Factors Controlling High-temperature Zone Resistance to Airflow during Iron Ore Sintering

Abstract

A fundamental study was carried out on the high-temperature zone flow resistance during iron ore sintering. In present work, firstly, quartz sand was used to replace iron ores to investigate the impact of temperature if bed structure has no change; then a three-layer bed structure was used to explore the primary factors controlling high-temperature zone structure for airflow. The zone where temperature above 700°C is defined as high temperature zone. High-temperature zone flow resistance depends on sinter bed temperature and high-temperature zone structure which was related to melt volume, melt properties, bed voidage, drive force and high temperature zone thickness. A new model which can suggest high-temperature zone flow resistance was established by using Support Vector Machine (SVM) model and predicted airflow rate well. Drive force has a very impact on high-temperature zone flow resistance. It can dilute gas channels in the high-temperature zone and increase or maintain sinter bed permeability. Sintering under lower suction has greater high-temperature zone resistance. Too much melt will deteriorate high-temperature zone permeability; sintering airflow rate with high coke rate in the bottom layer decreases by around 25% at a suction of 8 kPa. Similarly melt properties also have a great impact on high-temperature zone resistance; high viscosity is bad for gas channels formation in the high-temperature zone. Under a limited range increasing coke rate has little influence on high-temperature zone resistance.