Analysis of Coal Fly Ash by Bulk and Surface Characterization Techniques

Abstract

The application of different characterization techniques to the study of coal fly ash formation and of its behaviour in particulate control devices is discussed. Particle Induced X-ray Emission (PIXE) and Proton Induced Gamma-ray Emission (PIGE) are used for bulk elemental analyses, while X-Ray Photoelectron and Auger Spectroscopies are used for surface elemental analyses. Structural characterization is carried out by powder X-Ray Diffraction and Raman Microfocus Spectroscopy. The effect of different collection efficiencies of electrostatic precipitators on emitted fly ash characteristics is addressed. Furthermore size fractionated fly ash is analyzed to investigate the mechanisms of particle growth.

Raman Spectroscopy as a Versatile Tool for Investigating Thermochemical Processing of Coal, Biomass, and Wastes: Recent Advances and Future Perspectives

“…Minerals in coal fly ash could be also investigated by RS. Bellotto et al 278 studied both crystalline and amorphous phases in different grain sizes to research the mechanisms of particle growth by RS. In a 25 μm sized particle, the presences of αquartz, vitreous silica, and metasilicate glass were detected.…”

Impact of production parameters on physiochemical characteristics of wood ash for possible utilisation in cement-based materials

“…From the XRD analysis (coal fly ash included for comparison) in figure 3, the amorphous rise was observed from approximately 15°2θ to 35°2θ. A broad amorphous peak is common in XRD studies of coal fly ash due to the poorly ordered atomic structure of the amorphous glass content of the coal fly ash (Bellotto et al, 1989;van Roode et al, 1987;Yeboah et al, 2014), as seen in figure 3. For all the investigated WA no such peak was observed, thus they contain a very limited (if any) amount of amorphous glass.…”

Surface-analytical Studies on Environmental and Geochemical Surface Processes

“…A higher concentration of volatile elements in the submicron particles has been observed, because the surface area-to-volume ratio of the fine particles is higher than that of coarser particles with sizes in the micron range. The surface compositions of coal fly ash, as determined by XPS analysis, showed surface enrichment of S, Ca, Mg and P. 25,26 As synchrotron radiation facilities have come into widespread use, X-ray absorption fine structure (XAFS) spectroscopy, with a synchrotron radiation photon source, has recently been used in the field of analytical chemistry. To examine the radial distribution of the chemical bonding states of elements, Kawai et al 27,28 developed a new, soft X-ray absorption spectroscopic technique, in which the X-ray absorption spectra are recorded simultaneously in two different modes, i.e.…”