Ordinary bituminous coal. How to choose coal for heating, its characteristics and types. Benefits of using coal in heating systems

There are three types of coal for heating: brown stone and anthracite. Its marking is carried out using letter designations.

The first letter denotes the coal grade:

  • Brown coal is designated by the letter "B";
  • Bituminous coal is classified into:
    • D - long flame;
    • G - gas;
    • F - bold;
    • K - coke oven;
    • T - skinny;
  • Anthracite is designated by the letter "A"

The second is its size class (see table):

What kind of coal is used for home heating?

When deciding which coal is better for heating, anthracite is first of all remembered. This type of coal has the best fuel characteristics in terms of such parameters as minimum consumption, maximum heat transfer, uniform and long burning of each loaded batch, and the minimum amount of slags formed during combustion.

This grade of coal contains less than 1% sulfur and only about 10% ash, which allows us to speak of minimal harm environment (min sulfur dioxide emissions) and a significant increase in the service life of chimneys and boilers. Sulfur and steam, when interacting, form sulfuric and sulphurous acids, which negatively affect the design of chimneys and heating boilers.

The amount of coal that you need for the heating season directly depends on its quality.

Anyone who chooses coal for heating, despite all the advantages of anthracite listed above, cannot be definitely recommended, since anthracite has two disadvantages that play important role for owners of private houses. Firstly, anthracite is the most expensive coal. Secondly, it is extremely difficult to ignite.

Therefore, most often, long-flame coals (WPC) are preferred for heating a house with coal, which are well suited for almost any solid fuel heating boilers, as well as for classic fireplaces and stoves. As additional advantages of coals of this grade, it should be noted that they:

  • Convenient to ignite, easy to use;
  • Demonstrate the most optimal quality / price ratio;
  • They burn with a flame with long tongues, similar to burning wood;
  • The burning process of one bookmark takes a lot of time and is accompanied by the release of large amounts of heat;
  • For stable combustion, an additional blower is not required.

That is why long-flame coal is purchased not only by the owners of private houses, but also by the boiler houses of schools, administrations of different levels, hospitals, etc.

The specified coal in stationary boiler plants has proven itself well both in pulverized and in layer combustion. Therefore, the consumer is in demand for almost all commercially available fractions of coal of the specified grade: from "P" to "M".

Benefits of using coal in heating systems

Heating with coal in a private house has a number of significant advantages.

  • Coal is mined in Russia and is not subject to such price fluctuations as liquid fuels.
  • Its use does not require the presence of special gas pipelines, as for heating, running on gas.
  • The cost of coal is lower than that of gaseous or liquid fuels.
  • This type of fuel is easy to transport and easy to store.
  • Heating a house with coal is beneficial, as it is able to retain heat during combustion. Therefore, the air warmed up in the room does not cool down for a long time.
  • The high heat transfer of this fuel allows you to use its minimum volumes to maintain a comfortable temperature even in the most severe frosts.
  • Coal is a hassle-free fuel. In order for the heating to function properly, it is enough to initially install the correct chimney design and clean it in a timely manner.
  • Storage of the specified fuel is easier than the same firewood, for example. It is supplied to the consumer in bags. The only requirement for a coal storage location is that it must be dry.

The exact consumption of coal will always help you at the point of sale. And to roughly determine how much fuel you need for the heating season, the recommendations below will help. Despite the fact that this method is one of the simplest, it, at the same time, allows you to get fairly accurate results.

As a unit of measurement, we take a bucket with a capacity of 10 liters, which is necessarily available in any private house (although officially the volume of coal is usually measured in tons). We take the average weight of coal in one full bucket equal to 18 kg (you can check).

Practice shows that when using a typical solid fuel boiler for heating a house with an area of \u200b\u200babout 200 sq.m. depending on the season, there are the following rates of coal consumption for heating:

  • September-October - one bucket per day (i.e. 18 kg according to our assumption);
  • November - February - ten buckets per day, which is equal to 180 kg;
  • March-April - from one to two buckets per day. On average, 22 - 24 kg.

