One of the important transition metals and nonferrous metal. Its usefulness is due to the combination of chemical, physical and mechanical properties, and their electrical properties and abundance. Copper was one of the first metals used by humans.
Most of the world's copper is obtained from sulfide minerals such as chalcocite, covellite, chalcopyrite, bornite and enargite. The oxidized ores are cuprite, tenorite, malachite, azurite, chrysocolla and brochantite. The, once abundant in the United States, natural copper is extracted only in Michigan now.The grade of ore used in the production of copper decreased steadily, as they have exhausted the richest mineral and has grown the demand for copper. Large amounts of copper in the earth for future use if minerals of the lower grades are used, and there is no chance that they last for a long period.
Mining companies producing copper as raw material and its customers maintain a market of 30,000 million dollars annually.
Copper producers and their customers make transactions reddish metal in three international markets: the London Metal Exchange, the Comex in New York Mercantile Exchange and the Shanghai Metal Exchange.
By converging these three scenarios the producers and consumers have all the necessary to make their buying and selling facilities, while participating in a mechanism that facilitates the setting operations based on supply and demand prices.