Lead
Coal resources are of great significance to human development, because coal is an indispensable energy source in our development process, and in a long time, we need coal resources to form.
So how is coal formed?
Why is there such a thick coal seam?
What's the story?
And how is the scale of the dip coal seam formed?
1. Coal is a non-renewable resource.
As a non-renewable resource, the formation process of coal resources can be described as extremely difficult, and it also takes a long time to accumulate.
So how is coal formed?
Most of the formation of coal was formed in the Carboniferous, Permian, Jurassic and other periods of geological time.
There are two important conditions for the formation of coal: one is that there are enough plants, and the other is a closed environment with high pressure and high temperature.
On the earth, where there was no life, with the birth of plants, this laid the foundation for the formation of coal.
This is because plants absorb carbon dioxide as they grow and release oxygen, which provides the conditions for the survival of the next organisms on Earth.
At that time, the variety of plants was very abundant and very lush, which provided the conditions for the formation of coal.
After the plant dies, it will decay like early animals, and the microorganisms in the soil will decompose it and then turn it into a part of the soil, but under certain conditions, the decay process of the plant will be stopped, including drought, water flow, etc.
Through a certain amount of time accumulation, the death and decay of the plant will form a certain thickness, and then these accumulated traces of plant death will be buried in the ground, so that it will not decay and thus will not release carbon dioxide.
In this case, the remains of these plants can be preserved, and then over time, they will eventually form coal deposits.
If they don't sink into the ground, the plants will rot on the surface, releasing carbon dioxide, which means there is no coal resource.
So why do vegetable coal seams reach such a height of 9 meters?
This is because in order to form a coal deposit, the plants decay after a certain period of time, releasing carbon dioxide, which means that the volume of these plants decreases, which is why the coal deposit is so high.
Another condition is required for the formation of coal, that is, a closed environment with high pressure and high temperature.
During the decay process of the plant, water and oxygen are expelled because they are both absorbed by the decaying plant.
Under high pressure and high temperatures, this water and oxygen are squeezed out, so that the decaying plants have enough carbon and hydrogen and do not combine with oxygen, so that coal is formed.
In the formation of coal, the pressure is generally between 10 MPa and 30 MPa, and the temperature is between 200 and 400 degrees Celsius, which means that these environments can only be achieved when buried at a certain depth.
This provides the conditions for the burial of coal, which is typically buried at depths of between 100 and 400 meters, which is why the depth of coal resources in the ground is limited.
2. Why do large-scale coal seams have dips?
In the process of the earth's movement, the earth's crustal plates will squeeze each other, generally speaking, coal resources are formed on the continental plates, and in the process of the movement of the earth's crustal plates, some changes will also occur.
Sometimes the earth's crustal plates arch up, and sometimes the earth's crustal plates sink again, which is why the coal seam has a certain dip angle underground.
In the process of arching the crustal plates, if the coal seam has a certain depth underground, then this depth will become deeper with the extrusion of the crustal plates, so that the decaying plants will undergo a more high-pressure and high-temperature process, thus forming better coal resources.
In the process of subsidence of the earth's crustal plates, the depth of coal resources will become shallower, so that the decaying plants will not go through a higher pressure and high temperature process, and the quality of coal resources will deteriorate.
Most inclined coal seams are formed in the process of subsidence of crustal plates, which means that such coal resources will have clay minerals and ore-bearing peat minerals.
Therefore, in the process of arching the crustal plates, the coal resources formed will be better and more suitable for people to exploit, which is why many coal mines are in the places where the crustal plates are arched.
3. There are many types of coal in China and it is widely distributed.
What we call coal ore seam refers to the distribution of coal resources within a certain range, and the distribution of coal underground is very extensive, and there are coal resources in almost all places in the world, among which the most abundant coal resources are mainly in Eurasia.
Among China's coal resources, there is a certain area with the most abundant coal resources, that is, the Loess Plateau and the plain of the middle and lower reaches of the Yangtze River.
This is also due to the fact that in the process of the formation of China's coal resources, the continental plate changed, and eventually formed the geographical map of China.
China's coal resources can be divided into ten categories according to geological characteristics, namely lignite, bituminous coal, stone coal, anthracite, coal asphalt, pulverized coal, coal gangue, peat, lignite, and coal sludge.
Lignite is the most common coal resource, accounting for a considerable proportion of the mainland's coal resources, but the calorific value of lignite is relatively low.
Bituminous coal is one of the highest calorific value of coal resources, so it occupies a considerable proportion of the mainland's coal resources, and bituminous coal can be made into coke for steelmaking.
Anthracite is the transition between bituminous coal and lignite, and its calorific value is lower than that of bituminous coal.
Stone coal is the most common type of coal resource, and its calorific value is relatively high.
Coal pitch is a special coal resource in the mainland's coal resources, its calorific value is very low, but it has a wide range of uses in the chemical field.
Pulverized coal refers to a coal resource with a pulverized coal particle content of more than 80% in coal resources.
Coal gangue refers to a coal resource with an impurity content of more than 70% in coal resources.
Peat is the least common coal resource and has the lowest calorific value.
Lumonite is a kind of coal resource that contains more sulfur and calcium.
Coal sludge refers to the waste in coal mines, which has the lowest calorific value, but it has an important use in the chemical industry.
epilogue
Coal resources are an important energy source for the mainland and an important cornerstone of the mainland's economic development.
However, with the exploitation of coal resources in the mainland, this also means that coal resources are limited, and the mining of coal resources is also accompanied by some problems, such as the frequent occurrence of coal mine accidents.
Therefore, we need to standardize the mining of coal resources, improve efficiency, protect the environment, and achieve sustainable development of coal resources.