The wheat straw and Tiefa coal co-firing ash was prepared in a muffle furnace to investigate its properties such as the yield

chemical component

fusion temperature and crystal phases structure under different combustion temperature and mixing ratio conditions.The results showed that

with an increase in temperature

the ash yield first increased and then decreased

it reached the maximum at 700℃

and nearly had no change when the temperature grew above 800℃.The chemical composition of co-firing ash was significantly affected by the temperature and mixing ratio.With the same mixing ratio

the proportion of Al2O3

SiO2and Fe2O3in ash increased while that of the K2O and Na2O decreased as the temperature raising.At the same co-firing temperature

the content of chemical composition in ash showed a non-linear relationship with the wheat straw proportion in mixed fuel.XRD results demonstrated that

at 700 ℃

the inorganic compounds in ash were mainly quartz(SiO2)

arcanite(K2SO4)

calcite(CaCO3)and sylvite(KCl)

while at 900℃

the monomer substances with high fusion temperature(such as SiO2and CaSO4)and high-temperature molten material constituted the inorganic compounds.The influence of biomass ratio in mixed fuel on ash fusion characteristics was significant.When the wheat straw proportion was larger than 25%

the co-firing ash deformation temperature(DT)decreased obviously.However

at the same mixing ratio

the combustion temperature had little effect on ash fusion characteristics.