Limestone extraction method. Limestone extraction methods. Explosive mining

According to the established tradition, I analyze the next task of the MCTF Information Security Olympiad. This time we will write an exploit for a server application written in Python in an organized manner.

It is well known that an exploit is a computer program, a piece of program code or a sequence of commands that are exploited by vulnerabilities in software and used to attack a computer system. The purpose of the attack is to seize control of the system or disrupt its correct operation (from) the wiki.

As a test subject, a server code in Python with a somewhat strange implementation of the protocol is offered. You can get acquainted with the application code, then I will comment on its most striking fragments. But first of all, we need to install it on a local machine for thoughtful dissection. so

Running server.py file on Ubuntu

In general, there are no special pitfalls here, Python is included in all distributions everywhere, but here the little-known mmh3 library is SUDDENLY used (about the trick that it puts).
Unfortunately, it is not in the ubuntu distribution, so we install it from the sources
sudo apt-get install python-pip sudo apt-get install python-dev sudo python -m pip install mmh3
As a result, the sources of this module are downloaded and compiled, after which the server can be started with the command
python server.py
In addition, for error-free operation of the server, you need to put the flag.txt file in its working directory and the plug-in ../file_handler.py directory above.

In general, the purpose of the tasks in this Olympiad is to find some "flags". So the goal of the server.py hack is to read the contents of the flag.txt file, which is located in the same directory as the server executable.

Limestone is a sedimentary rock, which consists mainly of calcium carbonate (formula: CaCO 3). Most of its mass is the result of deposits of hard shells and shells of ancient marine organisms. Less common is limestone formed by chemical means.

Due to the presence of acids in the water, this rock tends to gradually dissolve, which leads to the appearance of caves and karst cavities. When heated, it decomposes with the release of carbon dioxide. This reaction is used in the production of cement and is also the cause of the presence of gas in mineral waters.

Limestone deposits vary in age. Its appearance also depends on it. For example, the Jurassic limestones differ significantly in appearance from the Triassic limestones.

Different impurities give this rock different properties. Thanks to the admixture of manganese oxide, dolomitic limestones are formed. An admixture of sulfur oxide is characteristic of marl rocks. Sandy limestones contain impurities of quartz, opal, chalcedony. Rocks with an admixture of clay are also known.

The color of limestones is predominantly light shades, it can be white, gray, yellow. Less common are reddish and brown. Sometimes you can find greenish and brown shades. The rarest color option is black.

The density of different types of limestone is from 2500 to 3000 kg per cubic meter.

Distribution of limestone rock

Limestone is a fairly common rock. There is a lot of it on the territory of Russia, Europe and North America. The only region where it does not exist is Australia. Deposits of this rock are usually confined to the bottoms of the ancient seas, where aquatic organisms with calcareous shells lived. Many European mountains (such as the Alps) are composed almost entirely of limestone.

Limestone: where it is mined

The large distribution of limestone makes it possible to extract it in various regions of the world. In Russia, most of the large deposits are confined to the western part of the country. There are quarries for the extraction of this stone in the Leningrad, Voronezh, Tula, Belgorod, Arkhangelsk and Vologda regions. Limestone is also mined in the North Caucasus, in the Urals, in certain regions of Siberia and in the Moscow region.

In the Vologda Oblast, limestone is mined in quarries located near the plant where it is processed.

The most famous of the Russian deposits are Shvakinskoye and Savinskoye. They are located in the Arkhangelsk region. The limestone mined from them is sent to cement plants. The total reserves of this rock in these fields exceed 100 thousand tons. Approximately half of this volume will be used in subsequent production.

The most profitable deposits are located in the central regions of the European territory of Russia. In the Urals, the Chelyabinsk region has the largest reserves, and in Siberia - the Novosibirsk, Kemerovo regions and the Krasnoyarsk Territory.

Active development of limestone for the production of cement is carried out in the vicinity of Novorossiysk.

