UNIQUE CIRCULAR SOLUTION TO
COMPLEX WASTE CHALLENGE
A unique use of complex waste has been developed in collaboration between Stena Aluminium and Stena Recycling. The step from destruction to material recycling in the waste hierarchy provides a cost- and resource-effective solution for all parties, and for the environment.
Stena Recycling Jönköping’s customer Husqvarna casts with magnesium and aluminum alloys in its foundry in Huskvarna. The process gives rise to 125 tonnes of magnesium skim each year, which is a complex waste material that corresponds to 5.8 percent of Huskvarnasiten’s total waste for destruction.
“Previously, Stena Recycling Jönköping received the magnesium skim, which has then been destroyed by incineration. The residue powder has then gone to landfill. This has entailed both high costs and a non-circular solution as the material is lost,” says Joacim Dahlström, local customer manager at Stena Recycling in Jönköping, who therefore began to consider whether it would be possible to extract magnesium from the skim.
He placed the question to Kristoffer Johansson (Totte) who works at Stena Aluminum’s reception site in Älmhult. After several tests in different furnaces, Kristoffer had determined that the skim works well in the melting process and that it is possible to extract 16 percent magnesium from it. This is higher than expected as magnesium skim is a relatively low-quality material from the beginning, with about 40 percent debris in the form of dust and oxides. It is also flammable, which makes it difficult to handle.
“At the smelter, we use magnesium as an additive to produce aluminum alloys for Husqvarna and other customers. With more circular additives in our own aluminum production, we at Stena Aluminum can buy smaller volumes of primary magnesium, which is expensive and needs to be imported from abroad,” Kristoffer explains.
For Husqvarna, the waste solution means reduced destruction costs and reduced environmental impact.
“It also reduces the risk that in the future, the customer being without a solution for a complex process waste, as the possibility may be closed for destruction for this type of waste and Husqvarna would then need to ship the waste abroad. This gives us a strengthened and long-term business relationship with our customer,” says Tony Lidberg, sales representative at Stena Aluminum.
Through Stena Aluminum’s and Stena Recycling’s collaboration in the region, a unique circular solution to a complex waste challenge is now in place.
“We are working in a fun but challenging industry. Here we can benefit from each other as sister companies by working together to find solutions that are good for both our customers and the company, and at the same time help to reduce the use of resources for a more sustainable future,” Kristoffer Johansson concludes.
