Limestone extraction methods. Limestone mining methods Limestone mining sites and methods

Limestone is one of the oldest rocks on Earth. This rock was born millions of years ago and mined at the bottom of the ocean, which made up most of the planet's surface. The main constituent is calcium.

Extraction by conventional method

In order to get a limestone slab, you can use the good old way to do this. The main thing is to find a small way out from under the ground. Next, with the help of a shovel, it is necessary to clear the area in which the limestone will be mined. Use a crowbar to form a crack in the limestone slab, and then pry off the edge of the slab. Then you need to lift it up. Since limestone lies underground in layers, only a small plate of it can be lifted.

Take the plate and take it out of the place where the limestone lies. You can cut this breed with the help of the most ordinary saw. And in order to make it easier, take water and soften the stove.

Explosive way

Limestone can also 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.

Further, a quarry in which limestone has already been mined must be covered with earth and planted with herbs and plants. This method can be used in large deposits, and as for small ones, there is no need to use an explosive method. In them, limestone must be removed in blocks that have the shape of rectangles. This is due to the fact that contour gaps are created.

This technology is called bar working and is based on the fact that an array of limestone is created with cuts that are directed perpendicular to natural cracks.

The work is carried out with the help of various machines that are engaged in cutting stone, and in this process one cannot do without the participation of an excavator. This technology has the advantage of:

• it is comparatively simple;
• the blocks immediately have a good shape;
• easy to transport and handle.

Due to the fact that it has a porous structure, limestone is commonly used in construction. From it you can build temples, palaces and estates.

Similar content

Limestone is a sedimentary rock of organic origin. There is also a chemogenic origin of limestone, when the rock is formed as a result of chemical precipitation during the evaporation of water or from aqueous solutions. The basis of the rock is mainly calcium carbonate, presented in the form of calcite crystals of various sizes. The extraction of limestone is in demand, since a person uses this rock in many areas.

Description

The basis of limestone is calcium carbonate - a substance that can dissolve in water. As a result, karst is formed. It can decompose into bases and carbon dioxide. This is carried out at great depths, because due to the influence of the heat of the Earth, limestone forms a gas for mineral waters.

Limestone may include impurities of clay minerals, dolomite, quartz, gypsum, pyrite. Natural limestone has a light gray color, although it can be black and white. Impurities give a blue, pink, yellow tint. Limestone mining is in demand because of its wide application. The breed is durable, known for its unique characteristics that make it unlike other materials.

Classification

A common type of rock is the shell rock, which consists of the shells of marine animals and their fragments. There are other types of limestone:

• Bryozoan, which includes the remains of bryozoans - small invertebrates living in colonies in the seas.
• Nummulitic, consisting of extinct unicellular organisms nummulites.
• Marble. It happens thinly layered and massively layered.

During metamorphism, limestone undergoes a process of recrystallization, due to which this rock forms marble.

Monomineral rock is limestone, the method of extraction of which may differ, depending on the type of impurities, structure, geological age. There are organizations that mine limestone. Places and methods of extraction are determined by the terrain, types of rocks and other characteristics.

Place of Birth

As can be seen from the above, limestone is considered to be a sedimentary rock that appeared with the participation of living organisms living in sea basins. The breed is mined in many regions of our country and other states. Russia is considered one of the leaders in terms of its presence.

Limestone is considered the "building material" for mountain ranges. An example is the Alps, although it can occur in other mountainous areas. Limestone mining takes place all over the world. There are many reserves in our country. Moreover, all limestone mining sites make it possible to obtain different types of natural material: dense, white, flux, shell-oolitic.

Limestone mining is known in Russia. Deposits are popular in the western part of the country. Developments are carried out from the Belgorod and Tula regions to Moscow, the Vologda, Voronezh regions. Mining is carried out near St. Petersburg, in the Krasnodar Territory, Arkhangelsk, in the Urals, in Siberia. Of the neighboring countries, there are deposits in the Donetsk region of Ukraine.

Mining methods

Mining is carried out by an open pit method. The top layer of soil and clay is removed. This is how a quarry is formed. Limestone mining involves pyrotechnical work to crush and detach portions of rock. Then it is taken out by cars for processing.

The breaking method is considered the world's first mining method. This name was obtained due to the fact that the rock was removed with crowbars, and then stones were knocked out of the formation with hammers. An alternative to this method is now being used. Explosive method is used. A small crumb is obtained from the breed. The excavator collects it, loads it onto dump trucks, and then everything is transported to the plant, where it is processed and cleaned.

