What is coking coal and where it is used

The increase in oil prices and the search for alternative energy sources not only led to the development of new technologies, but drew attention to another, no less useful raw material - coal. The most important for the industry is coking coal. What is its value and where it is mined is set forth in this article.

What is coking coal?

This is coal, from which, under coking conditions, coke is obtained of a certain strength and size. It is of great value to the industry and is in great demand in many industries. Thus, coking coal is used as the main fuel in the production of steel and power.

Coking coals differ from other coals by the property of transitioning to a plastic state and caking when exposed to high temperatures without access to oxygen.

Composition of coking coal

Coking coal in concentrated and unenriched form is characterized by low ash content (less than 10%), low content of volatile components (from 15 to 37%) and sulfur (less than 3.5%). Compared with other types of coal, coking coals have a high combustion temperature and are characterized by a lower content of impurities. The ratio of constituents in different coal deposits may differ slightly. This is very important to consider in the process of its coking. So, before processing of coal it is necessary to determine its composition, coking ability, caking and other parameters. In the territory of the post-Soviet space, such types of coal are used for coking:

• K - coke.
• F - fat.
• D - gas.
• OS - otoshchenno-sintering.
• SS - strongly baking.

Coking process

By coking means the technological process of converting coal to coke. It consists of several stages. At the first stage, coal is prepared for coking. The extracted coal is crushed and forms special mixtures - charge. Coking is carried out in the next stage. It occurs in special chambers of a coke oven with the use of gas heating. The prepared batch is placed in the furnace for 15 hours, where the temperature is raised to 1000 ° C all the time. As a result of this process, a "cake pie" is obtained.

The technology of coking during the twentieth century has changed greatly, which allowed the development of new coal deposits.

According to calculations, about 10% of the world's coal production is coking. This fact confirms the high demand of the industry for coking coals.

What is the difference between coking and energy coal

The greatest value for the industry is provided by coking coals, which are used as a technological fuel in many production branches of the national economy. For example, for smelting cast iron. The main feature that distinguishes coking coal from energy is the presence of vitrene. This is an ash component part of the coal, which is formed as a result of the decomposition of plants in the absence of oxygen. The properties of vitrene are the ability to melt and cake under the influence of high temperature. Thus, the coal microparticles are glued together into one dense mass. The higher the concentration of vitrene, the higher the quality of coking of such coal.

The greatest quantity of fusible substances is contained in such coal grades: coke, gas, fatty, otoshchenno-sintering and coke fatty.

Coal grades

In nature, there are many varieties of coal, which differ in technical composition, caking index and the release of volatile constituents. Only a few grades of coal are suitable for coking. But not all of them are suitable for sintering in pure form. Sometimes you need to add some components. So, there are the following brands of coking coal:

1. K is a coke oven. When coking this brand of coal in its pure form, the metallurgical coke is produced. To obtain the highest quality coal, add other brands - fatty or gas.
2. QL - coke fatty. Has the best coking ability, mainly used to produce coke without adding other brands of coal. The composition of coking coal contains up to 30% of volatile components. The reflection of vitrin is 1.3%. The thickness of the plastic layer is 18 mm. Without changes in the quality of coke, it is allowed to add up to 20% of KC, OC and KO to this brand.
3. KO - coke oven. The thickness of the layer is 10-12 mm, the reflection of vitrene - up to 1%. As a rule, this brand is not used separately, but only in combination with LCD and GLC coal.
4. STS - coke weakly baking low-metamorphous. During sintering, this type of coal forms a washable coke with a low strength, so it is mainly used for sintering with other grades or for producing a synthetic gas.
5. COP - coke weakly sintering. The thickness of the plastic layer is up to 9 mm. Characterized by low sinterability. Coal grade KCs are used by coke-chemical enterprises as an exhaustive component. It is also used in some areas of production for layer combustion.
6. GK - gas coking. Coking gives a well-alloyed coke, but with a low mechanical strength. The sintering product is easily divided into small pieces. Usually, the gas is used in mixtures with other coking coals.

The best for sintering are the following grades of coking coal: bold, weakly sintering, gas, otoshchenno-caking and coke in its pure form. They contain the least amount of impurities, and they have a high plasticity.