Limestone mining in Novosibirsk

A large modern quarry, where limestones of the Sokolsko-Sitovsky deposit are being developed, is located two kilometers northeast of Lipetsk. This quarry produces the so-called flux limestone, about 15 percent of which is obtained here. This is one of the largest sections in the world: its dimensions are 1.5 by 0.5 km, the depth is 50 m. At the current level of production, the reserves of the extracted raw materials will be sufficient for development for more than 30 years.

The CIS countries also have large reserves of this breed. The largest deposit in Europe is located in the Donetsk region near the village of Yelenovka. Dolomite is also mined here. The development of the deposit has been carried out for 150 years.

Some sections are distinguished by the special quality of the rock extracted from them. In Russia, this is the famous deposit near the village of Myachkovo, located near the Moscow River. The limestone mined on it is distinguished by its white color and high strength. This allows it to be used for laying pavements and in the construction of mills.

How limestone is mined

Limestone is mined in quarries. This option of extracting minerals is called open. At the first stage, the so-called stripping works are carried out. They consist in removing the upper layers of soil, under which there is a mineral. During the operation of a quarry, mining is carried out directly. After its completion, reclamation activities are carried out.

The extraction procedure consists in grinding (crushing) the rock on the spot, followed by its transportation to the processing site.

Explosions and other methods and technologies are used to grind it. The latter include excavators - giant machines that bite into a layer of limestone rock. Hydraulic loosening methods are also used.

Ways to use limestone

The widest scope of this breed is construction and finishing work. Entire houses are built from it. Layers of high-quality limestone are used for finishing and pavements. Containing the imprints of ancient animals, this stone is a hit with decorators and designers.

Application of limestone

One of the varieties of limestone - marl - is actively used to produce cement. It is also used for the production of lime.

Another type of this breed is chalk - used for drawing, when creating devices for welding, in the production of rubber. Certain types of limestone are used in printing. It is also used in the production of thermal insulation materials, in the metallurgical, chemical and food industries. It is often used to create embankments, including in the construction of railways.

In the past, limestone was successfully used in the construction of large structures. It was used to create such famous objects as the Great Wall of China, the Egyptian pyramids and many others. Some of them were built over a thousand years ago and are well preserved. In Russia, various churches were built with its help (the temple of Boris and Gleb, the Church of the Intercession on the Nerl), as well as other buildings in Moscow, Suzdal, St. Petersburg and other cities. It was used for paving sidewalks, in the construction of stairs, columns, fences. This stone was brought to Russia from Estonia.

In Greece, it was used to create sculptures, in Western Europe - in the construction of buildings and temples. Notre Dame Cathedral, famous in France, was also built from this stone. The famous Belém Tower in Lisbon was also built using limestone.

A detailed production report from the Sokolsko-Sitovskoye flux limestone quarry, located a couple of kilometers northeast of Lipetsk. Under the cut are large excavators, BelAZ trucks, a factory, conveyors, an explosion and much more...

1. Some official data: The quarry is being developed by Studenovskaya Joint-Stock Mining Company, currently a member of the NLMK Group and one of the Russian leaders in the production of flux limestone, used mainly in the metallurgical industry and construction.

2. Mining volumes account for more than 15% of the mined flux limestone in Russia.

3. The dimensions of the quarry are impressive: 1500x500 meters, and the depth is 50 meters. Here you can easily build more than 10 football fields or lay a track for Formula 1...

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4. According to geologists, the reserves of raw materials in the quarry at the current capacity will be enough for at least 30 years of operation.

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5. Limestone is a widespread sedimentary rock formed with the participation of living organisms in marine basins. Once upon a time, approximately 350-370 million years ago, in the Devonian period of the Paleozoic era, the Lipetsk region, like many regions of the central part of Russia, was a sea. Often in the fragments of the rock you can find fossil remains of the ancient life of those years ...

