . Stack . T. Daniel P. . 2004-02-01 . Structure and Spectroscopy of Copper−Dioxygen Complexes . Chemical Reviews . en . 104 . 2 . 1013–1046 . 10.1021/cr020632z . 14871148 . 0009-2665.
  66. Lewis . E.A. . Tolman . W.B. . 2004 . Reactivity of Dioxygen-Copper Systems . Chemical Reviews . 104 . 1047–1076 . 10.1021/cr020633r . 2 . 14871149.
  67. McDonald . M.R. . Fredericks . F.C. . Margerum . D.W. . 1997 . Characterization of Copper(III)–Tetrapeptide Complexes with Histidine as the Third Residue . Inorganic Chemistry . 36 . 3119–3124. 10.1021/ic9608713. 11669966 . 14.
  68. A. . Hickman . M. . Sanford . High-valent organometallic copper and palladium in catalysis . Nature . 484 . 177–185 . 2012 . 7393 . 10.1038/nature11008 . 22498623 . 4384170 . 2012Natur.484..177H .
  69. Well-defined organometallic Copper(III) complexes: Preparation, characterization and reactivity . He . Liu . Qilong . Shen . . 442 . 2021 . 213923 . 10.1016/j.ccr.2021.213923.
  70. A Timeline of Copper Technologies, Copper Development Association, https://www.copper.org/education/history/timeline/
  71. Web site: CSA – Discovery Guides, A Brief History of Copper. Csa.com. 12 September 2008. 3 February 2015. https://web.archive.org/web/20150203154021/http://www.csa.com/discoveryguides/copper/overview.php. dead.
  72. Book: 56. Jewelrymaking through History: an Encyclopedia. Greenwood Publishing Group. 2007. 978-0-313-33507-5. Rayner W. Hesse. No primary source is given in that book.
  73. Web site: Copper. Elements.vanderkrogt.net. 12 September 2008.
  74. Book: Renfrew, Colin. Colin Renfrew, Baron Renfrew of Kaimsthorn. Before civilization: the radiocarbon revolution and prehistoric Europe. 21 December 2011. 1990. Penguin. 978-0-14-013642-5.
  75. Thoury . M. . Mille . B. . Séverin-Fabiani . T. . Robbiola . L. . Réfrégiers . M. . Jarrige . J.-F. . Bertrand . L. . 2016-11-15 . High spatial dynamics-photoluminescence imaging reveals the metallurgy of the earliest lost-wax cast object . Nature Communications . 7 . 13356 . 10.1038/ncomms13356 . 2041-1723 . 5116070 . 27843139. 2016NatCo...713356T .
  76. News: Cowen, R.. Essays on Geology, History, and People: Chapter 3: Fire and Metals. 7 July 2009. 10 May 2008. https://web.archive.org/web/20080510150436/http://www.geology.ucdavis.edu/~cowen/~GEL115/115CH3.html. dead.
  77. Book: Timberlake, S.. The Archaeology of Alderley Edge: Survey, excavation and experiment in an ancient mining landscape. Prag A.J.N.W.. 2005. John and Erica Hedges Ltd.. Oxford. 396. 10.30861/9781841717159. 9781841717159. amp.
  78. Web site: CSA – Discovery Guides, A Brief History of Copper. CSA Discovery Guides. 29 April 2011. 3 February 2015. https://web.archive.org/web/20150203154021/http://www.csa.com/discoveryguides/copper/overview.php. dead.
  79. Pompeani . David P . Steinman . Byron A . Abbott . Mark B . Pompeani . Katherine M . Reardon . William . DePasqual . Seth . Mueller . Robin H . On the Timing of the Old Copper Complex in North America: A Comparison of Radiocarbon Dates from Different Archaeological Contexts . April 2021 . Radiocarbon . en . 63 . 2 . 513–531 . 10.1017/RDC.2021.7 . 2021Radcb..63..513P . 233029733 . 0033-8222.
