There are many indicators to judge the quality of coal, among which the most important indicators are the ash and sulfur content of coal. Generally speaking, the ash and sulfur contents of coal are generally low in continental deposits; Due to the alternate deposition of marine and continental phases, the ash and sulfur content of coal is usually high.
The ash content of China coal is generally high. Jurassic coalfield is a continental deposit in north Qinling, north Shanxi, north Shaanxi, Ningxia, Huaibei and northeast China. Generally, the ash content of coal is 10% ~ 20%, some of which are below 10%, and the sulfur content is generally less than 1%, and the sulfur content in Northeast China is generally less than 0.5%. The limestone period, south of Qinling Mountains, Qianyang coal measures in Hunan and Liangshan coal measures in Hubei, which are widely distributed in northern China, belong to the coal deposited by land and sea, with ash 15% ~ 25% and sulfur content of 2% ~ 5%.
The late Permian coal seams in Heshan, Guangxi and Shangsi, Sichuan belong to shallow-sea sedimentary coal, and the sulfur content can be as high as 6% ~ 10%.
According to statistics, the ultra-low ash coal with ash content less than 10% in China only accounts for about 17% of the proven reserves. The ash content of most coals is 10% ~ 30%. Ultra-low sulfur coal with sulfur content less than 1% accounts for more than 43.5% of proven reserves, while high sulfur coal with sulfur content greater than 4% accounts for only 2.28%. Coking coal in China is generally medium ash and medium dilute coal, with less low ash and low sulfur coal. The ash content of coking coal is generally above 20%; Coking coal with sulfur content greater than 2% accounts for more than 20%. Another major feature of coking coal in China is that the higher the sulfur content, the stronger the fluidity of coal and the generally poor washability.
China lignite is mainly aged lignite. The ash content of lignite is generally 20% ~ 30%. The sulfur content of lignite in Northeast China is mostly below 1%, and the sulfur content of lignite in Guangdong, Guangxi and Yunnan is higher, and some even reach more than 8%. Generally, the total moisture content of lignite can reach 20% ~ 50%, the analytical base moisture content 10% ~ 20%, and the low calorific value is only1.71~16.73 mj/kg.
China bituminous coal is characterized by low ash and sulfur. The ash content of raw coal is mostly below 15%, and the sulfur content is less than 1%. Some coalfields, such as Shenfu and Dongsheng coalfields, have only 3%-5% ash in raw coal, which is called natural clean coal. The second characteristic of bituminous coal is the high sericite content in coal and rock components, generally above 40%, so China bituminous coal is mostly high-quality power coal. China lean coal has a high ash content and sulfur content, with ash content of 15%-30% and mobile content of 1.5%-5%. Lean coal can be used as high-quality power coal and gasification coal after washing.
There are few typical anthracite and aged anthracite in China, and most of them are No.3 young anthracite. Its main characteristics are high ash and sulfur, most of which are medium ash, medium sulfur, medium calorific value and high ash melting point. Mainly used as power coal, and some can be used as gasification raw coal.
Respondent: Pumpkin Lane-Manager Level 4 1-5 15:00.
Coal quality characteristics, also known as coal quality characteristics and coal quality indicators, mainly include five items, namely calorific value, sulfur, ash, moisture and volatile matter.
So the feature 4 you said refers to the moisture content; Feature 3 refers to the ash content; Feature 5 refers to volatile content.
Respondent: Guo Huashi-Juren Grade 4 1-5 15:3 1.
coal
How is coal formed?
Coal is called black gold and industrial food. Since18th century, it has been one of the main energy sources used in the human world. Although its important position has been replaced by oil, it will inevitably decline in the future for a long time, and coal will become one of the irreplaceable energy sources in human production and life because of its huge reserves and rapid development of science and technology.
Coal is a very thick layer of black humus, which has been accumulated on the ground by the branches and roots of plants for millions of years. Due to the change of the earth's crust, it is buried underground for a long time and isolated from the air. After a series of complicated physical and chemical changes at high temperature and high pressure, black fossils are formed, which is the formation process of coal.
