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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. |
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This mission against clandestine gold panning was conducted in a deep-forest environment where the troops were temporarily housed in villages of Brazilian gold panners. But crippling arthritis in his joints, after injuries suffered in an auto accident, kept him away during his latter years from some of the things he loved, like fishing, rock hounding, gold panning and treasure hunting. Each season offers residents an array of mountain activities available at their front door whether it is hiking, biking, fishing, skiing, rafting, gold panning, bird watching, hunting, 4-wheeling, snow mobiling or if you just wanted to relax and hear the rush of the creek, birds chirping or rustling of the leaves in the light breeze. |
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