As a by-product of large scale power plant

fly ash has become an important raw material of concrete through comprehensive exploitation and utilization for many years.However

fly ash composition changes when its color get darker.Its quality will decrease

which affects the sale of fly ash.In order to solve the existing problems

by means of analyzing the gray scale of fly ash

this paper quantified its color and studied the related influence factors.The results show that

carbon content

particle size

chemical composition and reducing atmosphere in the furnace are the factors affecting gray scale of the coal ash.Properly increasing the oxygen content and decreasing the oxygen deviation of both sides are effective means of operation adjustment to prevent the fly ash color from getting darker.In terms of opposed firing boiler applying low NOxcombustion technology

research on gray scale of fly ash is of certain reference and guidance significance.