Addition of scrap and DRIHBI to the blast furnace
This paper is presented in three parts to describe how to overcome technical limitations of the blast furnace related to adding alternative iron units (AIUs), which are typically scrap and direct reduced iron/hot briquetted iron. First, the prior art regarding AIU additions is reviewed. From this, the energy shortfall as increasing amounts of AIUs are added the blast furnace is estimated. Lastly, stack injection of hot gas using electrically powered plasma torches is evaluated as a strategy to overcome this energy shortfall and enable greater AIU addition rates. The analysis focuses on North American blast furnace practice using an all-pellet burden and natural gas injection.