Gas-reduction ironmaking process
Although steel is the most recycled material globally, steel manufacture is still energy-intensive and exhibits a high carbon footprint. Scientists at the University of Utah have evaluated the conventional steel manufacturing process to improve its environmental performance. In the typical method of producing pig iron (crude iron) in steel making, a coke oven or blast furnace is used to process raw iron ore into sinter and pellets. High quantities of heat and forced air are required to melt the materials, resulting in a high embodied energy of 16–20 MJ/kg and a CO2 footprint of 1.4–1.6 kg/kg for cast iron.
The researchers have developed a new flash iron-making process that avoids using coke, instead employing hydrogen or natural gas to reduce iron ore particles directly. This innovative method allows steel manufacturers to forgo the blast furnace entirely, shorten the processing time to seconds, and use smaller equipment for the same production volume—all of which lowers costs. Also, the new process is expected to reduce energy consumption by 20 percent and CO2 emissions by 39 percent compared with traditional iron-making methods (the use of pure hydrogen would drop CO2 emissions near zero).
Contact: University of Utah Metallurgical Engineering & Chemical Engineering, Salt Lake City, UT, USA.
For more information, see Transmaterial Next: A Catalog of Materials that Redefine Our Future