JFE Steel and NEDO begin demo testing of ferro coke production at medium-scale; reducing ironmaking energy consumption and CO2 emissions by 10% each
In Japan, the New Energy and Industrial Technology Development Organization (NEDO) and JFE Steel Corporation have built a medium-scale ferro coke production facility with a daily production capacity of 300 tons and begun demonstration testing. The goal is to develop ferro coke production technology that reduces both energy consumption and CO2 emissions in the ironmaking process by approximately 10% by around 2023.
Ferro coke improves the efficiency of the iron ore reduction reaction that occurs inside a blast furnace and significantly reduces the resulting amount of CO2 emissions. Ferro coke is a composite of metallic iron and coke, produced by crushing, mixing and briquetting coal and iron ore, followed by heating the briquette in a shaft furnace in which continuous carbonization and iron ore reduction proceed simultaneously.
The catalytic effect of metallic iron, which accounts for approximately 30% of the content of ferro coke, significantly increases the reduction efficiency of iron ore, reducing the coke rate at the blast furnace, thereby significantly reducing the resulting amount of CO2 emissions.
Using ferro coke allows the low-grade coal and iron ore usage rates to be increased compared to conventional technology.
Process flow of ferro coke.
In the blast furnace, a certain amount of ordinary coke can be replaced with ferro coke. CO2 is generated by a reduction reaction of iron ore (sintered ore) by carbon monoxide (CO) inside the blast furnace. Super-fine metallic iron contained in the ferro coke becomes a catalyst in a gasification reaction (C + CO2 = 2CO) between CO2 and coke (C), which significantly improves regeneration of reducing gas (CO). As a result, CO concentration increases and the reduction reaction of iron ore (sintered ore) is possible even at low temperature, which is expected to significantly lower the reducing agent rate, resulting in energy conservation and reduced CO2 emissions.
The test, which is being implemented in cooperation with Kobe Steel, Ltd. and Nippon Steel Corporation, is part of a project “Technological development of Ironmaking process utilizing ferro coke”. The new facility is located at JFE Steel’s West Japan Works in Fukuyama, Japan.
JFE Steel Corporation, one of the world’s leading integrated steel producers, was established through the consolidation of NKK Corporation and Kawasaki Steel Corporation in 2003.
The medium-scale facility is one-fifth the 1,500-ton daily production capacity envisioned for commercial operation. It comprises equipment crushing and drying, mixing and briquetting, and shaft furnace. Crushed low-grade coal, low-grade iron ore, and a binder are mixed and briquetted, and then subjected to shaft furnace to obtain ferro coke containing metallic iron.
Ferro coke will be produced at the new facility until fiscal year 2022. The effects on the reducing-agent rate and operational stability will be evaluated by continuously charging ferro coke into an actual blast furnace over a long period of time.
The project has a total planned budget of ¥20.1 billion (US$190 million), 50% of which will be subsidized by NEDO and the rest paid for by the participating companies. Subsidies have been granted to JFE Steel Corporation, Kobe Steel, Ltd. and Nippon Steel Corporation. The project’s joint research partners are Tohoku University and Kyushu University.