The thickness of coal seam in coal mine is related to the speed of crustal decline and the accumulation of plant residues in this area. The earth's crust is falling rapidly and the plant remains are piled thick, so the coal seam in this coal mine is thick. On the contrary, the earth's crust is slowly falling, and the plant remains are piled very thin, so the coal seam of this coal mine is very thin. Due to the tectonic movement of the earth's crust, the original horizontal coal seam was folded and fractured. Some coal seams are buried deep underground, while others are pushed out of the surface or even exposed to the ground, which is easy to be found. There are also some coal seams that are relatively thin and small in area and have no mining value. So far, there is no updated statement about the formation of coal.
Is coal formed in this way? Whether some expositions should be further studied and discussed. Large coal mines have thick coal seams and excellent coal quality, but the area is generally not very large. If it is formed by the natural growth of leaves and roots of plants for millions of years, its area should be very large. Because the earth was full of forests and grasslands in ancient times, there should be traces of coal storage everywhere underground; The coal seam is not necessarily very thick, because the leaves and roots of plants rot into humus, which will be absorbed by plants. If it is repeated, it will not be so concentrated when buried underground, and the boundary between soil layer and coal seam will not be so clear.
However, the undeniable fact and basis is that coal is indeed formed by the systematic evolution of plant residues, which is an unbreakable truth. As long as you look at the coal carefully, you can see the traces of leaves and roots of plants; If you slice coal and observe it under a microscope, you can find a very clear plant tissue structure. Sometimes things like tree trunks are still preserved in coal seams, and some coal seams are still wrapped with complete insect fossils. Why it is so concentrated and of such high quality is worth discussing.
I remember when I was in primary school, my family lived in a village not far from the city. Whenever the midsummer rainy season comes, after a rainstorm, there will be a rushing "stream" in the middle of the village, and many of our children will run into it to play. Due to the extension of heavy rain, this stream will become smaller and smaller and eventually dry up. But before the water is cut off, you will find that many water flows are blocked by floating objects such as wooden sticks and weeds, forming small water barriers. In order to make the water flow smoothly, we tear open those small water barriers from time to time, and sometimes build a "dam" on the stream. Even living in the city now, after a heavy rain, there will be all kinds of floating objects blocking the water flow and the sewer mouth in many places on the street, and many floating objects are concentrated in one place.
It can be inferred that the formation of coal may be directly related to the flood. Without such a powerful force and carrying function as flood, the formation of coal would never be so concentrated and of such high quality.
We can imagine that in the geological and historical period millions of years ago, because of the very suitable climatic conditions, lush and tall plants grew on the ground, and a large number of plants grew in coastal and inland swamp areas. At that time, the rainfall was quite abundant. When natural disasters such as the once-in-a-century flood or tsunami come, grasslands and large forests will be flooded, and plants, large and small, there will be uprooted and floating on the water. The soil at the roots of plants will also be washed away. These trees and grass with roots and branches will also climb and entangle each other and go down the river. Once they are washed to shallows and bays, they will run aground, where they will settle down and screen out all the floating objects like a sieve. Soon, a barrier will be formed here, and this place will also be the accumulation place of plant remains (and many animal remains) in the next flood. When the flood recedes, a winding pile of plant debris will form here. After long-term geological changes, this pile of plant debris will gradually be buried underground and eventually evolve into today's coal mine.
Then some people may ask, why didn't this happen when China was hit by a rare flood in 1998? I think that's because the current forest coverage rate in China is very low. Most places with forests are at high altitudes, and the plains are full of grain fields, almost to the point where there is no forest to flood, but some farmland shelterbelts are flooded, and the trees in farmland shelterbelts are rare, and the roots of trees are well developed, so they can firmly grasp the land, and short-term soaking and impact will not cause much damage. The trees in the forest are different. Many trees live together. In order to absorb the energy of the sun, they grow up desperately, and their roots are underdeveloped. Once a tree is uprooted by the flood, it will be destroyed by the flood, just like putting a raft down the river, unstoppable, and finally all piled up in one place.
In addition, due to the enhancement of human understanding of nature, the ability to resist sudden natural disasters has been continuously improved. Building water conservancy projects, building strong dams and strengthening river embankments have greatly slowed down the impact of fierce floods, and the phenomenon of flooding has become less, even obediently obeying the call of human beings, turning fierce floods into electric energy, kinetic energy and heat energy, benefiting mankind and serving human society.
