Compared with the conventional pulverized coal(100 micrometer level)

both the physical properties and combustion characteristics of the superfine pulverized coal(20 mm) can be improved dramatically. By taking Shenhua bituminous coal as the study subject

several instruments

such as the elemental analyzer

Fourier transform infrared spectrometer(FTIR) and scanning electron microscopes(SEM)

were adopted to investigate the element composition

functional groups

and microscopic surface morphology of testing samples with five different particle sizes. The thermogravimetric analyzer(TGA) was used to investigate the pyrolysis and combustion characteristics of the coals with different sizes. The results show that

as the particle size decreased

the carbon content increased

the coal particle surface became rougher

the number of hydroxyl group increased while that of aromatic hydrocarbon C=C and CH_3 functional groups decreased. The coal pyrolysis was composed of three stages: drying period

fast pyrolysis stage and thermal condensation stage. The final weight loss decreased with the coal particle size. In coal combustion process

with the decreasing of particle size

both the ignition temperature(T_i) and burnout temperature(T_f) reduced

the maximum burning rate(dω/dt)_(max) and the comprehensive combustion characteristic index(S) increased. The combustion characteristics of superfine pulverized coal were greatly improved.