MIT researchers have developed a new process to help steelmaking more eco-friendly, steel products to be of higher purity and eventually, cheaper.
Mr Donald Sadoway, the John F Elliott Professor of Materials Chemistry at MIT, is the senior author and Mr Antoine Allanore, the Thomas B King Assistant Professor of Metallurgy at MIT, and former postdoc Mr Lan Yin, are the co-authors of the paper published in the journal “Nature”.
According to steel industry figures, the worldwide steel production currently totals about 1.5B tonnes per year and accounts for as much as 5% of the world’s total greenhouse to gas emissions.
The prevailing process that makes steel from iron ore, mostly iron oxide, by heating it with carbon, forms carbon dioxide as a by-product. Production of a tonne of steel generates almost two tonnes of CO2 emissions.
Mr 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, finding that it produced steel as a by-product. Sadoway’s method used an expensive and rare iridium anode, which makes it unsuitable for bulk steel production on Earth. However, 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.