slag

Among the many sounds and smells of the steelworks, Steve's most notable memory is the smell of "rotten eggs", which comes from the slag that's formed during the steel-making process.

"I always remember the smell. My father used to smash up the slag from the torpedoes and he had to break it up with his crane. That smell has lived with me for the rest of my my life."

“There were high concentrations of slag in these, which is a glass-like material that makes them maybe a little bit more brittle in the cold,” she says.

The Cambridge researchers found that used cement is an effective substitute for lime flux, which is used in steel recycling to remove impurities and normally ends up as a waste product known as slag.

"We found the combination of cement clinker and iron oxide is an excellent steelmaking slag because it foams and it flows well," said Dunant.