Effect of iron ores and sintering conditions on flame front properties

In iron ore sintering, the properties of the flame front are clearly critical as they determine the heat imparted to the particulate bed and, hence, the strength of the formed sinter. This study explores the factors that influence flame front temperature and also the speed at which it descends down a bed. These two properties are dependent on post-ignition airflow rate and the properties of the sinter mix. Post-ignition airflow rate is a strong function of the pre-ignition airflow rate and the flow resistance of the flame front. This study reiterates the strong dependence of flame front resistance on gas flow velocity, flame front temperature and applied suction. Dense ores produce higher bulk density and lower porosity beds and, as a consequence, they have the effect of slowing down and broadening the flame front. The influence of flame front speed on flame front properties for different ores was also established. For comparable flame front properties results show that sinter basicity has a large influence on sinter strength and yield. Studies of coke combustion efficiency show decreasing values with increasing flame front speed and values increased significantly when sintering YANDI ore. Many of the obtained quantitative dependences will be used to verify a sintering mathematical model that is under development