Not only floods have the ability to carry animals and plants, but tides, typhoons and tsunamis also have this ability. Tsunamis caused by earthquakes, volcanic eruptions and other factors can make the waves rise by more than 30 to 40 meters, and instantly wipe out the animals and plants on an island; Plunder all living things near the coastline.
Moreover, the material on the surface cannot wait for the earth to sink forever, and the material on the surface is constantly circulating. Therefore, whether the "flood theory" makes coal so concentrated and high-quality still makes sense, which is convincing and can be convincing.
The material on the earth's surface can't wait for the earth to sink forever. The material on the earth's surface is constantly circulating. Therefore, whether the "flood theory" makes coal so concentrated and high-quality still makes sense, which is convincing and can be convincing.
It is an irrefutable fact that coal is indeed formed by the systematic evolution of plant residues. As long as you look at the coal carefully, you can see the traces of leaves and roots of plants. If you slice coal and observe it under a microscope, you can find a very clear plant tissue structure. Sometimes things like tree trunks are still preserved in coal seams, and some coal seams are still wrapped with complete insect fossils. Why it is so concentrated and of such high quality is worth discussing.
Due to the deposition of a large number of ancient plants, they were buried deep underground, subjected to high pressure and high temperature, and turned into coal after hundreds of millions of years.
Coal mines, like other mines, are layered, not everywhere. If it is accumulated by surface plants, it will not be so concentrated, and it should be everywhere, so I think what the book says is wrong. Carbon exists in the earth. Most of the carbon on the surface exists in the form of compounds, while the carbon in the center of the earth exists in the form of simple substances. When the carbon in the center of the earth is sprayed to the surface, it is partly diamond, partly graphite and mostly coal (different substances are formed under different conditions), which is the same as the origin of most other mines.
Plants are pressed underground and will form coal under the condition of long-term hypoxia and high pressure.
In Carboniferous, the plants on the earth flourished, which provided a strong material basis for the formation of coal, and the subsequent orogeny provided external conditions for the formation of coal. Many years later, there was coal.
Interviewee: yanxi 5288mm- magician trainee II 1-5 19:24.
Basic characteristics of coal resources in China
(1) The total resources are rich and relatively concentrated. The total coal resources in China are predicted to reach 5,059.2 billion tons, of which 1000 meters is 2,670.4 billion tons, and 970 billion tons have been proved by the end of 1990. Of the total resources predicted in the country, Taihang Mountain-west of Xuefeng Mountain 1 1 provinces and regions account for 89% of the whole country, and only11%in the east; The area north of Qinling-Dabie Mountain line accounts for 93.6% of the whole country, while the area south only accounts for 6.4%. In particular, the so-called "Three Wests" (Shanxi, Shaanxi and Western Inner Mongolia) and the four provinces of New Gansu, Ningxia and Qinghai each account for 40% of the country. Among the proven reserves, "Sanxi" accounts for 62%, and the four northwestern provinces and the three southwestern provinces of Yunnan, Guizhou and Sichuan each account for 10%. The coal resources in the whole east and the vast areas south of the middle and lower reaches of the Yangtze River are limited, and only Heilongjiang, Hebei, Shandong and Anhui are relatively rich.
(2) The types of coal are complete, but the quantity and regional distribution are unbalanced. 1989 reserves at the end of, low metamorphic lignite, low rank bituminous coal (weak, non-sticky, long flame coal, etc. ) accounts for 52.9%, coking coal accounts for 28.7%, and high metamorphic anthracite and lean coal account for 18.4%. The proportion of coking coal varieties is uneven, with gas coal accounting for 52%, strongly bonded main coking coal accounting for only 19% and fat coal accounting for only 12%. In addition, some coking coals are scattered or have high ash and sulfur content, and only about half of them can really be used for coking.
