The Sense to Sort. Or: Sorting Makes More Sense Than Ever

Improving the material quality helps to increase the selling price again.

In this article, we concentrate on the non-ferrous metals after the crushers, i.e. on the light and heavy metals such as aluminium, magnesium, zinc, copper, lead and stainless steel in a changed recycling world where Chinas bans material fractions that where welcome before. In the US new tariffs have been imposed this year to impact the steel and aluminum industries.

Consequently, sales markets have reduced as territories have closed their doors to inferior material qualities, or changed economically. With the sales markets getting smaller and thus the supply getting bigger recyclers have to deal with further price reduction. Improving the material quality helps to increase the selling price again.

The situation has changed: Need to upgrade Al sorting to avoid penalties for low material quality. Opportunities for SMEs.

Shredder Residue, ZORBA, ZURIK: Let us look at how sorting quality can be improved cost efficiently by SME recyclers with different investment opportunities, because sorting better requires some invest. Todays recycling facility applies different sorting technologies behind shredder and magnet. To improve sorting efficiency in metal recycling, this is where we start to look into the process, focusing only on the sorting machines in this type of plant. The essential part of this material stream called shredder residue, does not contain too many metallic components, only 5-10% is metal. These are sorted out with the first sorting step, the eddy currents separators (ECS). Here, the Eddy Current Separator produces the so-called Zorba and Zurik material fractions.

Improving ZORBA: This Aluminium rich light metal fraction still contains some contaminating heavy metals like zinc, copper and stainless steel, but also PCBs (Printed Circuit Board). So far the quality of ZORBA aluminium fraction used to be 85-93% which – for todays changed situation – is no longer pure enough. The contaminating heavy metals cause price deductions and thus reduce the income of the recycler. Recyclers are faced with the need to upgrade their Al fraction to avoid penalties for low quality material. Zorba has several separation options because of different sorting opportunities. With our spectroscopy-based sorters like S2S XRF-Sense and S2S LIBS-Sense, all metal types and alloys can be analysed and sorted based on their elemental properties. Now the customer will indicate his interest in terms of required sorting qualities and material streams. For example, wrought and cast sorting and the separation of the heavies, to reduce the zinc content or recover all high Fe aluminium alloys. Zorba can be a “pure” aluminium fraction using XRF and LIBS sensor based sorting technologies. These technologies are also applied by secondary aluminium smelters directly to cost efficiently create smelt ready metal packages.

The good news is, todays sorting technologies allow the automatic sortation according to their elemental composition, thus even alloys can be classified.

For their part, secondary aluminium smelters are opting to buy lower-cost scrap and process it into melt-ready packages. This ‘greener’ process approach not only makes their raw material supply more predictable but also increases the margin on their final product. Construction material, beverage containers and, most recently, the explosive growth in aluminium usage in vehicle manufacturing are the driving forces behind this approach.

Improving ZURIK: The other post Eddy Current Separator fraction is supposed to be the waste fraction; at least it was called so, for many years, until the induction sorter was introduced into the European Metal Recycling market end of the last century. There is still a lot of metals to be recovered in the Zurik material stream: mainly wires and plastic coated wires, stainless steel, PCBs and a minimum amount of other non-ferrous metals, that are missed by the ECS can be recovered with induction sorters such as our S2S Metal-Sense. This machine is used for two steps in the Zurik application. First step is the stainless steel separation followed by the second step, where all wires and other metals are sorted out. The rest fraction is free of metals (>99%). The first step is getting more and more importance since stainless steel is unwanted in the copper wire fraction. The stainless steel fraction will have parts of metal rich PCBs and big copper pieces, so a quality control is needed by hand sorting or by applying our S2S-RobotSense, to automate manual sorting easily.

Adding to providing standard sorting solutions for improving sorted material qualities in recycling applications, it has been our passion to supply customized plant solutions, integrating existing sorting technologies at the customers yard and improve the process to more efficiency by redesigning the process to todays standards economically, and this –on reduced footprint.

For upgrading smaller material quantities, the company Sense2Sort has developed “Plug ‘n Sort”-sorters based on different sensor technologies.

Sense2Sort Toratecnica, S.L. has built and serviced sensor-based sorting machinery for recycling applications all over the world. Their classic product offering is based on common sorting technologies such as Induction, CCD, NIR, XRF, LIBS and combinations thereof.

Sense2Sort has been a continuous innovator and its aim is the perfect closing of the recycling loop using latest material identification methods. Using their deep know-how and experience, Sense2Sort’s experts consult on new and existing concepts for plant improvement and sorting perfection, achieving the highest process profitability for their customers.

Please contact us at info@sense2sort.com. Sense2Sort is your partner for sensor based sorting applications in Metal Recycling.

This article is published by Sense2Sort – Toratecnica

Sorting technologies have developed considerably in the last 15 years. Today, they are accepted as standard equipment for the processing of primary and secondary bulk materials. In many cases, this has also led to the development of highly technological and complicated machinery. And in many cases, new sorting devices are added to the traditional ...

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