Charcoal is the substance's name and formula. Coal. Properties, mining and use of coal. How bituminous coal is formed

Coal in its various modifications can range in color from brown to black. It is a good fuel, therefore it is used in the conversion of thermal energy into electrical energy. It is formed as a result of the accumulation of plant mass and the passage of physicochemical processes in it.

Various coal modifications

The accumulation of wood pulp in swampy soil leads to the formation of peat, which is a precursor to coal. The peat formula is quite complex; in addition, there is no specific stoichiometric ratio for this type of coal. Dry peat consists of carbon, hydrogen, oxygen, nitrogen and sulfur atoms.

Brown coal or lignite.
Bitumen.
Anthracite.

The end product of this chain of transformations is solid graphite or graphite-like coal, the formula of which is pure carbon C.

Carboniferous wood

About 300 million years ago, during the Carboniferous period, most of the land on our planet was covered with giant fern forests. Gradually, these forests died out, and wood accumulated in the marshy soils on which they grew. Large amounts of water and dirt obstructed oxygen penetration, so the dead wood did not decompose.

For a long time, the newly dead wood covered the older layers, the pressure and temperature of which gradually increased. The accompanying geological processes ultimately led to the formation of coal deposits.

Carbonization process

The term "carbonization" refers to the metamorphic transformation of carbon associated with an increase in the thickness of wood layers, tectonic movements and processes, as well as an increase in temperature, depending on the depth of bedding.

The increase in pressure primarily alters the physical properties of the coal, chemical formula which remains unchanged. In particular, its density, hardness, optical anisotropy and porosity change. An increase in temperature changes the very formula of coal towards an increase in carbon content and a decrease in oxygen and hydrogen. These chemical processes lead to an increase in the fuel characteristics of coal.

This modification of coal is very rich in carbon, which leads to a high heat transfer coefficient and determines its use in the power industry as the main fuel.

The formula of bituminous coal consists of bituminous substances, the distillation of which allows the extraction of aromatic hydrocarbons and a substance known as coke, which is widely used in metallurgy processes. In addition to bituminous compounds, there is a lot of sulfur in coal. This element is the main source of air pollution from coal combustion.

Coal is black in color and burns slowly, creating a yellow flame. Unlike brown coal, its heat of combustion is higher and amounts to 30-36 MJ / kg.

Coal's formula is complex and contains many compounds of carbon, oxygen and hydrogen, as well as nitrogen and sulfur. Such a variety of chemical compounds was the beginning of the development of a whole direction in chemical industry- carbochemistry.

Currently coal It is practically replaced by natural gas and oil, however, two important areas of its use continue to exist:

the main fuel in thermal power plants;
a source of coke obtained by the oxygen-free combustion of coal in closed blast furnaces.

Coal is one of the oldest fuels. known to man... And even today it occupies a leading position in terms of the volume of use. The reason for this is its prevalence, ease of extraction, processing and use. But what is it? What is the chemical formula of coal?

Actually this question not entirely correct. Coal is not a substance, it is a mixture of various substances. There are a lot of them, so it is impossible to fully determine the composition of coal. Therefore, under the chemical formula of coal in this article, we will mean rather its elemental composition and some other features.

But what can we learn about the state of this substance? Coal is formed from plant remains over many years due to exposure to high temperatures and pressures. And since plants are organic in nature, organic matter will prevail in the composition of coal.

Depending on the age and other conditions of origin, coal is divided into several types. Each species is distinguished by its elementary composition, the presence of impurities and other important characteristics.

It is the youngest type of coal. It even has a plant woody structure. It is formed directly from peat at a depth of about 1 kilometer.

This type of coal contains a fairly large amount of moisture: from 20 to 40%. When exposed to air, it evaporates, and the coal crumbles into powder. Next, we will focus on the chemical composition of this particular dry residue. The amount of inorganic impurities in brown coal is also large and amounts to 20-45%. These impurities are silicon dioxide, oxides of aluminum, calcium and iron. It may also contain alkali metal oxides.

There are many volatile organic and inorganic substances in this coal. They can be up to half the mass of this type of coal. The elemental composition, minus inorganic and volatile substances, is as follows:

Carbon 50-75%.
Oxygen 26-37%.
Hydrogen 3-5%.
Nitrogen 0-2%.
Sulfur 0.5-3%.

By the time of formation, this type of coal is next after brown. It has a black or gray-black color, as well as a resinous, sometimes metallic luster.

