Researchers find new way of making steel without greenhouse-gas emissions

Last Updated: Thursday, May 9, 2013 - 14:08

Washington: Steel-making, a major emitter of climate-altering gases, could be transformed by a new process developed at MIT.

The new process even carries a couple of nice side benefits: The resulting steel should be of higher purity, and eventually, once the process is scaled up, cheaper.

Donald Sadoway, the John F. Elliott Professor of Materials Chemistry at MIT and senior author of a new paper describing the process, said that this could be a significant `win, win, win` proposition.

The paper, co-authored by Antoine Allanore, the Thomas B. King Assistant Professor of Metallurgy at MIT, and former postdoc Lan Yin, has just been published in the journal Nature.

The prevailing process makes steel from iron ore, which is mostly iron oxide, by heating it with carbon; the process forms carbon dioxide as a by-product.

Sadoway found that a process called molten oxide electrolysis could use iron oxide from the lunar soil to make oxygen in abundance, with no special chemistry.

He tested the process using lunar-like soil from Meteor Crater in Arizona - which contains iron oxide from an asteroid impact thousands of years ago - finding that it produced steel as a byproduct.

Sadoway`s method used an iridium anode, but since iridium is expensive and supplies are limited, that`s not a viable approach for bulk steel production on Earth.

But after more research and input from Allanore, the MIT team identified an inexpensive metal alloy that can replace the iridium anode in molten oxide electrolysis.

Allanore, who worked in the steel industry before joining MIT, said progress has been slow both because experiments are difficult at these high temperatures, and also because the relevant expertise tends to be scattered across disciplines.


First Published: Thursday, May 9, 2013 - 14:08
comments powered by Disqus