To solve the serious coking and contamination problems occurred on heating surface of utility boilers firing Xinjiang Zhundong coal

a one-dimensional furnace was used to simulate the actual combustion environment and the anti-slagging effects of several additives were experimentally investigated.Moreover

the mechanism against slagging was also analyzed.The results show that

the kaolin and clay have better anti-slagging effect.There are two additives having great effect in against slagging and the proportion of practical application in utility boilers shall not be less than 3%.By appearance comparison and phase analysis of slag

it is found that the additives act when the content of Na

Ca and Fe is controlled in a reasonable level

especially the content of Na_2O is declined below 3% and there is no obvious increase in that of Ca and Fe.In addition

the SiO_2/Al_2O_3 ratio in coal ash with additives plays an important role in against slagging.A rational SiO_2/Al_2O_3 ratio helps alkali/alkaline metal compounds with low melting point to form high-melting-point aluminosilicate.Only increasing mass fraction of Al_2O_3 has no obvious effect on anti-slagging.