  80. Pleger, Thomas C. "A Brief Introduction to the Old Copper Complex of the Western Great Lakes: 4000–1000 BC", Proceedings of the Twenty-Seventh Annual Meeting of the Forest History Association of Wisconsin, Oconto, Wisconsin, 5 October 2002, pp. 10–18.
  81. Emerson, Thomas E. and McElrath, Dale L. Archaic Societies: Diversity and Complexity Across the Midcontinent, SUNY Press, 2009 .
  82. Bebber . Michelle R. . Buchanan . Briggs . Holland-Lulewicz . Jacob . 2022-04-26 . Refining the chronology of North America's copper using traditions: A macroscalar approach via Bayesian modeling . PLOS ONE . en . 17 . 4 . e0266908 . 10.1371/journal.pone.0266908 . 1932-6203 . 9041870 . 35472064 . 2022PLoSO..1766908B . free .
  83. Malakoff . David . 2021-03-19 . Ancient Native Americans were among the world's first coppersmiths . Science . 10.1126/science.abi6135 . 233663403 . 0036-8075.
  84. Pompeani . David P. . Abbott . Mark B. . Steinman . Byron A. . Bain . Daniel J. . 2013-05-14 . Lake Sediments Record Prehistoric Lead Pollution Related to Early Copper Production in North America . Environmental Science & Technology . 47 . 11 . 5545–5552 . 10.1021/es304499c . 23621800 . 2013EnST...47.5545P . 0013-936X.
  85. Bebber . Michelle R. . Eren . Metin I. . 2018-10-01 . Toward a functional understanding of the North American Old Copper Culture "technomic devolution" . Journal of Archaeological Science . en . 98 . 34–44 . 10.1016/j.jas.2018.08.001 . 2018JArSc..98...34B . 134060339 . 0305-4403. free .
  86. Book: Dainian, Fan. Chinese Studies in the History and Philosophy of Science and Technology. 228.
  87. Book: Wallach, Joel. Epigenetics: The Death of the Genetic Theory of Disease Transmission.
  88. Web site: Tainted ores and the rise of tin bronzes in Eurasia, c. 6500 years ago . Miljana . Radivojević . Thilo . Rehren . Antiquity Publications Ltd . December 2013 . 5 February 2014 . 5 February 2014 . https://archive.today/20140205001504/http://antiquity.ac.uk/ant/087/ant0871030.htm . dead .
  89. Book: 13, 48–66. Encyclopaedia of the History of Technology. McNeil, Ian . Routledge. 2002. London; New York. 978-0-203-19211-5.
  90. Book: Eastaugh . Nicholas . Walsh . Valentine . Chaplin . Tracey . Siddall . Ruth . 2013-06-17 . Pigment Compendium: Optical Microscopy of Historical Pigments . 10.4324/9780080454573. 9781136373794 .
  91. The Nomenclature of Copper and its Alloys. Rickard, T.A. . Journal of the Royal Anthropological Institute. 62. 281–290 . 1932. 2843960. 10.2307/2843960.
  92. Timberlake . Simon . New ideas on the exploitation of copper, tin, gold, and lead ores in Bronze Age Britain: The mining, smelting, and movement of metal . Materials and Manufacturing Processes . 11 June 2017 . 32 . 7–8 . 709–727 . 10.1080/10426914.2016.1221113. 138178474 .
  93. The State of Our Knowledge About Ancient Copper Mining in Michigan. The Michigan Archaeologist. 41. 119. Martin, Susan R.. 1995. 2–3. dead. https://web.archive.org/web/20160207073036/http://www.ramtops.co.uk/copper.html. 7 February 2016.
  94. Chastain . Matthew L. . Deymier-Black . Alix C. . Kelly . John E. . Brown . James A. . Dunand . David C. . 2011-07-01 . Metallurgical analysis of copper artifacts from Cahokia . Journal of Archaeological Science . en . 38 . 7 . 1727–1736 . 10.1016/j.jas.2011.03.004 . 2011JArSc..38.1727C . 0305-4403.
