Coal is a mineral and one of the most important fuel resources. It began to be mined commercially at the end of the 19th century. This article will discuss the main places and methods of coal mining in the modern world. We will talk about which countries are leaders in the development of this resource. Among other things, you will find out which method of coal mining can be considered the most efficient and cheapest.
Coal and its mining
Coal is a type of solid fuel, an organic substance based on the chemical element carbon. Its international name comes from the Latin word carbo. Coal is considered the first type of fossil fuel that has been used by reasonable humans.
Coal is nothing but the remains of rich vegetation left over from more ancient geological eras. Over time, these plant masses sank underground to a considerable depth. There they underwent slow decomposition and metamorphization under the influence of high temperatures and in the absence of oxygen.
Three main types of coal are distinguished depending on the carbon content:
- Brown coal (carbon content not more than 75%).
- Coal (75β95%).
- Anthracite (over 95%).
Around the 60s of the last century, there has been a worldwide trend towards a decrease in coal production. This fuel resource was gradually replaced by oil and gas. But when world oil prices rise, the use of coal as an energy carrier also increases markedly.
The main deposits and methods of mining coal
The largest coal basins of the planet:
- Tungusky (Russia).
- Kansk-Achinsky (Russia).
- Donbass (Ukraine, Russia).
- Kuzbass (Russia).
- Illinois (USA).
- Ruhr (Germany).
- Upper Silesian (Poland).
- Damodar (India).
Russia has enormous reserves of coal and brown coal. True, quite often their layers occur in hard-to-reach areas, which complicates the process of developing this resource. The most promising coal deposits in the Russian Federation are Elegest and Elginsk. For the development of both deposits, a quarry method of coal mining can be applied.
As of 2013, the top ten countries for coal mining are as follows:
- China (3,680 million tons per year).
- USA (893 million tons).
- India (605 million tons).
- Australia (478 million tons).
- Indonesia (421 million tons).
- Russia (352 million tons).
- South Africa (257 million tons).
- Germany (197 million tons).
- Poland (143 million tons).
- Kazakhstan (115 million tons).
If we talk about Russia, in recent years, coal production has been increasing. So, in 2017, a total of about 410 million tons of this energy resource was extracted from the country's bowels.
Coal is mined today in three main ways:
- open (career);
- closed (mine);
- hydraulic.
Next, we consider the features, advantages and disadvantages of each of the above methods.
Open way
Benefits:
- low cost;
- relative labor safety;
- Comparatively little time is spent on the extraction of one unit of fuel.
Disadvantages:
- coal mined in this way contains a large number of various impurities;
- An open way does much more harm to the environment.
An open-pit method of coal mining is represented by quarries and open pits, which may have different depths and areas. Career mining involves the use of heavy equipment: bulldozers, draglines, crushing plants, water guns, bucket-wheel excavators. In Russia, about 75% of all coal is mined open-pit.
Closed way
Benefits:
- relative environmental friendliness;
- higher quality of coal mined;
Disadvantages:
- high cost;
- job insecurity;
- a large proportion of manual hard labor.
The closed method of coal mining requires huge capital investments. Indeed, some layers lie very deep (at a depth of up to 1000 meters or more).
Hydraulic way
One of the main dangers in the work of all miners is water, which at any moment can break through a powerful stream into the mine shaft. However, in the 30s of the twentieth century in the USSR, a hydraulic method of production was developed, which involved the use of groundwater pressure to transport extracted raw materials to the earth's surface.
Today, hydraulic coal mining is considered one of the most promising and safe ways. It greatly facilitates the already difficult and dangerous work of miners. According to statistics, in the modern world only 7.5% of coal is mined using the hydraulic method.
Which coal mining method is more efficient?
There can be no single answer to this question. Which method of coal mining should be chosen in each specific situation will depend on a number of factors. First of all, from the depth of the location of the formation and its thickness (thickness).
So, if the coal seam is at a sufficiently large depth, the mine method of its development will be appropriate. If the mineral is shallow and also has a large capacity, then it would be more expedient to use an open mining method.
If we talk about the financial side of the issue, then the underground method of coal mining is more costly than quarry.
What is a "digger"?
Nowadays, there is another, archaic and rather exotic, method of coal mining. We are talking about the so-called diggers.
Kopanka is a makeshift and, as a rule, illegal coal mining enterprise. Most often this is a small mine. Kopanks are common in areas where industrial development of coal seams has already been discontinued.
Kopanks are one of the symbols of modern Donbass. Some residents of the Donetsk and Lugansk regions of Ukraine manage to extract coal from the bowels of the earth directly in their personal plots. More or less large diggers bring their owners a solid "catch" - about 300 tons of solid fuel per year.