- Artistic products made of stone We make status and exclusive art products from natural stone for every taste and budget - unique works that are created in a single copy.
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Care products for natural stone
In order for a natural stone to always please with its natural beauty, it needs care. For this, leading manufacturers have developed natural stone care products. -
Remains of natural stone in the warehouse, breccia
In the process of manufacturing products, the warehouse accumulates a large number of remnants of natural stone. We sell leftovers at super low prices. -
Respectable interior of office, hotel, restaurant
Style is in the details. A single color scheme, designer compositions for decorating a shop window and tables in the hall, accents correctly placed with the help of lighting, high-quality textiles, original dishes - there are no secondary details when decorating an elite interior.
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Gift ideas from KAM Group
In the portfolio of KAM Group you will find a lot of ideas for original, useful and bright gifts. Whether you are going to please the household, surprise colleagues or impress business partners - we will help you choose the right present for different audiences. -
What is the difference between artificial marble and natural
With the development of technology, artificial marble for architectural and interior work appeared on sale. Such materials allow you to make a budget and quite beautiful repair, but they are far from the aesthetics and nobility of natural marble. -
Private residences: from classic to high-tech
Although the fashion at the residence and rich life always relevant, time has made its own adjustments to the architectural appearance and interiors of private houses - many new styles have appeared, building technologies have stepped forward. -
Stone processing: from quarry to product
How is the extraction of stone in quarries and subsequent processing. Preparing blanks for special equipment and subsequent production. -
Skyros - natural stone from Greece
Skyros stone was used by the ancient Greeks for construction as early as the 8th century. BC e. From them, the love for this type of marble was inherited by the architects of the Roman Empire and Byzantium. This material experienced its second birth at the end of the 19th century, when it again and now forever entered the arsenal of architects and designers. -
Arbor made of stone
The gazebo is an aesthetic architectural form that adds grace and comfort to the garden and park ensemble. It is nice to relax in it on a warm summer evening, gather guests for a picnic, celebrate a holiday, organize a romantic candlelit dinner or just spend a couple of hours in peace and quiet.
The area of the site from which the overburden is removed depends on the annual need for lime and the thickness of the limestone layer.
So, for example, if the annual demand for lime is 500 tons, then it is necessary to burn approximately 1000 tons of limestone.
When limestone is crushed, waste is obtained in the form of fine gravel, and losses partially occur during its transportation, which is about 25%. Consequently, for the extraction of 1250 tons of limestone (with a mass of 1 m3 about 2 tons), it is necessary to develop 625 m3 of it.
To obtain an annual supply of limestone with an average layer thickness, taking into account its possible layers in the overburden, equal to 2 m, it is necessary to free the area from overburden: 625: 2 = 312.5 m2.
Overburden, if possible, is removed by bulldozers and excavators during the warm season.
The selected infertile soil is transported from the development site as the overburden is removed to ravines, depressions, and excavations.
LIMESTONE MINING
Methods for the development of limestone depend on the structure and nature of the strata. Limestone layers can be arranged in layers horizontally or with a certain angle of inclination to the horizon. There are limestones with almost vertically arranged layers.
In limestones with a layered structure, there are usually layers of clay between the layers, in addition, the layers are often cut through by cracks, which helps to facilitate limestone breaking.
To develop such limestone, scrap is driven into the interlayer between the layers, a solid object is placed under it (another scrap, a hammer or a strong stone), and by pressing on the free end of the scrap, the slab is lifted. Usually pieces of limestone are easily separated by interlayers and cracks.
If the limestone is a solid mass and has few cracks, then to facilitate the breaking out of the blocks on top of the massif, a caulk is cut down with a pick in the place where it is desirable to separate the block from the formation. Then the layer is knocked out with a crowbar and the block is broken out in the usual way. The height of the detached block should not exceed 0.8 ... 1 m.
With a horizontal arrangement of layers, as well as with a small angle of inclination, the development of layers is carried out in any direction. It is somewhat easier to carry out the development towards the direction of falling layers. But this is allowed only if the slope of the layers is small and does not exceed the angle of inclination at which the broken blocks can themselves roll down the exposed layers. If the limestone layers are located at a steep angle, it is developed in the opposite direction.
When developing limestone deposits, it is necessary to comply with the requirements of safety and labor protection. Work can be carried out in ledges, breaking out a stone simultaneously on two or even more layers of limestone. The height of the ledge should not exceed 2 meters, the sole should have a flat platform cleared of debris with a width of at least 0.7 m. Sheer walls should be given a slight slope, 10 ... 15 cm per meter of height.
