Flame front propagation and sinter strength properties of permeable sintering bed prepared via enhanced granulation with hydrated lime.

This paper is focused on investigating the influences of enhanced granulation with hydrated lime on the propagation of flame front and strength properties of the produced sinter in iron ore sintering. Pilot‐scale sinter pot experiments were performed at three hydrated lime levels, and the porous structures of sinter were reconstructed by high resolution X‐ray tomography. When hydrated lime increased from 0% to 2%, more permeable green bed with enlarged granule mean size and narrowed granule size distribution could be obtained, and sinter productivity increased from 37.3 to 40.7 t/m2/d while tumbler index of sinter decreased from 62.7% to 55.0%. Both the bed temperature and pressure profiles verified that hydrated lime addition fasten sintering by reduction of heat accumulation and acceleration of flame front speed in sintering bed. The three‐dimensional stress analysis based on the actual microstructures showed that more irregular sinter particles with higher porosity are obtained with higher hydrated lime due to the insufficient melt formation and coalescence during sintering. Sinter with 2% hydrated lime was much more compliant under the fixed compression, exhibiting larger potential to be deformed in locations including bridges with the small cross sections and notches with the small fillet radius. [ABSTRACT FROM AUTHOR]