Redox Reaction in Silicate Melts Monitored by ''Static'' In-Situ Fe K-Edge XANES up to 1180 deg. C

Journal Article · Fri Feb 02 00:00:00 EST 2007 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.2644505· OSTI ID:21054617

Wilke, Max ^[1]; Partzsch, Georg M ^[2]; Welter, Edmund ^[3]; Farges, Francois ^[4]

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1. Institut fuer Geowissenschaften Universitaet Potsdam, D-14415 Potsdam (Germany)
2. Mineralogisches Institut, Universitaet Heidelberg, INF 236, D-69120 Heidelberg (Germany)
3. Hamburger Synchrotronstrahlungslabor HASYLAB at DESY, D-22603 Hamburg (Germany)
4. Laboratoire de Mineralogie (USM 201), Museum National d'Histoire Naturelle, CNRS UMR 7160 (Mineralogie-Petrologie), 61 rue Buffon, 75005 Paris (France)

A new experimental setup to measure in-situ kinetics of redox reactions in silicate melts is presented. To study the progress of the Fe-redox reaction, the variation of the signal is recorded at an energy, where the difference between the spectra of the oxidized and reduced Fe in the melt is largest (''static XANES''). To control the redox conditions, the gas atmosphere could be changed between to types of gases using computer-controlled valves (N2:H2 and air, respectively). In this way, a number of reduction/oxidation cycles can be monitored in-situ and continuously. Applied at the Fe K-edge in molten silicates, we obtained a set of high quality data, which includes the very first steps of the redox reaction. An Avrami-type equation is used to investigate rate-controlling parameters for the iron oxidation/reduction kinetics for two melts (basaltic and Na trisilicate) for temperatures up to 1180 deg. C.

• OSTI ID: 21054617
• Journal Information: AIP Conference Proceedings, Vol. 882, Issue 1; Conference: XAFS13: 13. international conference on X-ray absorption fine structure, Stanford, CA (United States), 9-14 Jul 2006; Other Information: DOI: 10.1063/1.2644505; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA); ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
ABSORPTION SPECTRA
ABSORPTION SPECTROSCOPY
IRON
OXIDATION
REACTION KINETICS
REDOX REACTIONS
REDUCTION
SILICATES
TEMPERATURE DEPENDENCE
VARIATIONS
X-RAY SPECTRA
X-RAY SPECTROSCOPY