The recycling company Alba has commissioned an aluminum sorting plant at its Hoppegarten site. This marks the beginning of a new circular era for metal recycling of secondary raw materials. It is the first commercial application of a laser-based sorting technology, the development of which was paved the way by the German Federal Foundation for the Environment (DBU) with project and prototype funding amounting to more than one million euros, as well as three medium-sized companies with technical finesse and engineering skills.
"This is groundbreaking high-tech. Scrap becomes environmental protection." said DBU Secretary General Alexander Bonde.
Benefits for the economy and the environment
Far from being useless waste, the scrap metal is a valuable raw material that can be remelted into high-quality alloys. The benefits are relevant to both the economy and the environment, as a major impetus is given to a circular economy.
"The pioneering ideas of the medium-sized companies involved not only reduce energy costs, but also ensure greater environmental and climate protection because fewer raw materials have to be taken from the earth," Bonde added.
The marketability of the aluminum sorting system is due to several years of development and research - largely through cooperation between the two NRW companies Clean-Lasersysteme GmbH and cleansort GmbH and OSR GmbH & Co.KG from Baden-Württemberg. Clean-Lasersysteme was responsible for suitable measurement technology, cleansort for plant construction, and OSR, which specializes in scrap metal trading and the processing of raw materials, was ultimately the decisive key to putting the prototype plant into operation in Rosengarten (Ostwürttemberg). The German Federal Foundation for the Environment provided technical and financial support for the high-tech project.
Specific high-performance materials thanks to precise alloying proportions
"The technology used is characterized by the highest precision. For various sectors such as the automotive industry, alloy components are of utmost importance. High-performance materials such as car body panels or axle beams require exact alloy components," says DBU head of department Dr. Michael Schwake.
Here, two processes are combined with the aim of precisely determining the alloy of the scrap parts. In metallurgy, alloys are homogeneous metallic materials consisting of several chemical elements, at least one of which is a metal.
Bonde to revolutionize the scrap market
The Hoppegarten plant ensures just that. The plant will sort aluminum scrap because of the expected positive sustainability and cost effects, but in principle it can separate all metallic materials for later reuse.
In a first step, the roughly palm-sized scrap pieces, such as stamped-out sheets, are transported on a conveyor belt. Cameras inspect each piece and identify multiple inspection points. Then the high-tech lasers are used at these inspection points: first to clean the surface of dirt and surface layers down to the base metal - then with punctual laser pulses directly onto the scrap part. As a result, the material vaporizes, and the chemical composition is determined from the light emissions of the metal atoms. A blow-out unit at the end of the process uses air pressure to separate the scrap pieces. In the future, such a laser-based sorting technique - known in the trade as laser-induced breakdown spectroscopy (LIBS) - will allow the scrap to be precisely targeted for melting according to its alloy content.
"This highly complex technology is an outstanding development and could revolutionize the scrap market," says DBU Secretary General Bonde.
Higher demand for aluminum scrap
LIBS technology makes it possible to significantly increase the amount of secondary raw materials used as recycled material to produce high-performance materials. In Germany, these materials account for 43 percent of copper, 69 percent of lead, 60 percent of aluminum and 44 percent of crude steel in metal production. Around 22 million metric tons of secondary raw materials and an additional three million metric tons of alloying metals are used for the roughly 50 million metric tons of steel produced in this country each year.
The Association of German Metal Traders and Recyclers (VDM) highlights the urgent need for new technologies in scrap recycling. According to VDM, the demand for aluminum scrap in the EU will rise to around nine million tons in the coming decades - with excellent prospects: the use of aluminum scrap saves 95 percent of the energy compared to the energy consumption in primary production, according to VDM. According to cleansort calculations, a plant like the one in Hoppegarten can save around six million euros in costs every year in a two-shift operation based on German electricity prices - and almost 18,000 tons of climate-damaging carbon dioxide.
