DOE Researchers Develop Method for Low-cost Optical Sorting of Aluminum Scrap

SEATTLE (Scrap Monster): A team from Pacific Northwest National Laboratory (PNNL) and Argonne National Laboratory has developed a method to to color-code scrap aluminum pieces by alloy family and also demonstrated low-cost optical sorting of cast from wrought pieces to upgrade the scrap stream. A paper on their work is published in the journal Resources, Conservation and Recycling.

Shredded post-consumer aluminum scrap streams contain a mixture of cast and wrought aluminum pieces with very different compositions, resulting in downcycling of the mixed scrap into non-structural cast aluminum alloys and parts. The sorting of material types and alloy grades instead could reduce the need to import primary aluminum by upgrading the scrap stream.

The team’s color-coding process reacts the scrap pieces with non-acidic chemicals. With the new method, the color difference enabled more than 95% purity in the optically sorted cast and wrought fractions.

 Funding for this work was provided by the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, Vehicle Technologies Office, through the LightMAT and Lightweight Metals Core Programs (LMCP).

Courtesy: www.greencarcongress.com