Having calculated the total amount of required coal, we find that during the heating season, the consumption of coal for heating a house will be about 580 buckets. Multiplying this amount by 18, we get that for the season we need about 10,440 kg.

If you consider this option of calculations archaism, and are inclined to solve everything from a scientific point of view, then we offer you the following option for preliminary determination of the required volumes of coal.

In order to receive 1 kW of energy, it is necessary to burn about 200 g of coal in the boiler.
For the entire season, while heating is required, it will be necessary to obtain about 50,000 kW.

This implies. What you need for the season 0.2 x 50,000 \u003d 10,000 kg. That is the same 10 tons that we reached in the previous version.

Having resorted to this simple arithmetic, do not forget that each type of coal has own indicator energy efficiency. Therefore, having made a decision to purchase and choosing a seller, consult on the spot about how much coal consumption for heating your house will be when you buy coal of this brand.

The article is devoted to coal brands and their differences. To distinguish the types of coal, there is a division into grades:

  • A - anthracite
  • B - brown
  • G - gas
  • OS - lean sintered
  • SS - slightly sintered
  • T-skinny.
  • D - long flame
  • F - bold
  • K - coke oven

There are 17 grades of coal in total: “D”, “DG”, “Zh”, “KZh”, “G”, “GZhO”, “GZh”, “K”, “KO”, “KSN”, “KS "," OS "," TS "," SS "," T "" AM "," AO "," AS "," AK "," AKO "," ASh "" B1 "," B2 "," B3 ". Coals are divided into industrial products for enrichment - the metallurgy industry. For concentrates this is our energy, for power plants and sludge, for the population and for coal briquetting. Oxidation is designated OK, OK2, OK1.

Anthracite coal fraction designation:

  • P - plate (≥100mm)
  • AK - large (50 - 100mm)
  • ACO - fist nut (25-100) ()
  • JSC - walnut (25-50mm) ()
  • AM - small (13-25mm) ()
  • AS - seed (6-13mm) ()
  • ASh - pin (0-6mm) ()
  • P - private (0-200)
  • quarry 0-300 mm

There are also mixed brands. If we give an example of the designation of grades, then GKOM (K - 50–100, O –25–50, M - 13-25) is 13–100 mm. When coal is formed, this process is also called metamorphism, then the formed coals are divided into stone, brown and anthracite. Anthracites have the highest calorific value. For the energy industry, Ukarinas look the most pleasant coal, because they have the most favorable ratio based on the amount of money spent to the heat of combustion. For example, coals of grade D and grade G can be cited, they transfer an excellent amount of heat and can burn without blowing, they are often used for combustion in boiler houses. But coals SS, T and OS are used as a rule in power engineering. The justification for the use of these types of coals is appropriate if they are used in large quantities, since the implementation of the combustion process requires more economic costs. For the production of steel and cast iron, G and Zh grades are used.
Grade "A" (anthracite). Large fractions of anthracite are used mainly in the household sector of Ukraine. They are very popular and widely used among the population of Ukraine. Also, this grade A coal is widely used in the energy sector due to the high heat of combustion.

Grade "B" (brown coal). What is characteristic of this brand is the yield of volatile substances over 45%. They are divided by humidity into: 1 B (above 43%), 2 B (29-45%), 3 B (up to 32%).

Designation of coking coal grades.

Grade "D" (long-flame coal). It has poor sintering properties. As well as grade A coal can be used both in the energy sector of Ukraine, and in the household sector and in the chemical industry of Ukraine, for molded coke, in the coking process.

DG grade (long-flame gas coal). On the contrary, it possesses high sintering capacity and insignificant fragility. However, the resulting coke is unsuitable for further use, since it has high reactivity and low strength. In terms of fractional composition, this brand has coals of medium and large grades.
Grade "G" (gas coals). It is used in the public utilities sector of our state as a cheaper replacement for grade A coal. Due to its properties, it can be involved in the process of gasification, coke molding, and semi-coking process. They are subdivided into the following technological groups: inertinite, vitrinite. Low-ash vitrinite is used to produce synthetic fuels.

