Cleaning – Analyzing – Sorting – Recycling

Resource-conserving scrap sorting

cleanSORT is a new method for laser-based real-time analysis for scrap recycling. While the components are conveyed through the laser device at approx. 3 m per second, the machine recognizes the type and quality of metal recyclables. This makes it possible to separate and recycle the valuable metals by type, even if lacquers or metallic coating materials are on the secondary metal.

Laser Spectroscopy and Laser Ablation

Modern metallic high-performance materials are characterized by precisely matched alloy components. In order to increase the proportion of recycled material in these materials, it is necessary to precisely determine the alloy composition of the scrap used. Conventional analysis methods cannot penetrate coatings made of lacquers or metals. This can be remedied by combining two methods: laser spectroscopy and laser ablation.

Metallrecycling mit cleanSORT-Anlage
cleanSORT Laserspektroskopie und Laserablation

First cleaning, then analyzing

Laser spectroscopy recognizes the substances by their unique optical spectrum. The method uses this “fingerprint of light” to precisely analyze the alloy composition of metal scrap at high conveying speeds in the mass flow. It is therefore essential to clean the measuring range beforehand and remove coatings. With this laser ablation, a high-performance laser first cleans a small area on the surface of a piece of scrap in one to two hundredths of a second, even several times in succession. In the second sub-process, a laser-induced plasma spectroscopy (LIBS) is performed on the previously cleaned surface with the same laser.

A spectral analysis determines the chemical composition of the examined scrap piece. With this data, the metal can be sorted according to the actual alloy requirement of a target melt. Sorting is carried out by air pulse technology with up to 30 scrap pieces per second. Thanks to the support of the “Deutsche Bundesstiftung Umwelt” (German Federal Environmental Foundation), the prototype was realized, tested and further developed under operating conditions.

Economic benefit

    • The new “COLA” process (collaboration of LIBS and laser ablation) works with high productivity rates and is therefore both resource-saving and economical. One system
      • sorts about 10,000 tons of steel scrap annually
      • thus saves about 27,000 MWh of primary energy
      • avoids around 11,000 tons of CO2
      • replaces approx. 200 tons of imported alloying metals worth almost one million Euro
    • The process has great potential: from the automotive and aviation industries to waste incineration plants – scrap metal is produced in large quantities. With 100 “COLA” plants, around 1.1 million tons of CO2 can be saved in just one year. This corresponds approximately to the annual CO2 emissions of the city of Ulm.


cleanSORT …


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