Lh. Hsieh et Ja. Whiteman, EFFECT OF RAW-MATERIAL COMPOSITION ON THE MINERAL PHASES IN LIME-FLUXED IRON-ORE SINTER, ISIJ international, 33(4), 1993, pp. 462-473
In this study small tablet specimens of powdered commercial iron ores
mixed with fluxes and kaolin were heated in a reducing atmosphere and
then cooled slowly in air to simulate industrial sintering. The effect
of different ore and flux compositions on the phases found in the sin
ter bond was studied. An increase in basicity (CaO/SiO2) favoured the
formation of calcium ferrite and densification of the bond at a low si
ntering temperature. The amount of calcium ferrite decreased as the Al
2O3 content decreased and the amount of reoxidized hematite produced o
n cooling decreased. A decrease in Al2O3 content promoted a densificat
ion of the bond. An increase in MgO content, introduced by addition of
dolomite, decreased the amount of calcium ferrite slightly. When MgO
was added in the form of serpentine the calcium ferrite content increa
sed considerably. Increase in MgO markedly reduced the amount of reoxi
dized hematite but produced a less dense bond. Generally the same comp
osition and sintering temperature produced similar mineral composition
s in the bond independent of the iron ore used. The only exception was
when an ore with coarse dense hematite was used, in which case the bo
nd contained some unreacted hematite. The porosity of the bond did var
y with the type of ore used. Limonitic ore produced a bond with closed
pores and less reoxidized hematite at lower temperature and basicity
than did hematite ores.