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Concentration of Gold Ores - a Key to Reducing Mercury Use in Artisanal and Small Scale Gold Mining

In artisanal gold mining, mercury is essentially used to concentrate the gold. It does this by bonding with the gold to form a heavy amalgam that is then easily separated from the other minerals. It follows therefore, that if mercury is used as a mechanism of concentration, producing concentrates of gold ores through other means can enable reduction or even elimination of mercury use. In other words, a good process of concentration can replace mercury and lead to big environmental and health improvements.
Concentrating gold ores before applying mercury greatly reduces the mass of material that comes into contact with mercury. This reduces the amount of material that becomes contaminated and also the amount of mercury that is required to be applied. And of course, if concentration is done with sufficient sophistication and knowledge, mercury is not needed at all.
As an important first step along the way to eliminating mercury, concentrating avoids a worst practice called whole-ore-ama…