Since ancient times, coal has been a source of energy for humanity, not the only one, but widely used. Sometimes it is compared to solar energy, preserved in stone. It is burned to obtain heat for heating, heating water, converted into electricity at thermal stations, and used for smelting metals.
With the development of new technologies, we have learned to use coal not only to produce energy by burning. The chemical industry has successfully mastered production technologies for rare metals - gallium and germanium. Composite carbon-graphite materials with a high carbon content, gaseous fuel with high calorie content are extracted from it, and plastic production methods have been developed. The lowest grade coal, its very fine fraction and coal dust are processed and are excellent for heating as production premises and private houses. In total, using the chemical processing of coal, more than 400 types of products are produced, which can cost tens of times more than the original product.
People have been actively using coal as a fuel for generating and converting energy for several centuries; with the development of the chemical industry and the need for rare and valuable materials in other industries, the need for coal is increasing. Therefore, exploration of new deposits is being intensively carried out, quarries and mines, and raw material processing enterprises are being built.
Briefly about the origin of coal
On our planet, many millions of years ago, vegetation developed rapidly in a humid climate. 210...280 million years have passed since then. For thousands of years, millions of years, billions of tons of vegetation died off, accumulated at the bottom of swamps, and became covered with layers of sediment. Slow decomposition in an oxygen-free atmosphere under the powerful pressure of water, sand, and other rocks, sometimes at high temperatures due to the close proximity of magma, led to the petrification of layers of this vegetation, with gradual degeneration into coal of varying degrees of carbonization.
Main Russian deposits and coal mining
The planet has coal reserves of more than 15 trillion tons. The largest mineral production comes from coal, approximately 0.7 tons per person, which is more than 2.6 billion tons per year. In Russia, hard coal is available in different regions. It has different characteristics, features and depth. Here are the largest and most successfully developed coal basins:
The active use of Siberian and Far Eastern deposits is limited by their remoteness from industrial European regions. In the western part of Russia, coal with excellent performance is also mined: in the Pechersk and Donetsk coal basins. In the Rostov region, local deposits are being actively developed, the most promising of which is Gukovskoye. Processing of hard coal from these deposits produces grades of hard coal high quality— anthracites (AS and AO).
Main quality characteristics of coal
Different industries require different grades of coal. Its qualitative indicators vary widely even among those that have the same marking and largely depend on the deposit. Therefore, before purchasing coal, enterprises become familiar with the following physical characteristics:
According to the degree of enrichment, coal is divided into:
- — Concentrates (burned for heating in steam boilers and generating electricity);
- — Industrial products used in the metallurgical industry;
- — Sludge is actually a fine fraction (up to 6 mm) and dust after rock crushing. It is problematic to burn such fuel, so briquettes with good properties are formed from it. performance characteristics and used in household solid fuel boilers.
By degree of carbonization:
- — Brown coal is partially formed hard coal. It has a low heat of combustion, crumbles during transportation and storage, and has a tendency to spontaneous combustion;
- — Coal. It has many different brands (grades) with different characteristics. It has a wide range of uses: metallurgy, energy, housing and communal services, chemical industry etc.
- — Anthracite is the highest quality form of coal.
If we compare peat and coal, the calorific value of coal is higher. The most low heat combustion for brown coal, the highest for anthracite. However, based on economic feasibility, in great demand uses simple coal. It has the optimal combination of price and specific heat of combustion.
There are a lot of different characteristics of coal, but not all of them may be important when choosing coal for heating. In this case, it is important to know only a few key parameters: ash content, humidity and specific heat capacity. Sulfur content may be important. The rest are required when selecting raw materials for processing. What is important to know when choosing coal is the size: how large the pieces are offered to you. This data is encrypted in the brand name.
Size classification:
Classification by brands and their brief characteristics:
Depending on the characteristics of coal, its brand, type and fraction, it is stored different times. (The article contains a table showing the shelf life of coal depending on the deposit and brand).
Particular attention should be paid to protecting coal during long-term storage (more than 6 months). In this case, a special coal shed or bunker is required, where the fuel will be protected from precipitation and direct sunlight.