The most valuable type of coking coal. Structural strength is one of the distinctive features of coke obtained from the Zh coal grade.

GZhO brand (gas fat lean coal). They make up more than half of the charge and are an excellent product for coking. They can also be used for the household needs of the population of Ukraine, if they are fusinite. Unsuitable for the production of coke for metallurgy.

The main purpose is to obtain standardized metallurgical coke. However, they are not mixed with other types of coals.

Grade "KZh" (coke oily coal). It is widely known that this coal grade is used in the by-product coke industry on the territory of Ukraine. The highest coking index, which makes it possible to obtain metcoke from this type of coal. They have the following indicators:

  • - vitrinite reflections from 1.5 to 1.9%,
  • - the yield of volatile substances is not more than 19.6%,
  • - humidity 6-13%,
  • - ash content from 6 to 39%,
  • - carbon 78-92%,
  • - hydrogen 4.2-5,%.

SS - slightly sintered. Found application in power plants, boiler houses and in the household sector of Ukraine. This type of coal is characterized by following indicators:

  • - vitrinite reflections 0.5-1.78%,
  • - humidity 8-9%,
  • - ash content from 8 to 45%,
  • - sulfur no more than 0.8%,
  • - carbon from 74 to 90%,
  • - hydrogen from 4.0 to 5.0%.

T-skinny. One of the main indicators is complete absence sintering capacity. Found application in the energy sector of Ukraine, as well as for household needs.


A - anthracite

B - brown

D - gas

D - long flame

F - bold

TO - coke oven

OS - lean sintered

SS - slightly sintered

T - skinny

At the end of the name of the coal brand there may be an abbreviation OK (OK1, OK2), indicating the oxidation state.

Also, depending on the degree of beneficiation, coals are divided into concentrates, middlings and sludge. Concentrates are usually used in boiler houses and to generate electricity. Industrial products are usually used for the needs of metallurgy. The slimes can be used to make briquettes and retail them to the public for personal use.

Depending on the degree of coalification (metamorphism), there are brown coals, bituminous coals and anthracites. The lowest heat of combustion is in brown coals, and the highest is in anthracites.

The most favorable ratio of price and specific heat of combustion has coal. Coals of grades D, G and anthracites are used, as a rule, in boiler houses, because they can burn without blowing. Coals of grades SS, OS, T are used to obtain electrical energysince they have a high calorific value, but the combustion of this type of coal is associated with technological difficulties, which are justified only if a large amount of coal is needed.

In ferrous metallurgy, grades G, Zh are usually used for the production of steels and cast iron.

By the markings of the coals, you can immediately determine their fraction.

Designation:

P - (plate) more than 100 mm

TO - (large) 50-100 mm

ABOUT - (nut) 25-50 mm

M - (small) 13-25 mm

FROM - (seed) 6-13 mm

Sh - (pin) 0-6 mm

R - (private) mine 0-200 mm, open-pit 0-300 mm

The fraction of a given coal grade is determined based on the lower value of the finest fraction and the larger value of the largest fraction indicated in the name of the coal grade. So, for example, the fraction of the DKOM brand (K - 50-100, O - 25-50, M - 13-25) is 13-100 mm.

Some solid fuel boilers can run on any fuel, but not all. Therefore, before buying coal, look at the passport of your unit. The brands for which the boiler was calculated should be indicated there. If there is no such information, you can go by trial. Most firms selling this type of fuel have bagged coal. You will need to take a bag of different grades and fractions, and alternately heat with each of them. Try to use the same amount of coal and evaluate the following parameters: amount of heat, duration of burning and amount of ash residue.

