TOMRA Sorting Recycling recovers materials for recycling from end-of-life vehicles. Here we ask Sales Manager Tom Jansen to explain how technology can still improve recycling rates, and how TOMRA’s sorting machines differ.
Q: Is there still potential for improvements in end-of-life vehicle recycling?
Tom: TOMRA sorting technologies have been used for ELV recycling for two decades now. This type of work started with the recovery of metals from residue streams, to divert residual metals which were missed by traditional non-sensor based equipment, such as magnets and eddy current separators, from landfill. This means the majority of metals are being recovered in developed markets. In less developed markets, however, this is still an area where recyclers can improve.
Q: How has technology improved the selection of metal scraps and influenced material recovery?
Tom: Typical traditional products of metal scrap, such as Zorba [mixed non-ferrous metals] and Zurik [mixed metals after FINDER induction sorters], were sold to Asia where they were sorted manually. Since the mid-to-late 2000’s, the focus of recyclers changed to further sort these mixed fractions by using sensor technologies. This creates added value by producing mono-fractions with more overall value than the mix, but it also provides more options to sell metal scrap products directly to local processors, such as remelters, instead of using traders in between.
After a difficult period for the recyclers in the first half of the 2010’s, this trend has again picked up in recent years. Existing sorting technologies are improving, increasing in speed and resolution; multiple technologies can be combined; and new technologies are being developed. This is allowing recyclers to add sorting steps and further increase purities. The real driver is that quality is king – recyclers producing mixed or contaminated products will increasingly have difficulties selling.
Q: Can you briefly tell us about the heart of a TOMRA machine, how the selection of ferrous and non-ferrous metals works?
Tom: For the recycling of ELV’s, four sorting technologies that are predominantly used, either separately or combined. At TOMRA, these are included in the four sorting units. I’ll say a few words about each.
First of all, there’s FINDER. This is a sorting unit which uses an electromagnetic [EM] or induction sensor. This sensor provides information on metal signal, as well as shape, size and to some extent metal type in the latest generations. The FINDER is mainly used for recovering metals from residue, and sorting them into stainless steel and copper wire concentrates.
Another of our sorting units is FINDERPOLY. This combines an EM sensor with near-infra red [NIR] or laser object detection [LOD] technology. NIR enables the recognition of plastics and other non-metals. Typical applications are the sorting of plastics and/or wood from residue, but also the upgrade of stainless steel and wire concentrates by LOD.
Then there’s X-TRACT XRT. This employs x-ray transmission [XRT] technology to sort material based on differences in density. It’s mainly used for the sorting of Zorba [the product of an eddy current: aluminum, copper, brass, zinc and others] into aluminum and mixed heavy metals.
Finally, there’s COMBISENSE. This uses an RGB colour camera combined with an EM sensor. This unit is mainly used for sorting mixed non-ferrous metals by colour. In ELV recycling, the mixed heavies are typically sorted into copper [red], brass [yellow], printed circuit boards [green] and zinc/alu [grey].
Q: At the end of the selection cycle, what secondary raw materials are recovered? And what does the rest of the material consist of, and where does it go to?
Tom: The answer to this depends on variables such as the location, market conditions, and regulations. For a typical state-of-the-art sorting plant in a developed EU country, the material fractions recovered are ferrous/steel; aluminium; copper; brass; zinc and other grey heavy metals; stainless steel; copper wires; and wood.
Residual fractions can include shredder light fraction (SLF), and plastics and rubbers. SLF is typically removed by windsifting at the shredder. This contains dust, foam, fluff, textiles and so on, and is typically treated in specialized plants to recover residual valuables. Plastics and rubbers can be further sorted at specialized plants, but are also used in incineration plants.
Q: Can TOMRA technology help improve the quality of the car fluff? And if so, how?
Tom: Yes, but it depends on how car ‘fluff’ is defined. Normally car fluff means the SLF, which is the most difficult material to sort efficiently by sensor equipment. Several mechanical treatment steps are needed to concentrate materials, then FINDER can be used to recover metals, NIR can be used to sort wood and/or plastics, and a COMBISENSE chute can be used to sort fine metal fractions.
In many cases, the low amount of valuable material, and the efforts needed to recover it, makes this technically and economically challenging. With continuing increases in recycling targets and costs of alternatives, however, the recovery and sorting of valuables out of fluff will also become more and more important.