Placer gold mines originated from mines. Because gold ore is exposed to the ground, after a long period of wind and rain, rocks are weathered and cracked, and gold is separated from veins with sediments, which naturally precipitate in sand and deposit in river bottom or sand as a gold-bearing layer, thus forming placer gold mines.
The characteristics of placer gold are: the particle size is different, the big one is like broad bean, the small one is like fine sand, and the shape is different. The color varies with the fineness. More than 90% is red and yellow, eight is light yellow and seven is cyan yellow.
Extended data:
The difference between gold and placer gold:
1, placer gold is a kind of gold and belongs to raw gold.
2. The difference between placer gold and gold mainly lies in purity. The purity of placer gold extracted by elutriation is equivalent to 95 and 96 gold.
Placer gold is cheaper than gold.
4. There are four textures of gold, including gold with different purity, and sand metal is one of gold.
5. Placer gold is different from gold. Placer gold is produced at the bottom of the river and in some low-lying areas. It is washed out by mixing gold with rocks, sand and mud.
6. The difference between gold extraction from placer gold mine and gold extraction from placer gold mine.
Placer gold mines use the physical properties of minerals to extract gold without chemical treatment or changing the properties of the original placer gold mine. So the purity is not as high as placer gold. Because placer gold refining changes the purity of gold through pyrometallurgy and electrolysis.
Extracting gold from placer gold mine: firstly, it is necessary to crush and grind the ore, and preconcentrate it through mineral processing or separate gold from the ore. Gravity separation and flotation are widely used in gold mineral processing. Gravity separation plays a very important role in placer gold concentrator and production of placer gold concentrator. Flotation is a widely used mineral processing method in rock gold mines.
Methods of extracting gold from placer gold mine: There are two main methods of extracting gold from placer gold mine, one is pyrometallurgy; One is to extract gold by electrolysis. Pyrometallurgical alchemy is to first crush the ore, concentrate it with heavy sand method, and then refine it in the furnace; Electrolytic gold extraction is to dissolve gold in ore with sodium cyanide solution, and then extract gold by electrolysis. With this extraction method, the purity of gold can reach 99.9%.
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