A STUDY OF THE REACTION MECHANISMS PRESENT DURING THE IRON
SEGREGATION PROCESS
*P. Kerr1, Q. Liu2 and T.H. Etsell2
1
MINEPROMET
55006 Boulevard Langelier
Quebec City, QC, Canada G1K 9A4
(*Corresponding author: pkerr@minepromet.ca)
2
University of Alberta
Chemical and Materials Engineering
9107 - 116 Street
Edmonton, AB, Canada T6G 2V4
ABSTRACT
The objective of this investigation was to study the reaction mechanisms during the reduction of iron
oxides in the presence of calcium chloride and carbon black. The gas phase was analyzed by mass
spectroscopy and the solid reaction products were analyzed by scanning electron microscopy. The mass
spectroscopic analysis revealed the presence of several varying gas phases at elevated temperatures over
time, and the scanning electron microscopic analysis illustrated the growth of a metallic iron phase on or
near the carbon substrate, as seen in Figure 1. The results correlate well with similar copper and nickel
segregation processes. Therefore, the formation and transport of gaseous iron species to the carbon
substrate in the presence of steam and hydrogen was evident during the reduction process that was studied.
Figure 1 – Metallic iron phase growing on or near the carbon substrate
These results help to better explain the chemical reactions and, in turn, the thermodynamics and kinetics of
iron segregation processes related to the beneficiation of complex iron ores and also applies to the
production of metallic iron and concentrated titanium dioxide from ilmenite ores. The benefit of this
process is that it allows ores containing iron, that are intimately associated with gangue minerals, to be
processed in circumstances where conventional processing techniques are not suitable or capable of
upgrading the material.
KEYWORDS
Iron Segregation, Segregation Roasting, Iron Metallization, Synthetic Rutile, Direct Reduced Iron (DRI)