How diamonds are mined and processed. Diamond processing plants

Greetings, friends! The legendary phrase from the movie “Cruel Romance” “An expensive diamond is expensive and requires cutting” is the true truth. And even though it had a metaphorical meaning in the movies, today we will prove how important the cutting process is in creating the most magnificent pieces of diamond production. This is the final stage of creating and processing the stone, which determines how it will sparkle and reveal all its splendor and inner glow.

Just imagine: a black, inconspicuous piece of carbon is transformed into a delightful faceted diamond during processing. One can only guess how much work goes into this, what efforts the master makes. The cutting of a diamond is designed to sharpen the mineral so much that its inner fire and magic become visible, enchant and give the owner all its attractiveness. At the same time, it is important not to use up more of the original material than necessary and to maintain its mass to the maximum.

First experiments in cutting

If we take into account the highest density of the stone and its manual processing, we can assume that a skilled cutter in modern jewelry is valued almost more than the diamonds themselves.

When did humanity realize that a cut diamond looks much more interesting and elegant than its rough counterpart? Historians note the first attempts to process stone back in the Middle Ages. On an uneven gem, planes were created by grinding, capable of refracting light rays. At first, the edges (their other scientific name is facets) were applied chaotically, but over time they acquired a certain order.

One of the first known cuts, Indian, involved creating an octagon from a wild stone. At the same time, the mineral had a pointed top, and the natural shape itself remained practically unchanged.

With the advent of more advanced equipment, experiments in diamond processing became even more successful, and various types and shapes appeared.

Interesting to know! Diamond is not only the modern name for a precious stone, but also the most popular type of diamond cut. Its appearance is associated with the name of Marcel Tolkowsky, who was the first to calculate the order of refraction of rays in a diamond in 1919 and proposed using a round shape and a brilliant cut to better reveal the aesthetics and inner strength of the stone.

This method helps light penetrate into the gem through the upper platform, refract there in the lower edges and, turning into a rainbow, come out. To the human eye it looks like a sparkle and glow that is instantly captivating. It is for the enchanting play of light that we love these precious stones.

How diamonds are cut

When you see the final product, you hardly think about how it was produced and how much work it cost its creators. Same with a diamond. Until you understand the intricacies of the process, you will not begin to value your jewelry as much as you should.

We decided to initiate you into the holy of holies and tell you how and what those very edges do that turn an uncut stone into a magical and desired diamond.

• The crystal is split. It happens that X-rays reveal defects inside a mineral, and then they need to be removed.
• On a special machine, the diamond is peeled, giving it corners and edges.
• The actual grinding takes place on an iron polishing wheel. Diamond powder is first poured onto it; it helps to sharpen the stone to an almost perfect state. It turns out that the diamond “processes itself.”
• Polishing. The final stage of giving the diamond shine.

When the process has already been established and the master has adapted and gained a lot of experience, the production of high-quality, defect-free stones goes like clockwork. If there is not enough experience, mistakes are possible, due to which diamonds are rejected for not meeting quality standards.

For example, a dome that is too large will cause light to be reflected incorrectly. It will come out not through the top, but through the bottom of the product. A disproportionately high height also leads to marriage.

If too large facets are applied to a large specimen, it will not play and refract the rays, which is why it will look dull and not a diamond at all.

Well, when a small stone doesn’t have enough edges, it will look more like a milky gem, and not like a legendary and luxurious diamond. In a word, the slightest mistake and the stone, instead of the counter of a fashionable jewelry boutique, ends up in a box with the inscription “reject”, and the master himself, with a high probability, remains without a job.

Before cutting, it is important to take into account the natural shape of the stone, with all its defects. To minimize the loss of precious source material, it is better to first create a model of the finished product on the computer.

Well, we’ve looked at the processing methods, it’s time to admire the types of cuts. At the same time, apply today's knowledge in practice. If you have a “treasury” of diamonds at home, open it and look at it. No? No problem. This is a great reason to visit a jewelry store with your loved one and surprise him with your knowledge in the field of jewelry!

