Theme I: Utilization of phosphate in the steelmaking slag as fertilizer
Chairpersons: J. Wasaki (Hiroshima Univ.), M. Tani (Obihiro Univ.), H. Matsunaga (JFE)

The research group focused on high-phosphate fertilizers, which represent the largest demand for recovered phosphorus from steel-making slags, and conducted studies from an academic perspective to investigate its utilization value. While it has been suggested that phosphorus in concentrated phosphate slag has the potential to be accumulated by crops, the mechanisms throughout the growing season, as well as the effective crop species and environmental conditions, remain unclear. It was also necessary to study the dynamics of phosphorus in slags in soil, the impact of slag fertilizer application on soil pH, the availability of other beneficial elements contained in slags (particularly magnesium and silicon), and the impact of other elements in slags (e.g. chromium) on crops. The research group conducted research to address these issues and explore the fertilizer value of high-phosphate slags. The aim of this Discussion Session is to present our group’s progress and accept related research presentations to facilitate broad discussion.

Theme II: Current state and challenges for future advancement of instrumentation technology for Iron making process Part 4
Chairpersons: M. Fujigaki (Fukui Univ.), Y. Isei (Nippon Steel)

Stable production is essential in the ironmaking process, which produces molten iron from raw materials such as iron ore and coal. In recent years, it has also been required to ensure high productivity while addressing the deterioration of raw material quality and reducing greenhouse gas emissions. If previously unmeasurable process conditions can be newly measured and reflected in operations, it may become possible to meet these demands. In this symposium, as the final report of the research group, we will share and discuss promising measurement technologies with potential applicability to the ironmaking process, along with the results of their preliminary evaluations.

Theme III: Rolling technology for high-quality, high- functional bar and wire rods
Chairpersons: A. Yanagida (TDU), K. Saitoh (Kansai Univ.)

The demands on the quality and functionality of bar and wire rod materials used in automobiles and machinery are becoming increasingly stringent each year. This session will discuss technologies for improving mechanical properties, surface characteristics, and dimensional accuracy in bar and wire rod rolling, as well as material prediction techniques and related equipment, control, and measurement technologies, exploring future technological trends.