Applications

The main purpose of coking coal is industrial fuel. During combustion, coking coal generates a large amount of thermal energy. Thus, the ignition temperature of this fuel is 470 ° C. But burning is not the only way to extract useful properties from this fossil. There are many other branches of the national economy in which coking coal is efficiently used. The use of this natural resource in industrial processes makes it possible to obtain lead, molybdenum, zinc, germanium, sulfur, gallium and other chemical elements from it. Industrial waste also has waste from the coal industry. So, they are processed into refractory materials and abrasives. Also from the waste produce building materials.

In total, more than 300 varieties of products are made from rock fuel. Coal is used as the main material for the production of carbon-graphite structural elements, high-nitrogen acids, which are used in fertilizers. Efficient use of substances that are released during the coking process. So, during dry distillation, coal tar and ammonia water are formed. They are also amenable to processing.

In addition, in the coking process, gaseous products are released that contain benzene, phenol, ammonia and toluene. They serve as sources of other useful substances.

Extraction of coking coals in Ukraine

Coking coal in Ukraine is mainly used by metallurgical enterprises. Thus, metallurgy accounts for about 90% of the total demand for this type of fuel. The country's mining industry provides coking coal with an internal market of only 60%. The remaining 40% of the consumed coal is imported. The main supplier of coking coal to Ukraine is Russia.

In recent years, there has been an increase in demand for foreign raw materials. This is due to a decrease in domestic production. Also, the demand for domestic raw materials is falling due to a decrease in its quality, as metallurgical plants can not use coal with a high sulfur content.

In Ukraine, coking coal is mined in the basins: Donetsk, Lviv-Volynsky, Dnieper. The largest amount of coal reserves is concentrated in Donetsk, Lugansk and Dnipropetrovsk regions. At the moment, due to political instability, the extraction of coking coal in the east of Ukraine is suspended.

Coal Mining in Russia

On the territory of Russia there are large deposits of coal. According to figures, the country occupies one of the first places in the world for coal reserves. More than 67% of them are coal. Of these, 10% are coking coals.

In Russia, coking coal is mined in the basins: Kuznetsk, Pechora, Yuzhno-Yakutsk, Donetsk and Kizelovsky. The first two pools produce the largest amount of coal.

The reserves of coking coals in Russia are 47.3 billion tons. However, only a small part is usable. In recent years, the production of coking coal in Russia is at the level of 70 million tons per year. This is enough to provide raw materials to the country's industrial enterprises.

Coking coal in Russia is produced at a stable rate. The increase in coal production will take place in the case of increased demand for this type of raw materials, due to the development of metallurgical and related industries of the Russian Federation.

Prospects of the coking coal market

In the coming years, the Russian coal industry is waiting for changes. The key directions of the industry development will concern the vertical system of coal production. Thus, state policy provides for the creation of small and medium-sized power facilities on the basis of coal mines. It is also planned to install equipment at coal-mining enterprises that allows processing coal into environmentally friendly synthetic fuels.

With regard to sales volumes, demand for coking coal in Russia will grow. The fact is that in addition to steel mills, coke uses non-ferrous metallurgy and many other industries. Thus, about 0.4 tons of coke is needed to produce 1 ton of pig iron. And alternative technologies that allow it to be replaced by a more profitable resource, are applied in a limited way.

Trends in the world coking coal market

To date, many coal companies of all countries are experiencing a crisis of lower prices for coking coal. This problem is aggravated by the states that supply coke in excess quantities. Also a great influence on prices is the desire of buyers to reduce costs. Another unfavorable situation arises from the desire of producers to reduce production costs. In Europe and China, the demand for coking coal continues to grow, but this is due to the production of higher categories. But in general, the volume of purchases of raw materials on the world market is falling.

The situation with energy raw materials in the US market has stabilized slightly. But the price for it continues to fall because of a drop in demand for steel. As a result, coking coal production in the United States and European countries may decline.

But experts predict an increase in imports of energy raw materials in India. By volume of import of coking coal this country takes the third place in the world.

Cost of raw materials

In the second quarter of 2015, there is a decline in prices for coking coal. Large world companies offer raw materials at a price that is 5-10% lower compared to the first quarter. So, the South African company Anglo American offered Japan coking coal of the highest quality at $ 116 USD per 1 ton. The average price for 1 ton of coking coal is 117 US dollars.