How are diamonds mined?
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It is considered to be the hardest diamondA natural mineral from all known, molecularly being a form of carbon. Among the precious stones, the diamond firmly occupies one of the most important places, and cut diamonds, or diamonds, are considered to be the most important jewels. How are diamonds mined?
Nature and deposits of diamonds
By its nature, the diamond is very harddielectric, which has a high wear resistance and elasticity, as well as the ability to luminescence. The overwhelming number of diamonds have a yellow or brown color, but in nature there are also pink, green, blue and even red diamonds (there are about 10 such diamonds in the world). Diamonds are used in the manufacture of drills and cutters, in the nuclear industry, as well as in the manufacture of microelectronics for computers and watches.
Before you understand how to get a diamond, you needknow the nature of the formation of these precious stones. Modern scientists adhere to the mantle theory of the origin of diamonds, according to which carbon atoms are formed into a diamond crystal lattice under high pressure under the earth at a depth of more than 200 km. Subsequently, such diamond rocks are pushed out by volcanic magma to the surface of the earth in the so-called "explosion tubes". In addition, these precious stones are found in river placers, therefore in the mining industry such deposits of diamonds are considered to be a secondary type of diamond deposit.
Initially, diamonds were mined over manycenturies from placers in India in the legendary mines of Golconda, but by the 18th century Indian diamond deposits were depleted. Since 1725, the main diamond-mining country has become Brazil, which supplied diamond crystals of high quality from a branched network of river placers. But after 150 years, diamond mining was radically changed due to the fact that in 1867 in South Africa in the town of Kimberley, the first "explosion tube" was found. That is why in the future diamond deposits began to be called kimberlite pipes, and the modern diamond mining industry is entirely built on the extraction of diamonds from kimberlite and lamproite pipes.
Now in the world there are about 35diamond mining countries, among which the leading are Botswana, Russia, Canada, South Africa. Angola and Namibia. In Russia, the richest deposits are diamonds in Yakutia, the Arkhangelsk region and the Perm region.
Stages of diamond mining
The extraction of diamonds is considered very costly andA complex process that initially requires large financial investments. In order to understand how diamonds are mined, it is necessary to consider all stages of the organization of diamond mining from start to finish:
- Reconnaissance stage. It is not one year, and sometimes even a decade, to first find a diamond deposit and obtain the first copy of it, which confirms the deposits of precious stone in this area.
- Infrastructural stage. After confirming the stock of diamonds, a site is prepared for the development of the stone, equipment and all necessary equipment are purchased, a residential infrastructure is created for people who will be engaged in mining and processing of stone. So, the following methods are used to prepare the site:
- If the kimberlite pipe lies at the bottom of the ocean,then the subsequent diamond mining will be carried out with the help of special robots equipped with electronic control, which, when extracting the rock, immediately find the precious stones and pack them in closed containers;
- If the kimberlite pipe is deep beneaththe development of diamonds is conducted using closed underground mines, which is considered to be an extremely dangerous and complex diamond production, which requires even greater investments.
- Factory stage. Once all the necessary infrastructure has been created, the construction of a dressing factory begins, where diamonds will be extracted from the rock. In addition, the management is engaged in the selection of personnel who will serve all stages of the diamond mining process.
- Extractive stage. This stage is considered both final and novice, after all it starts all production from extraction to processing of diamonds. How are diamonds mined at this stage? According to the widespread technology of diamond mining and processing, the whole process consists of the following stages:
- primary crushing of the ore to a volume of 50-150 mm,sifting and sorting of ore to diamond kimberlite and associated rock (this stage is carried out at the mine itself with the help of special mobile units);
- secondary crushing of ore to a volume of 1-32 mm,sieving, sorting of ore into 4 categories of pure diamond kimberlite (1-4 mm, 4-8 mm, 8-16 mm, 16-32 mm) and separating it from associated rocks (this stage is performed in the factory);
- sending to the sorting shop, where with the help of special technology, the diamonds, diameter and class are examined and selected for diamonds.
- As a rule, after completion of the sorting process, extracted with various technologies, diamonds are traded.
Diamond mining technologies
- How to get a diamond? Among the modern technologies for separating and sorting diamonds, the following are very popular:
- Use of fat plants. Fat plants are considered to be quite primitive, since when sorting diamonds tables are used, covered with a layer of fat, which is allowed to use a diamond kimberlite mixed with water. As a result, the rock is carried along with water, and the diamonds adhered to the fat surface are collected manually.
- Use of X-ray machines. X-ray installations are considered more advanced, because when irradiating ore diamonds begin to glow with blue light, which activates the pneumatic pusher, automatically cutting off precious stones.
- Use of electromagnetic installations. Since the diamond is practically not attracted by magnets, and the rock in which it is found, on the contrary, has a significant degree of magnetic radiation, then with the help of electromagnetic installations precious stones are easily separated from the ore.
- Use of slurry plants. This method is used in the extraction of precious stones from diamond placers by placing the diamond-bearing rock in a liquid with a high density (ferrosicilium). In this case, heavy stones go to the bottom, and the lungs remain on the surface and subsequently pass the stage of enrichment.
- Use of installations with a foam flotator. This method is used in the production of diamond dust, when rock diamond-containing rock is processed in workshops with millstones. Since kimberlite has a lesser hardness, the resulting diamond dust is recovered by means of a plant with a froth flotator.