Gold Mining
Gold mining includes exploration, drilling, geology, refining and refining to extract gold from the mines of this metal. Sources of gold element for mining are open, underground and alluvial. The gold mining process includes the following general steps.
Mining discovery: Mining discovery may take between 1 and 10 years and requires financial resources and the use of experts in the fields of geography, geology, chemistry and engineering. Less than 0.1% of the discovered mines have the potential to be developed and mined.
Mining development: Mine development is the second stage of gold mining. For mine development, planning, mine construction and necessary infrastructure are needed.
Extraction operation: The operation of extracting the element of gold includes mining, gold processing and converting the extracted ore into a metal alloy with a purity of 60 to 90.
closing the mine: After the end of mining and mine activity, the operation of mine closure and land reconstruction is done.
Resuscitation: After the closure of the mine, the environment should be cleaned of pollution and vegetation and soil should be restored as much as possible to reach stability.
Extracting gold from its ore includes crushing, processing minerals and applying hydrometallurgy and pyrometallurgy processes on the extracted ore. Gold was extracted from alluvial rock sources with placer methods. In hydraulic mining, water pressure is used to break alluvial deposits.
Extraction of gold element by carbon absorption
Extraction is done by using activated carbon porous matrix and absorbing gold in it. To separate the gold absorbed in the carbon matrix, a strong solution of sodium hydroxide (NaOH) and cyanide are used for elution.
Mercury process for elemental gold
Small-scale gold extraction is done using mercury and the formation of mercury-gold amalgam, but due to mercury pollution on a large scale, the use of this method has been stopped.
5 tons of gold ore are needed to extract only 10 grams of gold. The process of digging the ground, the use of heavy machinery for transportation and the use of chemicals such as mercury and cyanide cause damage to the environment. The environment of gold mining mines suffers a lot due to the construction of dams on rivers, deforestation and removal of mountains.