  95. Cortés . Leticia Inés . Scattolin . María Cristina . June 2017 . Ancient metalworking in South America: a 3000-year-old copper mask from the Argentinian Andes . Antiquity . en . 91 . 357 . 688–700 . 10.15184/aqy.2017.28 . 53068689 . 0003-598X. free .
  96. 10.1126/science.272.5259.246. History of Ancient Copper Smelting Pollution During Roman and Medieval Times Recorded in Greenland Ice. 246–249 (247f.). 1996. Hong. S.. Candelone. J.-P.. 5259. Patterson. C.C.. Boutron. C.F.. Science. 272. 1996Sci...272..246H. 176767223.
  97. de Callataÿ. François. 2005. The Graeco-Roman Economy in the Super Long-Run: Lead, Copper, and Shipwrecks. Journal of Roman Archaeology. 18. 361–372 (366–369). 10.1017/S104775940000742X. 232346123.
  98. Corinthian Bronze and the Gold of the Alchemists . Savenije, Tom J. . Warman, John M. . Barentsen, Helma M. . van Dijk, Marinus . Zuilhof, Han . Sudhölter, Ernst J.R. . Macromolecules . 2 . 33 . 2000 . 60–66 . 10.1021/ma9904870 . 2000MaMol..33...60S . dead . https://web.archive.org/web/20070929003743/http://www.goldbulletin.org/downloads/JACOB_2_33.PDF . 29 September 2007 .
  99. Book: Mining in World History. 60. 978-1-86189-173-0. Lynch, Martin. 2004. Reaktion Books .
  100. Web site: Gold: prices, facts, figures and research: A brief history of money. 22 April 2011.
  101. Web site: Copper and Brass in Ships. 6 September 2016.
  102. 10.1002/adem.200400403. Process Optimization in Copper Electrorefining. 2004. Stelter, M.. Advanced Engineering Materials. 6. 7. 558–562. Bombach. H.. 138550311 .
  103. Book: Gardner . E. D. . et al . Copper Mining in North America . 1938 . U. S. Bureau of Mines . Washington, D. C. . 19 March 2019.
  104. Book: Hyde . Charles . Copper for America, the United States Copper Industry from Colonial Times to the 1990s . 1998 . University of Arizona Press . Tucson, Arizona . 0-8165-1817-3 . passim.
  105. Web site: Outokumpu Flash Smelting. https://web.archive.org/web/20110724043222/http://www.outokumpu.com/files/Technology/Documents/Newlogobrochures/FlashSmelting.pdf. 24 July 2011. Outokumpu. 2.
  106. Karen A. Mingst . 1976 . Cooperation or illusion: an examination of the intergovernmental council of copper exporting countries . International Organization . 30 . 2 . 263–287 . 10.1017/S0020818300018270. 154183817 .
  107. Web site: Is Copper Bottom Paint Sinking?. BoatUS Magazine. Ryck Lydecker. 2016-06-03.
  108. Web site: Copper. American Elements. 2008. 12 July 2008. 8 June 2008. https://web.archive.org/web/20080608225006/http://www.americanelements.com/cu.html. dead.
  109. Pops, Horace, 2008, "Processing of wire from antiquity to the future", Wire Journal International, June, pp. 58–66
  110. The Metallurgy of Copper Wire, http://www.litz-wire.com/pdf%20files/Metallurgy_Copper_Wire.pdf
  111. Joseph, Günter, 1999, Copper: Its Trade, Manufacture, Use, and Environmental Status, edited by Kundig, Konrad J.A., ASM International, pp. 141–192 and pp. 331–375.
  112. Web site: Copper, Chemical Element – Overview, Discovery and naming, Physical properties, Chemical properties, Occurrence in nature, Isotopes . Chemistryexplained.com . 16 October 2012.