In terms of regional distribution, the area south of Qinling-Dabieshan line has a high degree of metamorphism, mostly smokeless, poor and thin coal. The metamorphic degree of Qinling-northern Dabie Mountain gradually weakened from Yanshan, Taihang Mountain and Funiu Mountain to the two wings, that is, from anthracite, lean coal, coking coal to low-grade bituminous coal. Anthracite is concentrated in Shanxi, Guizhou, Henan, Sichuan, Hebei, Beijing and other six provinces and cities, accounting for more than 90% of the country, of which Shanxi monopolizes 45%, which is a national high-quality anthracite base. Coking coal is mainly distributed in Shanxi, Hebei, Henan, Anhui, Shandong, Guizhou and Heilongjiang, accounting for about 80% of the country, of which Shanxi alone accounts for 56.4%. Gas, fat and lean brands also account for more than half of the country and are the main bases in the country. In other provinces, except Hebei, there are more gas coals in East China and Northeast China, but there is a shortage of fat coal and lean coal in Northeast China, and there is a shortage of main coke and lean coal in East China. Shanxi, Inner Mongolia, Ningxia, Xinjiang and Gansu account for 97% of the country's low-grade bituminous coal.
(3) The coal quality of different varieties is quite different. The ash content of coal in China is generally high and varies greatly. Generally, the ash content is 15% ~ 25%, and the ultra-low ash coal below 10% accounts for about 15% ~ 20% of the retained reserves. Ultra-low sulfur coal with sulfur content less than 1% accounts for about 45%, mainly distributed in the north; More than 4% of high-sulfur coal accounts for about 2% ~ 5%, mainly distributed in southwest, south-central and parts of Shanxi, Shandong and Shaanxi, and it is difficult to desulfurization.
The ash content of coking coal in China is generally above 20%, and low ash content is rare; The sulfur content is mostly medium sulfur, and the sulfur content above 2% accounts for more than 20% of coking coal; There are few coking coals with low ash and sulfur, and coking coals with strong cohesiveness often have high sulfur content, while most of the fat coals have sulfur content above 2%, and the general washability of low ash and high sulfur is poor; 75% of gas coal is low in sulfur, and most of it is easy to separate.
Most anthracite in China belongs to medium ash, medium low sulfur, medium calorific value and high ash melting point; A few mining areas have excellent coal quality, and low-grade bituminous coal is mostly low ash and sulfur, which is high-quality power coal, and some of it can be used as gasification raw coal and coking coal blending. Brown coal, low sulfur in the north and high sulfur in the south.
(4) The occurrence conditions of coal seams are mostly good and some are poor.
The coal seam is shallow, with the buried depth less than 300 meters accounting for about 35% of the reserves, and 300 ~ 600 meters accounting for 45%. Generally speaking, the buried depth in the eastern plain area is relatively deep, and the western mountainous area is relatively shallow.
The thickness of coal seam is mainly thin and medium thick, and the extremely thick coal seam is less; There are not many reserves suitable for open pit mining.
Judging from the well construction conditions, there are about 1/3 coalfields with overburden less than 100 meters, which is not difficult. Generally speaking, the conditions of well construction in the northern mining area are better than those in the south, the west is better than the east, and the geological conditions in Shanxi, Shaanxi and Mongolia are the best. Most mining areas lack water sources, especially in North China and Northwest China.
Respondent: Primary 2 2006- Assistant Level 3 1-5 2 1:45.
Coal characteristics
There are many indicators to judge the quality of coal, among which the most important indicators are the ash and sulfur content of coal. Generally speaking, the ash and sulfur contents of coal are generally low in continental deposits; Due to the alternate deposition of marine and continental phases, the ash and sulfur content of coal is usually high.
The ash content of China coal is generally high. Jurassic coalfield is a continental deposit in north Qinling, north Shanxi, north Shaanxi, Ningxia, Huaibei and northeast China. Generally, the ash content of coal is 10% ~ 20%, some of which are below 10%, and the sulfur content is generally less than 1%, and the sulfur content in Northeast China is generally less than 0.5%. The limestone period, south of Qinling Mountains, Qianyang coal measures in Hunan and Liangshan coal measures in Hubei, which are widely distributed in northern China, belong to the coal deposited by land and sea, with ash 15% ~ 25% and sulfur content of 2% ~ 5%.
The late Permian coal seams in Heshan, Guangxi and Shangsi, Sichuan belong to shallow-sea sedimentary coal, and the sulfur content can be as high as 6% ~ 10%.
According to statistics, the ultra-low ash coal with ash content less than 10% in China only accounts for about 17% of the proven reserves. The ash content of most coals is 10% ~ 30%. Ultra-low sulfur coal with sulfur content less than 1% accounts for more than 43.5% of proven reserves, while high sulfur coal with sulfur content greater than 4% accounts for only 2.28%. Coking coal in China is generally medium ash and medium dilute coal, with less low ash and low sulfur coal. The ash content of coking coal is generally above 20%; Coking coal with sulfur content greater than 2% accounts for more than 20%. Another major feature of coking coal in China is that the higher the sulfur content, the stronger the fluidity of coal and the generally poor washability.
