Yuki Iwai

Abstract:

In recent years, development of innovative energy saving technologies for preventing global warming becomes more important for the steel industry. Ferro-coke is an innovative ironmaking process for energy saving in terms of realizing the low reducing agent ratio (RAR) operation in the blast furnace. In the Ferro-coke process, coal and iron ore were mixed and formed by a briquetting machine, and carbonized in a vertical type carbonization furnace. Ferro-coke causes lower thermal reserve zone temperature in a blast furnace because of its high gasification reactivity by Fe catalytic effect.
In this study, the reactivity of ferro-coke was measured under the condition simulated a blast furnace. As a result, it was found that ferro-coke has remarkably higher reactivity and lower reaction starting temperature than normal coke and in the case of mixing sinter, the reduction of sinter was enhanced.
In the former NEDO project, 2000 ton of ferro-coke was produced by the pilot plant with a capacity of
30 ton/day and the effect on RAR was confirmed in the actual blast furnace.
For the next step, NEDO began the project “Environmentally Harmonized Steelmaking Process Technology Development (Ironmaking Process Technology Using Ferro-coke)” with a 6 year schedule from FY 2017. In this project, a ferro-coke production technology is to be established through a medium-scale plant producing 300 ton/day of ferro-coke with the aim of a 10% reduction in energy consumption in the ironmaking process by around the year 2022.