# Copper

The copper is a chemical element of symbol Cu and Atomic number 29.

## Characteristics

reddish Metal of color, it has high a thermal Conductivité and electric (with room temperature, only pure metal having a better electric conductivity is the Argent). Its reddish color differs it as well as gold by the generally gray color from metals. Copper could be the first metal well used, since parts going back to 8700 before J. - C. were found.
• Hardness: 3.5-4.5
• Density: 8.93
• Cleavage: absent
• Fracture: scaly
• Rupture: ductile (few impurities or insoluble impurities) or breakable (soluble impurities like Phosphorus)
• Color of the powder: red metallized
• Glare: metal
• Fluorescence: no
• Class: element
• crystalline System: cubic with centered face

## Copper ore

Copper is one of rare metals which exists in a native state. This fact besides probably explaining that it was the first metal used by the men. The occurrence of native copper is however rather weak. One most frequently finds it in the form of sulfide or of sulpho-salt.

### Sulfides

Often used to make instruments of kitchens and sometimes some under clothing can have genuine copper fibers

### Sulpho-salt

• the énergite 3Cu2S, As2S5

### Oxides

• Mélancolise or CuO tenorite, of black color.

• Cuprous oxide or Cuprite: Cu2O, of red color.

### Carbonates

• Azurite: 2CuCO3, Cu (OH) 2

• Malachite: CuCO3, Cu (OH) 2

### Silicates

• Chrysocolla: SiO4Cu, 2 H2O

### Sulfate and chloride

• Brochantite: Cu4 (SO4) (OH) 6

• Atacamite: Cu2Cl (OH) 3

## Metallurgy and refining

(to be supplemented)

The industrial Affinage of copper is carried out by electrolysis black copper anodes in a copper sulfate solution. The Ions copper migrate towards the Cathode and the impurities remain in the bath. This process makes it possible to obtain pure Métal to 99,95%

## Biological and ecotoxic properties

Copper, with very low dose is a trace element essential to the life. It is in particular necessary to the formation of the Hémoglobine and replaces even iron for the transport of oxygen at a species of arthropod, the Limule, whose blood is blue. In the man and the mammals, controlled by the liver, copper intervenes in the immunizing function (shown in the rat) and against the oxidizing stress. It is stored, excreted via the bile or is distributed towards the bodies. Its anti-infectious properties were already known and used in ancient Egypt.
Associé with lead, it seems to be able to worsen the risk of Parkinson's disease.
Le rate Os seux means “normal” at the man at the XXème century was estimated at 4.2 mg/kg by Scheinberg in 1979). One knows human and animal contaminations as of the Bronze Age, around in particular of the old mines of copper and lead of current Jordan.

Although the Porc does not require of more than 6 food mg/kg (NRC, 1998), of copper is added to its food because it showed a powerful growth factor if it is associated with a Zinc supplementation (with 150 to 250 Cu ppm in post-weaning in the food of piglets, that is to say 30 times their need normal is a current practice, which explains the increase in the polluting copper load of the liquid manures. The Mouton, would be killed to him by copper as of 15 Cu Mg per kg of food; death occurring after a haemolytic phase when the Cu rate in the liver exceeds 350 to 1000 ppm dry matter (according to Bremner 1998, Underwood and Suttle 1999). The sheep seems to be the most sensitive mammal, among those whose reactions to copper were studied.

Copper is also - with more raised amount and in its oxidized forms (Vert-de-gris, Cuprous oxide) - powerful a Poison for the Man, like - with sometimes negligible amounts - for many organizations (marine algae, foams, micro-organisms, microscopic mushrooms). This fact known since antiquity justified its use as Pesticide (ex: Pulp of Bordeaux) or like Biocide, in particular in the Antifouling S.

Its virtues Bactericidal S and antifongic and its ductility also have, as for the lead (which is him much more toxic) justified its use in the water pipelines and certain countries for the roofs and gutters (neither foam nor plants settle there, but water takes care there of copper). Copper was used for the tanks and pipings of manufacture of beer and distillation of alcohol, for the jam pots and the manufacture of cooked cheeses. Its corrosion resistance and its toxicity preventing the proliferation and the fixing of algae and marine organizations encouraged its uses in the navy, in the form of copper or more often of brass (nails, port-holes, locks, hinges, etc). Copper salts, like the sulfate or the oxychloride, present fungicidal properties made profitable for the vine growing and agriculture. A simple copper wire tended on made of a roof kills all foams and algae which could push there, although the rain takes care only one negligible quantity there of copper molecules.

The cuprous oxide of recent paintings Antifouling, for some voluntarily érodables to release their biocides longer, kills the bernacles and many other species as of their larval stage, but by slackening copper which contaminates on this occasion surrounding water. The copper used on the vines not being dégradable, it ends up accumulating in the low points where it reaches alarming rates in the ground and water, locally being able to cause the death of animals which are sensitive there, like the sheep.

