The Optical Spectra of Hydrogen Plasma Smelting Reduction of Iron Ore: Application and Requirements

Due to the ever‐increasing demand for high‐quality steel and the need to reduce CO 2 emissions, research and development of sustainable steelmaking processes have gained a lot of interest in the past decade. One of these processes is the hydrogen plasma smelting reduction (HPSR), which has proven to be a promising solution for iron ore reduction where water vapor is formed instead of CO 2 . However, due to the highly dynamic and sometimes unpredictable behavior of plasmas and their nonlinear interaction with the liquid oxides, the monitoring and control of the underlying processes must be improved. This article explores the usage of optical emission spectroscopy (OES) and image analysis for HPSR process monitoring at laboratory and pilot scale. The results cover the time evolution of the OES and camera data with the focus on the most interesting radiating species, such as atomic hydrogen, iron, and oxygen together with the FeO molecule. In addition, the advantages, disadvantages, and requirements of these methods for HPSR process monitoring are discussed.