Recovery of metals from fine shredder fractions: The BHS rotor impact mill is the centerpiece of the complete solution for recycling.
When automobile scrap and electronic equipment are shredded, the fine fractions of the crushed material still contain considerable amounts of precious metals which until now have invariably been deposited in landfills. Treatment plants from BHS-Sonthofen use a one-of-a-kind process to reclaim these metals, allowing them to be sold profitably.
Approximately 20 grams of gold, 200 to 300 grams of silver, as well as platinum and other precious and non-ferrous metals: this multitude of resources can be hiding in one tonne of heavy non-ferrous fraction. In the recycling process for automobile, electrical and electronic waste, the coarse components are shredded and treated, leaving this fraction behind.
Despite its great value, this fine material is usually disposed of at landfills or incinerated. As more and more electronic components and boards are used in vehicles and electronic devices, all the more valuable resources are lost.
With its complete solution for the fine treatment of shredder residues, BHS picks up where others have left off: substances once headed to the landfill or incinerator are now fed back into the material cycle and profitably recycled. Operators report that the sale of the materials, for example the heavy fraction of non-ferrous metals, brings them approximately 3,500 euro per tonne, and that their plants have paid for themselves within nine to twelve months. However, the plant does not just generate income from the sale of metals; it avoids landfill costs as well. In turn, this serves to unburden landfills, which is all the more significant in light of the new landfill directive. When compared to other systems, rotor impact mills for recycling applications (type RPMV) also feature low wear-related costs, contributing in large part to low costs of operation.
Shredding used to be of commercial interest mainly for ferromagnetic materials. In the 90s, the recycling of non-ferrous metals also became economically viable. Today, with modern plant technology, the sale of precious metals is lucrative as well. BHS pioneered this development with a one-of-a-kind machine: the rotor impact mill (RPMV), manufactured by BHS alone worldwide, set the stage for the clean separation of non-ferrous metals from other materials.
Building on its scrap crushing expertise and with many of its rotor impact mills integrated in similar processes, BHS has developed a complete solution for fine-grain treatment. It combines impact crushing technology with physical separation methods and comprises all process stages from the feeding of material to the separation of individual substances to the removal of dust.
In the first part of the process, the input material is crushed and the lightweight materials are separated. In the second stage, the remaining material is screened and sorted by density. The final products are thus various materials and metal fractions cleanly separated according to type and grain size.
The centerpiece of the plant is the rotor impact mill of type RPMV. It crushes the brittle-hard materials and shapes the ductile, metallic ones into balls. The standard plant, which BHS offers as a complete solution, achieves a throughput of approximately 10 tonnes per hour. On request, BHS designs larger plants tailored to specific customer requirements.
The rotor impact mill crushes and disaggregates the material (grain sizes between 0 and 20 mm). The machine works selectively here: brittle materials – for example mineral substances, glass or castings – are finely crushed and the composites are separated, while elastic materials such as rubber remain intact.
The key effect of the sorting is that ductile metals, i.e. those which can be deformed plastically, are shaped into balls in the rotor impact mill. This is why the machine is also referred to as the „ball shaper“. It lays the foundations for the next stage, which cleanly separates the non-ferrous metals from the other materials. In order to be separated and conveyed to the downstream process stages, the non-ferrous metal parts, which are often long and flat, should have as compact and spherical a form as possible.
The result: cleanly separated materials
At the end of the process, all of the fractions are cleanly separated in bins. In addition to proportions of the precious metals mentioned above – gold, silver and platinum – the fraction of non-ferrous metals contains considerable amounts of aluminum, copper and brass, which can also be sold. Depending on the composition of the waste material, the BHS fine treatment plant recovers between five and seven percent of this input as saleable non-ferrous metal.
A positive cost factor is that the whole process is to a large extent automatic and the entire plant can be controlled and monitored by just one employee. An additional employee spends about half of his working hours on the material logistics.
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About BHS-Sonthofen
BHS-Sonthofen GmbH, headquartered in Sonthofen / Allgäu, is an owner-operated group of companies in the field of machine and plant engineering. The company offers technical solutions in the field of mechanical process engineering, with a focus on mixing, crushing, recycling and filtration. With over 300 employees and a number of subsidiaries, BHS-Sonthofen has a global presence.
The Recycling Technology division offers a broad range of machines and plants for the recycling industry. The spectrum encompasses the treatment of brittle-hard waste materials such as electronic scrap, slag, shredder residue fractions, etc. or of elastic materials such as tires, cables and refuse-derived fuels.
For more information, visit www.bhs-sonthofen.de.
BHS-Sonthofen GmbH
Roland Schmid
An der Eisenschmelze 47
D-87527 Sonthofen, Germany
+49 8321 6099-231
press@bhs-sonthofen.de
http://www.bhs-sonthofen.de
VIP-Kommunikation
Regina Reinhardt
Süsterfeldstrasse 83
52072 Aachen, Germany
+49.241.89468-24
reinhardt@vip-kommunikation.de
http://www.vip-kommunikation.de
