Study of Chromium Oxide Activities in EAF Slags
2015 (English)In: Metallurgical and materials transactions. B, process metallurgy and materials processing science, ISSN 1073-5615, E-ISSN 1543-1916Article in journal (Refereed) Published
The activity coefficients of chromium in Cu-Cr melts were determined by equilibrating liquid copper with solid Cr<inf>2</inf>O<inf>3</inf> in CO-CO<inf>2</inf> atmosphere. The temperature dependence of the activity coefficients of chromium in Cu-Cr melts could be expressed as (Formula presented.) Based on the above results, the activities of bivalent and trivalent chromium oxide in some slags at 1873 K (1600 °C) were measured. The slags were equilibrated with Cu-Cr melts under two oxygen partial pressures ((Formula presented.) = 6.9 × 10−4 and 1.8 × 10−6 Pa, respectively). The morphology of the quenched slags and the solubility of chromium oxide in the melts were investigated by EPMA, SEM, and XRD. Under both oxygen partial pressures, the slags were saturated by the solid solution MgAl<inf>2−x</inf>Cr<inf>x</inf>O<inf>4−δ</inf>. At the low oxygen partial pressure (1.8 × 10−6 Pa), the content of Cr in the liquid phase varied from 0.4 to 1.6 mass pct with the total Cr content in the slags increasing from 1.3 to 10.8 mass pct. At the high oxygen partial pressure (6.9 × 10−4 Pa), the content of Cr in the liquid phase decreased to the level of 0.2 to 0.6 mass pct. Both the activities of CrO and Cr<inf>2</inf>O<inf>3</inf> in slag were found to increase approximately linearly with the increase of the total Cr content in slag. While the oxygen partial pressure had minor effect on the activity of Cr<inf>2</inf>O<inf>3</inf> in the slag, it had significant effect on the activity of CrO.
Place, publisher, year, edition, pages
Chromium, Liquids, Oxygen, Partial pressure, Temperature distribution, Chromium oxides, High oxygen partial pressure, Liquid copper, Liquid Phase, Low oxygen partial pressure, Oxygen partial pressure, Temperature dependence, Trivalent chromium, Slags
Metallurgy and Metallic Materials
IdentifiersURN: urn:nbn:se:kth:diva-177214DOI: 10.1007/s11663-015-0453-4ISI: 000368692300008ScopusID: 2-s2.0-84958170459OAI: oai:DiVA.org:kth-177214DiVA: diva2:874016
QC 201511252015-11-252015-11-172016-02-23Bibliographically approved