Lower limit of the energy consumption and the double ignition process for iron ore sintering.

Abstract

The lower limit of energy consumption in the actual iron ore sintering process was investigated by experiments and a simulation model. The energy consumption was reduced with the decrease in the induced air volume and in the coke breeze content in raw mix. Under the condition of maintaining the sinteryield more than 60%, the lower limit of the energy consumption was achieved at an induced air volume of 9Nm3/m2min, and a coke content of 2.6 wt% in sinter mix. This condition corresponds to the heating to the maximum temperature of more than 1250°C and the holding at high-temperatures above 1100°C over 5min.For the improvement of the utilization efficiency of oxygen, that is, the reduction of unit air volume, the application of the double ignition sintering was investigated. Under the conditions of the high bed height and high suction pressure, the sinter productivity reached to about 57t/m2 D and a slight reduction of energy consumption was accomplished, if the sinter strength values of 50 to 60(TI) are allowable.