Moon Base Work Yields Clean Steel Process




This is Scientific American 60-Second Earth. I'm David Biello. Your minute begins now.
Flaming cauldrons of molten metal have long been the primary venues for steel production.
But blast furnaces require a lot of coal, which means greenhouse gas pollution.
In fact, worldwide, steelmaking is responsible for 5 percent of annual emissions.
But scientists working on a way to harvest oxygen from the iron oxide in lunar soil for future moon bases realized that they happened on a better way to make steel here on Earth.
The trick?
Produce steel the way we make aluminum: use electricity rather than flame.
To make steel the old-fashioned way, you blast iron ore with heat and purify the resulting molten metal with oxygen.
The process removes carbon from the steel, but produces carbon dioxide.
Making a ton of steel releases roughly two tons of CO2,
and the world uses a lot of steel in cars, buildings and other infrastructure.
The new method involves passing a current through a molten pool of iron oxide, which drives off the originally sought-after oxygen.
The by-product is steel.
And depending on the source of the electricity, the process could be nearly CO2-free.
Which, as far as the atmosphere is concerned, would be very cool.
Your minute is up, for Scientific American 60-Second Earth. I'm David Biello,