Gold mining method for gold ore beneficiation

Mixture of gold mercury method is a simple and ancient method. It is based on the principle that gold particles are easily wetted by mercury, and mercury is then diffused into the gold particles to form gold amalgam (including amalgam). The amalgamation reaction can be expressed by the following formula:

Au+2Hg=AuHg2

The composition of gold amalgam (paste) varies with its gold content. When the mercury is mixed, the surface of the gold particles is first wetted by mercury, and then the mercury diffuses into the interior of the gold particles to form AuHg2, AuHg, Au3Hg, and finally forms the solid solution Au3Hg of gold in the mercury. When the amalgam is heated to above 375 °C, the mercury volatilizes in the form of elemental mercury, and the gold exists in the form of sponge gold.

Mercury amalgamation is generally not an independent process, and often forms a joint process with other methods of selection. In most cases, amalgamation is only an aid to gold recovery. Due to the poor working conditions of mercury, the labor intensity is high, it is easy to cause mercury poisoning, and the waste water containing mercury should be cleaned. It is gradually being replaced by flotation or re-election. However, the amalgamation method can recover the natural gold of the monomer, which can be used as a real estate gold, so it still occupies a certain position in the gold beneficiation . The principle flow of amalgamation and gold extraction is shown in Figure 8-1.