There are several types of coal

There are nine types of coal, namely coking coal, fertilizer coal, anthracite, lean coal, weakly bonded coal, gas coal, lignite, long-flame coal, and poor coal.

1, coking coal

Coking coal is the main coking coal in the coking coal, the degree of metamorphism is medium, coking and bonding is the best. Coking coal from Shanxi produces coke with large lump size, less cracks, high crushing strength and good abrasion resistance, which is a precious product of coking coal. By utilizing coking coal, coke, tar and coke oven gas can be obtained. In addition to supplying smelting, coke can also make gas and calcium carbide.

2, fat coal

Fat coal is a kind of coal for coking, the coke made from fat coal has more transverse cracks, coke root bee coke, easy to crumble, but the fat coal's adhesion is very strong, and can be combined with the coal with weaker adhesion to refine a high-quality coal, said that the fat coal is the mother of all coke coals. Because of the fat coal varieties are rare, only 5% of the country's proven coal resources and Shanxi proven fat coal reserves accounted for about 50% of the country, the main branch in Huoxian mining area, three mining area and Gujiao mining area.

3, anthracite

Anthracite is a highly metamorphic coal with hard, glossy and strong characteristics. It has a long burning time and strong fire. Anthracite is mainly used for fertilizer and chemical production. Yangquan anthracite is an ideal fuel for blast furnace blowing because of its good grindability. The anthracite in the area of Jincheng and Yangcheng is known as orchid charcoal. Shanxi ranks first in the country in terms of large reserves and good quality of anthracite coal resources.

4. Lean Coal

Lean coal is the allotment of coking coal, and its performance is similar to that of coking coal. Lean coal coke lump size, less cracks, but poor fusibility and abrasion resistance, its use in addition to coking coal, but also can be used with gas production, power generation and other power coal. Shanxi Qingshui Coalfield, Xishan Coalfield, Huoxian Coalfield and Hedong Coalfield are rich in lean coal resources.

5. Weakly Bonded Coal

Weakly bonded coal is the excessive coal between coking coal and non-coking coal, and it is mainly used as gas production, fuel and coking. The Datong mine in Shanxi Province produces low-sulfur, low-ash and low-phosphorus weakly-bonded coal, and is the largest high-quality power coal base in the country.

6, gas coal

Gas coal is one of the coking coals, the bonding is lower. It is mainly used for coking coal. Gas coal coke is easy to push coke, gas yield and coking product recovery rate is high, but the disadvantage is that the longitudinal grain, slender and fragile, gas coal coking alone can be used in the chemical industry. Shanxi is extremely rich in gas coal resources, reserves account for more than 63% of the coal used in coking.

7, lignite

Lignite is a metamorphosed coal, outside the decayed wood containing native humic acid. Its main characteristics are water content, small specific gravity, low heat, can produce activated carbon, coal sulfide, lignite wax, humic acid, ammonium humate fertilizer and other chemical products.

8, long-flame coal

Long-flame coal is the lowest degree of metamorphism of the coal, non-binding and coking mainly used as fuel. It can be used to make semi-coke, gas and tar by low temperature dry distillation, and can be used to make ammonia after gas production.

9, poor coal

Poor coal is the highest degree of metamorphosis of bituminous coal, non-binding. Burning flame is short, long continuation time is mainly used as power coal, can also be used for gas as ammonia raw materials and gas fuel. Taiyuan Xishan, Yangquan, and Shoushun, Shouyang mining areas are rich in poor coal resources.

Expanded Information:

Coal indicators

(1) Moisture (M)

The moisture of coal is divided into two kinds, one is intrinsic moisture (Minh), which is the moisture contained in the plant when it turns into coal; and the other is external water (Mf), which is the moisture attached to the surface of the coal and fissures during the process of mining, transportation and so on.

(2) Ash (A)

The residue left after coal is completely burned is called ash, which is divided into extrinsic and intrinsic ash. The extrinsic ash comes from the rock fragments in the roof slabs and pinch studies, and it has a great deal to do with the reasonableness or otherwise of the coal mining methods.

(3) volatile matter (V)

When coal is heated at high temperature and isolated from the air, the product of gas and liquid state is called volatile matter. The main components of volatile matter are methane, hydrogen and other hydrocarbons. It is one of the important indicators for identifying the type and quality of coal.

(4) Fixed Carbon Content (FC)

Fixed carbon content refers to the residue after removing moisture, ash and volatile matter, and it is an important indicator for determining the use of coal. The difference after subtracting the moisture, ash and volatile matter from 100 is the fixed carbon content of coal. Depending on the benchmark used to calculate volatile matter, the fixed carbon content can be calculated for different benchmarks such as dry basis, dry ashless basis, etc.

(5) Heat generation (Q)

Heat generation refers to the heat generated by the complete combustion of a unit mass of coal, which is mainly divided into high level heat generation and low level heat generation. The high level of heat generation of coal minus the heat of vaporization of water is the low level of heat generation.

(6) maximum thickness of the gelatinous layer (Y)

The maximum thickness of the gelatinous layer formed by bituminous coal after being heated to a certain temperature is the maximum value of the difference between the gelatinous body and the F layer measured by the probe in the determination of the gelatinous layer index of bituminous coal. It is one of the important criteria for coal classification. Power coal with a large thickness of the gelatinous layer is easy to coking; smelting refined coal has a clear requirement for the thickness of the gelatinous layer.

(7) Bonding index (G)

Under the specified conditions, it is one of the important standards for coal classification and an important index for smelting refined coal, with the ability of bituminous coal to bond special anthracite coal after heating. The higher the wither knot index, the stronger the coking.

Baidu Encyclopedia - Coal