  113. Joseph, Günter, 1999, Copper: Its Trade, Manufacture, Use, and Environmental Status, edited by Kundig, Konrad J.A., ASM International, p.348
  114. Web site: Aluminum Wiring Hazards and Pre-Purchase Inspections.. www.heimer.com. 2016-06-03. 28 May 2016. https://web.archive.org/web/20160528104324/http://www.heimer.com/Inspection-Information/Aluminum-Wiring.html. dead.
  115. Web site: Accelerator: Waveguides (SLAC VVC). SLAC Virtual Visitor Center. 29 April 2011. 7 February 2006. https://web.archive.org/web/20060207181019/http://www2.slac.stanford.edu/vvc/accelerators/waveguide.html. dead.
  116. IE3 energy-saving motors, Engineer Live, http://www.engineerlive.com/Design-Engineer/Motors_and_Drives/IE3_energy-saving_motors/22687/
  117. Energy‐efficiency policy opportunities for electric motor‐driven systems, International Energy Agency, 2011 Working Paper in the Energy Efficiency Series, by Paul Waide and Conrad U. Brunner, OECD/IEA 2011
  118. Fuchsloch, J. and E.F. Brush, (2007), "Systematic Design Approach for a New Series of Ultra‐NEMA Premium Copper Rotor Motors", in EEMODS 2007 Conference Proceedings, 10–15 June, Beijing.
  119. Copper motor rotor project; Copper Development Association; Web site: Copper.org: Copper Motor Rotor Project . 2012-11-07 . dead . https://web.archive.org/web/20120313102458/http://www.copper.org/applications/electrical/motor-rotor . 13 March 2012 .
  120. NEMA Premium Motors, The Association of Electrical Equipment and Medical Imaging Manufacturers; Web site: NEMA – NEMA Premium Motors . 2009-10-12 . dead . https://web.archive.org/web/20100402081307/http://www.nema.org/gov/energy/efficiency/premium/ . 2 April 2010.
  121. Seale, Wayne (2007). The role of copper, brass, and bronze in architecture and design; Metal Architecture, May 2007
  122. Copper roofing in detail; Copper in Architecture; Copper Development Association, U.K., www.cda.org.uk/arch
  123. Architecture, European Copper Institute; http://eurocopper.org/copper/copper-architecture.html
  124. Kronborg completed; Agency for Palaces and Cultural Properties, København, Web site: Kronborg completed – Agency for Palaces and Cultural Properties . 2012-09-12 . dead . https://web.archive.org/web/20121024101854/http://www.slke.dk/en/slotteoghaver/slotte/kronborg/kronborgshistorie/kronborgfaerdigbygget.aspx?highlight=copper . 24 October 2012.
  125. Web site: Berg. Jan. Why did we paint the library's roof?. 20 September 2007 . https://web.archive.org/web/20070625065039/http://www.deforest.lib.wi.us/FAQS.htm . 25 June 2007.
  126. Architectural considerations; Copper in Architecture Design Handbook, http://www.copper.org/applications/architecture/arch_dhb/fundamentals/arch_considerations.htm
  127. Peters, Larry E. (2004). Preventing corrosion on copper roofing systems; Professional Roofing, October 2004, http://www.professionalroofing.net
  128. Web site: Oxidation reaction: Why is the Statue of Liberty blue-green? How does rust work?. Chun. Wu. Engage Engineering. wepanknowledgecenter.org . 2013-10-25 . dead . https://web.archive.org/web/20131025094519/http://www.wepanknowledgecenter.org/c/document_library/get_file?folderId=517&name=DLFE-2454.pdf . 25 October 2013.
  129. 10.1016/S0010-938X(98)00093-6 . The chemistry of copper patination . 1998 . Fitzgerald . K.P. . Nairn . J. . Atrens . A. . Corrosion Science . 40 . 12 . 2029–50. 1998Corro..40.2029F .