Types of diamond cuts

1. Round. The same legendary one that Tolkowsky invented is still the most popular and universal. However, it also has a minus: a lot of material goes into consumption, or rather, into waste. After all, in order to achieve an ideal round shape, a natural diamond is sharpened and polished for a long time, removing “chips” from it.
2. Princess. You can recognize this type of cut by its square shape with sharp corners. It does not have the same elegance as the previous one, but the loss of mass when polishing it is minimal. In the jewelry world, this type is rated quite highly, but when purchasing, it is important to pay attention to the corners; they must be well secured and free from defects, otherwise the stone may fall out of the frame and get lost.
   
3. Pear. This cut is so delicate that it will emphasize the fragility of its young owners, and will give freshness and attractiveness to mature ladies. This look looks especially good in earrings and pendants, and enclosed in a ring it will visually lengthen your fingers.
4. Marquise. Few people know, but according to legend, this type was invented by King Louis the 14th for his Marquise de Pompadour. Or rather, the diamond was processed according to his order. He wanted the stone to certainly repeat the smile of his sweetheart and not fail. The elongated shape of the “boat” turned out to be so sophisticated that it looks divine on any woman’s hand, giving it aristocracy, and giving the owner of the jewelry charm.
5. Oval. The name alone makes it clear what shape this diamond is. It fits perfectly not only into rings, but also into pendants and earrings. If you are lucky enough to have a whole set with oval diamonds, you will become twice as charming, because oval earrings will make your face more expressive, and the pendant will unobtrusively create an accent on a beautiful neckline.
   
6. Heart. A rather young type of cut, adored by romantics and connoisseurs of unusual, exclusive diamonds. Usually these pebbles are the same in length and width, and the technology for processing them is very multi-stage and complex. “Heart” diamonds are therefore more expensive than others, but this beauty is priceless in its magnificence.
   
7. Emerald. Octagonal cut diamond, rectangular in shape. There is an opinion that the light with this cut is not refracted as variedly, but the flashes and highlights are brighter. This species is not as common as the others, but undoubtedly deserves attention and admiration.
   
8. Asher. It has more “steps” than emerald and is square in shape. Due to the multi-tiered structure, the effect of glare and play of light is achieved incredible. This is why this cut is valued and loved.

Surely, in a couple of years many more new varieties will be invented, because the popularity of diamonds is growing. People want not just luxury, but smart investments in their future, and precious stones are perfect for this.

Well, we are waiting for new exquisite specimens, which we will certainly tell you about right away and show you in the photo. If anything is worth attention, it’s the real creations of nature, carefully transformed by human hands into eternal works of art! See you again, jewelry lovers!

Team LyubiKamni

In this article:

Diamond is the hardest material in nature. Everyone knows that in order to get a diamond, the diamond is processed. But how can this be done, since this requires even harder materials? How are diamonds processed to make polished diamonds?

In fact, there are limits to the hardness of a diamond; it is different in different directions, so if you choose the right angle at which the cutting tool is directed towards the diamond, you can get acceptable results. In addition, quite a long time ago people realized that only another diamond or its fragment is suitable for these purposes.

Diamond cut

Diamond is highly crystallized carbon whose atoms have a geometric organization that allows pieces of diamond to be broken off parallel to the plane formed by the atoms. With this treatment, the surface becomes even and smooth.

Before diamond processing begins, the craftsman must study its internal structure. Any incorrectly calculated inclusion or crack can cause the stone to split during the cutting process. Diamond defects are assessed manually using a magnifying glass. Depending on the value and size of the stone, this process can take from several days to several years.

If the diamond has a matte surface, then before starting work, one side of it is polished so that its internal structure can be assessed. After this, if it is necessary to split the stone, split lines can be drawn with ink.

Split

The first stage of diamond processing is its splitting. Of course, it would be interesting to get the stone as large as possible and not split it at all, but this can entail high brittleness if there are multiple inclusions or cracks. Previously, splitting was done using a chisel and a hammer after careful calculations by the master. But this often led to errors, and the stone could be damaged.

Recently, sawing has begun to be used instead of splitting. For these purposes, a diamond saw blade is used, consisting of chalk and covered with precious stone chips. This blade rotates at a speed of 10 thousand revolutions per minute and gradually cuts the diamond.

The process can take a very long time; one stone weighing 1 carat can take up to 8 hours to cut. But recently an even more reliable method has appeared - now a laser is used for these purposes.

Friction - This procedure produces the rough shape of the diamond. Two diamonds are fixed on a lathe or special installation, after which they are installed in the correct direction and rub against each other.

