Reconstruction of the three‐dimensional distribution of elements in fly‐ash particles by micro‐XRF spectroscopy

Abstract

AbstractWith the very large information depth available in micro‐beam XRF, it is possible to generate two‐dimensional maps of the elemental distribution over large spherical fly‐ash particles with a resolution down to about 1 µm. These particles possess a large degree of spherical symmetry owing to the process of their formation. By applying special reconstruction algorithms, the symmetric part of the elemental distribution can be reconstructed from the two‐dimensional projection maps and subtracted from the original map. The results show that such a fly‐ash particle can be split into a radial symmetric part containing non‐volatile carbonaceous compounds and an asymmetric part representing precipitates or sub‐particles formed within the fly‐ash particle. The symmetric part shows a distinctly visible outer and an inner shell. By using the asymmetric part of the distribution, the interior of the fly‐ash particle can be studied without interference from the inner and outer shells. Copyright © 2003 John Wiley & Sons, Ltd.