Transformation behaviors of excluded pyrite during O 2 /CO 2 combustion of pulverized coal

The article was addressed to the transformation of excluded pyrite during O 2 /CO 2 combustion of pulverized coal. Raw pyrite mineral was added to a pulverized coal sample, which was density fractionated to remove the excluded minerals, to simulate the excluded pyrite present in coal. The mixed sample was burned in a drop tube furnace in O 2 /CO 2 and O 2 /N 2 conditions to generate the residue ash, which was characterized by Mössbauer spectroscopic and size analyses. It was found that, in comparison with O 2 /N 2 combustion at the same oxygen concentration, slightly less iron glass silicate was formed from excluded pyrite and silicates although the transformation of pyrite to oxides was slowed in O 2 /CO 2 combustion, different from the behaviors of included pyrite in pulverized coal those were observed in previous study. Additionally, less fragmentation of excluded pyrite particles was also observed in O 2 /CO 2 combustion. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.