Cut

Diamond cutting, or as it is also called, polishing, is done only with another diamond. This is possible due to the fact that the hardness of diamond is different in different directions. Therefore, before proceeding to this procedure, careful calculations are made. Diamond powder or chips are also used for these purposes.

On a horizontally rotating steel wheel, on the surface of which there is diamond powder and oil, the diamond edges are polished. In this case, the rotation speed of the circle is 2-3 thousand revolutions per minute.

Despite the wide variety of tools, an experienced cutter controls the position of the edges and the direction of the corners manually using a magnifying glass. There are certain mechanical machines for processing small stones, but they are rarely used.

When cutting diamonds, a very large amount of material is lost. On average, this figure can even reach 50-60%. When processing the legendary Cullinan diamond, it was about 65%. When polishing a diamond, diamond powder is additionally formed, which is also collected and used further.

Polishing - the grinding wheel has an additional strip on which very fine diamond chips (practically dust) are applied, which are used to further polish the diamond. This is done in order to remove all irregularities and traces of polishing the stone.

History of diamond processing

Diamond cutting began for the first time in India. At first they noticed that if you rub one diamond against another, their edges are polished and their shine increases. It was there that the legendary rose-shaped cut was invented. In Europe, diamond cutting began later - only in the 14th-15th centuries. For the first time in the middle of the 15th century, a jeweler cut a diamond, which later received the name “Sancy”.

Two years later, diamonds began to be cut. At first, such saws were made of iron wire with diamond powder applied to the surface. Large diamonds took a long time to cut; for example, it took two whole years to cut the Regent diamond. Therefore, this method has now been abandoned and preference has been given to copper or bronze disks.

Now almost the entire process is computerized. The machine calculates the cut shape, which will allow the stone to maximize its qualities such as brilliance and play of color. In addition to the laser, ultrasound and electrical erosion equipment are used for cutting and processing diamonds.

Despite all its obvious advantages, the stone also has some disadvantages, for example, chemical activity towards nickel and iron. At elevated temperatures, these metals form interstitial solutions with diamond, subsequently destroying the diamond. That is, diamond cannot be used to cut steel at high speed.

As one modern song says: “Diamonds are a girl’s best friend.” There is probably no person who can argue with such a statement. A jewelry factory that creates works of art from precious metals with diamonds encrusted in them is faced with the difficult task of processing diamonds, because a diamond is nothing more than a diamond that has been given the necessary cut using special technologies. And this task is not at all easy, because diamonds are considered the hardest stones in the world.

How is a diamond processed?
Diamond processing is based on two factors. The first is its structure, the second is the processing method. Speaking about the structure of diamond, it should be noted that diamond is carbon that has a high degree of crystallization. The carbon atoms that make up a diamond always create a geometric arrangement that allows pieces to be broken off parallel to the planes that the atoms create. After this kind of procedure, the surface becomes smoother. Surprisingly, the tool for processing a diamond is a diamond, or more precisely, its chipped pieces. A depression is made on one side of the crystal. A thin incisor is placed there. After hitting the cutter, another piece breaks off from the crystal. During diamond processing, the direction of this processing should not change. The crystal is sawed using special metal discs coated with diamond dust and lubricant. It turns out that with the help of diamonds we process diamond. Processing the hardest substance on Earth is a long and labor-intensive process. Only highly qualified specialists who have studied this craft for more than one year are allowed to perform such work. And the training will end with the person becoming only a trainee for many years. It won’t be long before he starts processing diamonds on his own.
Diamond (from the French brillant - brilliant, sparkling) is a diamond that has been given a special shape through processing, maximizing its natural brilliance. Diamonds are graded using the “4 Cs” system: cut, clarity, color and carat, which allows us to determine how close the stone is to perfection.

The main thing in assessing the cut of a stone is its quality: how geometrically accurate and proportional the edges are. The ideal cut is coded with the letter “A”, then in descending order of quality. Clarity is the most significant indicator of the quality of diamonds: it is expressed in the presence or absence of stone defects or foreign inclusions. A perfect diamond, without flaws, is called a pure diamond. By color, diamonds are divided into traditional (colorless and all shades of yellow) and fancy (pink, blue, indigo, green). The weight of diamonds is measured in carats (1 carat equals 0.2 grams).
The first forms of processing were quite primitive: they ground down one of the edges and polished it. In 1465, the court jeweler of the Duke of Burgundy, Ludwig van Berkem, first produced a rose-shaped cut. Over the centuries, jewelers have developed the perfect diamond cut, so that the light in the diamond is completely internally reflected. In 1961, Arpad Neji, who worked in this direction for 13 years, developed a new diamond cut - profile (“princess”). In recent years, this particular form of diamond has become very popular.

