Coal products are used in three main areas: electricity generation, metallurgical production, household consumption. The listed applications require coal grades with special thermal properties.
Homeowners are concerned about the price of a ton of briquettes and the quality "so as not to die." Utilities are worried about what raw materials to buy for the winter so that heating does not cost a pretty penny.
Power industry requires high calorific value concentrates to generate electricity.
Metallurgists who melt steel and iron choose the product to form coke with high structural density so that microcracks do not form.
Environmentalists seek to find the necessary coal parameters in the classification to calculate the amount of negative impact on atmospheric air during the production use of combustible material.
Alphabetic system
To order from the manufacturer and use carbon materials rationally, you should understand the parameters of the grades.
The registry has nine titles. Each is encoded with letters of the Russian alphabet. Deciphering the grade of coal begins with the specific amount of carbon:
- anthracite –A;
- lignite – B;
- gas - G;
- long-flame – D;
- bold – F;
- coke - K;
- lean sintered - OS;
- low caking – SS;
- skinny – T.
Consumer properties of raw materials
Grades of coal are characterized by the percentage composition of the active substance - carbon. The highest content in anthracite is 90%, and the lowest content is in brown coal, 76%.
Heating without oxygen blowing causes coal to decompose into gas and liquid fractions. This parameter is volatile substances. Oi are the second attribute of the coal brand. The highest yield in brown varieties is 41%. Anthracite has the lowest formation of volatile components - 8%. The percentage of volatiles is called carbonation.
The third characteristic is specific calorific value. It is measured in kcal/kg. The minimum value of the net calorific value of brown coal is 3900 kcal/kg. The maximum value is for anthracite. Here, 7500 kilocalories are released when 1 kg of material is burned.
The second product of the thermal decomposition of coal is coke, or kinglet.
When buying raw materials, users look at the price-quality ratio.
In ferrous metallurgy, products G and G are used. In the electric power industry, goods with the names OS, SS, and T are used. Briquettes A, G, and D are loaded into boiler furnaces.
Underground storeroom assortment
When forming a coal brand card, in addition to the species classification, a varietal classification is used. Sothe name consists of two characters: the brand plus the size of the granules. The man who named the varieties was clearly a poet and a romantic:
- P - reservoir;
- K - fist;
- O - walnut;
- M - small;
- С - seed;
- Ш - shtyb;
- P - private.
P and R are characterized by a size of 20 - 30 centimeters. These are the largest. Shtyb is a trifle up to one and a half centimeters in size.
An example of deciphering the grade of coal: in the card of marketable coal products, the group of letters AP means seam anthracite with a fraction size of 0.2 - 0.3 m.
Class B raw materials
The more mature the rock, the better the quality of the coal. To determine the maturity, we introduced the concept of vitrinite reflection OM - the reflectivity of plant organic matter in the composition of coal. The indicator is determined as follows - a monochrome beam is directed to a polished rock sample. After that, the intensity of the reflected beam is measured.
Grades of coal differ in the maturity of the rock. In brown coals, the vitrinite reflection index is less than 0.6%, the formation of volatile components is more than 41%. For comparison, the RH of anthracite is 2.59%. The calorific value of grade B is in the range from 3900 to 4500 kcal/kg depending on humidity:
- 1B – 40% or more;
- 2B - from 30 to 40%;
- 3B – less than 30%.
Grade B coal is often wooden at the break, smokes during combustion. Its only advantage is its low price.
In Russia, brown coal is mined in large volumes in Soltonsky, Tunguskaand the Kansk-Achinsk basin. Smaller production in Primorsky Krai, in the Chelyabinsk region on the Eastern slope of the Ural Mountains.
Brown coal is used not only as a fuel, but also as a raw material for the production of liquid fuel and gas, fertilizers and synthetic materials.
