Basic research on the impurities in steel
As the exhaustion of high-quality iron ore resources, the importance of utilizing low-quality iron ore and recycling iron scraps is increasing. To use the low-quality iron ore efficiently, we are investigating the refining agents (processes) which have high dephosphorization and desulfurization ability, low environmental burden. On the other side, since it is difficult to remove impurities from iron scrap, such as copper, it is necessary to develop a method to absorb the copper-concentrated phase on the steel surface into the iron oxide scale. Currently, we are working on clarifying the phenomenon of copper uptake into the iron oxide film to prevent immersion of the copper-concentrated phase into the steel. We are also focusing on the sulfurization of copper, when it remains in the iron phase, to stabilize it as a fine copper sulfide phase and use it for precipitation strengthening.