  130. Application Areas: Architecture – Finishes – patina; http://www.copper.org/applications/architecture/finishes.html
  131. Glossary of copper terms, Copper Development Association (UK): Web site: Glossary of copper terms . 2012-09-14 . dead . https://web.archive.org/web/20120820053020/http://www.copperinfo.co.uk/resources/glossary.shtml . 20 August 2012 .
  132. Finishes – natural weathering; Copper in Architecture Design Handbook, Copper Development Association Inc., Web site: Copper.org: Architecture Design Handbook: Finishes . 2012-09-12 . dead . https://web.archive.org/web/20121016080539/http://www.copper.org/applications/architecture/arch_dhb/finishes/finishes.html . 16 October 2012 .
  133. Book: Davis, Joseph R. . Copper and Copper Alloys. 3–6, 266. ASM International. 2001. 978-0-87170-726-0.
  134. Edding, Mario E., Flores, Hector, and Miranda, Claudio, (1995), Experimental Usage of Copper-Nickel Alloy Mesh in Mariculture. Part 1: Feasibility of usage in a temperate zone; Part 2: Demonstration of usage in a cold zone; Final report to the International Copper Association Ltd.
  135. http://www.copper.org/applications/cuni/pdf/marine_aquaculture.pdf Corrosion Behaviour of Copper Alloys used in Marine Aquaculture
  136. http://coppertouchsurfaces.org/antimicrobial/bacteria/index.html Copper Touch Surfaces
  137. Web site: 10 February 2021. EPA Registers Copper Surfaces for Residual Use Against Coronavirus. 11 October 2021. United States Environmental Protection Agency.
  138. Montero. David A.. Arellano. Carolina. Pardo. Mirka. Vera. Rosa. Gálvez. Ricardo. Cifuentes. Marcela. Berasain. María A.. Gómez. Marisol. Ramírez. Claudio. Vidal. Roberto M.. 2019-01-05. Antimicrobial properties of a novel copper-based composite coating with potential for use in healthcare facilities. Antimicrobial Resistance and Infection Control. 8. 1. 3. 10.1186/s13756-018-0456-4. 2047-2994. 6321648. 30627427 . free .
  139. Web site: May 2008. EPA registers copper-containing alloy products. dead. https://web.archive.org/web/20150929135757/http://www.epa.gov/pesticides/factsheets/copper-alloy-products.htm. 29 September 2015. United States Environmental Protection Agency.
  140. Biurrun. Amaya. Caballero. Luis. Pelaz. Carmen. León. Elena. Gago. Alberto. 32388649. Treatment of a Legionella pneumophila-Colonized Water Distribution System Using Copper-Silver Ionization and Continuous Chlorination. Infection Control and Hospital Epidemiology. 1999. 20. 6. 426–428. 10.1086/501645. 30141645. 10395146. https://web.archive.org/web/20190217195047/http://pdfs.semanticscholar.org/0709/96484f04d87e7c7858448f3d913a94b720c0.pdf. dead. 2019-02-17.
  141. Zaleski, Andrew, As hospitals look to prevent infections, a chorus of researchers make a case for copper surfaces, STAT, 24 September 2020
  142. http://www.rail.co/2011/07/22/chilean-subway-protected-with-antimicrobial-copper Chilean subway protected with Antimicrobial Copper – Rail News from
  143. http://construpages.com.ve/nl/noticia_nl.php?id_noticia=3032&language=en Codelco to provide antimicrobial copper for new metro lines (Chile)
  144. http://www.antimicrobialcopper.com/media/149689/pr811-chilean-subway-installs-antimicrobial-copper.pdf PR 811 Chilean Subway Installs Antimicrobial Copper
  145. Web site: Copper and Cupron . Cupron .
  146. Web site: GlobalData . 2023-11-17 . Global copper supply in 2023 will be supported by increased output from the DRC, Peru, and Chile . 2023-12-22 . Mining Technology . en-US.