There is a special device for the excavator, with which the extraction of limestone can be carried out without explosion. The driver changes the bucket for a mounted machine that loosens the rock. This method is used in areas with high population density. There is a method of extraction by a milling combine. This is the most profitable option. At the same time, rock is mined, crushed and transported.

Features of the traditional way

The old method is used to extract limestone slabs. You just need to find a way out from under the ground. Then the area where mining will be carried out is cleared with a shovel.

With a crowbar, you need to create a crack in the limestone slab, and then pry off the edge of the slab and lift it up. Since limestone is located underground in layers, only a small plate of it should be raised. It must be pulled out of the place where the limestone lies. They cut the rock with an ordinary saw. To simplify the work, the tool is moistened in water.

explosive method

Limestone is obtained using the explosive method. First, it is necessary to open the deposits, removing earth, clay and substandard limestone from them with the help of bulldozers. Wells are drilled near the edge of the mining site and explosives are placed there. With the help of explosions, limestone layers are broken off, which then needs to be loaded into dump trucks and taken out for further processing.

Then the quarry where the extraction was carried out is covered with earth, planted with herbs and plants. This method is used in large deposits. And in small ones, the explosive method should not be used. Then the limestone is taken out in blocks similar to the shape of rectangles. This technology is called bar working.

The work is done by different machines that cut stones. You definitely need an excavator. The technology has its advantages:

• Simplicity.
• Nice block shape.
• Easy transport and handling.

Since limestone has a porous structure, it is used in the construction industry. From it erect temples, palaces, estates.

Types and colors of limestone

Limestone mining allows you to get different rocks. They differ in color, structure, chemical composition, origin, area of ​​use and other characteristics. By type of application, limestones of different colors are found:

• White and gray - "pure" rock, in which there are no impurities.
• Red and brown are limestones with manganese.
• Yellow and brown - contain iron.
• Green - stones with seaweed inclusions.
• Dark gray and black - have organic impurities.

According to the structure and chemical composition, the rock is:

• Dolomitized - contains 4-17% magnesium oxide. If the proportion of magnesium increases, then dolomites are formed.
• Marbled - carbonate limestones with organic inclusions. Their palette can be from beige to gray-blue tones.
• Coral. The rocks have a porous structure. They are transformed into reefs from mollusk shells and shells of marine life.
• Clayey. The rock has a composition similar to limestone and marl. The formations are softer than limestones, brittle compared to shale clays.

By origin, limestones are:

• Jurassic - a rock with a history of hundreds of millions of years, has high strength, density and fine grain. In the Middle Ages, limestone was called "marble" due to the fact that it could be polished.
• Putilovsky. This limestone has unique physical characteristics, low moisture absorption and abrasion. During the formation of St. Petersburg was the main building material. It is named after the place of extraction - the Putilov quarry, located in the Leningrad region.

Applications

In the metallurgical industry, it is used as a flux. It is considered the main ingredient during the creation of cement and lime. It is used as an auxiliary component for the production of soda, mineral fertilizers, paper, sugar, glass.

The material is also used to produce rubber, paints, soaps, plastics, mineral wool. It is in demand in the construction industry for the manufacture of facing and wall blocks. It is used for the construction of foundations, roads. Limestone mining makes it possible to provide building materials for the entire country.

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Limestone is a natural stone of soft sedimentary rock, which has an organic or organo-chemical origin. The main constituent of limestone is calcium carbonate (calcite). In addition, limestone may also contain impurities of quartz, phosphate, silicon, clay and sand particles, calcareous remains of skeletons of microorganisms.

limestone formations

Limestone is formed mainly in marine shallow basins. However, there are cases when natural limestone was formed outside of the usual conditions - in a freshwater environment. Stone deposits are deposits and layers. Lime deposits are sometimes formed in the same way as salt and gypsum deposits - as a result of the evaporation of water from sea lagoons and lakes. But, despite this, the main localization of limestone deposits is in the seas, which are not characterized by intense drying.

The origin of limestone is mainly associated with the release of calcium carbonate by living organisms from sea water, which is necessary for the formation of skeletons and shells. The accumulation of these remains of dead organisms mainly occurs at the bottom of the seas. Coral reefs are one of the clearest examples of how calcite is extracted and accumulated. Sometimes, if you break the limestone rock, you can see the presence of individual shells. Sea currents and sea waves have a destructive effect on reefs, as a result of which calcium carbonate is precipitated from the water at the bottom of the seas, which is added to lime debris. In addition, young limestone rocks are formed with the participation of calcite, which comes as a result of the destruction of ancient rocks.