The moisture content of coal is much less than brown coal: only 1-12%. The volatile content of coal varies greatly depending on where it is mined. It can be minimal (from 2%), but it can also reach values similar to brown coal (up to 48%). The elementary composition is as follows:

Carbon 75-92%.
Hydrogen 2.5-5.7%.
Oxygen 1.5-15%.
Nitrogen up to 2.7%.
Sulfur 0-4%.

Hence, we can conclude that the chemical formula of bituminous coal consists of a greater amount of carbon than brown coal. It does given view coal with better quality fuel.

Anthracite

Anthracite is the oldest form of fossil coal. It has a dark black color and a characteristic metallic luster. This is the best coal in terms of the amount of heat it generates during combustion.

The amount of moisture and volatile substances in it is very small. About 5-7% for each indicator. And the elemental composition is characterized by an extremely high carbon content:

More than 90% carbon.
Hydrogen 1-3%.
Oxygen 1-1.5%.
Nitrogen 1-1.5%.
Sulfur up to 0.8%.

More coal is contained only in graphite, which is a further stage of anthracite coalification.

This type of coal is not fossilized, therefore it has some peculiarities in its composition. It is produced by heating dry wood to a temperature of 450-500 oC without air access. This process is called pyrolysis. During it, a number of substances are released from the wood: methanol, acetone, acetic acid and others, after which it turns into coal. By the way, wood burning is also pyrolysis, but due to the presence of oxygen in the air, the emitted gases ignite. This is what determines the presence of flames during combustion.

Wood is not homogeneous, it has a lot of pores and capillaries. A similar structure is partly preserved in the coal obtained from it. For this reason, it has good adsorption capacity and is used along with activated carbon.

The moisture content of this type of coal is very low (about 3%), but during long-term storage it absorbs moisture from the air and the percentage of water rises to 7-15%. The content of inorganic impurities and volatile substances is regulated by GOSTs and should be no more than 3% and 20%, respectively. The elemental composition depends on the production technology, and looks like this:

Carbon 80-92%.
Oxygen 5-15%.
Hydrogen 4-5%.
Nitrogen ~ 0%.
Sulfur ~ 0%.

The chemical formula of charcoal shows that in terms of carbon content it is close to stone coal, but in addition it has only a small amount of elements unnecessary for combustion (sulfur and nitrogen).

Activated carbon

Activated carbon is a type of carbon with a high specific pore surface area, which makes it even more adsorptive than wood charcoal. Charcoal and coal, as well as coconut shells are used as raw materials for its production. The starting material is subjected to an activation process. Its essence is to open the clogged pores by the action of high temperature, electrolyte solutions or water vapor.

During the activation process, only the structure of the substance changes, therefore the chemical formula activated carbon identical to the composition of the raw material from which it was made. The moisture content of activated carbon depends on the specific pore surface area and is usually less than 12%.

What is coal made of? What is the chemical formula of coal - all about travel to the site

1. Chemical properties coal

2. Classification of hard coal

3. Formation of coal

4.Coal reserves

Bituminous coal is sedimentary rock, which is a deep decomposition of plant remains (tree ferns, horsetails and lymphoids, as well as the first gymnosperms).

Chemical properties of coal

By chemical composition coal is a mixture of high molecular weight aromatic compounds with high mass fraction carbon, as well as water and volatiles with small amounts of mineral impurities. Such impurities form ash when burning coal. Fossil coals differ from each other in the ratio of their constituent components, which determines their heat of combustion. A number of organic compounds that make up coal have carcinogenic properties.

Most of the coal deposits were formed in the Paleozoic, mainly in the Carboniferous period, about 300-350 million years ago. By chemical composition coal is a mixture of high molecular weight polycyclic aromatic compounds with a high mass fraction of carbon, as well as water and volatile substances with small amounts of mineral impurities, which form ash when burning coal. Fossil coals differ from each other in the ratio of their constituent components, which determines their heat of combustion. A number of organic compounds that make up coal have carcinogenic properties. The carbon content in coal, depending on its grade, ranges from 75% to 95%.

Bituminous coal, solid fossil fuel of plant origin; a type of fossil coal with a higher carbon content and a higher density than brown coal... It is a dense rock of black, sometimes gray-black color with a shiny, semi-matt or matte surface. Contains 75-97% or more carbon; 1.5-5.7% hydrogen; 1.5-15% oxygen; 0.5-4% sulfur; up to 1.5% nitrogen; 45-2% volatiles; the amount of moisture ranges from 4 to 14%; ash - usually from 2-4% to 45%. The highest calorific value, calculated for a wet ashless mass of coal, is not less than 23.8 MJ / kg (5700 kcal / kg).

Coal is the remnants of plants that died many millions of years ago, the decay of which was interrupted as a result of the cessation of air access. Therefore, they could not release the carbon taken from it into the atmosphere. Air access stopped especially abruptly where swamps and swampy forests subsided as a result of tectonic movements and changes climatic conditions and covered with other substances on top. At the same time, plant remains were transformed under the influence of bacteria and fungi (coalified) into peat and then into brown coal, coal, anthracite and graphite.

According to the composition of the main component - organic matter, coals are divided into three genetic groups: humolites, sapropelites, saprohumolites. Humolites predominate, the source material of which is the remains of higher terrestrial plants. They were deposited mainly in bogs that occupied the low-lying coast of seas, bays, lagoons, and freshwater basins. The accumulated plant material as a result of biochemical decomposition was processed into peat, with a significant influence on the water cut and the chemical composition of the aquatic environment. The carbon content of coal ranges from 75 to 90 percent. The exact composition is dictated by the location and conversion conditions of the coal. Mineral impurities are either in a finely dispersed state in the organic mass, or in the form of the thinnest interlayers and lenses, as well as crystals and concretions. The source of mineral impurities in fossil coals can be inorganic parts of plants - coal-formers, mineral new formations falling out of water solutions circulating in peat bogs, etc.

As a result of prolonged exposure to high temperatures and pressure, brown coals are converted into coal, and the latter into anthracite. An irreversible gradual change in the chemical composition, physical and technological properties of organic matter at the stage of transformation from brown coal to anthracite is called coal metamorphism.

The structural and molecular rearrangement of organic matter during metamorphism is accompanied by a sequential increase in the relative carbon content in coal, a decrease in the oxygen content, and the release of volatile substances; changes in hydrogen content, heat of combustion, hardness, density, fragility, opticality, electricity, and other physical properties. Bituminous coals at the middle stages of metamorphism acquire sintering properties - the ability of gelified and lipoid components of organic matter to pass when heated under certain conditions into plastic condition and form a porous monolith - coke. In zones of aeration and active action of underground waters near the surface of the Earth, coals are subject to oxidation.

In terms of its effect on the chemical composition and physical properties, oxidation has the opposite direction compared to metamorphism:

coal loses its strength and sintering properties;

the relative oxygen content in it increases, the amount of carbon decreases, humidity and ash content increase, and the heat of combustion sharply decreases.

The depth of oxidation of fossil coals, depending on the modern and ancient relief, the position of the water table, the nature of climatic conditions, material composition and metamorphism, ranges from 0 to 100 meters vertically.

The specific gravity of coal is 1.2 - 1.5 g / cm3, the heat of combustion is 35000 kJ / kg. Bituminous coal is considered suitable for technological use if, after combustion, ash is 30% or less. The primitive mining of fossil coal has been known since ancient times (Greece). Coal began to play a significant role as a fuel in Britain in the 17th century. The formation of the coal industry is associated with the use of coal as coke in the smelting of pig iron. Since the 19th century, transport has been a major purchaser of coal. The main areas of industrial use of coal: the production of electricity, metallurgical coke, combustion for energy purposes, the production of various (up to 300 items) products during chemical processing. The consumption of coal for the production of high-carbon carbon-graphite structural materials, rock wax, plastics, synthetic, liquid and gaseous high-calorific fuels, aromatic products by hydrogenation, and high-nitrous acids for fertilizers is increasing. Coke obtained from coal is required in large quantities in metallurgical industry.

Coke production is carried out at by-product coke plants. Bituminous coal is subjected to dry distillation (coking) by heating in special coke ovens without air access to a temperature of C. This produces coke - a solid porous substance. In addition to coke, during dry distillation of coal, volatile products are also formed, when cooled to 25-75 C, coal tar, ammonia water and gaseous products are formed. Coal tar is subjected to fractional distillation, resulting in several fractions:

light oil (boiling point up to 170 C) it contains aromatic hydrocarbons (benzene, toluene, acids and other substances;

medium oil (boiling point 170-230 C). These are phenols, naphthalene;

heavy oil (boiling point 230-270 C). This is naphthalene and its homologues

anthracene oil - anthracene, phenatrene, etc.

The composition of gaseous products (coke oven gas) includes benzene, toluene, xiols, phenol, ammonia and other substances. After purification from ammonia, hydrogen sulfide and cyanide compounds, crude benzene is extracted from coke oven gas, from which individual hydrocarbons and a number of other valuable substances are isolated.

Amorphous carbon in the form of coal, as well as many carbon compounds play crucial role v modern life as sources of obtaining different types energy. Burning coal produces heat that is used for heating, making food, and many production processes... Most of the heat received is converted into other types of energy and spent on mechanical work.

Bituminous coal is a solid fuel, a mineral of plant origin. It is a dense rock of black, sometimes dark gray color with a shiny matte surface. Contains 75-97% carbon, 1.5-5.7% hydrogen, 1.5-15% oxygen, 0.5-4% sulfur, up to 1.5% nitrogen, 2-45% volatiles, the amount of moisture ranges from 4 to 14%. The highest calorific value, calculated for a wet ashless mass of coal, not less than 238 MJ / kg.

Coal is formed from the decomposition products of organic matter of higher plants, which have undergone changes under the pressure of various rocks of the earth's crust and under the influence of temperature. With an increase in the degree of metamorphism in the combustible mass, coal increases the carbon content and at the same time decreases the amount of oxygen, hydrogen, and volatile substances. The heat of combustion of coal also changes.

Typical physical properties of bituminous coal:

density (g / cm3) - 1.28-1.53;

mechanical strength (kg / cm2) - 40-300;

specific heat C (Kcal / g deg) - 026-032;

the refractive index of light is 1.82-2.04.

The largest coal deposits in the world in terms of production are the Tunguska, Kuznetsk, Pechora basins - in Russian Federation; Karaganda - in Kazakhstan; Appalachian and Pennsylvania basins - in the United States; Ruhr - in the Republic of Germany; Great Yellow River - in China; South Uelsky - in England; Valenciennes - in France, etc.

The use of coal is diverse. It is used as a household fuel, energy fuel, for metallurgical and chemical industry, as well as for the extraction of rare and trace elements from it. Coal, coke-chemical, and heavy industries process coal by coking. Coking is an industrial method of coal processing by heating up to 950-1050 C without air access. The main coke-chemical products are: coke oven gas, processed products of crude benzene, coal tar, ammonia.

Hydrocarbons are recovered from coke oven gas by washing in scrubbers with liquid absorption oils. After distillation from oil, distillation from the fraction, purification and re-rectification, pure commercial products are obtained, such as benzene, toluene, xylenes, etc. Coumarone resins are obtained from unsaturated compounds contained in crude benzene, which are used for the production of varnishes, paints, linoleum and in the rubber industry. Cyclopentadiene, which is also obtained from coal, is also a promising raw material. Coal - raw material for the production of naphthalene and other individual aromatic hydrocarbons. The most important processed products are pyridine bases and phenols.

A total of over 400 different products can be obtained through processing, the cost of which, in comparison with cost of coal itself, increases 20-25 times, and by-products obtained at coke plants exceed price the coke itself.

Combustion (hydrogenation) of coal with the formation of liquid fuel is very promising. For the production of 1 ton of black gold, 2-3 tons of coal are consumed. Artificial graphite is obtained from coal. They are used as inorganic raw materials. When processing coal, vanadium, germanium, sulfur, gallium, molybdenum, and lead are extracted from it on an industrial scale. Ash from coal combustion, mining and processing waste is used in the production of building materials, ceramics, refractory raw materials, alumina, and abrasives. For the optimal use of coal, it is enriched (removal of mineral impurities).

Bituminous coal contains up to 97% carbon, it can be said that it underlies all hydrocarbons, i.e. they are based on carbon atoms. Amorphous carbon is often encountered in the form of coal. By structure, amorphous carbon is the same graphite, but in a state of the finest grinding. Practical use amorphous forms of carbon are diverse. Coke and coal - as a reducing agent in metallurgy in iron smelting.

Coal classification

Coal is formed from the decomposition products of organic remains of higher plants that have undergone changes (metamorphism) under the pressure of the surrounding rocks of the earth's crust and a relatively high temperature. With an increase in the degree of metamorphism in the combustible mass of coal, the carbon content sequentially increases and at the same time the amount of oxygen, hydrogen, and volatiles decreases; the heat of combustion, the ability to sinter and other properties also change. The industrial classification adopted in the USSR is based on the change in these qualities, determined by the results of the thermal decomposition of coal (the yield of volatile substances, the characteristics of the non-volatile residue).

Bituminous coal by brands:

long-flame (D),

gas (G),

gas fatty (GZh),

fatty (F),

fatty coke ovens (KZh),

coke oven (K),

lean sintered (OS),

skinny (T),

slightly sintered (SS),

semi-anthracites (PA)

anthracites (A).

Sometimes anthracites are distinguished as a separate group. For coking, mainly coal grades G, Zh, K and OS are used, partially D and T. As the coal moves from grade D to grades T — A, moisture in the working fuel decreases from 14% for grade D coal to 4 , 5-5.0% for T-A grades; a decrease in the content (in the combustible mass) of oxygen from 15% to 1.5%; hydrogen - from 5.7% to 1.5%; content sulfur, nitrogen and ash does not depend on belonging to a particular brand. The heat of combustion of the combustible mass of coal sequentially increases from 32.4 MJ / kg (7750 kcal / kg) for grade D to 36.2-36.6 MJ / kg (8650-8750 kcal / kg) for grade K and decreases to 35 , 4-33.5 MJ / kg (8450-8000 kcal / kg) for grades PA and A.

By the size of the lumps obtained during the extraction, coal is classified into:

slab (P) - more than 100 mm,

large (K) - 50-100 mm,

nut (O) - 26-50 mm,

small (M) - 13-25 mm,

seed (C) - 6-13 mm,

pin (W) - less than 6 mm,

private (P) - not limited in size.

Belonging to the brand and the size of the pieces of coal are indicated by letter combinations - DK, etc.

Classifications of bituminous coal in a number of Western European countries are based on approximately the same principles as in the USSR. V USA the most widespread classification is bituminous coal, based on the yield of volatile substances and the heat of combustion, according to which they are divided into sub-bituminous ones with a high yield of volatile substances (corresponds to the Soviet brands D and G), bituminous ones with an average yield of volatile substances (corresponds to the grades PZh and K), bituminous with a low yield of volatile substances (OC and T) and anthracite coals, divided into semi-anthracites (partly T and A), actually anthracites and metaanthracites (A). In addition, there is an international classification of bituminous coal, based on the content of volatile substances, caking capacity, coking capacity and reflecting the technological properties of coal.

Coal formation

The formation of coal is typical for all geological systems from the Silurian and Devonian; coal is very widespread in the sediments of the Carboniferous, Permian and Jurassic systems. Coal occurs in the form of seams of varying thickness (from fractions of m and up to several tens or more m). The depth of coal is different - from emergence to the surface to 2000-2500 m and deeper. With the modern level of mining technology, coal mining can be carried out in an open way to a depth of 350 m.

For the formation of coal, an abundant accumulation of plant matter is necessary. In ancient peat bogs, starting from the Devonian period, accumulated organic matter from which fossil coals were formed without oxygen. Majority industrial deposits fossil coal dates from this period, although there are also younger deposits. The oldest coals are estimated to be about 350 million years old.

Coal is formed when rotting plant material accumulates faster than bacterial decomposition occurs. The ideal environment for this is created in swamps, where stagnant water, depleted in oxygen, interferes with the vital activity of bacteria and thereby protects the plant mass from complete destruction. At a certain stage process the acids released during its course prevent further bacterial activity. This is how peat appears - the original product for the formation of coal. If then it is buried under other sediments, then the peat is compressed and, losing water and gases, is converted into coal.

Under the pressure of a 1-kilometer-thick sediment layer, a 4-meter-thick brown coal seam is obtained from a 20-meter peat layer. If the depth of burial of plant material reaches 3 kilometers, then the same layer of peat will turn into a layer of coal 2 meters thick. At a greater depth, about 6 kilometers, and at a higher temperature, a 20-meter layer of peat becomes an anthracite layer 1.5 meters thick.

The way coal is mined depends on the depth of its occurrence. Opencast mining is carried out if the depth of the coal seam does not exceed 100 meters. It is not uncommon for such cases when, with an ever greater deepening of a coal pit, it is further advantageous to develop a coal deposit by an underground method. To extract coal from great depths, mines are used. The deepest mines in the territory Of Russia coal is mined from a level of just over 1200 meters.

Along with coal, coal-bearing deposits contain many types of geo-resources that are of consumer value. These include host rocks such as raw material for the construction industry, groundwater, coalbed methane, rare and trace elements, including valuable metals and their compounds. For example, some coals are enriched with germanium.

Coal reserves

The general geological reserves of coal in the USSR are about 4700 billion tons (according to 1968 estimates), including by brands (in billion tons): D - 1719; D — G - 331; G - 475; GZh - 69.4; F - 156; KZh - 21.5; K - 105; OS - 88.2; SS - 634; T - 205; T - A - 540; PA, A - 139.

The largest reserves of coal in the USSR are located in the Tunguska basin. The largest developed coal basins in the USSR are Donetsk, Kuznetsk, Pechora, Karaganda; v USA- Appalachian and Pennsylvanian, in Poland - Upper Silesian and its continuation in Czechoslovakia - Ostrava-Karvinsky, in FRG- Ruhr, in China- Greater Huanghebass, in England- South Wales, in France- Valenciennes and in Belgium - Brabant. The use of coal is diverse.

It is used as a household energy fuel, a raw material for the metallurgical and chemical industries, as well as for the extraction of rare and trace elements from it.

For two decades in a row, coal has been in the shadow of the oil boom. Mountains of unmarketable coal grew into the sky. Numerous mines were closed, hundreds of thousands of miners lost theirs. The Appalachian region of the United States, once a flourishing coal basin, has become one of the darkest disaster areas. The indiscriminate transition under pressure from monopolies to cheap, imported - mainly from the Middle East - oil doomed coal to the role of "Cinderella", deprived of the future. However, this did not happen in a number of countries, including in the former USSR, which took into account the advantages of an energy structure based on national resources.

Coal reserves are scattered all over the world. Most industrial countries they are not deprived. The land is surrounded by two rich coal zones. One stretches across countries the former USSR, through China, North America to Central Europe. Another, narrower and less affluent, runs from South Brazil through South Africa to East Australia.

The most significant deposits coal are located in the countries of the former USSR, the USA and China... Bituminous coal dominates in western Europe. The main coal basins in Eurasia: South Wales, Valenciennes-Liege, Saar-Lotharginsky, Ruhr, Asturian, Kizelovsky, Donetsk, Taimyr, Tungusky, South Yakutsky, Funshunsky; in Africa: Gerada, Abadla, Enugu, Uanki, Witbank; in Australia: Great Sinclinal, New South Wales; v North America: Green River, Yunta, San Juan River, Western, Illinois, Appalachian, Sabinas, Texas, Pennsylvania; in the flaming continent: Carare, Junin, Santa Catarina, Concepcion. In Ukraine, the Lvov-Volyn basin and the rich in deposits Donbass should be noted.

Sources of

bse.sci-lib.com/ Great Soviet Encyclopedia

ru.wikipedia.org Wikipedia - the free encyclopedia

www.bankreferatov.ru abstracts

dic.academic.ru Dictionaries and encyclopedias on Academician

geography.kz Geography

www.bibliotekar.ru Librarian

poddoni.com/ PalletEk

Investor encyclopedia. 2013 .

Synonyms:

Coal is one of the most ancient types of fuel known to man. And even today it occupies a leading position in terms of the volume of use. The reason for this is its prevalence, ease of extraction, processing and use. But what is it? What is the chemical

In fact, this question is not entirely correct. Coal is not a substance, it is a mixture of various substances. There are a lot of them, so it is impossible to completely determine. Therefore, under the chemical formula of coal in this article, we will mean rather its elemental composition and some other features.

It is the youngest type of coal. It even has a plant woody structure. It is formed directly from peat at a depth of about 1 kilometer.

This type of coal contains a fairly large amount of moisture: from 20 to 40%. When exposed to air, it evaporates, and the coal crumbles into powder. Next, we will focus on the chemical composition of this particular dry residue. The amount of inorganic impurities is also large and amounts to 20-45%. These impurities are silicon dioxide, oxides of aluminum, calcium and iron. It may also contain alkali metal oxides.

Carbon 50-75%.
Oxygen 26-37%.
Hydrogen 3-5%.
Nitrogen 0-2%.
Sulfur 0.5-3%.

By the time of formation, this type of coal is next after brown. It has a black or gray-black color, as well as a resinous, sometimes metallic luster.

Carbon 75-92%.
Hydrogen 2.5-5.7%.
Oxygen 1.5-15%.
Nitrogen up to 2.7%.
Sulfur 0-4%.

Hence, we can conclude that the chemical formula of bituminous coal consists of a greater amount of carbon than brown coal. This makes this type of coal a better fuel.

Anthracite

Anthracite is the oldest form of fossil coal. It has a dark black color and a characteristic metallic luster. This is the best coal in terms of the amount of heat it generates during combustion.

The amount of moisture and volatile substances in it is very small. About 5-7% for each indicator. And the elemental composition is characterized by an extremely high carbon content:

More than 90% carbon.
Hydrogen 1-3%.
Oxygen 1-1.5%.
Nitrogen 1-1.5%.
Sulfur up to 0.8%.

More coal is contained only in graphite, which is a further stage of anthracite coalification.

This type of coal is not fossilized, therefore it has some peculiarities in its composition. It is produced by heating dry wood to a temperature of 450-500 o C without air access. This process is called pyrolysis. During it, a number of substances are released from the wood: methanol, acetone, acetic acid and others, after which it turns into coal. By the way, wood burning is also pyrolysis, but due to the presence of oxygen in the air, the emitted gases ignite. This is what determines the presence of flames during combustion.

Carbon 80-92%.
Oxygen 5-15%.
Hydrogen 4-5%.
Nitrogen ~ 0%.
Sulfur ~ 0%.

Activated carbon

During the activation process, only the structure of the substance changes, therefore the chemical formula of activated carbon is identical to the composition of the raw material from which it was made. The moisture content of activated carbon depends on the specific pore surface area and is usually less than 12%.

A ghost town without coal. This was the Japanese Hasima. In the 1930s, it was recognized as the most populous. On a tiny piece of land, 5,000 people fit. They all worked in the coal industry.

The island turned out to be literally built from a stone energy source. However, by the 1970s, coal reserves were depleted.

They all left. There was only a dug island and buildings on it. Hashima is called a ghost by tourists and the Japanese. The island clearly shows the importance of coal, the impossibility of humanity to live without it. There is no alternative.

There are only attempts to find it. Therefore, let's pay attention to the modern hero, and not to vague perspectives.

Description and properties

Coal- this is rock organic origin. This means that the stone is formed from decomposed remains of plants and animals. For them to form a dense layer, constant accumulation and compaction is required.

Suitable conditions at the bottom of water bodies. Where there is coal deposits, once there were seas, lakes. Dead organisms sank to the bottom, pressed down by the water column. So it was formed. Coal is a consequence of its further compression under the pressure of not only water, but also new layers of organic matter.

The main coal reserves belong to the Paleozoic era. Since its end, 280,000,000 years have passed. This is the era of giant plants and dinosaurs, the abundance of life on the planet. It is not surprising that it was then that organic deposits accumulated especially actively.

More often than not, coal was formed in swamps. There is little oxygen in their waters, which prevents the complete decomposition of organic matter.

Externally coal deposits resemble burnt wood. In terms of chemical composition, the rock is a mixture of high-molecular type aromatic carbon compounds and volatiles with water.

Mineral impurities are negligible. The ratio of the components is not stable. Depending on the predominance of certain elements, they distinguish types of coal... Anthracite also belongs to the main ones.

Brown coal is saturated with water and therefore has a low calorific value. It turns out that the rock is not suitable as a fuel, like a stone one. And brown coal has found other uses. Which?

This will be given special attention. In the meantime, let's figure out why the water-saturated rock is called brown. The reason is in the color.

The charcoal is brownish, without luster, loose. From a geological point of view, the mass can be called young. That is, the processes of "fermentation" are not completed in it. Therefore, the stone has a low density; during combustion, many volatile substances are formed.

Fossil coal anthracite type - fully formed. It is denser, harder, blacker, shiny. It takes 40,000,000 years for a brown rock to become like this. Anthracite contains a high proportion of carbon - about 98%.

Naturally, the heat transfer of black coal is at a height, which means that the stone can be used as fuel.

Coal formations are most often found in swamps

The brown species in this role is used only for heating private houses. They don't need record-breaking energy levels.

All that is needed is ease of handling fuel, and anthracite is problematic in this regard. Lighting up black coal is not easy. Manufacturers, railroad workers, got used to it. The labor costs are worth it, because it is not only energy intensive, but also does not bake.

Bituminous coal - fuel, from the combustion of which ash remains. What is it from if organic matter turns into energy? Remember the note on mineral impurities? It is the inorganic constituent of the stone that remains at the bottom of the furnaces.

A lot of ash remained in the Chinese deposit in the province of Liuhuangou. The anthracite deposits there burned for nearly 130 years. The fire was extinguished only in 2004. Every year 2,000,000 tons of rock were burned.

So count it, how much coal wasted. Raw materials could be useful not only as fuel.

Application of hard coal

Coal is called solar energy enclosed in stone. Energy can be transformed. It doesn't have to be thermal.

The energy obtained from the combustion of the rock is converted, for example, into electricity. Combustion temperature of coal brown type almost reaches 2,000 degrees. To get electricity from anthracite, it will take about 3,000 Celsius.

