Development and Prospects of Refining Techniques in Steelmaking Process

The development of refining techniques in the steelmaking process over the last 60 years and the prospects for the future were reviewed. In Japan, hot metal pretreatment started in the 1960s with the aim of reducing refining costs and improving quality, and its purposes have now transitioned to meeting new requirements for reduced treatment time, reuse of steelmaking slag and use of diverse iron sources. In converter refining, in addition to high speed decarburization, visualization of phenomena and sensing modeling techniques are becoming more important for combined use with data science techniques. In ladle metallurgy (secondary refining), techniques to realize high speed treatment and heating of the molten steel are key issues. The necessity of process revolution to contribute to a sustainable social environment is also discussed briefly.