Effects of MgO and Al2O3 Addition on Redox State of Chromium in CaO-SiO2-CrOx Slag System by XPS Method
2015 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916, Vol. 46, no 4, 1802-1808 p.Article in journal (Refereed) Published
The effects of MgO and Al2O3 on the redox state of chromium in CaO-SiO2-CrO), system have been investigated at 1873 K (1600 degrees C) under Ar-CO-CO2 atmosphere and analyzed by means of X-ray photoelectron spectroscopy. From the analysis of the Cr 2p core level spectra, it was found that both Cr(II) and Cr(III) exist simultaneously in CaO-MgO/Al2O3-SiO2-CrOx, and the quantitative ratio Cr(II)/Cr(III) has been obtained by deducing from the area under the computer-resolved peaks. Substitutions of CaO by MgO, SiO2 by Al2O3 favored the Cr(II) state existing in the system in the composition ranges of 3 to 10 wt pct MgO and 5 to 20 pct Al2O3. Meanwhile, from the analysis of the Ols spectra in CaO-MgO-SiO2-CrOx, it was found that the ratio of the non-bridging oxygen content increased first due to the CrO contribution to the electron distribution uniformly as 0- at MgO low content. Afterward, it went to decreasing with continuing addition of MgO because ionic contribution of MgO is less than that of CaO and the influence of the CrO clustering on the non-Bridging oxygen is limited due to only 5 wt pct Cr Ox. In CaO-Al2O3-SiO2-CrOx system, COI) acts as a network modifier to compensate Al-3 charge balance to make the structure stable, so the non-bridge oxygen in this system continues decreasing. (C) The Minerals, Metals & Materials Society and ASM International 2015
Place, publisher, year, edition, pages
2015. Vol. 46, no 4, 1802-1808 p.
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-173154DOI: 10.1007/s11663-015-0353-7ISI: 000359022000028OAI: oai:DiVA.org:kth-173154DiVA: diva2:854779
QC 201509172015-09-172015-09-072015-09-17Bibliographically approved