Automated scrap metal sorting using laser spectroscopy - AUSOM

Metals and minerals can in theory be recycled almost indefinitely. By reusing materials, you can save up to 80% energy compared to extracting and remanufacturing the metal. It also minimizes the use of new raw materials and the need for ore mining. In practice, however, there are many challenges with metal recycling, one such challenge is efficient sorting of the metal to be recycled.

Efficient scrap metal sorting with the help of lasers

This project developed a robust and cost-effective sorting technology for scrap metal. A laser-based sensor system measures what material the scrap piece contains and the system sorts the metal into the correct compartment.

The laser system is called LIBS, a well-established method for analyzing the chemical content of materials. In LIBS (laser induced breakdown spectroscopy), a high-energy laser pulse is fired at the material to be analyzed. This creates a local plasma where the content of the material can be identified spectroscopically.

Unlike other analysis techniques, such as XRF, LIBS can also identify the lighter alloying elements in steel, such as Si, Al and Mg. A LIBS-based system can therefore be used to sort scrap with better precision than if you use other measurement techniques.

A European consortium

The AUSOM project developed a LIBS-based analysis system that enables cost-effective and improved sorting of scrap metal in recycling facilities. The sorting system can contribute to:

• Environment and circularity: Less use of virgin material and the production of secondary raw materials of higher value.
• Social aspects: Better working conditions through reduced need for manual sorting.
• Economic and strategic benefits: Better access to high-quality secondary raw materials for European industry, less dependence on critical raw materials and associated import dependence.

This activity has received funding from EIT RawMaterials, initiated and funded by the European Institute of Innovation and Technology (EIT), a body of the European Union, under the Horizon 2020, the EU Framework Programme for Research and Innovation.