Future Steelmaking Model by Direct Reduction Technologies

Abstract

Steel production requires iron ore and coal, and accompanies greenhouse gas emissions. The annual production of the world crude steel increased from 0.9 to 1.3 billion tonnes since 2002, and is anticipated to increase due to the continuous economic growth in developing countries especially in Asia.About two thirds of the crude steel is produced by BF-BOF route whose ratio in the total crude steel production has gradually been increasing. The BF-BOF process is an excellent process in terms of productivity and energy efficiency, the process, however requires high grade iron ore and coal, and the large steel production by the BF-BOF route will accelerate the exhaustion of the high grade raw materials. The CO2 emissions are also anticipated to increase as does the steel production, since approximately 2 tonnes of CO2 is generated per tonne of steel by the BF-BOF process.On the other hand, world in-use steel stock has been increasing year by year due to the continuous large steel production, and will be recycled as a large amount of scrap to the market in the future.Steelmaking by feeding Iron Nuggets to EAF together with the scrap can significantly decrease the CO2 emissions while satisfying the steel quality by diluting the impurities containing in the scrap, as well as conserving the natural resources of high grade iron ore and coal. Steel production by using the direct reduction processes together with the scrap is a suitable and reasonable solution for a sustainable iron and steel making.

Predictcion of Next-Generation Ironmaking Process Based on Oxygen Blast Furnace Suitable for CO₂ Mitigation and Energy Flexibility

“…12,15) The MIDREX process, which is a representative direct reduction process based on natural gas, is also considered to be favorable for CO 2 mitigation. 32,33) These expansions of the operating area in the gas composition by hydrogen lead to CO 2 mitigation. Figure 12 indicates the relationships between input energy and energy supply to downstream.…”

Simulation Study on Performance of Z-path Moving-fluidized Bed for Gaseous Reduction of Iron Ore Fines

“…Direct reduction based on fluidized bed systems have become one of the most competitive technologies in these alternative processes. [1][2][3] The main advantage of fluidized-bed reduction technology is that ore fines can be directly charged to the process without prior treatment. However, its disadvantages are particle agglomeration and high gas/solid ratio.…”

Evolution of Blast Furnace Process toward Reductant Flexibility and Carbon Dioxide Mitigation in Steel Works

“…The MIDREX process, which is a representative direct reduction process based on natural gas, is also considered to be favorable for CO 2 mitigation. 57,58) The expansion of the operating area to a hydrogen-rich gas composition leads to CO 2 mitigation.…”