China lignite is mainly aged lignite. The ash content of lignite is generally 20% ~ 30%. The sulfur content of lignite in Northeast China is mostly below 1%, and the sulfur content of lignite in Guangdong, Guangxi and Yunnan is higher, and some even reach more than 8%. Generally, the total moisture content of lignite can reach 20% ~ 50%, the analytical base moisture content 10% ~ 20%, and the low calorific value is only1.71~16.73 mj/kg.
China bituminous coal is characterized by low ash and sulfur. The ash content of raw coal is mostly below 15%, and the sulfur content is less than 1%. Some coalfields, such as Shenfu and Dongsheng coalfields, have only 3%-5% ash in raw coal, which is called natural clean coal. The second characteristic of bituminous coal is the high sericite content in coal and rock components, generally above 40%, so China bituminous coal is mostly high-quality power coal. China lean coal has a high ash content and sulfur content, with ash content of 15%-30% and mobile content of 1.5%-5%. Lean coal can be used as high-quality power coal and gasification coal after washing.
There are few typical anthracite and aged anthracite in China, and most of them are No.3 young anthracite. Its main characteristics are high ash and sulfur, most of which are medium ash, medium sulfur, medium calorific value and high ash melting point, which are mainly used as power coal and some of which can be used as gasification raw coal.
Respondent: Pumpkin Lane-Manager Level 4 1-5 15:00.
Coal quality characteristics, also known as coal quality characteristics and coal quality indicators, mainly include five items, namely calorific value, sulfur, ash, moisture and volatile matter.
So the feature 4 you said refers to the moisture content; Feature 3 refers to the ash content; Feature 5 refers to volatile content.
coal
How is coal formed?
Coal is called black gold and industrial food. Since18th century, it has been one of the main energy sources used in the human world. Although its important position has been replaced by oil, it will inevitably decline in the future for a long time, and coal will become one of the irreplaceable energy sources in human production and life because of its huge reserves and rapid development of science and technology.
Coal is a very thick layer of black humus, which has been accumulated on the ground by the branches and roots of plants for millions of years. Due to the change of the earth's crust, it is buried underground for a long time and isolated from the air. After a series of complicated physical and chemical changes at high temperature and high pressure, black fossils are formed, which is the formation process of coal.
The thickness of coal seam in coal mine is related to the speed of crustal decline and the accumulation of plant residues in this area. The earth's crust is falling rapidly and the plant remains are piled thick, so the coal seam in this coal mine is thick. On the contrary, the earth's crust is slowly falling, and the plant remains are piled very thin, so the coal seam of this coal mine is very thin. Due to the tectonic movement of the earth's crust, the original horizontal coal seam was folded and fractured. Some coal seams are buried deep underground, while others are pushed out of the surface or even exposed to the ground, which is easy to be found. There are also some coal seams that are relatively thin and small in area and have no mining value. So far, there is no updated statement about the formation of coal.
Is coal formed in this way? Whether some expositions should be further studied and discussed. Large coal mines have thick coal seams and excellent coal quality, but the area is generally not very large. If it is formed by the natural growth of leaves and roots of plants for millions of years, its area should be very large. Because the earth was full of forests and grasslands in ancient times, there should be traces of coal storage everywhere underground; The coal seam is not necessarily very thick, because the leaves and roots of plants rot into humus, which will be absorbed by plants. If it is repeated, it will not be so concentrated when buried underground, and the boundary between soil layer and coal seam will not be so clear.
But the undeniable fact and basis is that coal is indeed formed by the evolution of plant residue system, which is an unbreakable truth. As long as you look at the coal carefully, you can see the traces of leaves and roots of plants; If you slice coal and observe it under a microscope, you can find a very clear plant tissue structure. Sometimes things like tree trunks are still preserved in coal seams, and some coal seams are still wrapped with complete insect fossils. Why it is so concentrated and of such high quality is worth discussing.
I remember when I was in primary school, my family lived in a village not far from the city. Whenever the midsummer rainy season comes, there will be storms. %E