Within extraction metallurgy, erosion or concentration (or ore processing) is the processing of ores into a useful concentrate: the metal content is driven by removing outings. Methods

Because ore consists of different minerals, it is important to separate them from each other and then select them. Techniques used are: Tailings

In addition to the ore concentrate, the tailings also arise. This is usually a large amount, especially when the ore grade (with useful metal in the ore) is low. The tailings are often environmentally hazardous due to high levels of heavy metals and a large external surface. This is because it is ground rock.

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