Gold is generally found mixed with rock. Two methods are used to extract gold, or to separate it from the rock in which it is found. The gold will dissolve in the mercury to form an amalgam or alloy of mercury. The amalgam is then filtered and heated so that the mercury evaporates, leaving pure gold behind.
in the second method the minerals containing gold are added to a sodium cyanide solution. This reacts with the gold in the minerals form a new compound of gold. The solution is then filtered to remove impurities. In the next step, zinc is added to the solution with the compound to produce pure gold.
Using these methods, about 1500 tons of gold are produced annually in the world. Did you know that most of this gold comes from South Africa.
