Where Coal Is Used: Spheres and Areas of Application

Coal has long been one of the main sources of heat and energy. Today its importance depends on the region and industry: in power generation it is gradually being restricted because of environmental requirements, but in metallurgy, chemical production and some technological processes coal and its processing products remain in demand.

What is coal and how is it mined?

Coal is a solid combustible fossil, usually black or dark brown. It forms from plant organic remains that turn into coal rock over millions of years under pressure, temperature and geological processes. This process is called coalification. Coal consists mainly of carbon, but the exact composition depends on rank, ash content, moisture and the amount of sulfur, hydrogen, oxygen and nitrogen. For metallurgical coal, coking capacity and caking ability are especially important.

The coal industry occupies an important place among extractive industries. Mining methods depend on seam depth, seam thickness, geology and economic feasibility. When coal lies near the surface, open-pit or strip mining is used; deeper seams are mined underground. Different countries use longwall mining, room-and-pillar systems, blasting and mechanized methods.

Types and Grades of Coal

Coal is divided into types according to many criteria: color, size, structural and genetic features, processing technology and other factors.

There is a generally accepted marking system for coal mined and used in production. Coal may be long-flame (D), gas coal (G), fat coal (Zh), coking coal (K), lean coal (T) and so on. Some mined coal is also classified as intermediate, for example gas-fat coal. Separate countries also use their own classification systems, including the United States and Japan.

In Which Areas Is Coal Used?

Coal is used as a fuel, a technological raw material and a source of processing products. Coking is especially important for metallurgy and the chemical industry, but not every coal application is connected with coking. Let us look at the main areas in more detail:

1. Energy and fuel. Coal is used at thermal power plants, in boiler houses and in some industrial furnaces. Technologies also exist for producing liquid fuels from coal, including direct and indirect coal liquefaction, but their use is limited and depends on economics, oil availability and environmental requirements.
2. Metallurgy. Coking coal is converted into metallurgical coke. It serves as both fuel and reducing agent in blast-furnace ironmaking and is also used in some foundry and ferroalloy processes.
3. Chemical industry. Coking produces coke oven gas, coal tar, ammonia products and other by-products. Coal tar can be processed into pitch, naphthalene, phenolic compounds and aromatic fractions used in chemical production, materials, electrodes, protective coatings and some plastics.
4. Agriculture and soil materials. Coal itself is not a typical fertilizer. In agriculture, certain coal processing products, ammonium compounds, humic materials or carbon additives may be used, but their use depends on composition and production technology.
5. Transport and construction. Historically, coal was widely used as railway fuel. Today its role in transport is smaller, but coal processing products, coke, tar, pitch and ash-slag materials may be used in road construction, industrial coatings and some infrastructure works.

As can be seen, coal is used not only as fuel, but also as a raw material for metallurgy and the chemical industry. At the same time, its use is increasingly assessed through emissions, environmental standards and the transition to cleaner technologies. Therefore the role of coal will change across countries and industries, but it remains an important raw material in some industrial processes.