2014 Volume 54 Issue 4 Pages 715-720
Serpentine was applied as a magnesium additive upon preparing oxidized pellets of a Brazilian hematite concentrate, the effects of ballability, preheating and roasting performance were studied in this work. The results showed that with the increasing dosage of serpentine, the green ball moisture content was increased, the compressive strength was improved too, but drop strength and burst temperature were reduced. In terms of the preheated pellets, the compressive strength were increased first and then decreased, and last leveled off. The compressive strength of roasted pellets were all improved, especially the improvement was obvious when the roasting was conducted at the temperature of 1280°C. When the serpentine ratio was constant, with the preheated temperature increasing, the compressive strength of preheated and roasted pellets were all improved. Mechanism analysis showed that the solid phase reaction could be promoted with addition of serpentine, and the consolidation strength of pellets would be increased also. Although the iron grade and reduction of pellets were reduced, the reducing swelling was decreased, but the softening begin temperature was risen, the softening range was narrowed, and the metallurgical performance of pellets was improved at the same time.