Title
Chromites reduction reaction mechanisms in carbon-chromites composite agglomerates at 1773K
Date Issued
01 December 2007
Access level
open access
Resource Type
journal article
Author(s)
University of Sao Paulo
Abstract
Fe-Cr-C production is a very high electrical energy consuming process. When self-reducing agglomerates are used, it is expected to decrease up to 10% of this electrical energy. This paper presents the fundamental aspects of the reactions involved in reduction of chromites by use of self-reducing agglomerates. Brazilian chromite containing 41.2% Cr2O3 was mixed with petroleum coke and agglomerated with cement as the binder. The concept of "initial slag" was introduced and it was assumed that this "initial slag" is formed of fluxing agents, coke ash, silica formed, binder and dissolution of only 5% of the gangue from the chromite. This concept is important since the gangue of chromite is composed mainly by refractory oxides (MgO+Al2O3), which are difficult to dissolve into slag. The effects of "initial slag" composition, one with low liquidus temperature (∼1700 K) and the other with high liquidus temperature (∼1 750K) were investigated. The mixture was pelletized, dried and submitted at the temperature of 1 773 K until completion of the reactions and also the fractional reaction as a function of time was determined. The results showed that the pellets in which liquid slag phase was formed at high temperature presented significant better reduction behavior than the pellets in which the liquid slag phase was formed at low temperature. The microscopic analysis showed that a liquid phase was formed but the pellet did not collapse, and indicated that the coalescence of the metallic phase depended on the dissolution of the pre-reduced particles of the chromite into slag. © 2007 ISIJ.
Start page
1585
End page
1589
Volume
47
Issue
11
Language
English
OCDE Knowledge area
Bioquímica, Biología molecular
Química orgánica
Subjects
Scopus EID
2-s2.0-38549120228
Source
ISIJ International
ISSN of the container
09151559
DOI of the container
10.2355/isijinternational.47.1585
Sources of information:
Directorio de Producción Científica
Scopus