Quality indicators of coal

Bituminous coal contains a large number of very different components, each of which can affect the area of \u200b\u200buse, which makes coal quality control not easy at all. A number of defining characteristics are considered depending on the application. For example, when determining the suitability of coal for coking, more than 30 parameters are taken into account.

To determine suitable coal for a solid fuel boiler or not, it is not at all necessary to know all its properties. It's important to know:

Speaking of this fuel in general, anthracite is considered the best coal for household heating cola (denoted by the letter "A"): it burns for a long time, white smoke emitted during combustion (little soot is formed), has a low ash content. But not everyone loves it: firstly, it has a high price, and secondly, it is very difficult to flare up.

Long-flame coal has the most optimal characteristics in relation to the price for domestic boilers. It burns for a long time, while the flame is long, like when burning with wood (hence the name), has a sufficiently high calorific value and flares up easily. Long-flame coal is marked with the letter "D". Used for heating private houses and weakly baked "SS" and lean "T", but their quality indicators are much worse.

When marking fuel, in addition to the type of fuel, the size of the fraction (size of pieces) is also indicated:

So if long-flame coal is marked as WPC, it is slab coal, crushed into pieces from 50 to 100mm, DS is a long-flame "seed", etc. It is worth explaining what "raw coal" is. It has an unregulated composition, i.e. it may contain, for example, 80% of the large and medium fractions and only 20% of the shty, or maybe vice versa.

It is unambiguous to say which coal is better. Much depends on the boiler: some are designed for brown coal, and some for anthracite. And if it is indicated in the passport that it is recommended to use anthracite, then it is not necessary to look for a cheaper replacement for it: a ton of coal will cost less, but the amount of it will be needed much more. So you won't be able to save money, but ruining the boiler is easy.

For those who do not have a passport for the boiler or use a brick stove for heating, you can use the advice of experienced people. It is better to melt a household boiler with long-flame coal of the "walnut" fraction. After it flares up well, anthracite is poured into an even layer for heating in the daytime. It burns for a long time, giving out a large amount of heat. In the evening, in a cauldron well heated with anthracite, you can put a "seed", which will "keep" the temperature until morning. But we will repeat again, everyone has different boilers, so you need to choose the optimal mode yourself. The point here is not only in saving money, but in the optimal temperature regime, under which both people feel comfortable and the equipment works as usual.

The owners of brick ovens are advised to light it with wood. Then, when the oven warms up, coal briquettes are put into it (a good type of fuel) or a "seed" is poured into it, preferably a long-flame one. At the same time, until the coal has ignited, the blower must be kept open for maximum oxygen supply. When this bookmark has flared up well, and the oven gains heat, you can fill in a larger fraction, for example, "large" or "nut".

Others advise to lay a "nut" in a brick oven after firewood, and a "seed" at night. In this order, the seed smolders in a preheated oven, maintaining the temperature until morning.

How to calculate the amount of coal for the winter

The amount of coal needed to heat a house depends on many parameters:

  • from the heated area and from the material from which the house is built;
  • on how it is insulated and what the windows are, how tightly the doors are fitted;
  • on the type of heating and type of boiler, type of coal;
  • the severity of winters in your region and their average duration, etc.

All these "little things" are very important. So most of all coal will be needed to heat a brick house - 30-35% more than for a similar wooden area or a house made of aerated concrete blocks. For heating a well-insulated cinder-concrete house (wall thickness 45 cm) with an area of \u200b\u200b90 m 2, the owners spend 2.5-3.5 tons of coal (1 ton of anthracite "nut" and two "seed"). Stove heating. Others have about 6-7 tons per house, but without insulation.

The owners of 2-3 room apartments in the same region buy 1.5-2 tons to "feed" solid fuel boilers. In another region, for heating a wooden house of 80 m 2 from a bar, they buy 5 tons of coal and firewood, but their winters are harsh - up to -40 o C for a month and a half and the rest of the time -20 o C.