6. The deposit is developed by an open method. The technological process of mining can be divided into the following main types of work:
Stripping works
mining operations
Dumping and mining reclamation
Transport work
Mineral processing

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7. Overburden works.
First, with the help of a bulldozer or a loader, the top fertile layer of soil is removed - black soil, and stored for subsequent reclamation of lands disturbed by mining. This is followed by a clay layer with a thickness of about 20 meters, which is worked out by electric excavators with a bucket capacity of 8-10 cubic meters. Overburden works also include partial sampling of substandard (poor quality) limestone, which is located directly under the clay layer.

8. This photo clearly shows a section of the “quarry pie”: a layer of clay, a layer of substandard limestone and an even ledge of a mineral. The crumbling hill of limestone under the ledge is a consequence of the explosion. It is precisely these “consequences of the cry” that are loaded into BelAZ trucks and taken to the factory. And all overburden rocks are taken to the internal dump.

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9. Mining work.
It is customary for miners to say production, with an emphasis on the first syllable. Limestone mining itself is preceded by drilling and blasting - the most spectacular part of the whole process.

10. A hard layer of limestone, which cannot be scooped up with an excavator bucket, has to be drilled, explosive materials are placed in it and blown up. For drilling, drilling rigs of the SBR type, powered by electricity, are used.

11. Drilling rigs are serious, they drill holes with a diameter of 16 cm to a depth of up to 24 meters (7 floors). It takes 50 minutes to drill one well. A string of wells, elongated in a line, is drilled one by one 5 meters from the edge of the cliff.

12. Brave driller!

13. For the explosion, industrial and conversion explosives are used, the acquisition of which requires a whole bunch of various permits and licenses, as well as special vehicles for transportation and armed guards. You can't just buy gunpowder at the market ...

14. TNT checkers serve as a detonator.

15. On average, about 30 wells are drilled to carry out one explosion, where a total of 5-6 tons of explosives are laid.

16. To connect all the wells with explosives into a single circuit, a detonating cord is used.

17. An explosion is a very responsible matter! The quarry is completely cordoned off, guards are posted in the area of the future explosion. All equipment is taken to a safe distance, and BelAZ vehicles generally leave the quarry. Before the explosion, all cordon posts are polled by radio and the situation is clarified. If everything is fine, permission is given to carry out blasting. (The guard post and the transformer box are also being taken away).

18. The wells are not blown up simultaneously, but with a delay of several hundredths of a second, otherwise there will be an earthquake, and most of the buildings in Lipetsk will have windows blown out.

19. For a sense of scale - on the right side of the frame there is an excavator the size of a 4-story building ... Small pieces of rock can fly away to a distance comparable to the height of the main building of Moscow State University - 250 meters.

20. It can be seen how heavy pieces of hard rock are separated from the ledge in even rows and fall down.

21. The whole explosion passes in a few seconds and is well heard in the city. This is what collapsed rock looks like. After the smoke clears and the dust settles, the explosives will check for failed charges, after which the excavators and BelAZ trucks will go about their work.

22. The rock is loaded into BelAZ using a mechanical shovel (that is, an excavator), or rather, using a self-propelled full-turn excavation and loading machine. This monster runs on 6000 volt electricity, the photo shows a high-voltage cable that powers the excavator's engines. During a day of operation, the machine consumes as much energy as an ordinary nine-story residential building in a week.

23. At one time, the excavator can load 10 ordinary photographers, or 20 Chinese photographers.

25. The weight of such a bucket is 16 tons.

26. Each excavator employs two people to ensure the continuity of the production process.

27. In total, 6 large excavators (bucket with a volume of 8 and 10 cubic meters) and 2 smaller ones with a bucket volume of about 5 cubic meters work in the quarry.

28. Sometimes appliances break down. For example, the main gear of this excavator has failed and it is being repaired right in the quarry. The diameter of limply hanging steel ropes is 4 cm.