Large piles of coal long-term storage require temperature control, since in the presence of small fractions in combination with moisture and high temperature, they have a tendency to spontaneous combustion. It is advisable to purchase an electronic thermometer and a thermocouple with a long cord, which should be buried in the center of the coal pile. You need to check the temperature once or twice a week, because some brands of coal spontaneously ignite in very low temperatures. high temperatures: brown - at 40-60 o C, the rest - 60-70 o C. Cases of spontaneous combustion of anthracite and semi-anthracite rarely occur (such cases have not been registered in Russia).
Despite the fact that today they are increasingly used alternative sources energy, coal mining is relevant area industry. One of the most important areas of application of this type of fuel is the operation of power plants. Coal deposits are located in various countries of the world, and 50 of them are active.
World coal deposits
Largest quantity Coal is mined in the United States in deposits in Kentucky and Pennsylvania, Illinois and Alabama, Colorado, Wyoming and Texas. Stone and brown coal, as well as anthracites. Russia takes second place in the extraction of these minerals.
China is in third place in coal production. The largest Chinese deposits are located in the Shanxing coal basin, in the Great Chinese Plain, Datong, Yangtze, etc. A lot of coal is also mined in Australia - in the states of Queensland and New South Wales, near the city of Newcastle. India is a major coal producer, and the deposits are located in the northeast of the country.
In the deposits of Saarland and Saxony, Rhine-Westphalia and Brandenburg in Germany, hard and brown coal have been mined for more than 150 years. There are three coal basins in Ukraine: Dnieper, Donetsk, Lviv-Volyn. Anthracite, gas coal and coking coal are mined here. Quite large-scale coal deposits are located in Canada and Uzbekistan, Colombia and Turkey, North Korea and Thailand, Kazakhstan and Poland, the Czech Republic and South Africa.
Coal deposits in Russia
A third of the world's coal reserves are located in Russian Federation. The largest number of deposits is located in the eastern part of the country, in Siberia. The largest Russian coal deposits are as follows:
- Kuznetskoye - a significant part of the basin lies in the Kemerovo region, where about 80% of coking coal and 56% of hard coal are mined;
- Kansk-Achinsk basin – 12% of brown coal is mined;
- Tunguska basin - located in part of Eastern Siberia, anthracite, brown and hard coal are mined;
- The Pechora basin is rich in coking coal;
- The Irkutsk-Cheremkhovo basin is a source of coal for Irkutsk enterprises.
Coal mining is a very promising sector of the economy today. Experts say that humanity is consuming coal too intensively, so there is a threat that the world's reserves may soon be used up, but some countries have significant reserves of this mineral. Its consumption depends on the application, and if you reduce the consumption of coal, it will last for a longer time.
Coal is one of the most famous fuel resources. The ancient Greeks were the first to learn about the flammable properties of this mineral. How coal is mined in modern world? Which countries are the leaders in its production? And what are the prospects for the coal industry in the near future?
What is coal and how is it used?
Coal is a hard and combustible mineral, a dark gray or black rock with a slight metallic sheen. “This substance flares up and burns like charcoal“- this is how Theophrastus of Eres, a student of Aristotle, described the breed. The ancient Romans actively used coal to heat their homes. And the Chinese learned to produce coke from it back in the 1st century BC.
How was coal formed? In ancient geological eras, large areas earth's surface were covered with dense forests. Over time, the climate changed, and all this woody mass was buried under the thickness of the earth. Under conditions of high temperature and pressure, dead vegetation turned first into peat and then into coal. This is how powerful layers enriched with carbon arose underground. Coal was most actively formed in the Carboniferous, Permian and Jurassic periods.
Coal is used as an energy fuel. It is on this resource that the majority of all thermal power plants operate. In the 18th-19th centuries, active mining of coal became one of the decisive factors in the industrial revolution that took place in Europe. Nowadays, coal is widely used in ferrous metallurgy, as well as in the production of so-called liquid fuel(by liquefaction).
Based on the amount of carbon in the rock, there are three main types of coal:
- brown coal (65-75% carbon);
- coal (75-95%);
- anthracite (over 95%).