To determine how much a ton of coal will last for you, it is recommended to buy several bags of the selected brand (and in the place where you plan to buy) and see how much of it is required per day to maintain a comfortable temperature. Take the "outboard" temperature into account and compare it to the winter average. Draw conclusions based on the results. If you are drowning for the first year, try to take with some margin. If it remains, it does not matter, it does not lose its properties (unless you bought brown coal), but if you don’t have enough, it’s already unpleasant.

How to store coal

Coal of different brands and even different deposits behaves differently during storage. Some can be stored for years with practically no loss of quality, and some six months later turns into dust and dust. It all depends on the composition and quality of the fuel, as well as on the storage conditions.

Depending on its resistance to oxidation (due to which there is a change in characteristics and "weathering"), coal is divided into four categories:

  • The most sustainable... This group includes anthracites and semi-anthracites, which in large pieces (from a soccer ball to the size of the "P" fraction) can be stored without a noticeable loss of quality up to 36 months, smaller fractions from "K" and less - up to 24 months... This category includes coal from pools:
    • Suchanskoye - TR, GR - stored for 36 months;
    • Cheremkhovskoe - DR, DKO - 36 months;
    • Pechorsky - ZhR, ZhSSh, ZhSh - 24 months;
    • Donetsk - TR, KR - 24 months;
    • Podgorodnenskoe - TR - 24 months.
  • Oxidation resistant. Stored for 18 months
    • Donetsk basin - GK, GKO, GO, GM;
    • Kuznetsk deposit - TR, TK, TO, SS K, SSKO, SSM;
    • Irtysh (Ekibastuz) - SSR;
    • Karagandinskoe - KR, KZhR;
    • Sakhalin ZR, KR GR, GKO;
    • Ural GR
    • Shartunskoe SSH
    • Kuu-Chekinskoe K2R
    • Bukakachinskoe GR
  • Medium stability. Stored for 12 months.
    • Kuznetskiy - DKO, DM, KR, KZhR, ZhR, K2R, GK, GKO, GO, GM, GKOM;
    • Kizelovsky - GR, GMSSH, GSSH, SAME;
    • Donetsk - DKO, DM, DK, DO, GR, GMSSH, GSSH, GSH, R, Zh;
    • Pechorsky - DKO;
    • Sakhalinskoe - DR, DSH;
    • Lvovsko-Vsyanskoe - GR, GK, GMSSH, GSSH;
    • Egorshinskoe - GR;
    • Shargunskoe - coal briquette;
    • Tuva, Neryunfinskoe - KR;
    • Zyryanskoe, Chulmanskoe - ZhR.
  • Unstable. Stored for 6 months.
    • Kuznetskiy - GR, GSSH, GMSSH;
    • Pechorsky, Donetsk, Lipovetskoe - DR, DSSH;
    • Khakasskoe - DR, Children's Medical School;
    • Central Asian - DK, DOM, DKOM, DR, DSSH;
    • Tkvarchelskoe - ZhR;
    • Tkibulskoe - DK, DKO, DOMSH, DR, GR, coal briquette;
    • Arkagalinskoe, Beringovskoe, Dzhebari ki-Khaya, Kotuyskoe, Sangarskoe, Tal-Yuryakhskoe, - DR.
  • Brown coals. Stored for 6 months.
    • Artemovskoe, Tavrichanskoe - BK, BKOM, BR, BOM, BSSh;
    • Raichikhinskoe - BK, BO, BMSSH, BR;
    • Podmoskovny - BR, BK, BO, BOM, BOMSH, BMSSH, BSSH;
    • Right-bank Ukraine - BR, brown coal briquette;
    • Chelyabinsk - BK, BKO, BMSSH, BO, BSSH, BR;
    • Babaevskoe - BR, brown coal briquette;
    • Smolyaninovskoe, Maykhinskoe - BKOM, BSSh, BR;
    • Retgikhovskoe - BP, BSSh, BKOM, BR;
    • Azeiskoe, Anadyrskoe, Akhaltsikhskoe, Arbagaoskoe, Bogoslovskoe, Volchanskoe, Veselovskoe, Gusinoozerskoe, Zakarpatskoe, Irsha-Borodinskoe, Kolomiyskoe, Kangalakskoe, Tarbagataiskoe, Soginskoe (Tiksi Bay), Chernov, Kharanorskoe, Baranorskoe
  • Brown coals. Stored for 4 months.
    • Central Asian - BSH, BR;
    • Angrenskoe - BOMSH, BR;
    • Lengerovskoe, Nazarovskoe - BR.