Diamond is a natural mineral that is carbon with an allotropic crystal lattice. Due to the peculiarities of its molecular structure, it is an extremely hard material that can be stored indefinitely.

The chemical composition of diamond can be changed under the influence of various factors: high temperature, pressure and/or vacuum. As a result of their action, diamond turns into another chemical element - graphite, which has a different composition of qualitative characteristics.

Diamonds are obtained through natural mining and artificial mining. In the second method, the chemical element graphite is exposed to high temperature and pressure. The graphite material changes its molecular structure and turns into diamond raw material, acquiring characteristic strength properties.

The resulting raw material requires additional processing before further use. The factor of increased diamond hardness requires a special approach to the methods of its implementation.

Story

The history of diamond mining is extremely young. This is explained by the complexity of searching and extracting the mineral, as well as the difficulties associated with its processing. The technology of processing the described material using another diamond began to gain popularity only in the 14th-15th centuries AD. Until this time, this method was used only by ancient Indian masters, who carefully kept the secrets of the technology.

On the territory of Russia, the development of mineral deposits and the development of technologies for its processing took on an industrial scale only in the second half of the 19th century. Today in Siberia, work is underway to extract this mineral from mines that are on the list of the largest in the world. At the same time, all types of diamond processing have been mastered.

Processing Features

The processing technology and the set of technical devices suitable for this are determined by the name of the final purpose for which the processed diamond will be used.

The characteristics of diamond necessitate its use in various technological systems, tools and devices. For example, a small diamond fraction - crumbs - is used as a coating that covers the working surfaces of any cutting devices. Diamond spraying is used for application on cutting discs, saws, and tapes intended for cutting metal, stone, concrete, ceramics and other materials.

Despite the resistance of diamond to a wide range of destructive loads, it is a brittle material. The use of impact-pressing technology makes it possible to grind diamonds into crumbs. The mineral is crushed using a hydraulic press (this processing option is rarely applicable).

Roll grinding technology is more widely used. As part of this process, raw materials are fed through a conveyor into a special chamber in which cylindrical rollers in contact with each other rotate. Passing between them, the rough diamonds crumble. Taking into account the strength coefficient of diamond, several blocks with rotating rollers with different gap sizes between them are used on the conveyor. This allows you to reduce the load on the mechanism, since stage-by-stage crushing is carried out according to the principle from larger to smaller.

The working surface of the rollers is coated with diamond coating, since no other material is able to withstand this load in such an effective equivalent.

The dimensional parameters of the crumb fraction are determined by the name of the final purpose for which it will be used. Diamond chips of a coarser grain size are used for rough processing of materials with a high strength coefficient: ceramics, granite, porcelain stoneware. For example, large chips are used as a cutting element applied to the working edge of circular bits designed for cutting round holes in hard materials: ceramic tiles, concrete, granite slabs and others.

Diamond chips of finer grain size are used for fine processing of certain materials. As part of this processing, materials are cleaned, ground, and polished. Polishing is done with a special paste based on diamond dust. Obtaining diamond chips of different grain sizes is achieved by crushing and subsequent sifting.

Passing crushed diamond through mesh panels with different mesh sizes makes it possible to obtain fractions of a fixed diameter.

The process of obtaining diamond materials suitable for industrial use is a more labor-intensive procedure than impact-pressing technology. These materials are used, for example, circles for cutting glass, tips of lathe cutters and others. They are elements consisting entirely of diamond mass. The production of such additions involves production procedures associated with resource costs and the use of several processing technologies simultaneously.

The strength properties of diamond significantly complicate the production of parts that place high demands on dimensional parameters and shape accuracy.

The only material that can be used to effectively process rough diamonds is the diamond itself.

The correct combination of factors affecting the processing tool and the material being processed allows processing to be performed as efficiently as possible. For example, in some cases, the workpiece is heated within a medium temperature range, and the temperature of the processing tool is kept in the low thermal range. In this case, the heated workpiece can be processed, and the percentage of tool wear is reduced.

