Copper was known to some of the oldest civilizations on record, and has a history of use that is at least 10.000 years old. The use of bronze became so pervasive in a certain era of civilization that it has been named the Copper and Bronze Age.
Copper and bronze artifacts had been found in Egypt; there are signs of copper smelting at 1083°C in primitive air-blast fireplace, the way impossible for iron smelting 1530°C; as well as the refining of copper from simple copper compounds such as malachite or azurite. Bronze alloys were found in Egypt almost as soon as copper was found; also in Sumerian and Mesopotamian cities, on Caucasus, and other ancient areas.
During the Roman Empire, copper was principally mined on Cyprus, hence the origin of the name of the metal as Cyprium, "metal of Cyprus", later shortened to Cuprum. |
Copper is contained in liver in significant amounts: 0.0004 mg per 100 g of body weight; and the blood of a grown-up human being contains 0.001 mg/l of copper. Copper plays essential role in haematogenesis and enzymatic oxidation. It is a constituent part of some enzyme molecules such as lactase and oxygen in the blood of most mollusks, and some arthropods such as the horseshoe crab, and are responsible for oxygenation causing a color change, contain 0.15 - 0.26% copper.
Plants also need copper. It is one of the most important microelements; copper plays significant roles in photosynthesis process and it is necessary for nitrogen fixation. The copper deficiency in soils causes plants sterility. Copper fertilizers contribute to the processes of aluminium and only one 600th of iron's. Native copper is one of the few metals to naturally occur as an uncompounded mineral. However it is a constituent part of 200 minerals, some of which have bright vivid colours. Bornite Cu5FeS4 and azurite Cu3(OH)2CO3 are blue, chalcopyrite CuFeS2 has a golden yellow color; the Malachite Room in the Hermitage in St. Petersburg in Russia which features malachite decorations and, especially, malachite coupe and malachite vases.
Sulphide ores and copper sandstones are the main sources of copper production. However all rich deposits are already exhausted. Nowadays copper is recovered from low-quality rocks which contain less than 1% of the metal. |