Gold

Production

Economic gold extraction can be achieved from ore grades as little as 0.5 g/1000 kg (0.5 ppm) on average in large easily mined deposits, typical ore grades in open-pit mines are 1?5 g/1000 kg (1-5 ppm), ore grades in underground or hard rock mines are usually at least 3 g/1000 kg (3 ppm) on average. Ore grades of 30 g/1000 kg (30 ppm) are usually needed before gold will be visible to the naked eye, therefore even in gold mines you will often not see any gold.

Related Topics:
Gold extraction - Open-pit - Hard rock

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Gold is extracted from alluvium ores by techniques of placer mining and from hard rock ores using extractive metallurgy. Refining of the metal is frequently accomplished by chlorination or electrolysis. The old method of using cyanides to chemically extract gold from the mined ore is cheaper, but highly controversial due to the resulting large-scale environmental pollution. The year 2000 spill of a cyanide reserve lake in Romania caused extremely severe fish and bird extinction alongside the river Tisza and hurt political relations in Eastern Europe.

Related Topics:
Placer mining - Extractive metallurgy - Chlorination - Electrolysis - Cyanide - Environmental pollution - Romania - Tisza - Eastern Europe

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It is claimed all the gold that has been mined thorughout the history of mankind could be incorporated in a solid ball with a diameter of 27 meters. However, a huge reserve of gold is found in solution in the world's seas at 0.1 to 2 mg/1000 kg (0.1?2 ppb) depending on sample location. However, as of 2004 there is no profitable method for recovering gold from sea water.

Related Topics:
Meter - Mg - Ppb - As of 2004

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Since the 1880s South Africa has been the source for about two-thirds of the world's gold supply. The city of Johannesburg was built atop the world's greatest gold finds. Gold fields in the Orange Free State and the Transvaal were deep and require the world's deepest mines. The Boer War of 1899–1901 between the British and the white Boers was at least partly over the rights of miners and possession of the gold wealth in South Africa. Other major producers are Canada, United States and Western Australia. Mines in South Dakota and Nevada supply two-thirds of gold used in the United States. Siberian regions of the USSR also used to be significant in the global gold mining industry.

Related Topics:
South Africa - Johannesburg - Orange Free State - Transvaal - Boer War - 1899 - 1901 - British - Boers - Canada - United States - Western Australia - South Dakota - Nevada - Siberian - USSR

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The idea of making gold out of lesser metals or other cheap substances has fascinated people throughout the centuries. Scientists, kings and charlatans obsessed with the secret art of alchemy accidentally invented practically useful materials (e.g. porcelain), while searching in vain for the philosopher's stone, which was supposed to turn mercury into gold. Modern science has since proven the impossibility of making gold from other elements via chemical reactions.

Related Topics:
Charlatan - Alchemy - Porcelain - Philosopher's stone - Mercury

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However, it is possible to obtain infinitesimally small amounts of gold by artificial nuclear transformations in particle accelerators The gold isotopes produced would likely be radioactive. No economically feasible method to manufacture gold artifically has been found or published yet. The possibility of cheap man-made gold would have unforeseen economic and political consequences.

Related Topics:
Nuclear transformation - Particle accelerator - Isotope - Radioactive - Economically feasible - Political

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