Coal quality test, Mt, Mad, Aad, Vad each represents what mean
Third indicators: volatile (full name of the volatile yield) VRefers to the coal after the decomposition of organic matter and some mineral products, not all of the inherent components of coal, as well as some of the pyrolysis products, so called volatile yieldThe volatile content is related to the degree of metamorphism of coal. The higher the quality of coal, the lower the yield of volatile matterIn combustion, used to determine the type of boiler in coking, used to determine the proportion of coal blending; at the same time is an important indicator of vaporization and liquefactionOften used in the air dry base volatile (Vad), dry base volatile (Vd), dry ash free base volatile (Vdaf) and received volatile base (Var)Vdaf is one of the important indexes of coal classification
Second indicators: AshThe residue left after coal combustionIt is not the sum of the minerals in the coal, but the residue of the minerals in the chemical and decomposedThe ash content is high, which indicates that the combustible component in coal is low and the calorific value is lowAt the same time, the ash content determines the ash content of cokeThe available ash indicators are air dried base ash (Aad), dry base ash (Ad), etc. also useful for receiving base ash (Aar)
1, all water (Mt), is the sum of all the internal moisture and external moisture in coal, also commonly used Mar said. Usually under 8%2, air dry base moisture (Mad), refers to the coal in the air dry state contained in the water can also be considered to be the internal moisture, the old national standard has called "analysis of base water"
The first indicator: moistureThe moisture in coal is divided into internal water, external water, crystal water and waterToo much water in the coal, is not conducive to processing, transportation and so on, combustion will affect the thermal stability and thermal conduction, coking will reduce the coke yield and extend the coking cycleNow we often report the moisture index:
