Gold cyanidationGold cyanidation (also known as the cyanide process or the MacArthur–Forrest process) is a hydrometallurgical technique for extracting gold from low-grade ore by converting the gold to a water-soluble coordination complex. It is the most commonly used leaching process for gold extraction. Cyanidation is also widely used in the extraction of silver, usually after froth flotation. Production of reagents for mineral processing to recover gold represents more than 70% of cyanide consumption globally.
Hydraulic miningHydraulic mining is a form of mining that uses high-pressure jets of water to dislodge rock material or move sediment. In the placer mining of gold or tin, the resulting water-sediment slurry is directed through sluice boxes to remove the gold. It is also used in mining kaolin and coal. Hydraulic mining developed from ancient Roman techniques that used water to excavate soft underground deposits. Its modern form, using pressurized water jets produced by a nozzle called a "monitor", came about in the 1850s during the California Gold Rush in the United States.
Dolaucothi Gold MinesThe Dolaucothi Gold Mines (ˌdɔlaiˈkɔθɪ; Mwynfeydd Aur Dolaucothi) (), also known as the Ogofau Gold Mine, are ancient Roman surface and underground mines located in the valley of the River Cothi, near Pumsaint, Carmarthenshire, Wales. The gold mines are located within the Dolaucothi Estate which is now owned by the National Trust. They are the only mines for Welsh gold outside those of the Dolgellau gold-belt, and are a Scheduled Ancient Monument.
Underground hard-rock miningUnderground hard-rock mining refers to various underground mining techniques used to excavate "hard" minerals, usually those containing metals, such as ore containing gold, silver, iron, copper, zinc, nickel, tin, and lead. It also involves the same techniques used to excavate ores of gems, such as diamonds and rubies. Soft-rock mining refers to the excavation of softer minerals, such as salt, coal, and oil sands. Accessing underground ore can be achieved via a decline (ramp), inclined vertical shaft or adit.
Placer miningPlacer mining (ˈplæsər) is the mining of stream bed (alluvial) deposits for minerals. This may be done by open-pit (also called open-cast mining) or by various surface excavating equipment or tunneling equipment. Placer mining is frequently used for precious metal deposits (particularly gold) and gemstones, both of which are often found in alluvial deposits—deposits of sand and gravel in modern or ancient stream beds, or occasionally glacial deposits.
Klondike Gold RushThe Klondike Gold Rush was a migration by an estimated 100,000 prospectors to the Klondike region of Yukon, in north-western Canada, between 1896 and 1899. Gold was discovered there by local miners on August 16, 1896; when news reached Seattle and San Francisco the following year, it triggered a stampede of prospectors. Some became wealthy, but the majority went in vain. It has been immortalized in films, literature, and photographs. To reach the gold fields, most prospectors took the route through the ports of Dyea and Skagway, in Southeast Alaska.
Mercury (element)Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum (haɪˈdrɑrdʒərəm ) from the Greek words hydro (water) and argyros (silver). A heavy, silvery d-block element, mercury is the only metallic element that is known to be liquid at standard temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature.
MiningMining is the extraction of valuable geological materials from the Earth and other astronomical objects. Mining is required to obtain most materials that cannot be grown through agricultural processes, or feasibly created artificially in a laboratory or factory. Ores recovered by mining include metals, coal, oil shale, gemstones, limestone, chalk, dimension stone, rock salt, potash, gravel, and clay. The ore must be a rock or mineral that contains valuable constituent, can be extracted or mined and sold for profit.
California Gold RushThe California Gold Rush (1848–1855) was a gold rush that began on January 24, 1848, when gold was found by James W. Marshall at Sutter's Mill in Coloma, California. The news of gold brought approximately 300,000 people to California from the rest of the United States and abroad. The sudden influx of gold into the money supply reinvigorated the American economy; the sudden population increase allowed California to go rapidly to statehood in the Compromise of 1850.
Ancient Roman engineeringThe ancient Romans were famous for their advanced engineering accomplishments. Technology for bringing running water into cities was developed in the east, but transformed by the Romans into a technology inconceivable in Greece. The architecture used in Rome was strongly influenced by Greek and Etruscan sources. Roman roads Roads were common at that time, but the Romans improved their design and perfected the construction to the extent that many of their roads are still in use today.