This is the shelf life for businesses selling coal from open areas. About the same amount of coal will be stored in a private courtyard without losing its characteristics. Then the process of oxidation and weathering begins. You can extend the shelf life of coal by storing it under a roof. A charcoal shed or basement should be kept cool and preferably not in direct sunlight. Oxidation of coal begins at 20-25 o C. At a temperature not exceeding 40 o C, the process occurs slowly and is expressed in a decrease in the strength of the pieces, the appearance and deepening of cracks. This process is also called weathering. Since oxidation occurs with the release of heat, the temperature inside the large pile of coal gradually rises, which can lead to spontaneous combustion. This problem is most likely when using low quality fuel with a high content of fines and / or dust. Brown coals have the highest probability of spontaneous combustion, followed by porous coals (lignites and subbitominous coals). Anthracites are least susceptible to oxidation and spontaneous combustion.

Storing coal properly is no easy task

If you store coal of fine fractions such as "seed" or "shtyb" you need to periodically check its condition. If the reserves are large, it makes sense to purchase an electronic thermometer, to which you connect a long thermocouple (temperature sensor) and periodically, at least once a week, monitor the condition. Auto-ignition temperature of coal:

  • Brown - 40-60 o C;
  • Fatty coals - 60-70 o C;
  • Lean and anthracite - 70 o C.

It is not recommended to wet the coal to bring down the temperature - wet coal absorbs oxygen much better than dry coal, and when it dries, gas exchange even improves, which makes the oxidation process even more active. The most reliable way to prevent spontaneous combustion is to restrict oxygen access - cover with tarpaulin, thick plastic wrap, etc.

As an alternative to coal can be considered. These are small fractions of coal that are pressed into briquettes. They have a high calorific value and ash content, less than that of the original product, they burn for a long time and practically without smoke. Another type of fuel, for which you do not need to alter a conventional solid fuel boiler - fuel. They give a little less heat per kilogram, but they are much cheaper, and very little ash remains after combustion.

Bituminous coal is one of the most demanded minerals, the extraction of which requires colossal efforts and takes place in very unsafe conditions. Its deposits are located deep underground, formed as a result of the disturbance of plant rotting caused by the lack of oxygen. In everyday life and industry, various grades of coal are used that correspond to the accepted classification based on quality characteristics.

Coal grades vary. at least in quality

Description and purpose of the mineral

In wetlands, plants are transformed into peat under the action of many bacteria, then into brown coal, which, in turn, turns into stone coal after many years. The latter is characterized by more high rate calorific value and therefore is used as fuel. The spheres of its consumption are:

  • electric power industry;
  • thermal power equipment of industrial enterprises;
  • chemical plants;
  • housing and utilities;
  • heating systems of private houses.

Depending on the marking of the coal, it can be used as a solid fuel for modern heating boilers and conventional stoves in old houses. Despite the outward similarity and even belonging to the same type, fossils may differ, for example, in terms of sulfur content, heat of combustion, humidity, etc.