The use of this method is due to the properties of diamond, which it acquires under the influence of high temperatures. The higher the temperature, the lower the strength coefficient of the mineral.

How to make a split?

Another method of diamond processing is hot iron processing. This mineral is capable of entering into a chemical reaction with metal heated to high temperatures. The hot iron begins to absorb the carbon component of the diamond. At the point of contact between the hot metal and the mineral, the latter melts at the molecular level.

This method has low production efficiency, however, only with its help can one achieve certain results in the processing of diamond material.

The hot steel method is used when it is necessary to saw a large volume of raw materials with a minimum waste coefficient. This method uses hot steel wire driven by rotating shafts. In this case, the cutting line is as thin as possible, and the loss of the main raw material is kept to a minimum.

Using the hot sawing method, you can only perform manipulations aimed at general processing. Detailed cutting is performed using more complex grinding technologies. This method also uses hot drilling technology. In this case, the drilling steel element is also heated to high temperatures. The effectiveness of the method is also increased due to the heating of both parts as a result of friction against each other.

Diamond drilling is used to perform roughing. Holes of the required diameter are drilled along the split line of the workpiece. Special anchor expanders are immersed in them. The technology allows you to control the expansion of anchors one by one or simultaneously. Thanks to this, it becomes possible to perform controlled splitting of the workpiece along a given line.

The angle at which the holes are drilled plays a key role in the effectiveness of the method. Any deviation from the specified values ​​may lead to a violation of the splitting accuracy.

How do you polish a diamond?

The main direction in processing technologies for this mineral is its grinding. Through this procedure, diamonds acquire their final shape, and in some cases turn into gemstones.

When making diamonds, craftsmen resort to step-by-step processing methods. The rough workpiece is cleaned of impurities of other minerals, if any. Then rough sawing is carried out, thanks to which the basic shape of the future product is formed. After this, cutting begins.

To grind diamond minerals, devices are used that are equipped with special attachments - disks or plates that have a thickness, shape and material that corresponds to the name of the procedure being performed. Fractions of diamond chips of various diameters are applied to the working surfaces of these nozzles.

If cutting is carried out to obtain a precious stone - a diamond, then many attachments with a wide range of dimensional parameters are used. The plates or disks with the largest diameter diamond chips are used first. As the process progresses, the grain size of the nozzles decreases. Final polishing is carried out using diamond nanoparticles.

Diamonds were formed more than 300 million years ago. Kimberlite magma formed at a depth of 20-25 km. Magma gradually rose along faults in the earth's crust, and when the upper layers could no longer contain the pressure of the rocks, an explosion occurred. The first such pipe was discovered in South Africa in the city of Kimberley - that’s where the name came from.

1. In the mid-50s, the richest primary diamond deposits were discovered in Yakutia, where about 1,500 kimberlite pipes have been discovered to date. The development of deposits in Yakutia is carried out by the Russian company ALROSA, which produces 99% of diamonds in the Russian Federation and more than a quarter in the world.

2. The city of Mirny is the diamond “capital” of Russia, located in Yakutia (Sakha) 1200 km away. from Yakutsk.
The Mir diamond-bearing pipe, discovered by geologists in the summer of 1955, gave its name to a workers’ settlement that grew up in the taiga and became a city 3.5 years later.

3. The population of the city is about 35 thousand people. About 80% of this population works at enterprises associated with the ALROSA group of companies.

4. Lenin Square - the city center.

5. Mirny Airport

Providing Mirny with food and consumer goods occurs in the following ways: aviation, shipping supplies (for the period while navigation is open on the Lena) and along the winter road.

6. Il-76TD cargo plane of ALROSA airlines

7. The headquarters of Russia's largest diamond mining company, ALROSA, is located in Mirny.
The history of the company began with the Yakutalmaz trust, formed to develop the primary diamond deposits of Yakutia in the early 1950s.

8. The main deposit of Yakutalmaz was the Mir kimberlite pipe, discovered on June 13, 1955.
Then geologists sent an encrypted telegram to Moscow: “We have lit the pipe of peace. The tobacco is excellent."

