Melted steel wires complete the recycling of car tires. - © Birn

Circular project raises money

At the Danish foundry Birn, Holstebro, an optimization project has increased the share of so-called „doughnut briquettes“ from 15 % to 25 %. These consist, among other things, of steel wire from used car tires, which are used as a feedstock in the melting furnaces.

After having done their duty on Denmark’s roads, most Danish car tires are reused as playground swings or artificial turf pitch granules. Alongside rubber, care tires also feature steel cords. The steel cords are sent to the foundry Birn in Holstebro in Western Denmark for reuse. The foundry adds the newly recycled steel cord briquettes with added cast iron shavings from its production to its melting iron. Kurt Bjarne Larsen, foundry technical manager at Birn, invented these briquettes roughly ten years ago.

Through a circular optimization project, the foundry has successfully increased that share to about 25 percent. And even though a 10 percent increase seems modest, this percentage increase means, that Birn can process the steel wires from all car tires produced in Denmark. However, these must be delivered quickly to avoid rust. The steel wires are therefore a cost-effective input material that would otherwise has to be disposed of, and recycling them also reduces the burden on the environment.