In this video you will learn about the specifics of csr grade coal:

The cost of each grade of coal is also determined separately. Their characteristics affect how much a ton of fuel will be estimated for an industrial or private facility. Study of properties and features produced in several directions:

  • elemental analysis (identification and calculation of oxygen, hydrogen, organic sulfur, carbon and nitrogen in the total mass);
  • technical research - analysis of quality indicators that must comply with the established standards requirements (humidity and sulfur content, ash content and heat of combustion, the release of volatile components);
  • mechanical analysis - the ability of a fossil not to crack or collapse, not to change size under the influence of friction or impact (important for foundry and electrode production);
  • thermal tests - allow you to determine the strength of coal under the influence of high temperatures (grades intended for furnaces, semi-coking);
  • determination of electrical properties - depending on the stage of conversion, coals can be dielectrics and semiconductors at the initial stages, and at the later stages - conductors.

Special laboratories examine absolutely all brands of coal. Their characteristics allow you to sort pieces by size (coarseness), as well as other properties that affect quality.

Classification and properties

In the Russian classification, it is customary to distinguish 8 groups. This division does not coincide with the marking adopted in western countries. Bituminous coal is available in several grades with the corresponding letter designation:

  • brown (B) - with a heat of combustion of 7000-7500 kcal / kg;
  • skinny (T) - from 7300 to 8700;
  • long-flame (D) -7500-8000;
  • gas (G) - when burning, it releases heat from 7900 to 8600 kcal / kg;
  • anthracite (A) - 8100-8750;
  • bold (F) - 8300-8700;
  • coke oven (K) - 8400-8700;
  • lean sintered (OS) - 8400-8780.

The most common in the private economy and industry are long-flame coal (marking WPC or DPKO, popularly referred to as "fist" or "nut"), skinny (marked with TPK and TPKO, sizes 50-200 mm and 25-50 mm) and Anthracite coal (used most often in energy).

Group characteristics

D-grade stone minerals are considered to be the most suitable fuel for the operation of furnaces and heating boilers. This is a long-flame coal, which gets its name from the formation of high flames, like firewood. It maintains a long burning process and emits a large amount of heat, does not bake. This type of fuel can be used in almost any system (even those not equipped with a natural draft system or forced draft). It flares up very quickly, it allows you to effectively heat private houses and medical institutions, administrative buildings.

The second most popular coal can be considered grade T coal. It is called "lean", characterized by the release of volatile substances in the range of 9-17%, does not sinter, and practically does not emit a flame during combustion. It contains about 90% carbon, so this coal is considered the richest. It is irreplaceable in the fuel industry, chemical production, gas generating plants, housing and communal services and mobile power plants.


So, brand D is the most popular

The third group is represented by long-flame gas DG coal, low-sintering, with low fragility and high strength. Not suitable for coke blends because the resulting coke is radioactive. The yield of volatile substances is in the range of 27-30%, refers to energetic rocks.

Under the brand J, there are two groups of fossils, the separation of which is based on the VOC and vitrinite reflectance. It is a highly coking, highly valuable type of fuel that, as a result of combustion, forms a high-strength structural coke. For the production of pig iron or steel in ferrous metallurgy, coal of grade Zh is most preferred, the characteristics of which make it possible to avoid technological difficulties associated with the combustion process.

Anthracite combines a group of coals with VLV of about 8%, which are irreplaceable in the energy industry. Large and medium-sized units are used as smokeless fuel in the utilities and household sectors. In addition, anthracite is required for the production of carbide (aluminum and silicon).

Intermediate marking

The marking, adopted on the basis of quality indicators, allows you to distinguish several groups and select a suitable mineral depending on the needs. Depending on the production basins, an intermediate classification is adopted, which highlights:

  • gas fat (GZh);
  • slightly sintered (SS);
  • fatty coke (QL);
  • coke second (K2).

When mining coal, it is possible to get pieces of different size, on the basis of which they are divided into classes. Class P (slab) includes specimens over 100 mm, large (K) - pieces from 50 to 100 mm. Class O (walnut) is represented by stones of 26-50 mm, and class M (small) - rocks of 13-25 mm. Group C (seed) contains small coals of 7-13 mm each, and all residues less than 66 mm in size are called spike (W). The designation P (private) is assigned to an unlimited size fossil.

 

It might be useful to read: