Copper

Copper is the building material, together with as a unit of various metal alloys, such(a) as sterling silver used in jewelry, cupronickel used to take marine hardware as well as coins, and constantan used in strain gauges and thermocouples for temperature measurement.

Copper is one of the few metals that can occur in species in a directly available metallic have native metals. This led to very early human usage in several regions, from circa 8000 BC. Thousands of years later, it was the first metal to be smelted from sulfide ores, circa 5000 BC; the first metal to be cast into a quality in a mold, c. 4000 BC; and the first metal to be purposely alloyed with another metal, tin, to create bronze, c. 3500 BC.

In the Roman era, copper was mined principally on Cyprus, the origin of the name of the metal, from aes сyprium metal of Cyprus, later corrupted to сuprum Latin. Coper Old English and copper were derived from this, the later spelling first used around 1530.

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

Copper used in buildings, commonly for roofing, oxidizes to form a green verdigris or patina. 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 necessary to all alive organisms as a trace dietary mineral because it is a key detail 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. The adult body contains between 1.4 and 2.1 mg of copper per kilogram of body weight.

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. The amount of copper in use is increasing and the quantity available is barely sufficient to allow all countries todeveloped world levels of usage. An option source of copper for collection currently being researched are polymetallic nodules, which are located at the depths of the Pacific Ocean about 3000–6500 meters below sea level. These nodules contain other valuable metals such(a) as cobalt and nickel.

Copper has been in use at least 10,000 years, but more than 95% of all copper ever mined and ]

The price of copper has historically been unstable, and its price increased from the 60-year low of US$0.60/lb US$1.32/kg in June 1999 to $3.75 per pound $8.27/kg in May 2006. It dropped to $2.40/lb $5.29/kg in February 2007, then rebounded to $3.50/lb $7.71/kg in April 2007.[] In February 2009, weakening global demand and a steep fall in commodity prices since the previous year's highs left copper prices at $1.51/lb $3.32/kg. Between September 2010 and February 2011, the price of copper rose from £5,000 a metric ton to £6,250 a metric ton.

The concentration of copper in ores averages only 0.6%, and most commercial ores are sulfides, particularly chalcopyrite CuFeS₂, bornite Cu₅FeS₄ and, to a lesser extent, covellite CuS and chalcocite Cu₂S. Conversely, the average concentration of copper in polymetallic nodules is estimated at 1.3%. The methods of extracting copper as alive as other metals found in these nodules put sulphuric leaching, smelting and an a formal request to be considered for a position or to be allowed to do or have something. of the Cuprion process. For minerals found in land ores, they are concentrated from crushed ores to the level of 10–15% copper by froth flotation or bioleaching. Heating this fabric with silica in flash smelting removes much of the iron as slag. The process exploits the greater ease of converting iron sulfides into oxides, which in recast react with the silica to form the silicate slag that floats on top of the heated mass. The resulting copper matte, consisting of Cu₂S, is roasted to convert the sulfides into oxides:

The cuprous oxide reacts with cuprous sulfide to converted to blister copper upon heating:

The Sudbury matte process converted only half the sulfide to oxide and then used this oxide to remove the rest of the sulfur as oxide. It was then electrolytically refined and the anode mud exploited for the platinum and gold it contained. This step exploits the relatively easy reduction of copper oxides to copper metal. Natural gas is blown across the blister to remove near of the remaining oxygen and electrorefining is performed on the resulting material to produce pure copper:

Like aluminium, copper is recyclable without any loss of quality, both from raw state and from manufactured products. In volume, copper is the third most recycled metal after iron and aluminium. An estimated 80% of any copper ever mined is still in use today. 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.