9. The quarry is located in close proximity to Mirny.

10. From 1957 to 2001, $17 billion worth of diamonds were extracted from the deposit, and about 350 million m3 of rock were removed.
Over the years, the quarry expanded so much that dump trucks had to travel 8 km along a spiral road. from bottom to surface.

11. The quarry has a depth of 525 m and a diameter of 1.2 km, and is one of the largest in the world: the height of it could include the Ostankino TV tower.

12. The quarry was mothballed in June 2001 and since 2009, diamond ore has been mined underground at the Mir mine.

13. In the area where the Mir pipe is located there is an aquifer. Water is now entering the quarry and thus poses a threat to the mine underneath. Water must be continuously pumped out and directed into the faults that geologists have found in the earth's crust.

14. The volume of diamond production at the mine in 2013 amounted to more than 2 million carats.
Resources (including reserves) – more than 40 million tons of ore.

15. About 760 people work at the mine.
The company operates seven days a week. The mine operates on a three-shift basis, with shifts lasting 7 hours.

16. Surveyors determining the direction of excavation through the ore body.

17. 9 roadheaders (Sandvik MR 620 and MR360) are used for excavation in the mine
The combine is a machine with an executive body in the form of an arrow with a milling crown, which is equipped with cutting tools - teeth.

18. This Sandvik MR360 combine has 72 teeth made of hardened metal.
Since the teeth are subject to wear, they are inspected every shift and, if necessary, replaced with new ones.

19. To deliver ore from the combine to the ore pass, 8 loading and delivery vehicles (LODs) operate.

20. Main converter belt 1200 meters long from the kimberlite pipe to the ore pass skip.
The average diamond content exceeds 3 carats per ton.

21. From this place to the bottom of the quarry is about 20 meters.

To prevent flooding of the underground mine, a pillar 20 meters thick was left between the bottom of the quarry and the mine workings.
A waterproof layer is also laid at the bottom of the quarry, which prevents water from penetrating into the mine.

22. The mine also has a water collection system: first, groundwater is collected in special settling tanks, then it is supplied to an elevation of -310 meters, from where it is pumped to the surface.

23. In total, 10 pumps with a capacity of 180 to 400 cubic meters per hour operate at the mine.

24. Installation of the main tape

25. And this is underground work on another pipe - “International” (“Inter”).

It is located 16 km from Mirny. Open-pit diamond mining here began in 1971, and when the quarry reached 284 m by 1980, it was mothballed. It was with Inter that underground diamond mining began in Yakutia.

26. “International” is the company’s richest kimberlite pipe in terms of diamond content in ore - more than 8 carats per ton.
In addition, Inter diamonds are of high quality and are valued on the world market.

27. Mine depth - 1065 meters. The pipe has been explored to 1220 meters.
The length of all workings here is more than 40 km.

28. The combine beats ore with a working tool (cone cutter) with cutters installed on it.

29. Next comes loading into loading and delivery vehicles, which transport the ore to the ore passes (mining openings designed to transport ore from the working area to the transport horizon located below), then the trolleys transport it to the main ore pass, through which it is fed into the skip shaft and protruded to the surface.

30. 1,500 tons of ore are mined at Inter per day. The volume of diamond production in 2013 amounted to more than 4.3 million carats.

31. On average, one ton of rock contains 8.53 carats of diamonds.
So, in terms of diamond content per ton of mined ore from Inter, there are 2 tons of ore from Mir, 4 tons from Aikhal, or 8 tons from Udachninsky.

32. Work at the mine is carried out day and night, seven days a week. There are only two holidays - New Year and Miner's Day.

33. Nyurbinskaya kimberlite pipe

The Nyurbinsky mining and processing plant was created in March 2000 for the development of deposits of the Nakyn ore field in the Nyurbinsky ulus of the Republic of Sakha (Yakutia) - the Nyurbinskaya and Botuobinskaya kimberlite pipes, as well as adjacent placers. Mining is carried out by open-pit and placer mining.

34. For the first time in the history of the association of Yakutalmaz and the Alrosa company, the Nyurbinsky GOK uses a rotational method - with the involvement of workers living in Mirny (320 km), in Nyurba (206 km) and in the village of Verkhnevilyuysk (235 km. )

35. As of July 1, 2013, the depth of the Nyurbinsky quarry is 255 meters.
The open pit will be mined up to 450 meters (up to -200 meters from sea level). There is potential to operate down to -320 meters.