Coal mining
Today, the total volume of industrial coal reserves on our planet reaches one trillion tons. Thus, this fuel resource will last humanity for many years to come (unlike oil or natural gas).
Coal is mined using two methods:
- open;
- closed.
The first method involves the extraction of rock from the bowels of the earth in quarries (coal mines), and the second - in closed mines. The depth of the latter varies widely from several hundred meters to one and a half kilometers. Each of these coal mining methods has its own advantages and disadvantages. Thus, the open method is much cheaper and safer than the underground method. On the other hand, mines cause much less damage environment And natural landscapes than a career.
It is worth noting that coal mining technologies do not stand in one place. If a hundred years ago primitive carts, picks and shovels were used to mine coal seams, now the latest ones are used for the same purposes. technical machines and equipment (jackhammers, combines, augers, etc.). In addition, a completely new extraction method is being developed and improved - hydraulic. Its essence is this: a powerful jet of water crushes a layer of coal and carries it into a special chamber. From there, the rock is delivered directly to the factory for further beneficiation and processing.
Geography of world coal mining
Coal deposits are distributed more or less evenly around the world. Deposits of this resource are present on all continents of the planet. However, about 80% of all deposits are located in North America and post-Soviet countries. At the same time, a sixth of the world's coal reserves are contained in the subsoil of Russia.
The largest coal basins on the planet are the Pennsylvania and Appalachian (USA), Henshui and Fushun (China), Karaganda (Kazakhstan), Donetsk (Ukraine), Upper Silesian (Poland), Ruhr (Germany).
As of 2014, the top five leading countries in coal production in the world are as follows (the percentage of global coal production is indicated in parentheses):
- China (46%).
- USA (11%).
- India (7.6%).
- Australia (6.0%).
- Indonesia (5.3%).
Problems and prospects of the coal industry
The main problem of the coal mining industry, of course, is environmental. Fossil coal contains mercury, cadmium and other heavy metals. When rock is removed from the ground, it all ends up in the ground, atmospheric air, surface and underground waters.
In addition to the damage caused to the natural environment, the coal industry also poses enormous risks to human life and health. First of all, this concerns miners. Excessive dust in the air in closed mines can lead to serious diseases such as silicosis or pneumoconiosis. We should not forget about the large number of tragedies that annually claim the lives of hundreds of coal industry workers around the world.
But, despite all the problems and dangers, humanity is unlikely to be able to abandon this fuel resource in the near future. Especially against the background of the rapid decline in oil and gas reserves in the world. Today, the coal mining industry is dominated by an increasing trend in anthracite production. In some countries (in particular, Russia, Turkey, Romania) the volume of brown coal production is growing.
Coal mining in Russia
Russia was first introduced to this mineral by Peter the Great. While relaxing on the banks of the Kalmius River, the king was shown a piece of black rock that burned beautifully. “If not for us, then for our descendants this mineral will be useful,” the sovereign rightly summed up then. The formation of the Russian coal industry took place in the first half of the 19th century.
Today, coal production in Russia amounts to over 300 million tons annually. In general, the country's depths contain about 5% of the world's reserves of this fuel resource. The largest coal basins in Russia are Kansko-Achinsky, Pechora, Tungussky and Kuzbass. Over 90% of all the country's deposits are located in Siberia.
Coal is a sedimentary rock that forms in the earth's formation. Coal is an excellent fuel. It is believed that this is the most ancient look fuel that our distant ancestors used.
How is coal formed?
To form coal it is necessary huge amount plant mass. And it is better if the plants accumulate in one place and do not have time to decompose completely. The ideal place for this is swamps. The water in them is poor in oxygen, which prevents the life of bacteria.
Plant matter accumulates in swamps. Without having time to completely rot, it is compressed by subsequent soil deposits. This is how peat is obtained - the source material for coal. The following layers of soil seem to seal the peat in the ground. As a result, it is completely deprived of oxygen and water and turns into a coal seam. This process is long. Thus, most of the modern reserves of coal were formed in the Paleozoic era, i.e. more than 300 million years ago.
