Iron speciation in coal fly ashes-chemical and Mossbauer analysis

Iron speciation analysis of fly coal ashes was performed using transmision Mossbauer spectrometry as well as chemical methods. The investigated samples of ashes came from stoker-fired boiler and pulverized-fuel boiler (of significantly higher combustion temperature). The Mossbauer spectra show noticeable differences in iron-bearing phases content. In the first case aluminosilicate glass dominates, whereas in the second one-a spinel-type phase.