The feasibility of using color index of ash to distinguish the slagging characteristics of coal was investigated.By TCP2C type colorimeter

indexes of coal from different coal-cumulating areas such as color tristimulus value(including rectangular coordinate

polar coordinate

brightness)

yellowness and whiteness of the color were obtained

then combined with the proximate analysis

ash melting point and composition

and the ash slagging index Sc predicted according to both of the melting point and composition

these data were inputted into the database of ash slagging prediction system.Results show that

the brightness of bituminous coal ash has good relativity with Sc.But for lignite coal ash

the correlation between brightness and Sc is not that good

the brightness value should be modified selectively.This open prediction system can rehandle the original data and the newly additional ash and color measurement data

so as to obtain the new prediction rule

and improve the accuracy gradually.