What Is Coal Analysis?
The industrial analysis of coal refers to the general term for the determination of four analysis items including coal moisture (M), ash (A), volatile content (V), and fixed carbon (Fc). The industrial analysis of coal is the main indicator for understanding the characteristics of coal quality, and also the basic basis for evaluating coal quality. Generally, the moisture, ash, and volatiles of coal are measured directly, while fixed carbon is calculated by subtraction. Broadly speaking, the industrial analysis of coal also includes the determination of total sulfur and calorific value of coal, which is also called the full industrial analysis of coal. According to the analysis results, you can roughly understand the content of organic matter in coal and the level of heat generation, so as to preliminary judge the type of coal, processing and utilization effects, and industrial applications. According to industrial analysis data, the calorific value of coal and the yield of coking products can also be calculated . The industrial analysis of coal is mainly used in the production and mining of coal and in the commercial sector and various users of coal, such as coking plants, power plants, chemical plants, etc.
Industrial analysis of coal
- The moisture content of coal is one of the most basic indicators of coal valuation.
- The moisture content of coal directly affects the use, transportation and storage of coal. The moisture content of coal increases, the useful components in coal are relatively reduced, and the moisture becomes steam to absorb heat during combustion, which reduces it.
- The ash of coal refers to the residue left after the coal is completely burned. Because this residue is completely combustible in the coal,
- The volatile content of coal, that is, the content of coal after being cut off from air and heated at a certain temperature, and the moisture (gas or liquid) is reduced. The remaining residue is called
- Remove the moisture, ash, and volatiles from the coal, and the rest is fixed carbon.
- The fixed carbon of coal, like volatiles, is also an indicator of the degree of metamorphism of coal, which increases with the degree of metamorphism. So some countries use
- (1) the form of sulfur in coal
- Sulfur in coal is divided into organic sulfur and inorganic sulfur according to its existing form. Some coal has a small amount of elemental sulfur.
- Organic sulfur in coal is in the form of organic matter and sulfur in coal. Its structure is complex and it is not enough to understand so far. It generally has the following functional groups:
- Thiols, R-SH (-SH, is a thio group);
- Thiophenes, such as thiophene, benzothiophene, thioquinones, such as p-thioquinone, thioethers, RSR '; thioanthracenes, etc.
- Inorganic sulfur in coal is sulfur that exists in coal in the form of inorganic matter. Inorganic sulfur is divided into
- The calorific value of coal, also known as the calorific value of coal, is the heat emitted by the complete combustion of a unit mass of coal.
- Basic value of coal calorific value when calorific value of coal. Coal is mainly used as power fuel
- The existence of nitrogen in coal is very complicated. It can be divided into two types: organic nitrogen and inorganic nitrogen. XPS analysis found that the former mainly includes three types of pyrrol nitrogen, pyridine nitrogen and quaternary nitrogen. Exist in fatty chains. Due to the different coal formation conditions of different coal types, the existence forms of nitrogen in coal are not exactly the same, that is, the proportions of the above-mentioned forms of nitrogen in different coals are also different.
- Sampling - crushing - drying - sample preparation - experimental analysis : as shown below
- General steps of coal quality analysis
- Details:
- 1. Raw coal sampling: according to the national coal sampling method
- 2. Crushing: use crusher to crush the sampled coal sample size below 6mm for test use
- 3. Drying: Use the drying box to dry the sample coal sample according to the national standard, and make the total moisture value.
- 4. Sample preparation: use the sample machine to make the dried coal sample into an analysis coal sample with a particle size of 0.2mm for analysis experiments
- 5. Analytical experiments: Weighing with electronic balances for all analytical experiments
- Analysis of water (internal water): made with digital display electric blast drying oven
- Ash, Volatile: Made with industrial analyzer or muffle furnace
- Sulfur: made with a sulfur tester
- Calorific value: made with a calorimeter
- Other analysis items: made with corresponding professional analysis equipment