Title
High carbon ferro-chromium by self-reducing process: Fundamentals
Date Issued
01 January 2009
Access level
metadata only access
Resource Type
journal article
Author(s)
Escola Politecnica of the University of Sao Paulo
Publisher(s)
Prince of Songkla University
Abstract
Fe-Cr-C production is a very high electrical energy consuming process. When self-reducing agglomerates are used, it is expected to reduce up to 10% of this electrical energy. This paper presents the fundamental aspects of the reactions involved for reduction of chromites from 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 by fluxing agents, coke ash, silica, binder and only dissolution of 5% of the gangue from the chromite. This concept is important since the gangue of chromite is composed mainly of refractory oxides (MgO+ Al2O3), which are difficult to dissolve into slag. The effects of "initial slag" composition, one with low liquidus temperature (~1700K) and other with high liquidus temperature (~1750K) were investigated. The mixture was pelletized, dried and submitted to a temperature of 1773K until completion of the reaction. The reaction fraction as a function of time was determined. The results show that pellets containing components with liquid slag phase formed at higher temperature presented significant better reduction behavior than pellet with the liquid slag phase formed at lower temperature. The scanning electron microscopy analysis showed that a liquid phase was formed but the pellet did not collapse and indicated that the coalescence of the metallic phase depends on the dissolution of the pre-reduced particles of the chromite into slag.
Start page
433
End page
439
Volume
31
Issue
4
Language
English
OCDE Knowledge area
Ingeniería de materiales
Subjects
Scopus EID
2-s2.0-70350029375
Source
Songklanakarin Journal of Science and Technology
ISSN of the container
01253395
Sources of information:
Directorio de Producción Científica
Scopus