Development and Application of the Operating Line for the CHORSF Process

To achieve carbon emission reduction in the long ironmaking process with blast furnace-basic oxygen furnace (BF-BOF), the Hebei Iron & Steel Group and Northeastern University have jointly developed the Reduction Smelting Furnace with Carbon-Cycling, Hydrogen-Rich, and Pure-Oxygen (CHORSF) ironmaking process. This new process employs advanced technology to overcome the hydrogen enrichment limitation of traditional BFs and the problems of “hot at the lower part and cold at the upper part” in all-oxygen BFs. This paper establishes an operating line for the CHORSF ironmaking process, systematically analyzes the influence mechanisms of key smelting parameters on CHORSF, and provides guidance for optimizing the process. The results show that the slopes of the operating lines in the indirect reduction zone can characterize the reducing gas consumption under actual conditions; under the smelting conditions of this study, the reducing gas consumption falls within a specific range. The slope of the operating line in the softening–melting–dripping zone can be used to quantify the coke ratio. Furthermore, increasing the metallization ratio at the bottom of the indirect reduction zone leads to a slight increase in reducing gas consumption, while a 1% increase in the same metallization ratio results in a notable decrease in the coke ratio.