  147. Web site: Woods . Bob . 2023-09-27 . Copper is critical to energy transition. The world is falling way behind on producing enough . 2023-12-22 . CNBC . en.
  148. Web site: China drives copper to 4-month low, raising global economic alarms . 2023-12-22 . Nikkei Asia . en-GB.
  149. Web site: Repairing aluminum wiring . U.S. Consumer Product Safety Commission . 23 December 2023 . https://web.archive.org/web/20161225171612/https://www.cpsc.gov/pagefiles/118856/516.pdf . 25 December 2016 . 1 . A national survey conducted by Franklin Research Institute for CPSC showed that homes built before 1972, and wired with aluminum, are 55 times more likely to have one or more wire connections at outlets reach "Fire Hazard Conditions" than homes wired with copper..
  150. News: Manufacturing Mayday: Production glitches send Airbus into a tailspin . . Hellemans, Alexander . 1 January 2007 . 19 June 2014.
  151. Web site: Global copper market under supplied, demand on the rise – report. 2019-01-06. Mining.com. en. 2019-01-13.
  152. Web site: 15 January 2015. Will the Transition to Renewable Energy Be Paved in Copper?. www.renewableenergyworld.com. 2019-01-13. 22 June 2018. https://web.archive.org/web/20180622060455/https://www.renewableenergyworld.com/articles/2016/01/will-the-transition-to-renewable-energy-be-paved-in-copper.html. dead.
  153. Web site: Copper and cars: Boom goes beyond electric vehicles. 2018-06-18. MINING.com. en. 2019-01-13.
  154. Web site: Impact of electric cars in medium-term copper demand 'overrated', experts say. 2018-04-12. MINING.com. en. 2019-01-13.
  155. Web site: Why are Premiums for Copper Bullion So High? . Provident Metals . 23 January 2019. 2012-08-20 .
  156. News: Chace . Zoe . Penny Hoarders Hope for the Day The Penny Dies . NPR.org . NPR . 23 January 2019.
  157. 961545 . 1976 . Walker . W.R. . Keats . D.M. . An investigation of the therapeutic value of the 'copper bracelet'-dermal assimilation of copper in arthritic/rheumatoid conditions . 6 . 4 . 454–459 . Agents and Actions.
  158. Richmond SJ, Gunadasa S, Bland M, Macpherson H . Copper bracelets and magnetic wrist straps for rheumatoid arthritis – analgesic and anti-inflammatory effects: a randomised double-blind placebo controlled crossover trial . PLOS ONE . 8 . 9 . e71529 . 2013 . 24066023 . 3774818 . 10.1371/journal.pone.0071529 . 2013PLoSO...871529R . free .
  159. Richmond. Stewart J.. Brown. Sally R.. Campion. Peter D.. Porter. Amanda J.L.. Moffett. Jennifer A. Klaber. Jackson. David A.. Featherstone. Valerie A.. Taylor. Andrew J.. Therapeutic effects of magnetic and copper bracelets in osteoarthritis: A randomised placebo-controlled crossover trial. Complementary Therapies in Medicine. 17. 5–6. 2009. 249–256. 0965-2299. 10.1016/j.ctim.2009.07.002. 19942103.
  160. Web site: Find the Truth Behind Medical Myths. University of Arkansas for Medical Sciences. 6 January 2014. 6 January 2014. https://web.archive.org/web/20140106233901/http://www.uams.edu/update/absolutenm/templates/medical.asp?articleid=3454. While it's never been proven that copper can be absorbed through the skin by wearing a bracelet, research has shown that excessive copper can result in poisoning, causing vomiting and, in severe cases, liver damage..
  161. Metals, minerals and microbes: geomicrobiology and bioremediation. Microbiology. Geoffrey Michael Gadd. Geoffrey Michael Gadd. 156. 3. March 2010. 609–643. 10.1099/mic.0.037143-0. 20019082. free.