The second ledge should in no case come close to the slope of the first one, so that there is no shedding of limestone from the surface of the wall of previously mined layers (located above the ledge).
Blocks of limestone broken out of an array or from a layer are broken into smaller pieces with sledgehammers and stored in stacks no more than 2 m high. In terms of stacks, they should have a regular rectangular shape, which makes it easier to measure them and calculate the volume of the stone.
A limestone warehouse is arranged near the place of firing. For this purpose, it is necessary to choose a flat, dug out area that is not flooded with water.
LIMESTONE KILNING IN A KILN
Lime kilns are various types. The most accessible for collective farms are shaft furnaces of low power (11).
The walls of the furnace are laid out of brick. The furnace has a firebox, which serves for the initial kindling of the furnace. The discharge opening is located above the grate. Roasting of limestone is carried out in a bulk way with layer-by-layer loading of stone and anthracite coal into the mine. For ease of loading, the furnace is located in the slope of a ravine or on a steep slope. It is more expedient to place the furnace directly in the quarry, in the slope of the mine.
First, firewood is loaded onto the grate, on which the first layer of stone of the same size is laid, with a layer thickness of 25 ...
In batch furnaces, the consumption of coal per 1 ton of lime is 300...400 kg. The subsequent loading of stone and fuel is carried out with the same alternation of layers.
To weaken the temperature effect on the walls during the combustion of fuel, the thickness of the coal layer near the walls is reduced.
The stove is loaded with stone and fuel first at about 2/3 of the height of the stove, then firewood is placed under the grate and kindled. After heating the furnace, continue loading the furnace to the top. After that, the walls are built up by laying the stone dry to a height of up to 70 cm and the increased volume of the furnace is filled with fuel. After the firing is completed, the volume of stone setting in the kiln will decrease and the lime will fall to the level of the top of the main volume of the kiln.
The finished lime is unloaded through the unloading opening, for which a brick is removed from it.
To obtain 1 ton of lime, it is required to burn 1.2 ... 1.4 m3 of limestone. Lime must comply with GOST 9179-77.
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.
IN Lately use powerful cone drilling rigs with a capacity of up to 30 m / h (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 allows us to solve two important tasks integrated use subsoil: organization of selective mining of rocks of various quality and 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 blasted and washed material is then classified by size into individual factions for firing in the 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. For this, along with the quality of the fired product ( chemical composition, crystal structure), first of all, the firing temperature plays a role, which determines the pore structure of the roasted product. In the following, the most important reactions and processes for lime firing are described in detail.
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. Fossils can often be found in rock fragments ancient life those years...
6. The deposit is developed by an open method. Technological process 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, using a bulldozer or loader, remove the top fertile layer soils - chernozem, and store it for the 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 mined-out space 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, for example big Stone, a special wheeled bulldozer will take 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
Sedimentary rock of organic, less often chemogenic origin, consisting mainly of calcium carbonate in the form of calcite crystals of various sizes.
Limestone, consisting mainly of the shells of marine animals and their fragments, is called shell rock. In addition, there are nummulite, bryozoan and marble-like limestones - massively layered and thinly layered. During metamorphism, limestone recrystallizes and forms marble.
Calcium carbonate, which is part of limestone, is able to slowly dissolve in water, and also decompose into carbon dioxide and the corresponding bases. The first process is the most important factor in the formation of karst, the second, occurring at great depths under the influence of the deep heat of the Earth, provides a source of gas for mineral waters.
Application area
limestone brick The most widely used limestone is construction material. The strength of many varieties of limestone is sufficient for the construction of multi-storey buildings. Thin layers of wear-resistant stone - limestone flagstone - are a finished material, such limestone is used to line buildings and pave paths.
Layered limestone with a pronounced weathering relief is valued by decorators, designers and landscape architects.
Manufacturers of natural stone products often successfully play with the biological origin of the rock. The shells of ancient mollusks, preserved in limestone deposits, become an important expressive element. finishing materials. Indispensable for any construction and cements - which, in turn, are made from a mixture of limestone and clay verified in percentage terms.
Limestone marl Marl - this is the name of the variety, which includes the right amount of aluminosilicates. It is mined in many regions of the world.
How limestone is mined
Limestone can be mined using an explosive method. To do this, you first need to open the deposits by removing the earth from them with the help of bulldozers. It is also necessary to remove clay and substandard limestone from them. Along the edge of the mining site, it is necessary to drill wells and put explosives there. If the explosions are properly organized, they will break off large layers of limestone, which later need to be loaded into dump trucks and taken to the processing site.
