Question:

How to test coal

On behalf of the company to study the coal test, which can help me to explain the online test of coal each indicator of the process, thank you

Answer:

1, the moisture of coalThe water content of coal is an auxiliary index in coal pricing.The moisture of coal directly affects the use, transportation and storage of coal. With the increase of the water content of coal, the useful component in coal is relatively reduced, and the water is changed into steam when it is burnt to absorb heat, thus reducing the calorific value of coal. The increase in the moisture content of the coal, but also increased the invalid transport, and bring difficulties to the unloading. The characteristics of winter cold area, often frozen car, truck production influence, influence effect, wagon turnover, exacerbated by transport stress.The coal moisture is also easy to cause the coal to stick the storehouse and reduces the coal bunker capacity, even has the storehouse accident.With the increase of mining depth, the development of mining mechanization and the strengthening of underground safety production, as well as the implementation of measures such as spraying water, coal seam water injection and comprehensive dust prevention, the water content of raw coal is increasing. To this end, in addition to all aspects of coal mining, coal mining in design and in the process of mining excavation, ventilation and transportation for reducing coal moisture measures, measures should also be taken in the ground processing of coal to reduce the moisture content of coal.
(2) the external and internal moisture of coalThe free water of coal is divided into external and internal water.External moisture, which is attached to the surface of coal particles. The external water is easy to evaporate in the dry air at the normal temperature, and the vapor pressure which evaporates to the surface of the coal particles does not evaporate when the air pressure is balanced with the air.Internal moisture, which is adsorbed in the pores of the coal particles. The temperature of the internal water needs to be above 100C to evaporate after a certain time.
(1) free water and combined water in coalThere are two types of water in coal according to their different forms. Free water is based on the physical adsorption state in coal particles and coal particles attached to the capillary inner surface of the water; combined water is also called crystal water is combined with mineral water in the coal chemical way. Crystalline water, such as calcium sulfate (NaSO4.2H2O) and aged soil (AL2O3.2SiO2.2H2O). Free water in 105 ~ 110C temperature after 1 to 2 hours can be evaporated, and the crystallization of water is usually more than 200C in order to decompose precipitation.In the industrial analysis of coal, only the free water is measured.
Copy the following into a DOC file, print, slowly lookIndustrial analysis of coal 1The industrial analysis of coal, also called the technical analysis and practical analysis of coal, is the basic basis for evaluating the quality of coal. In the national standard, the industrial analysis of coal includes the determination of moisture, ash, volatile matter and fixed carbon. Determination of moisture, ash, volatile matter and fixed carbon in coal. Generally, the moisture, ash and volatile matter of coal are measured directly, while the fixed carbon is calculated by subtraction. Broadly speaking, coal industry analysis including coal - Determination of total sulfur content and calorific value of the whole industry, also called coal analysis.

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