Calcium carbonate, which is part of the rock, is able to dissolve in water, resulting in the formation of karst. There are also cases of its decomposition into a base and carbon dioxide. However, this requires proper conditions, therefore, calcium carbonate decomposes only at great depths, as a result of which, under the influence of the heat of the earth, gas is released for mineral waters.

Depending on the conditions of formation, limestone is divided into types. The most common is the shell rock. Fragments and many shells of marine animals participate in its formation. However, in addition to this type, there are others, among which are:

• Mshankovy limestone. Its main components are the remains of bryozoans, i.e. invertebrates that are quite small in size and live in colonies in the seas.
• Nummulitic limestone. The composition of this type of stone includes extinct unicellular organisms of nummulites, which belong to the order of foraminifers.
• Marble limestone. This type is subdivided into two subtypes: thin-layered and massively layered. It is no secret that metamorphism causes limestone to recrystallize, resulting in the formation of marble.

Thus, it is worth saying that limestone is a monomineral rock that has in its composition, in addition to the main component, a wide variety of impurities. The name of limestone, as a rule, depends on the type of these impurities, as well as the structure, their geological age and the nature of occurrence: oolitic limestones, ferruginous limestones, limestone limestones, Triassic limestones, etc.

Natural limestone is characterized by a light gray color, but, despite this, it can also be black or white. The existence of limestone with a bluish, pink or yellow tint is acceptable, depending on the impurities that are in the composition of the stone.

limestone deposits

There is no shortage of limestone in the world, since it belongs to fairly common sedimentary rocks formed with the participation of living organisms in the aquatic environment.

Whole alpine chains are formed from limestones. Limestones also took part in the formation of the Crimean mountains. However, these are not the only places in the world where the stone is found. Its deposits are known on the territory of the former USSR (Central Economic Region), on the territory of the North Caucasus, the Volga region, the Baltic states, the Moldavian SSR, and the Azerbaijan SSR. Among the main lime deposits are:

• Afanasievskoye field, located in the Moscow region. It is the main source of extraction of white limestone, which is used in the production of cement;
• Barsukovskoye field, which is located on the territory of the Tula region. Flux limestone is mined from it;
• Guryevskoe (Venevskoe) field. It is also located in the Tula region and is a source of dense limestone mining, from which crushed stone is produced;
• Oknitskoye deposit (Moldavian SSR). It contains shell-oolitic limestone used in the process of forming saw wall blocks;
• Badraksko-Alma deposit. Located in the Crimea. It was there that deposits of white shell sawn limestone were discovered, which is the main material for the production of facing and wall materials;
• Shakhtakhtinskoe field (Azerbaijan SSR). It is a deposit of grayish-yellow and light brown sawn cavernous travertine limestone, from which facing slabs are produced;
• The Zhetybai deposit, located on the Mangishlak peninsula, contains deposits of pink, light gray, gray-yellow porous shell saw limestone, which is also used for the production of facing slabs.

limestone mining

When extracting limestone, several methods are used to extract it from the bowels of the earth. These methods include:

• open career path. Considered the most common. With this method, the upper soil layer is removed and a quarry is formed, in which pyrotechnic works can be carried out, by which portions of limestone are crushed and detached. The next stage of this method is to transport the stone to the places of its processing. For this process, mining vehicles are used.
• explosive way. In this case, the deposits are opened by removing the earth from them with bulldozers. After that, clay and substandard limestones are also removed from them. In such places where limestone is mined, wells are formed into which explosives are laid. With the proper organization of this process, rather large limestone layers are broken off, which are taken out by dump trucks for further processing.
• mining with a milling machine. This method mechanically converts the rock into crumbs. Thus, several processes are carried out simultaneously - grinding, loading and transportation.

It is worth noting that after the extraction of limestone, the quarry should be covered with earth, as well as planted with herbs and plants. Usually these actions are carried out in places of large deposits. In small deposits, limestone is mainly mined using an explosive method. From such deposits, the extraction of stone is carried out in the form of blocks having a rectangular shape. This is due to the creation of contour gaps.

It should be noted that each of the methods is more or less economically costly. However, one of the cheapest options is stone mining with an excavator and a hydraulic ripper. But there is the most economical way, which is to use a mining combine. This method is about 7% cheaper than the previous one.

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 of 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 kaiavka 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 must have a regular rectangular shape, which facilitates their measurement and calculation of the volume of 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 of 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 on 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.