Bituminous coal is used as fuel

If we talk about the fuel role of coal, it is used not only in its pure form.

In laboratories, they learned how to obtain liquid and gaseous fuels from organic rock, and coke has been used at metallurgical plants for a long time.

It is obtained by heating coal to 1,100 degrees without oxygen. Coke is a smokeless fuel. The possibility of using briquettes as reducing agents for iron ore is also important for metallurgists. So, coke comes in handy for casting.

Coke is also used as a batch disintegrant. This is the name of the mixture of the initial elements of the future alloy. Being loosened with coke, the charge is more easily remelted. By the way, some components for alloys are also obtained from anthracite.

It can also contain gallium as impurities - metals are rare and rarely found anywhere else.

They also strive to buy coal for the production of carbon-graphite composite materials. Composites are masses of several components, with a clear boundary between them.

Artificially created materials are used, for example, in aviation. Here composites increase the strength of the parts.

Carbon masses can withstand both very high and low temperatures; they are used in the supports of overhead contact networks.

In general, composites have already become firmly established in all spheres of life. Railway workers are covering new platforms with them.

Supports of building structures are made from nano-modified raw materials. In medicine, using composites, it is suggested to fill in bone chips and other injuries that are not subject to metal prosthetics. Here what kind of coal multifaceted and multifunctional.

Chemists have developed a method for producing plastics from coal. At the same time, waste does not disappear. The low-grade fraction is pressed into briquettes.

They serve as fuel, which is suitable for both private houses and production halls. A minimum of hydrocarbons remains in the fuel briquettes. They, in fact, are the females of value in coal.

It can be used to obtain pure benzene, toluene, xylenes, coumoran resins. The latter, for example, serve as the basis for paints and varnishes and interior decoration materials such as linoleum.

Some of the hydrocarbons are aromatic. People are familiar with the smell of mothballs. But, few people know that they produce it from coal.

In surgery, naphthalene serves as an antiseptic. In the household, the substance fights moths. In addition, naphthalene is able to protect against the bites of a number of insects. Among them: flies, gadflies, horseflies.

Total, coal in bags purchase for production of more than 400 types of products.

Many of them are by-products obtained in the by-product coke industry. Interestingly, the cost of additional lines is usually higher than that of coke.

If we consider the average difference between coal and goods made from it, it is 20-25 times.

That is, the production is very profitable, it pays off quickly. Therefore, it is not surprising that scientists are looking for more and more technologies for processing sedimentary rock. There must be supply for the growing demand. Let's get acquainted with it.

Coal mining

Coal deposits are called pools. There are more than 3,500 of them in the world. The total area of the pools is about 15% of the land. Most of all coal is in the USA.

23% of the world's reserves are concentrated there. Bituminous coal in Russia- this is 13% of the total reserves. Bronze from China. 11% of the rock is hidden in its depths.

Most of them are anthracites. In Russia, the ratio of brown coal to black coal is approximately the same. In the United States, the brown type of rock predominates, which reduces the value of deposits. Despite the abundance of brown coal, US deposits are striking not only in volume, but also in scale.

The Appalachian coal basin alone has reserves of 1,600 billion tons. In the largest basin of Russia, by comparison, only 640 billion tons of rock are stored. It's about the Kuznetsk deposit.

It is located in the Kemerovo region. A couple more promising basins were discovered in Yakutia and Tuva. In the first region, the deposits were called Elga, and in the second - Elegets. The deposits of Yakutia and Tuva are of the closed type. That is, the rock is not near the surface, at a depth.

It is necessary to build mines, adits, shafts. It raises coal price... But, the scale of the reservoir is worth the cost. As for the Kuznetsk Basin, they operate on a mixed system. About 70% of the raw materials are extracted from the depths hydraulically.

30% of coal is mined openly using bulldozers. They are sufficient if the rock lies near the surface and the overlying layers are loose.

Coal is also mined in China. Most of the fields in the PRC are located far outside the cities. However, this did not prevent one of the deposits from causing inconvenience to the population of the country. This happened in 2010.

Beijing has sharply increased its demand for coal from Inner Mongolia. It is considered a province of the PRC. So many trucks with goods set off on the road that the 110th highway stood up for almost 10 days. The traffic jam began on August 14th, and only resolved on the 25th.

True, it was not without road works... Coal trucks made the situation worse. Highway 110 is a national road. So, not only the coal was delayed in transit, but other contracts were under threat.

On the Internet, you can find videos where drivers who were driving on a Chinese highway in August 2010 report that they covered the 100-kilometer section for about 5 days.

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