Characteristics and types of coal
(Brown coal)
The chemical composition of coal depends on its age.
The youngest species is brown coal. It lies at a depth of about 1 km. There is still a lot of water in it - about 43%. Contains a large amount volatile substances. It ignites and burns well, but produces little heat.
Hard coal is a sort of “middle peasant” in this classification. It lies at depths of up to 3 km. Since the pressure of the upper layers is greater, the water content in coal is less - about 12%, volatile substances - up to 32%, but carbon contains from 75% to 95%. It is also flammable, but burns better. And due to the small amount of moisture it gives more heat.
Anthracite- an older breed. It lies at depths of about 5 km. It contains more carbon and virtually no moisture. Anthracite - solid fuel, does not ignite well, but specific heat combustion is the highest - up to 7400 kcal/kg.
(Anthracite coal)
However, anthracite is not the final stage of transformation organic matter. When exposed to more severe conditions, coal transforms into shuntite. At higher temperatures, graphite is obtained. And under ultra-high pressure, coal turns into diamond. All these substances - from plants to diamonds - are made of carbon, only the molecular structure is different.
In addition to the main “ingredients,” coal often includes various “rocks.” These are impurities that do not burn, but form slag. Coal also contains sulfur, and its content is determined by the place where coal is formed. When burned, it reacts with oxygen and forms sulfuric acid. The less impurities in the composition of coal, the higher its grade is valued.
Coal deposit
The location of hard coal is called a coal basin. There are over 3.6 thousand coal basins known in the world. Their area occupies about 15% of the earth's land area. The largest percentage of the world's coal reserves is in the United States - 23%. In second place is Russia, 13%. China closes the top three countries with 11%. The largest coal deposits in the world are located in the USA. This is the Appalachian coal basin, whose reserves exceed 1,600 billion tons.
In Russia, the largest coal basin is Kuznetsk, in the Kemerovo region. Kuzbass reserves amount to 640 billion tons.
The development of deposits in Yakutia (Elginskoye) and Tyva (Elegestskoye) is promising.
Coal mining
Depending on the depth of coal occurrence, either closed or open mining methods are used.
Closed or underground mining method. For this method, mine shafts and adits are built. Mine shafts are built if the depth of coal is 45 meters or higher. A horizontal tunnel leads from it - an adit.
There are 2 closed mining systems: room and pillar mining and longwall mining. The first system is less economical. It is used only in cases where the discovered layers are thick. The second system is much safer and more practical. It allows you to extract up to 80% of the rock and evenly deliver coal to the surface.
The open method is used when the coal lies shallow. To begin with, they analyze the hardness of the soil, determine the degree of weathering of the soil and the layering of the covering layer. If the soil above the coal seams is soft, the use of bulldozers and scrapers is sufficient. If the upper layer is thick, then excavators and draglines are brought in. The thick layer of hard rock lying above the coal is blasted.
Application of coal
The area of use of coal is simply enormous.
Sulfur, vanadium, germanium, zinc, and lead are extracted from coal.
Coal itself is an excellent fuel.
Used in metallurgy for iron smelting, in the production of cast iron and steel.
The ash obtained after burning coal is used in the production of building materials.
From coal, after special processing, benzene and xylene are obtained, which are used in the production of varnishes, paints, solvents, and linoleum.
By liquefying coal, first-class liquid fuel is obtained.
Coal is the raw material for the production of graphite. As well as naphthalene and a number of other aromatic compounds.
As a result of chemical processing of coal, over 400 types of industrial products are currently obtained.
Coal called sedimentary rock, formed during the decomposition of plant remains (tree ferns, horsetails and mosses, as well as the first gymnosperms). The main reserves of coal currently mined were formed during the Paleozoic period, about 300-350 million years ago. Coal has been mined for several centuries and is one of the most important minerals. Used as solid fuel.
Coal consists of a mixture of high molecular weight aromatic compounds (mainly carbon), as well as water and volatile substances with a small amount of impurities. Depending on the composition of coal, the amount of heat released during its combustion changes, as well as the amount of ash produced. The value of coal and its deposits depends on this ratio.
