At a growing number of its 19 remelting plants Hydro is focusing on recycling in addition to the remelting of process scrap.

In 2010, Hydro remelted more than 1Mt of aluminium – of that, about 260kt was recycled from packaging, building products, automotive parts and other sources. The company’s strategy is to increase recycling to 1Mt/y by 2020.

Plans to build a new recycling center in Karmøy, in western Norway, are part of this effort. An advantage of recycling aluminium this way is that it takes just 5% of the energy needed to produce primary.

The sources of aluminium for recycling are near Hydro’s remelting plants, making for efficient transport – and giving rise to the phase ‘urban mining.’

Hydro researcher Hans Ole Riddervold said: “Post-consumed material comes from many different sources, consists of a number of different alloys, and the composition of scrap varies over time. The question is: How can we plan and handle this as effectively and profitability as possible?”

To answer that question, Hydro went to MIT in Cambridge, Massachusetts. The research project builds upon a 20-year-long history of cooperation between the company and the American research institute.

The big variations in various alloys is at first glance a challenge. At the same time, alloy components, such as silicon, have considerable value if they are extracted effectively.