The Moût S of grape always contain important copper contents; some tenth of mg/l result from the Vigne, but the major part comes from the various undergone treatments. During fermentation this copper, tiny room out of sulfide, are eliminated with the Levure S and the Lie S. the new Vin contains of it only 0,2 to 0,3 mg/l, percentage which can increase after a few months of conservation, following contacts with bronze or brass, copper material. In the white wines maintained safe from the air, when the potential of oxydoreduction reaches a sufficiently low level, copper is tiny room in the presence of Sulfur dioxide free and precipitated with the state of Sulfure S which disturb the wine if the copper amount approaches 1 mg/l. Moreover, copper, acting like catalyst (even with low dose), supports much the oxidation of iron and the white Casse. One eliminates copper from the wines by treatment the Ferrocyanure of potassium or by sodium monosulfure which precipitates it with the sulfide state.

## Toxicology

Copper is a trace element for the Man, but Holland and White showed in experiments, in vitro, in 1988 qu ' it causes in the rat a nonreversible immobilization of sperm (in vitro, after caused inhalation of a cuprous chloride aerosol). Changes histomorphologic, and in the mobility of sperm are observed correlatively witha modification of the weight of the testicles and rates of sex hormones after 4 months of exposure to 19,6 copper mg/m3 (Gabuchyan, 1987). The authors notice that this toxicity could explain the contraceptive effectiveness of the copper coils. More, to see report/ratio INERIS on copper.

## Ecotoxicology

In addition to impacts on the Fertility of the rat, in laboratory, copper (used as pesticide since antiquity) has a very important toxic action on the Algue S and Mousse S. As it is a product not Biodégradable, it has accumulated and ends up reaching sufficient rates to kill for example sheep grazing downstream from vines treated for several decades. In France, approximately a million old hectares of Vignoble S are thus so charged with copper that from here a few years or decades the toxic threshold will be reached there for the mammals. In the areas of spreading of the porcine liquid manures, the content of copper and Zinc of the grounds are also in alarming increase.

## Applications in mechanical engineering and electric

Copper is seldom used pure, except for the electric conducting and if one wishes large a thermal Conductivité. Pure copper is very ductile (elongation with the high rupture).

• parts of conduction: It is shown that thermal and electric conductivity copper are dependant very strongly. That results from the mode of transmission of heat and electricity in metals which is done mainly by displacement of electrons. It will be noted for this reason that copper being useful in this field must be extremely pure (usually 99,999% Cu). The soluble impurities in the copper matrix such as phosphorus (even in very small proportion) very strongly decrease conductivity. At present, copper is often isolated with the profit of aluminum. This last presents in fact a conductivity report/ratio on density much more favorable. More no radiator of car is today out of copper. When it is also known that aluminum is much less expensive than copper, it is included/understood why it is the same for electric cables HT.

• copper is usually used in laboratory as target in the tubes with x-rays for the Diffraction on Poudre S. the line K$\ alpha$ of copper has for average Wavelength 1,54182 Å.

The Alloys of copper, on the other hand, are very largely used in many fields. The most famous alloys are certainly brass (Cu-Zn) and bronzes it (Cu-Sn) which were well elaborate before one makes the first cast ones of pure copper. The Baptismal font of collegial St Barthelemy of Liege fascinated the researchers on this level. It was necessary to go obviously which brass is more easily élaborable than pure copper and pure zinc separate. That results simply from the thermodynamics of the solutions, to produce an impure metal starting from an impure ore is easier than to extract a pure metal from an impure ore.

• machine elements: pure copper or slightly ally present of the satisfactory mechanical properties but it is generally not used because of its high density (compared with magnesium and aluminum or even with iron), its scarcity and its cost of development (and thus of purchase) limit strongly its use. Currently, the presence of copper in certain alloys is more for its semi-noble character than mechanical pure.

• parts of friction and wear: to see the article Tribology
• parts having to resist the Corrosion, the copper oxide is stable with room temperature and generally recovers by a fine insulating layer the copper parts. It is rather similar to aluminum on this level.

## Symbolic system

The Noces of copper symbolize the 32 years of Mariage in the French folklore.

Traditionally, copper is associated with the Planet Venus. The Alchimiste S used the symbol ♀ to represent it. It is thus a metal associated with femininity, youth and the love. Old mirrors, symbol of narcissism, were made of copper.

## Economy

In 2004, the worldwide production of copper is of 16,015 million tons. The principal producers are the Chile (37,3%), the the United States (8%, including 62% in Arizona), the Peru (7,1%) and the Indonesia (5,7%). In Europe, the principal producer is the Poland with 585.000 tonnes/an.

In April 2006, the course of copper is with approximately 6300 euros/ton, in big rise compared to 2005, due mainly to an Asian strong demand. Over the first 8 months of the year 2006, the rise was assembled to 69%.

The first copper consumer is the China, which absorbs 22% of the worldwide production (3 MT).

The secondary worldwide production of copper starting from recycling amounted to 2 MT in 2005, that is to say 13% of the total production of this metal.

## References

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