29. And this is a now decommissioned veteran who honestly gave the enterprise about 40 years. Despite his considerable age and shabby appearance, grandfather, in case of emergency, can be taken to work in a quarry.

30. Dumping and mining reclamation.
At a constant depth, the quarry bowl constantly moves in the direction along which the limestone occurs. On one side of the quarry, overburden is removed and limestone is mined, on the other, the goaf is filled with overburden, limestone crushing screenings and black soil.

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32. Screenings are brought from the crushing and processing plant in dump cars, which are formed after limestone crushing and are not suitable for use. The excavator dumps everything on the dump, filling the mined-out space of the quarry. Then the dumps will be covered with previously opened soil and top with black soil.

33. This mechanical shovel is smaller - with a bucket for 5 cubes.

34. Next, plowing of the land is carried out and biological reclamation is carried out - the sowing of land with useful plants. In a few years, the recultivated lands can be used again for agricultural purposes. Previously, the quarry started right from the landings (on the right in the frame) and has shifted 600 meters in 20 years. Now there is a field. In the future, the quarry may advance another 2.7 kilometers.

35. Transport work.
Every day, 12 BelAZ trucks operate on the line in the quarry, which ensure the transportation of overburden rock to dumps, and the mined limestone to the DOF - to the crushing and processing plant.

36. Belazists work around the clock in three shifts, eight hours each. During the day, BelAZ makes up to 100 walkers, and transports up to 16 thousand tons of mined limestone. In three months, the car runs the distance from Moscow to Vladivostok.

37. The carrying capacity of such a BelAZ is 55 tons, more than its own weight. BelAZ trucks with a higher carrying capacity in this quarry are not advisable to use for several reasons: the depth of the quarry, the distance of transportation, the volume of production, and so on. This baby mammoth is powered by a 700 hp diesel engine.

38. If during transportation from BelAZ something falls out onto the road, such as a large stone, a special wheeled bulldozer will remove it back to the face, to the excavator.

39. They actively fight dust in the quarry, the roads are constantly doused with a special watering can. And in winter, watering is replaced by sprinkling with a sand-salt mixture.

40. To take this shot, I had to ask the driver on the radio (each piece of equipment in the quarry is equipped with a radio station) to drive outside the watered road. The permissible speed in the quarry is 20 km/h.

41. The quarry has 14 km of technological roads built in bulk, there are also electrification and substations to power excavators. The roads are excellent, you can easily move on them by car.

42. Shop for the repair and maintenance of BelAZ.

44. The body and engine were removed from this BelAZ.

45. The mined mineral is brought to the DOF and unloaded into the receiving bunker, before that the dump truck is weighed and by simply subtracting the weight of the empty BelAZ, the weight of the cargo is obtained.

46. Receiving hopper.

47. Mineral processing.
This is the first building of the factory - the building of coarse crushing. Here, the jaw crusher rough crushes large pieces of rock. Fractions up to 10 cm in size are obtained.

49. Approximately 15,000 tons of rock are transported on a conveyor belt per day.

50. Cone crusher performs medium crushing.

51. Cunning system of vibrating screens. In closed devices, the products are divided into fractions (according to the size of the stones) and distributed along the conveyors.

52. An ordinary five-story house can easily fit in the workshop ...

53. Quite small limestone - screenings up to 1 cm are sent for unloading into dump cars for subsequent transportation to the quarry dump.

54. Corps of sorting and loading. The finished product is delivered here, where it is loaded into railway wagons. The main consumer of the products is the Novolipetsk Iron and Steel Works.

56. One car includes 69 tons of crushed stone.

58. Loading into vehicles is taking place nearby.

59. Work in a quarry does not stop at night. For this, backlighting works on excavators.

61. UFO.

62. The 55-ton BelAZ trucks used in the quarry are relatively small, and by miners' standards, they are just babies. Someday I will definitely look at the work of 320-ton trucks!

