Gold extraction process using mixed mercury method

Gold extraction process using mixed mercury method

The mixed mercury method is a method for extracting precious metals, usually not as an independent beneficiation process, but used in combination with other methods to assist in the recovery of precious metals such as gold. The process characteristic of the mixed mercury method is that it can prevent coarse gold from entering the flotation operation, thereby improving the recovery rate.

Process flow of mixed mercury method for gold extraction

  • 1. Ore preparation:Similar to a single beneficiation method, the extracted ore is first crushed and ground to achieve appropriate fineness for subsequent beneficiation processes.
  • 2. Mixed mercury:Mix the ground slurry with mercury to form mercury slurry. Mercury has a good affinity with gold and can form a mercury gold alloy (amalgam) with gold. Coarse gold is prone to combine with mercury during the mercury mixing process, forming a mercury gold alloy, which can be recovered in advance.
  • 3.Separation and purification:The slurry mixed with mercury needs to be separated and purified. This typically involves steps such as filtration, washing, and drying to remove excess mercury and tailings, resulting in a gold containing mercury gold alloy.
  • 4.Mercury alloy extraction of gold:Heat or chemically treat the separated mercury gold alloy to separate gold from the alloy and form a gold containing solution. Then, pure gold can be further extracted through electrowinning, substitution, or other methods.
  • 5.Mercury recovery and treatment:The mercury used in the mercury mixing process needs to be recovered and treated. The recycled mercury can be recycled, reducing mercury waste and environmental pollution.

Characteristics of the mixed mercury process

  • Avoiding loss of coarse gold particles:The mixed mercury method can recover coarse gold in advance during the grinding stage, avoiding gold from entering flotation operations and reducing gold loss.
  • Improve recovery rate:The mixed mercury method can improve the recovery rate of gold, especially for the recovery of coarse and fine gold particles.
  • Strong adaptability:The mixed mercury method is suitable for various types of gold mines, especially those containing more coarse gold particles.
  • Used in conjunction with other methods:The mixed mercury method is often used in combination with other mineral processing methods (such as flotation, gravity separation, chemical mineral processing, etc.) to achieve better mineral processing results.
  • Environmental and health risks:It should be noted that the mixed mercury method uses mercury as a collector, which is a toxic heavy metal that poses certain risks to the environment and human health. Therefore, when using the mixed mercury method, it is necessary to strictly control the exposure and emission of mercury, and take appropriate safety and environmental measures.
  • The mixed mercury method is an effective auxiliary method for gold extraction, which can avoid the loss of coarse gold particles and improve the recovery rate. However, due to the environmental and health risks associated with the use of mercury, it is necessary to reasonably control and treat mercury exposure and emissions to ensure the sustainability and safety of the mineral processing process.

Typical beneficiation plant

Kangshan Gold Mine in Luanchuan, Henan Province: The main metal minerals in the ore are limonite and pyrite, the main vein mineral is quartz, followed by kaolin and sericite, and the main useful element is gold. The specific process is as follows: