Iron-bearing minerals are key slag-inducing minerals in coal. To optimize the coal blending scheme

comparison study on distribution characteristics of iron-bearing minerals between coal A and coal B was carried out by a computer–controlled scanning electron microscope(CCSEM). Coal A and coal B have similar Fe_2O_3 mass fraction in the ash

while coal A has much higher ash slagging propensity than coal B. The research results show that

Coal A and coal B have similar iron-bearing minerals species. However

coal A has 12% higher mass fraction of Fe_2O_3 in pyrite than coal B. The mass fraction of Fe_2O_3 in included pyrrhotite and included iron aluminosilicate in coal A is 8% and 5% higher than that in coal B

respectively. Higher mass fraction of pyrite and included ironbearing minerals in coal A than coal B is dominant reason for severe ash slagging of coal A. Though coal B has higher mass fraction of CaO in the ash than coal A

combination of Ca and iron-bearing minerals seems do not worsen iron-bearing mineral slagging problem. In order to reduce the risk of ash slagging

the mass fraction of pyrite and pyrrhotite in coal should be controlled when using de-NO_x combustion technology.