Effect of Decreasing Gas Flow Rate between Two Ignition Furnaces on Sinter Yield at REMO-tec (Re-ignition sintering) Process

Abstract

Conventionally, it has been known that the product yield of the upper part of the sintering layer is extremely low, because of the heat loss caused by transferring heat toward the space above sintering layer, and of the large amount of unburned carbon in upper sintering layer.

As a countermeasure, REMO-tec (Re-ignition Method for Optimization of Total Energy Consumption) has been developed. Here, REMO-tec is the sintering technique of re-igniting sintering packed bed at certain intervals after first ignition. This method has an effect on improving sinter yield with maintaining high sinter reducibility.

This paper focuses on gas flow rate control between first ignition and re-ignition for the purpose of further improving product yield.

It has been clear that certain decrease of gas flow rate between these two ignitions, has an effect on increasing heat storage amount in coke combustion zone at re-ignition caused by controlling vertical position of coke combustion zone.

This method has been applied in Kimitsu No.3 sinter plant. Product yield improves by 0.3% with increasing high temperature holding time.