By using YX-HRD type ash fusility detecter

the slagging behavior of seven common biomass ashes

such as ash of wheat stalks

rise stalks

and poplar wooden scraps etc.

as well as their mixedly burning ash with coal have been detected.Results show that the slagging distinguishable index of coal can't completely and reliably predict the slagging behavior of biomass ash and their mixdely burning ash with coal.Based on the composition of biomass ash

the slagging distinguishable index of biomass A=(MgO+Al2O3+Fe2O3)/(CaO+P2O5) has been deducted for the Pearson correlation coefficient of ash fusion temperature.Addition of biomass can reduce the ash fusion point of coal in different degrees.In a range of low proportioning ratio

the ash fusion point of mixed coal is gradually reduced as the addition of biomass is increased.Along with the increasing of proporting ratio of mixed stalks like biomass

the oxide content of alkaline metalls increases

making the effect of reducing ash fusion point of mixed coal to be weakened

but at the same time

the A value is higher

thereby the ash fusion point of mixed coal is heightened on the contrary.When the proportioning ratio of mixed stalks like biomass is less than 20%

and the mixed proportioning ratio of distiller's grain

peanut shells

and poplar wooden scraps being less than 40%

60%

and 60% respectively

the serious slagging phenomenon can all be avoided.