Leoben Mining University (Leoben, Austria):

Schenck J., Dr. Eng., Prof., Head of Iron and Steel Metallurgy

VDEh Steel Institute (Düsseldorf, Germany):
Lüngen H. B., Dr. Eng., Prof., Technical Director, e-mail: hans-bodo.luengen@vdeh.de

The processes of direct reduction and smelting reduction of iron ores reduce the ores by avoiding coke metallurgy. The natural gas-based direct reduction processes have lower CO₂ emissions in comparison to the coal-based and liquid hot metal producing processes “blast furnace” and “smelting reduction”. Regarding energy consumption all three routes are of equal level. For an application of the routes that form an alternative to the blast furnace in Europe the integration into an existing integrated iron and steel works is evaluated. A replacement of the blast furnace — converter route by gas-based direct reduction with a subsequent electric steelmaking with the target to reduce CO₂ emissions does not seem to be an economic solution. It is stated that direct reduced iron (obtained in direct reduction units) and cast iron (from reducing melting units) are very important products in regional level. Energy consumption of the three observed technological routes (blast furnace — basic oxygen converter, reducing melting unit — basic oxygen converter, direct reduction unit — electric arc furnace) is relatively equal, with small advantage in the first of them. The route including DRI technology is characterized by essentially lower CO₂ emissions per ton of raw steel. It is noted that the potential of integration of DRI process and reducing melting in the operating metallurgical works is rather good. However, to achieve additional decrease of CO₂ emissions, it is recommended to develop iron ore reduction via hydrogen technology.

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