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placer mining |
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placer mining: see mining mining, extraction of solid mineral resources from the earth. These resources include ores, which contain commercially valuable amounts of metals, such as iron and aluminum; precious stones, such as diamonds; building stones, such as granite; and solid fuels, such as ..... Click the link for more information. . placer miningOldest method of recovering gold from alluvial deposits. It takes advantage of gold's high density, which causes it to sink more rapidly from moving water than the lighter siliceous materials with which it is found. Panning, used by 19th-century miners, employed a pan in which a few handfuls of the gold-bearing soil or gravel and a large amount of water were placed; by swirling the pan's contents, the miner washed the siliceous material over the side, leaving the gold and heavy materials behind. Dredging is the most important placer-mining method today. Used worldwide is the bucket-ladder dredge, with its continuous chain of buckets rotating around a rigid adjustable frame called the ladder. In sluicing, a slightly sloping wooden trough called a box sluice, or a ditch cut in hard gravel or rock called a ground sluice, is used as a channel along which gold-bearing gravel is carried by a stream of water. Riffles placed transversely along the bottom of the sluice cause the water to eddy into small basins, retarding the current so that gold may settle. How to thank TFD for its existence? Tell a friend about us, add a link to this page, add the site to iGoogle, or visit webmaster's page for free fun content. |
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Striking "paydirt" as a placer miner involved a considerable degree of chance and most claims did not supply steady forms of income. All samples are being processed by Jerry Bryde, a veteran placer miner and 1984 World Gold Panning Champion. This number is considered a minimum because much of the gold recovered was not reported and, of course, placer miners are still actively mining gold more than 100 years after the initial discovery in 1896. |
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