36. To transport ore and overburden rocks, dump trucks of large and especially large loading capacity are used - from 40 to 136 tons.

37. Caterpillar CAT-777D dump trucks with a lifting capacity of 88 tons are used in the quarry.

38. Nyurba Mining and Processing Plant has the highest growth rates in natural diamond production in AK ALROSA.

39. The volume of diamond production in 2013 amounted to 6.5 million carats.

40.

41.

42. The average diamond content in ore is 4.25 carats per ton.

43. There are about 300-400 carats in the back of such a dump truck.

44. From a quarry or mine, ore is sent by dump trucks to a factory, where the minerals themselves are extracted from it.

45. The beneficiation of diamonds at the Mirny Mining and Processing Plant is carried out at factory No. 3, which in the 70s of the last century was the flagship of the country's diamond mining industry.
The capacity of the processing complex is 1,415 thousand ores per year.

46. ​​Coarse crushing body and jaw crusher.

In it, grinding occurs by friction of the movable “cheek” against the stationary one. 6 thousand tons of raw materials pass through the crusher per day.

47. Medium crushing body

48. Spiral classifiers

Designed for wet separation of solid material into sand (sediment, particle size up to 50 mm), and drain containing fine suspended particles.

49. Wet autogenous mill

50. Mill diameter - 7 meters

51. Rumble

52. The stones are sifted through a sieve, where they are divided into groups according to size.

53.

54. Finely processed rock is sent to spiral classifiers (screw separators), where all raw materials are separated depending on their density.

55. The heavy fraction comes from the outer side, and the light fraction comes from the inner side.

56. Pneumatic flotation machine

Fine material, together with the addition of aqueous reagents, enters a pneumatic flotation machine, where crystals of small classes adhere to foam bubbles and are sent for finishing. The smallest diamonds are extracted using a pneumatic flotation machine – from 2 mm or less.

57. This is a film machine where reagents are used to create a layer to which small diamond crystals adhere.

58. X-ray luminescent separator

This separator uses the property of diamonds to glow in X-rays. The material, moving along the tray, is irradiated with X-rays. Once in the irradiation zone, the diamond begins to glow. After the flash, a special device detects the glow and sends a signal to the cutting device.

59. Central control panel of the processing plant.
The factory also has a finishing shop where diamonds are cleaned, scattered, hand-selected, sorted and packaged.

60. Diamond Sorting Center

All diamonds mined at the company’s fields in Yakutia are sent to the Sorting Center in Mirny. Here, diamonds are separated by size class, an initial assessment of raw materials from different deposits is carried out and its monitoring is carried out to plan the work of mining and processing plants.

61. There are no perfect crystals or two identical diamonds in nature, so their classification involves sorting.
16 sizes x 10 shapes x 5 qualities x 10 colors = 8000 positions.

62. Vibrating sieve screen. Its task is to divide small diamonds into size classes. For this, 4-8 sieves are used.
About 1,500 stones are placed into the device at a time.

63. The larger ones are handled by weighing machines. The largest diamonds are sorted by people.

64. The shape, quality and color of crystals are determined by appraisers using magnifying glasses and microscopes.

65. Dozens of diamonds pass through a specialist per hour, and if they are small, then the number goes into hundreds.

66. Each stone is looked at three times.

67. Manually weighing a diamond

68. The weight of a diamond is determined in carats. The name "carat" comes from the seed of the carob tree, carat.
In ancient times, the carat seed served as a unit of measurement for the mass and volume of precious stones.

69. 1 carat - 0.2 g (200 mg)
Stones weighing more than 50 carats are found several times a month.

The largest diamond on the planet, the Cullinan, weighs 621 grams and costs about 200 billion rubles.
The largest diamond among the Yakut ones is the “XXII Congress of the CPSU”, it weighs 342 carats (more than 68 grams).

70. In 2013, ALROSA group enterprises produced more than 37 million carats of diamonds.
Of these, 40% goes for industrial purposes and 60% for jewelry.

71. After selection, the stones go to the cutting plant. There diamonds become diamonds.
Cutting losses range from 30 to 70% of the weight of the diamond.

72. As of 2013, the reserves of the ALROSA group amounted to 608 million carats, and the forecast reserves are about one third of the global total.
Thus, the company is provided with a mineral resource base for 30 years in advance.