What's that smelt? Iron smelting goes green

Massachusetts Institute of Technology engineers have demonstrated a more eco-friendly way to make iron. The method eliminates greenhouse gases typical of conventional iron production methods says team leader Donald R. Sadoway of MIT's Dept. of Materials Science and Engineering. The researchers have shown the technical viability of producing iron by molten oxide electrolysis (MOE). The work funded by the American Iron and Steel Institute (AISI) and DoE Technology Roadmap Program (TRP) aims to help U.S. steel industry become more competitive. MOE passes an electric current through a liquid solution of iron oxide. The iron oxide breaks down into liquid iron and oxygen gas. Electrolysis itself is nothing new -- all of the world's aluminum is produced this way. And that is one advantage of the new process: It is based on a technology that metallurgists are already familiar with. Unlike aluminum smelting, however, MOE is carbon-free, says Sadoway. "No one has ever studied the fundamental electrochemistry of a process operating at 1,600°C. We're doing voltammetry at white heat. We have been able to confirm that, with MOE, we'll see iron productivities at least five times that of aluminum, maybe as high as ten times. This changes everything when it comes to assessing technical viability at the industrial scale."MIT is continuing to study ways of boosting iron production rates and is trying to find new materials capable of extending the life of certain reactor components to industrially practical limits. The work will set the stage for construction of a pilot-scale cell to further validate the viability of the MOE process and identify scale-up parameters.