63. Night quarry and factory are beautiful!

Separately, I want to say about the people with whom I worked for two shooting days. Open, kind, cheerful miners, happy to talk about their work and equipment. Real men!
Thanks to all staff

Limestone is predominantly mined in open pit mines. Limestone without clay or sand impurities is rare. Limestone is mined mainly by drilling and blasting, sometimes mining is done with the help of rippers and bulldozers.

To do this, boreholes with a diameter of 100 ... 300 mm are passed, located in one or several rows in a checkerboard pattern, explosives are laid and a mass explosion is carried out. Drilling of wells is carried out with the help of rope-percussion machines, pneumatic percussion or drilling machines.

Recently, powerful cone drilling rigs with a capacity of up to 30 m / h have been used (Figure 1.51). Rocks are loaded by excavators with a bucket capacity of up to 8 m 3 or by loaders.

Figure 1.51 - Cone drilling machine

After the explosion, the material may contain oversized pieces - large pieces that the excavator cannot capture. Oversized cutting is carried out by an explosive method using overhead charges or small holes, as well as with the help of butoboys. The drilling machine with the help of special attachments is quickly converted into a rock drill.

In some cases, to reduce the cost of mining, blasting is abandoned and mining is carried out with the help of special rippers mounted on powerful tractor tractors. Their application makes it possible to solve two important problems of the integrated use of subsoil: the organization of selective mining of rocks of various quality and the extraction of raw materials in protected areas where the use of blasting is unacceptable. The efficiency of loosening depends on the strength of the rock, the degree of its fracturing, the power of the engine of the loosening-bulldozer unit, the total mass and tractive effort. Abroad, in many enterprises, instead of the explosive method, mechanical loosening is also used.

The blasted ore is transported to a crushing plant, which can operate in one or two stages. Excavators or loaders are used to load the blasted rock. If necessary, the crushed rock is released in the washing drums from clay and sandy contaminants. The limestone of some deposits contains only minor amounts of contaminants, so washing may not be necessary. The blown and washed material is then classified by size into separate fractions for firing in a kiln and for sale.

Limestone powder is also produced from limestone, for which fine grinding is carried out while drying, for example, high-speed hammer mills are used.

Upon receipt of high-quality clinkers, selective extraction of raw materials is carried out, i.e. batches of raw materials of the required composition are mined with a minimum content of harmful impurities. When mining softer rocks (for example, chalk), the need for blasting is eliminated. Soft rocks are mined using heavy bulldozers or bucket wheel excavators.

Exploded ore is transported by dump trucks to the crushing plant, which can operate in one or more stages.

Lime firing

The purpose of lime burning is to convert calcium carbonate to calcium oxide. Theoretically, this requires 3154 kJ/kg CaO (at 20 °C). At 900 °C, the partial pressure of CO 2 reaches 1 bar. In practice, the firing temperature of lime is much higher. A number of users (eg steel mills) want, in addition to a low residual CO 2 content, also a good reactivity, which is obtained only in certain types of furnaces. To this end, in addition to the quality of the fired product (chemical composition, crystal structure), the firing temperature first plays a role, which determines the pore structure of the fired product. In the following, the most important reactions and processes for lime firing are described in detail.

This is how you live and do not notice what is happening under your nose))) Ten kilometers from the house is the Sokolsko-Sitovsky quarry, from which on Thursdays (and sometimes on Tuesdays) an explosion is sure to spread - limestone layers are torn. In the early 1990s, I even worked there as an assistant excavator operator. Moreover, he also unlearned as an excavator operator, but did not begin to work ...

I, of course, know how limestone is mined. But, I did not know that it could look so beautiful and romantic)))

Original taken from chistoprudov How is limestone mined.

2. Mining volumes account for more than 15% of the mined flux limestone in Russia.

3. The dimensions of the quarry are impressive: 1500x500 meters, and the depth is 50 meters. Here you can easily build more than 10 football fields or lay a track for Formula 1...

