Traditionally, gold is one of the most popular financial investments, because especially in times of crisis, gold is considered a safe haven. But there is a long way to go before the coveted precious metal is on the market.
Gold is stored in the earth’s crust. It must therefore first be dissolved from the ore surrounding the gold before it can be used as a pure precious metal. This is done in different ways in the large gold mines of this world.
How gold is mined
In order to extract gold in large quantities, there are various methods. In the large mines, the precious metal is extracted either by open pit or underground mining.
Mines that produce gold by open pit mining usually consist of huge areas, some of which can cover several square kilometers. Underground mines, meanwhile, operate in the same way as conventional mines, cutting vertical and inclined shafts and horizontal tunnels into the earth to create a branching underground tunnel system in which the gold is extracted.
To obtain the precious metal in its pure form, the original method involves first crushing the gold-bearing rock by machine and then adding water so that the gold grains it contains can settle to the bottom.
Another procedure is amalgamation. In this process, mercury is added to the gold-bearing rock slurry, which combines with gold to form amalgam. This method is mostly used in the smaller mines.
Industrial gold mining, meanwhile, is usually done by cyanide leaching. In this process, the gold-bearing rock is sprinkled with a sodium cyanide solution while oxygen is added until the gold particles it contains dissolve.
Since these methods of gold extraction are all harmful to the environment, new methods have increasingly developed in recent years that bypass the use of hazardous chemicals. These include the Wilfley process, the Knelson principle and the JIG process.
The largest gold mines in the world
If the world’s largest gold mines are summarized in a ranking, this almost invariably refers to the production volume of a year and not to the gold deposits in the mines concerned. Therefore, such a ranking can also change from year to year.
Definitely among the largest mines in this world are the Muruntau mine in Uzbekistan, the Grasberg mine in Indonesia, the Goldstrike mine and the Cortez mine in the USA, and the Pueblo Viejo mine in the Dominican Republic.
The Muruntau mine, the Grasberg mine and the Pueblo Viejo mine are open pit mines. The Muruntau mine has been in existence since 1967 and has now assumed huge proportions. In addition to gold, copper is also extracted at the Grasberg mine. It also has the largest gold deposits of all the mines.
Both the Goldstrike mine and the Cortez mine are located in the US state of Nevada. Actually, each of them is three mines. Gold is mined at both large mines, both open pit and underground.