‘Worldwide to 50 million tonnes is discarded every year’
What is the status of the amount of electric and electronic equipment and the collection of them in Europe? These are known as electric & electronic equipment (EEE) and waste electric & electronic equipment (WEEE). The annual quantity of equipment with a plug or battery (EEE) rose from 7.6 million tonnes in 2012 to 12.4 million tonnes in 2020, reports Eurostat, the European bureau for statistics. And no wonder as almost all products these days contain electronics or electric engines. The amount of collected WEEE rose from three to 4.7 million tonnes a year (10.5 kilograms per European), thereby remaining a little behind purchase in terms of percentage.
Previously, MYNE developed together with TU Delft the Xortrer, a sorting line with 64 robots for aluminium alloys.
© MYNE
Waste goes through a series of separation techniques: sieving, roller sorting and magnetic separation.
© MYNE
Metal recycling company MYNE now buys electrical scrap and wire harnesses from the Netherlands, Belgium, Germany and France.
© MYNE
TU Delft technology
The latest and most advanced step in separating electric and electronic waste is the so-called Magnetic Density Separation (MDS). Rem had previously designed this technique to separate plastics with minimum density differences. Post-doc Dr Lin Wang is now adapting the technique for the maximum separation of electronic components and cables. The container in which the separation is done looks like it contains oil, but this is not the case. The black liquid is water containing suspended magnetic nanoparticles.
A strong permanent plate magnet beneath the container exerts a pull force on the liquid that increases the density. This causes the parts that would normally sink in water to float. The plate magnet is placed at a slant beneath the basin so that the density of the liquid decreases the further away from the magnet it is. The entry point is on the side with the shortest distance to the magnet and the highest density where everything is still suspended. The particles suspended in the solution flow in rows of similar density and land on the bottom at a distance from the entry point that matches the density. Wang drains the black liquid and points to where the components have landed. On the left with the highest density are the non-magnetic metals like aluminium cooling fins and computer chips, in the centre the cinch cables and other plastic and metal connectors, and on the right mostly plastic parts.
‘They are economical separation techniques’
The left part is the most interesting for recovering precious metals. “They are the most economical separation techniques,” emphasises Rem. The magnets are permanent and some running electric engines are the only parts that use energy. At the moment, MDS is the cornerstone in the sorting and reprocessing process of electrical and electronic waste. At the end of its journey, the contents of the bucket of mixed electronic waste has been separated into 30 to 40 containers.
Businessmodel
At the beginning of November, an industrial MDS machine prototype was brought to the lab. Before this, Wang had to fill and empty the basin for each new load of waste components. The industrial machine has a conveyor belt below the MDS separation basin. This means the continuous outflow of separated components. The prototype is sponsored by MYNE, formerly Reukema, a metal recycling company in Harderwijk. Its Director, Martijn van de Poll, contacted Peter Rem in 2014. At the time, all the electronic waste was being shipped to Asia to be separated there by hand. Van de Poll saw electronic waste as one of the fastest growing waste markets and started looking for ways to be involved. He asked Rem if he and his team could design a separation technology that was cheaper than the hand separation in Asia. This was the start of research into the processing of electrical and electronic waste at TU Delft.
MYNE now buys electronic scrap from the Netherlands, Belgium, Germany and France. The material does not go to Asia anymore. The first MDS machine that was to separate the waste more cheaply than sending it to workers in Asia has now, after 10 years of development, been built and is being tested in Civil Engineering’s recycling lab. The machine is expected to separate 1.5 tonnes an hour. “A recycling plant should be able to process 30,000 tonnes a year,” estimates TU Delft alumnus Van de Poll, who graduated in Applied Earth Sciences at TU Delft in 2001. “But 50,000 to 100,000 tonnes would be even better to keep the plant economically viable. If you do some calculations, you will need five to 10 MDS separators.” “If we would buy five machines, it would be because we believe that it is a viable business model,” says Van de Poll, whose MYNE company is also part of Circular Circuits. “There is pressure everywhere. Legislation is underway that will require recycling to include the reuse of raw materials at the design stage. The biggest step now is that the automobile industry and IKEA are working on their CO2 footprint and the traceability of raw materials. This is a huge step forward compared to five years ago.”