How to distinguish the quality of coal

According to moisture, ash, volatile matter, fixed carbon content, calorific value, maximum thickness of colloidal layer, adhesion index, etc.

1, humidity (m)

There are two kinds of water in coal. One is intrinsic moisture (Minh), which is the moisture contained in plants when they turn into coal. The second is external water (Mf), which is the water attached to the surface and cracks during coal mining and transportation. Total water quantity is the sum of external water quantity and internal water quantity of coal. Generally speaking, the greater the degree of coal metamorphism, the lower the internal moisture. Generally, lignite and long-flame coal have higher internal moisture, while lean coal and anthracite have lower internal moisture.

The existence of water is extremely unfavorable to the utilization of coal, which not only wastes a lot of transportation resources, but also when coal is used as fuel, the water in coal will become steam when it evaporates, consuming heat. In addition, the moisture of clean coal also has a certain influence on coking. Generally, for every 2% increase in moisture, the calorific value decreases 100kcal/kg (kcal/kg); For every 65438 0% increase in clean coal moisture, the coking time is prolonged by 5-65438 00 minutes.

2. Fixed carbon content (FC)

Fixed carbon content refers to the residue after removing water, ash and volatile matter, and is an important index to determine the use of coal. The fixed carbon content of coal is 100 minus water, ash and volatile matter. According to the standards used to calculate volatile matter, the fixed carbon content of different standards such as dry basis and dry ash-free basis can be calculated.

Extended data:

Coal is an important raw material for producing many fertilizers and other chemical products. The main way to produce these products is to produce synthesis gas by coal gasification. The primary chemical products directly produced from synthesis gas include methanol, hydrogen and carbon monoxide, which are the basic components of chemical products, from which a full range of chemical products can be continuously produced, including olefins, acetic acid, formaldehyde, ammonia, urea and so on.

As the precursor of primary chemicals and high-value derivatives, the versatility of syngas provides a new choice for producing various high-value commodities using relatively cheap coal.

Historically, the chemical production of coal has been used since 1950, and the market has been established. According to the 20 10 global gasification database and the investigation of existing and planned gasifiers, from 2004 to 2007, chemical production increased the gasification share of products from 37% to 45%. From 2008 to 20 10, 22% of new gasifiers were used in chemical production.

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