The moisture in coal is divided into internal moisture, external moisture, crystallization water and decomposition water.
Too much water in coal is not conducive to processing and transportation, which will affect the thermal stability and heat conduction during combustion, and will reduce the coke yield and prolong the coking cycle during coking.
Ash refers to the residue left after coal combustion. It is not the sum of minerals in coal, but the residue of these minerals after chemical and decomposition. High ash content means low combustible components in coal. Low calorific value.
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Accurately weigh the air-dried coal sample (10.1) g (calibrated to 0.0002g) with the particle size less than 0.2mm, put it in a beaker (3.3.4), and add (0.5 ~ 1) ml ethanol (3.2.7) for wetting.
Add (2~3) drops of methyl orange indicator (3.2.8) to the filtrate, neutralize it with ammonia water (3.2.2) until it is slightly alkaline (the solution is yellow), then add hydrochloric acid to adjust the solution to be slightly acidic (the solution is red), then excess 2mL, heat it to boiling, and dropwise add 10% barium chloride solution (constantly stirring)
Refer to the above content: Baidu Encyclopedia-Coal Quality Detection