The influence of agitating in pelletizer at HPS process on granulation and sintering properties was investigated with using typical iron ores and pellet feeds. Pellet feeds added in the sintering mixture easily formed the large aggregates bearing large amount of water and other portion of pellet feeds remained in the small size fraction in quasi-particle. The large quasi-particles generated at HPS process were mainly observed at the specific area in pelletizer due to size segregation effect. These large quasi-particles could be destructed selectively by agitating motion of impeller, resulting in achieving not only uniform quasi-particle size distribution after pelletizing but also improvement of granularity after following coke breeze coating. HPS process with agitating method showed higher permeability due to the decrease in charging density, leading to improvement of productivity. In addition, product yield also improved in spite of higher flow rate compared to conventional HPS process. Based on material and heat balance analysis, it was found that combustion efficiency improved by agitating treatment. Heat transfer from combustion heat to sensible heat of sintering cake was enhanced by agitating. In terms of rotation conditions, it was found that particle flow pattern was changed greatly and destruction efficiency decreased at the higher impeller speed according to DEM simulation. The optimum rotation speed observed in the experiment could be explained by the impact force to quasi-particle and macroscopic flow dynamics.
