Carbothermic Reduction of Synthetic Chromite with/without the Addition of Iron Powder
Number of Authors: 7
2016 (English)In: ISIJ International, ISSN 0915-1559, E-ISSN 1347-5460, Vol. 56, no 12, 2147-2155 p.Article in journal (Refereed) Epub ahead of print
Carbothermic reduction of chromite is an important industrial process for extracting chromium from the chromite. To have a better understanding of the effect of iron on the carbothermic reduction of chromite, the reduction of synthetic chromite (FeCr2O4) by graphite with/without the addition of iron powder was investigated in this paper by Thermogravimetric Analysis (TGA) in argon atmosphere. The fractional reduced samples were examined by SEM/EDS and XRD analysis, and the reduction process was thermodynamically and kinetically evaluated. The experimental results show that the iron powder addition enhances the reduction of FeCr2O4 and this effect increases when increased amounts of iron powder are added. This phenomenon is attributed to the in situ dissolution of chromium into the iron and mixed carbide (Cr,Fe)7C3, which can decrease the activity of the nascent chromium formed by the reduction of the FeCr2O4. The experimental results indicate that the reduction of FeCr2O4 with up to 80 wt.% iron powder addition is likely to be a single-step process and the kinetic analysis suggests that the reduction reaction is likely to be either (a) chemical reaction at the surface of FeCr2O4 or (b) diffusional dissolution of the product (FeCr2) into the iron/alloy particles or the mixed control of (a) and (b).
Place, publisher, year, edition, pages
2016. Vol. 56, no 12, 2147-2155 p.
Metallurgy and Metallic Materials
Research subject Process Metallurgy
IdentifiersURN: urn:nbn:se:ltu:diva-60121DOI: 10.2355/isijinternational.ISIJINT-2016-337ScopusID: 2-s2.0-85007240939OAI: oai:DiVA.org:ltu-60121DiVA: diva2:1044336
Validerad; 2017; Nivå 2; 2017-01-13 (andbra)2016-11-032016-11-032017-01-13Bibliographically approved