Coal stone: properties. Coal: origin, extraction, price

Since ancient times mankind has used coal as one of the sources of energy. And today this mineral is used widely enough. Sometimes it is called solar energy, which is conserved in stone.

Application

Coal is burned, receiving heat, which goes for hot water and heating of houses. The mineral is used in the technological processes of smelting metals. At thermal power plants, coal is converted into electricity by combustion.

Scientific advances have made it possible to use this valuable substance differently. Thus, in the chemical industry, a technology has been successfully mastered that makes it possible to obtain liquid fuel from coal, as well as rare metals such as germanium and gallium. Of the valuable fossil at present, carbon-graphite composite materials with a high carbon concentration are extracted. Methods have also been worked out to produce plastics and gaseous fuel of high caloric value from coal.

Very low fraction of low-grade coal and its dust after processing is pressed into briquettes. This material is great for heating private homes and industrial premises. In general, more than four hundred different products are produced after chemical processing, to which coal is exposed. The price for all these products is tens of times higher than the cost of raw materials.

Over the past several centuries, mankind has been actively using coal as a fuel for obtaining, as well as converting energy. And the need for this valuable fossil has recently increased. This is facilitated by the development of the chemical industry, as well as the need for valuable and rare elements derived from it. In this regard, in Russia today, intensive exploration of new deposits is underway, mines and quarries are being created, enterprises are being built to process this valuable raw material.

The origin of the fossil

In ancient times on Earth there was a warm and humid climate, in which varied vegetation was rapidly developing. From it in the future, and formed coal. The origin of this fossil lies in the accumulation of billions of tons of dead vegetation on the bottom of the marshes, where they were covered with sediments. Since that time, about 300 million years have passed. Under the powerful press of sand, water and various rocks, the vegetation slowly decomposed in an oxygen-free environment. Under the influence of high temperatures, which gave a closely located magma, there was solidification of this mass, which gradually turned into coal. The origin of all existing deposits has only such an explanation.

Mineral resources and mining

On our planet there are large deposits of coal. In total, according to estimates of experts, the earth's bowels store in themselves fifteen trillion tons of this mineral. And the extraction of coal by its volume is in the first place. In a year it makes 2.6 billion tons, or 0.7 tons per one inhabitant of our planet.

The deposits of coal in Russia are located in different regions. And in each of them the mineral has different characteristics and has its depth of occurrence. Below is a list, which includes the largest deposits of hard coal in Russia:

1. Elginsky deposit. It is located in the south-eastern part of Yakutia. The depth of occurrence of coal in these areas allows for the open extraction of a mineral. This does not require special expenses, which affects the cost of the final product.
2. The Tuva deposit. According to experts, about 20 billion tons of mineral are located on its territory. The field is very attractive for development. The fact is that eighty percent of its deposits are located in the same layer, having a thickness of 6-7 meters.
3. Minusinsk deposits. They are located in the Republic of Khakassia. These are several deposits, the largest of which are the Montenegrin and Izykh. Reserves of the basin are not large. According to experts, they are from 2 to 7 billion tons. Here, very valuable stone coal is extracted. The properties of the mineral are such that when it burns a very high temperature is fixed.
4. Kuznetsk coal basin. This deposit, located in the west of Siberia, gives the product used in the iron and steel industry. Coal, which is mined in these places, goes for coking. The volume of deposits here is simply huge.
5. Kuznetsk Alatau. This deposit gives the product the highest quality. The greatest depth of occurrence of seams of a mineral reaches 500 meters. The extraction is carried out both in open sections and in mines.

Coal in Russia is mined in the Pechora coal basin. Fields are actively being developed in the Rostov region.

Selection of coal for the production process

In different industries there is a need for different brands of minerals. What differences does coal have stone? Properties and quality characteristics of this product vary widely.

This happens even if the coal has the same marking. The fact is that the characteristics of the fossil depend on the place of its extraction. That is why every enterprise, choosing coal for its production, should familiarize with its physical characteristics.