  162. Book: Mycoremediation: Fungal Bioremediation. Harbhajan Singh. 509. 978-0-470-05058-3. 2006. John Wiley & Sons .
  163. Book: Katherine E. . Vest. Hayaa F.. Hashemi. Paul A.. Cobine. The Copper Metallome in Eukaryotic Cells . Lucia . Banci . Metal Ions in Life Sciences . 12. Metallomics and the Cell . 2013 . 451–78. Springer . 978-94-007-5560-4. 10.1007/978-94-007-5561-1_13. 23595680. electronic-book electronic-
  164. Web site: Fun facts. Horseshoe crab. University of Delaware. 13 July 2008. https://web.archive.org/web/20081022053340/http://www.ocean.udel.edu/horseshoecrab/funFacts.html. 22 October 2008. dead.
  165. S.J. Lippard, J.M. Berg "Principles of bioinorganic chemistry" University Science Books: Mill Valley, CA; 1994. .
  166. 10821735. Decker, H.. Terwilliger, N.. amp . COPs and Robbers: Putative evolution of copper oxygen-binding proteins. Journal of Experimental Biology . 203. 1777–1782 . 2000. Pt 12. 10.1242/jeb.203.12.1777. free.
  167. Book: Lisa K.. Schneider. Anja. Wüst. Anja. Pomowski. Lin. Zhang. Oliver. Einsle. No Laughing Matter: The Unmaking of the Greenhouse Gas Dinitrogen Monoxide by Nitrous Oxide Reductase. Peter M.H. Kroneck. Martha E. Sosa Torres. The Metal-Driven Biogeochemistry of Gaseous Compounds in the Environment. Metal Ions in Life Sciences. 14. 2014. Springer. 177–210. 10.1007/978-94-017-9269-1_8. 25416395. 978-94-017-9268-4.
  168. Book: Denoyer. Delphine. Clatworthy . Sharnel A.S.. Cater . Michael A. . Sigel. Astrid. Sigel. Helmut. Freisinger. Eva. Sigel. Roland K.O.. Metallo-Drugs: Development and Action of Anticancer Agents. 2018. 18. 10.1515/9783110470734-016. 29394035. de Gruyter GmbH. Berlin. Chapter 16. Copper Complexes in Cancer Therapy. Metal Ions in Life Sciences . 469–506. 978-3-11-047073-4.
  169. Web site: Amount of copper in the normal human body, and other nutritional copper facts. 3 April 2009. 10 April 2009. https://web.archive.org/web/20090410055140/http://www.copper.org/consumers/health/papers/cu_health_uk/cu_health_uk.html. dead.
  170. Adelstein. S. J.. Vallee. B. L.. Copper metabolism in man. New England Journal of Medicine. 1961. 265. 892–897. 10.1056/NEJM196111022651806. 13859394. 18.
  171. Copper transport . 9587137 . 1 May 1998 . M.C. Linder . The American Journal of Clinical Nutrition . 67 . 5 . 965S–971S . Wooten . L. . Cerveza . P. . Cotton . S. . Shulze . R. . Lomeli . N.. 10.1093/ajcn/67.5.965S . free .
  172. Book: 20170553 . 775938 . 1976 . Frieden . E. . Hsieh . H.S. . Ceruloplasmin: The copper transport protein with essential oxidase activity . Advances in Enzymology and Related Areas of Molecular Biology . 44 . 187–236 . 10.1002/9780470122891.ch6. Advances in Enzymology – and Related Areas of Molecular Biology . 978-0-470-12289-1.
  173. 2301561 . Copper transport from ceruloplasmin: Characterization of the cellular uptake mechanism . 1 January 1990 . S.S. Percival . American Journal of Physiology. Cell Physiology . 258 . 1 . C140–C146 . Harris . E.D. . 10.1152/ajpcell.1990.258.1.c140 .
