No abstract

In the present study, the influence of industrial sinter machine speed on the temperature distribution of the bed is evaluated using a one-dimensional transient mathematical model. The model is developed considering the law of conservation of mass, momentum, and energy of solid and gas phases. The prediction of bed temperature from the model is compared with the measured lab scale pot test and the exit gas temperature of an industrial sinter machine wind boxes shows a reliable agreement. The effect of machine speed on the temperature of the bed is quantified using Maximum Temperature, and the coke combustion characteristics are expressed in terms of Duration Time of Coke Combustion and Combustion Zone Thickness. Eventually, the Melting Zone Thickness and melt fraction of the bed is evaluated. This model result demonstrates that the increasing industrial sinter machine speed significantly affects the temperature distribution of the top layer of the sinter bed.

Specular iron ores are medium grade iron ores suitable to use in agglomeration process. However, due to their hard texture, undesirable particle size and shape, poor assimilation performance and low reactivity at high temperature, its uses in agglomeration is very limited and restricted to almost 3-10% at most of the plant. In the present study effect of specular iron ore on sintering performance and sinter qualities are examined. It was observed that an increased proportion of specular iron ore in sinter blend has shown poor sintering performance in both laboratory scale studies and plant scale trials. In the present work, effect of blending of specular iron ore with goethite iron ore in sinter mix on sintering performance is examined and an optimum iron ore blend ratio for sustainable performance and quality is proposed. To increase the specular iron ore usage in sintering, goethitic iron ore up to 30% is introduced in sinter blend to overcome the deteriorating nature of specular iron ore. The goethite iron ore contains chemically bonded water which gets removed at higher temperatures (300-500?C) during sintering. The evaporated water gets cooled at lower bed and condenses which retards the air flow during sintering process and thus the combustion zone stays for longer time allowing better melt assimilation and sinter qualities. The poor melt assimilation of specularite is thus countered in presence of goethite iron ore. Having better reactive and hydrophilic nature of goethite iron ore, nullifying or reducing the ill effect of poor reactive and hydrophobic characteristics of specular iron ore during granulation and sintering process. Due to the which, the blended specular and goethite iron ore resulted in improved sintering rate and consequently improved sinter productivity. The present work proposed usage of up to 30% of specular iron ore when blended with goethite iron ore in sinter making.