Fly ash is a tiny ash particle discharged from the combustion process of fuel (mainly coal), and its particle size is generally between 1 to 100um, which belongs to hazardous waste. Fine solid particles in the ash of flue gas produced by fuel combustion. For example, fine ash collected from flue gas in coal-fired power plants. Fly ash is formed after pulverized coal enters into the furnace of 1300 to 1500℃, under the condition of suspended combustion, it is subjected to heat absorption by the hot surface and then cooled. Due to the surface tension, most of the fly ash is spherical, with a smooth surface and small pores. A part of them adhere to each other in the molten state and adhere to each other to form a honeycomb composite particle with a rough surface and many corners. The chemical composition of fly ash is related to coal composition, coal particle size, boiler type, combustion situation and collection method, etc.