  174. http://www.nationalacademies.org/hmd/~/media/Files/Activity%20Files/Nutrition/DRI-Tables/2_%20RDA%20and%20AI%20Values_Vitamin%20and%20Elements.pdf?la=en Dietary Reference Intakes: RDA and AI for Vitamins and Elements
  175. Copper. IN: Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Copper. National Academy Press. 2001, PP. 224–257.
  176. Web site: Overview on Dietary Reference Values for the EU population as derived by the EFSA Panel on Dietetic Products, Nutrition and Allergies . 2017 .
  177. Web site: Federal Register May 27, 2016 Food Labeling: Revision of the Nutrition and Supplement Facts Labels. FR p. 33982..
  178. Web site: Daily Value Reference of the Dietary Supplement Label Database (DSLD) . Dietary Supplement Label Database (DSLD) . 16 May 2020 . https://web.archive.org/web/20200407073956/https://dsld.nlm.nih.gov/dsld/dailyvalue.jsp . 7 April 2020 . dead .
  179. Bonham . Maxine . O'Connor . Jacqueline M. . Hannigan . Bernadette M. . Strain . J.J.. 2002. The immune system as a physiological indicator of marginal copper status? . British Journal of Nutrition. 10.1079/BJN2002558. 12010579. 87. 5. 393–403. free.
  180. Li. Yunbo. Trush. Michael. Yager. James. DNA damage caused by reactive oxygen species originating from a copper-dependent oxidation of the 2-hydroxy catechol of estradiol. Carcinogenesis. 1994. 15. 7. 1421–1427. 10.1093/carcin/15.7.1421. 8033320.
  181. Gordon. Starkebaum. John. M. Harlan. Endothelial cell injury due to copper-catalyzed hydrogen peroxide generation from homocysteine. 424498. 3514679. 10.1172/JCI112442. 77. 4. April 1986. J. Clin. Invest.. 1370–6.
  182. Web site: Pesticide Information Profile for Copper Sulfate. Cornell University. 10 July 2008.
  183. Hunt, Charles E.. William W. Carlton. amp . 5841854 . 1965. Cardiovascular Lesions Associated with Experimental Copper Deficiency in the Rabbit. Journal of Nutrition . 87. 385–394. 4. 10.1093/jn/87.4.385.
  184. Copper-Protein Nutrition of New Zealand White Rabbits under Egyptian Conditions. Ayyat M.S.. Marai I.F.M.. Alazab A.M. . 1995. World Rabbit Science . 3. 3 . 113–118. 10.4995/wrs.1995.249. free. 10251/10503. free.
  185. Brewer GJ . Copper excess, zinc deficiency, and cognition loss in Alzheimer's disease . BioFactors . 38 . 2 . 107–113 . March 2012 . 22438177 . 10.1002/biof.1005 . 16989047 . Review. 2027.42/90519 . free .
  186. Web site: Copper: Alzheimer's Disease. Examine.com. 21 June 2015.
  187. [OEHHA]
  188. Talhout. Reinskje. Schulz. Thomas. Florek. Ewa. Van Benthem. Jan. Wester. Piet. Opperhuizen. Antoon. Hazardous Compounds in Tobacco Smoke. International Journal of Environmental Research and Public Health. 8. 12. 2011. 613–628. 1660-4601. 10.3390/ijerph8020613. 21556207. 3084482. free.
  189. Investigation of Toxic Metals in the Tobacco of Different Iranian Cigarette Brands and Related Health Issues. Iranian Journal of Basic Medical Sciences. 15. 1. 636–644. 3586865. 2012. Pourkhabbaz. A.. Pourkhabbaz. H.. 23493960.
  190. 10.1080/15216540500459667. 16393783. Metals in cigarette smoke. IUBMB Life. 57. 12. 805–809. 2005. Bernhard. David. Rossmann. Andrea. Wick. Georg. 35694266. free.