Thermal and chemical analysis of massive use of hot briquetted iron inside basic oxygen furnace

Abstract

The integrated steelmaking cycle based on the blast furnace-basic oxygen furnace (BOF) route plays an important role in the production of plain and ultra-low carbon steel, especially for deep drawing operations. BOF steelmaking is based on the conversion of cast iron in steel by impinging oxygen on the metal bath at supersonic speed. In order to avoid the addition of detrimental chemical elements owing to the introduction of uncontrolled scrap and in order to decrease environmental impact caused by the intensive use of coke for the production of cast iron, HBI (hot briquetted iron) can be used as a source of metal and a fraction of cast iron. Forty industrial experimental tests were performed to evaluate the viability of the use of HBI in BOF. The experimental campaign was supported by a thermal prediction model and realized through the estimation of the oxidation enthalpy. Furthermore, the process was thermodynamically analyzed based on oxygen potentials using the off-gas composition and the bath temperature evolution during the conversion as reference data.