For the formation of a mineral, the following condition also had to be met: rotting plant material must have accumulated faster than its decomposition occurred. That is why coal was formed mainly on ancient peat soils, where carbon compounds accumulated and there was practically no access to oxygen. The starting material for the formation of coal is, in fact, peat itself, which was also used as fuel for some time. Coal was formed when peat layers were under other sediments. At the same time, the peat was compressed and lost water, resulting in the formation of coal.
Coal occurs when peat layers occur at a significant depth, usually more than 3 km. At greater depths, anthracite is formed - the highest grade of coal. However, this does not mean that all coal deposits are located at great depths. Over time, under the influence of tectonic processes various directions some layers experienced uplift, resulting in them being closer to the surface.
The method of coal mining also depends on the depth at which coal-bearing minerals are located. If coal lies at a depth of up to 100 meters, then mining is usually carried out open method. This is the name for removing the top of a deposit, in which the mineral appears on the surface. For mining from great depths, the shaft method is used, in which access is achieved through the creation of special underground passages - shafts. The deepest coal mines in Russia are located at a distance of about 1200 meters from the surface.
The largest coal deposits in Russia
Elga field (Sakha)
This coal deposit, located in the southeast of the Republic of Sakha (Yakutia) 415 km east of the city of Neryungri, is the most promising for open-pit mining. The field area is 246 km2. The deposit is a gentle asymmetrical fold.
The deposits of the Upper Jurassic and Lower Cretaceous are coal-bearing. The main coal seams are located in the deposits of the Neryungri (6 seams with a thickness of 0.7-17 m) and Undyktan (18 seams with a thickness of also 0.7-17 m) formations.
The coals here are mostly semi-shiny with a very high content of the most valuable component - vitrinite (78-98%), medium- and high-ash, low-sulfur, low-phosphorus, well-sintered, with a high calorific value. Elga coal can be enriched using special technology, which will produce a higher quality product that meets international standards. Thick, flat coal seams are overlain by thin deposits, which is very important for open-pit mining.
Elegest deposit (Tuva)
Located in the Republic of Tuva. This field has reserves of about 20 billion tons. Most reserves (about 80%) are located in one layer 6.4 m thick. The development of this deposit is currently ongoing, so coal production here should reach its maximum capacity around 2012.
Large deposits coal (the area of which is thousands of km2) are called coal basins. Typically, such deposits are located in some large tectonic structure (for example, a trough). However, not all fields located close to each other are usually combined into basins, and sometimes they are considered as separate fields. This usually happens according to historically established ideas (deposits were discovered in different periods).
Minusinsk coal basin is located in the Republic of Khakassia. Coal mining here began in 1904. The largest deposits include Chernogorskoye and Izykhskoye. According to geologists, coal reserves in this area amount to 2.7 billion tons. The basin is dominated by long-flame coals with a high calorific value. The coals are classified as medium ash. The maximum ash content is typical for coals of the Izykh deposit, the minimum – for coals of the Beiskoe deposit. Coal mining in the basin is carried out in different ways: there are both open-pit mines and mines.
Kuznetsk coal basin (Kuzbass)- one of the largest coal deposits peace. Kuzbass is located in the south in a shallow basin between the mountain ranges of Mountain Shoria and. This is the territory of the Kemerovo region. The abbreviation “Kuzbass” is the second name of the region. The first deposit in the Kemerovo region was discovered back in 1721, and in 1842 the geologist Chikhachev introduced the term “Kuznetsk coal basin.”
Mining here is also carried out in different ways. There are 58 mines and more than 30 open-pit mines on the territory of the basin. The quality of "" coals is varied and is among the best coals.
Coal-bearing strata of Kuznetsk coal basin consists of approximately 260 coal seams of varying thickness, unevenly distributed throughout the section. The predominant thickness of coal seams is from 1.3 to 4.0 m, but there are also thicker seams of 9-15 and even 20 m, and in some places up to 30 m.
The maximum depth of coal mines does not exceed 500 m (average depth is about 200 m). The average thickness of the developed coal seams is 2.1 m, but up to 25% of mine coal production occurs in seams over 6.5 m.
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