Article ID Journal Published Year Pages File Type
1486725 Journal of Non-Crystalline Solids 2005 7 Pages PDF
Abstract

The distribution of Fe in as-casted and annealed vitrified Pb- and Fe-rich solid industrial waste is studied by means of X-ray fluorescence mapping and micro-X-ray absorption fine structure spectroscopy. The studied samples were produced by co-melting of lead and iron contaminated ash with the appropriate quantities of vitrifying (SiO2) and flux (Na2O) agents at high temperatures (1400 °C) and were subjected to thermal treatment in the temperature range 400–800 °C for 2 h. It is demonstrated that annealing at temperatures higher than the glass transition temperature (440 °C) induces loss of homogeneity in the sample and promotes the formation of Fe-rich crystalline regions, embedded into the glass matrix. In addition to that, annealing modifies the coordination environment around the Fe3+ atom, which occupies octahedral sites in the crystalline regions and tetrahedral sites in the amorphous, glassy phase where it acts as a network former. Finally, the effect of the coordination environment of Fe on the chemical stability of vitreous and vitroceramic materials containing industrial wastes is disclosed.

Related Topics
Physical Sciences and Engineering Materials Science Ceramics and Composites
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