These indexes are directly related to combustion, processing (such as grinding into pulverized coal), transportation and storage. Ash characteristics refer to the chemical composition, high temperature characteristics and specific resistance of coal ash. These characteristics have great influence on the cleanliness after combustion, the corrosiveness to steel and the removal of coal ash.
Power coal mainly includes lignite, long-flame coal, unbonded coal, lean coal, gas coal and a small amount of anthracite (see Annex for coal types). As far as commercial coal is concerned, there are mainly washed blended coal, washed coal, pulverized coal and pulverized coal.
Broadly speaking, all coal used for power generation, locomotive propulsion, boiler combustion and other purposes. It belongs to power coal, referred to as power coal for short.
The quality of coal used in thermal power plants is an important basis for boiler design and production process control. The characteristics of coal combustion include two aspects: one is the characteristics of coal quality, and the other is the characteristics of ash. The characteristics of coal refer to moisture, ash, volatile matter, fixed carbon, element content (carbon, hydrogen, oxygen, nitrogen and sulfur), calorific value, ignition temperature, grindability and particle size.