Properties

Coal is distinguished by the following properties:

1. Density. This is one of the most important characteristics, which ranges from 1.28 to 1.53 grams per cubic centimeter. As the density increases, the specific heat of combustion of coal increases.
2. Carbon content. This indicator is between 75 and 97 percent. With a larger content of carbon in the fuel, less volume remains for foreign impurities. This allows you to get the maximum amount of energy during the combustion of the product.
3. Mechanical strength. This characteristic determines the ability of the fossil to transfer transportation. This parameter is in the range from 40 kilograms per square centimeter (for brown coals) to 300 (for anthracites).
4. Sulfur content. In coal, it can be from 0.5 to 5.4 percent. At a lower value of this value, it is safer to use fuel.
5. The yield of volatile components (2-45%).
6. Humidity. Fuel can contain between 4 and 15 percent moisture. From this indicator directly depends on whether coal is effective in burning coal. The properties of a more moist product are radically different from dry. Such coal crumbles and undergoes rapid weathering.
7. Ash content. This characteristic indicates the amount of non-combustible mixtures contained in the fossil. With a lower ash content, the specific heat increases . The lowest percentage of incombustible mixtures have anthracites. It is within 2%. For heating, the ash content is within thirty percent. The highest value of this characteristic is 45%.
8. Specific heat of combustion. This indicator is in the range from 6500 to 8600 kcal / kg. It characterizes the amount of heat that is generated when one kilogram of fuel is burned.

Extent of enrichment

Depending on the purpose of use, different coal can be purchased. The properties of the fuel become clear at the same time, based on the degree of enrichment. Allocate:

1. Concentrates. Such fuel is used in the production of electricity and heat.

2. Industrial products. They are used in metallurgy.

3. Sludge. This is a fine fraction of coal (up to six millimeters), as well as dust resulting from the crushing of the rock. From the slurry briquettes are formed, which have good operational properties for household solid fuel boilers.

Degree of coalification

On this indicator distinguish:

1. Brown coal. It is the same coal, only partially formed. Its properties are somewhat worse than that of a better fuel. Brown coal produces a low heat during combustion and crumbles during transportation. In addition, he has a tendency to spontaneous combustion.

2. Hard coal. This type of fuel has a large number of varieties (brands), whose properties are different. It is widely used in power engineering and metallurgy, housing and utilities and the chemical industry.

3. Anthracites. This is the most qualitative type of coal.

The properties of all these forms of mineral are significantly different from each other. So, the lowest heat of combustion is charcoal brown, and the highest - anthracite. What is the best way to buy coal? The price should be economically viable. Proceeding from this, the cost and specific heat in the optimal ratio are found in ordinary coal (within 220 dollars per ton).

Classification by size

When choosing a coal it is important to know its dimensions. This indicator is encrypted in the mineral mark. So, coal happens:

- "P" - plate, which represents large pieces of more than 10 cm.

- "K" - large, the sizes of which are from 5 to 10 cm.

- "O" is a nut, it is also quite large, with sizes of fragments from 2.5 to 5 cm.

- "M" - small, with small pieces of 1.3-2.5 cm.

- "C" - a seed - a cheap fraction for prolonged decay with dimensions of 0.6-1.3 cm.

- "Sh" - a shovel, which is mostly coal dust, intended for briquetting.

- "P" - ordinary, or non-standard, in which there may be fractions of different sizes.

Properties of brown coal

This is the least qualitative hard coal. The price at it the lowest (about hundred dollars for ton). Brown coal was formed in ancient bogs by pressing peat at a depth of about 0.9 km. This is the cheapest fuel, containing a large amount of water (about 40%).

In addition, brown coal has a rather low heat of combustion. It contains a large amount (up to 50%) of volatile gases. If brown coal is used for furnace heating, then it will resemble raw firewood in its qualitative characteristics. The product burns heavily, smokes strongly and leaves behind a large amount of ash. Often briquettes are prepared from this raw material. They have good performance characteristics. Their price is in the range of eight to ten thousand rubles per ton.

Properties of coal

This fuel is better. Coal is a rock that has a black color and a matte, semi-matt or glossy surface.

In this type of fuel contains only five to six percent of moisture, because of what it has a high calorific value. Compared with oak, alder and birch firewood, coal produces 3.5 times more heat. The downside of this type of fuel is its large ash content. The price for coal in summer and autumn ranges from 3900 to 4600 rubles per ton. In winter, the cost of this fuel increases by twenty to thirty percent.

Storage of coal

If fuel is to be used for a long period, it must be placed in a special shed or bunker. There, it must be protected from direct sunlight and from precipitation.

If the heaps of coal are large, then during storage it is necessary to constantly monitor their condition. Small fractions in combination with high temperature and moisture can self-ignite.