4. According to geologists, the reserves of raw materials in the quarry at the current capacity will be enough for at least 30 years of operation.

7. Overburden works.
First, with the help of a bulldozer or a loader, the top fertile soil layer, the black earth, is removed and stored for subsequent reclamation of lands disturbed by mining. This is followed by a clay layer with a thickness of about 20 meters, which is worked out by electric excavators with a bucket capacity of 8 - 10 cubic meters. Overburden works also include partial sampling of substandard (poor quality) limestone, which is located directly under the clay layer.

9. Mining work.
It is customary for miners to say production, with an emphasis on the first syllable. The actual extraction of limestone is preceded by drilling and blasting - the most spectacular part of the whole process.

12. Brave driller!

14. TNT checkers serve as a detonator.

15. On average, about 30 wells are drilled to carry out one explosion, where a total of 5-6 tons of explosives are laid.

16. To connect all the wells with explosives into a single circuit, a detonating cord is used.

20. It can be seen how heavy pieces of hard rock are separated from the ledge in even rows and fall down.

23. At one time, the excavator can load 10 ordinary photographers, or 20 Chinese photographers.

24.

25. The weight of such a bucket is 16 tons.

26. Each excavator employs two people to ensure the continuity of the production process.

27. In total, 6 large excavators (bucket with a volume of 8 and 10 cubic meters) and 2 smaller ones with a bucket volume of about 5 cubic meters work in the quarry.

28. Sometimes appliances break down. For example, the main gear of this excavator has failed and it is being repaired right in the quarry. The diameter of the limply hanging steel ropes is 4 cm.

31.

33. This smaller mechanical shovel has a 5 cube bucket.

34. Further plowing of the lands is carried out and biological reclamation is carried out - the sowing of lands with useful plants. In a few years, the recultivated lands can be used again for agricultural purposes. Previously, the quarry started right from the landings (on the right in the frame) and has shifted 600 meters in 20 years. Now there is a field. In the future, the quarry may advance another 2.7 kilometers.

38. If during transportation from BelAZ something falls out onto the road, such as a large stone, a special wheeled bulldozer will remove it back to the face, to the excavator.

39. They actively fight dust in the quarry, the roads are constantly doused with a special watering can. And in winter, watering is replaced by sprinkling with a sand-salt mixture.

41. The quarry has 14 km of technological roads built in bulk, there are also electrification and substations to power excavators. The roads are excellent, you can easily move on them by car.

42. Shop for the repair and maintenance of BelAZ.

43.

44. The body and engine were removed from this BelAZ.

46. Receiving hopper.

47. Mineral processing.
This is the first building of the factory - the coarse crushing building. Here, the jaw crusher rough crushes large pieces of rock. Fractions up to 10 cm in size are obtained.

49. Approximately 15,000 tons of rock are transported on a conveyor belt per day.

50. Cone crusher performs medium crushing.

51. Cunning system of vibrating screens. In closed devices, the products are divided into fractions (according to the size of the stones) and distributed along the conveyors.

52. An ordinary five-story house can easily fit in the workshop ...

53. Very fine limestone - screenings up to 1 cm are sent for unloading into dump cars for subsequent transportation to the quarry dump.

54. Corps of sorting and loading. The finished product is delivered here, where it is loaded into railway wagons. The main consumer of the products is the Novolipetsk Iron and Steel Works.

55.

56. One car includes 69 tons of crushed stone.

57.

58. Loading into vehicles is taking place nearby.

59. Work in a quarry does not stop at night. For this, backlighting works on excavators.

60.

61. UFO.

62. The 55-ton BelAZ trucks used in the quarry are relatively small, and by miners' standards, they are just babies. Someday I will definitely look at the work of 320-ton trucks!

63. Night quarry and factory are beautiful!

Separately, I want to say about the people with whom I worked for two shooting days. Open, kind, cheerful miners, happy to talk about their work and equipment. Real men!
Thanks to all staff