Liquisort BV has introduced the new Magnetic Density Seperation technique, a new method to efficiently separate different types of scrap metals or plastics in a new innovative way. By combining a magnetic liquid combined with a special magnetic field, it is possible to separate multiple types of scrap materials at the same time, thereby greatly enhancing the efficiency of waste seperation. Liquisort has started to succesfully apply this new technique in a joint venture with two Dutch recyling firms. It is expected that the technology will be diffused widely in the coming years.
Waste seperation techniques are an important aspect of an effective recycling mechnanism. Given the high cost and difficulty of introducing extensive waste seperation at the side of the end user, cost-effective post-collection seperation techniques are essential in improving society's resource effiiency. Two of the most useful types of seperated products are non-ferrous metals on the one side, and plastics on the other side. Traditionally, a sink/float principle is used to separate metals with different densities. The disadvantage of this system is the fact that only two types of densities can be seperated in a single step. The new Liquisort innovation uses a new technology, Magnetic Density Seperation, that makes it possible to separate multiple types of metals with different densities in one single procedure. Instead of a medium with a single density, a magnetic liquid is used, which when placed in a specially developed magnetic field has different densities at different heights. The magnetic liquid consists of magnetic iron oxide particles with a size of 10-20nm, which are in suspension (in water). These magnetic particles attract the liquid into a magnetic field, exceeding the force of gravity, thereby causing the apparent density of the liquid to increase. This is how an apparent density of up to twenty times the density of water can be achieved in the liquid, allowing even for gold particles to float on the magnetic streams. It is also possible to achieve densities that are lower than the density of water (1). This innovative technique makes it possible to separate both metals and plastics in one single step, thereby increasing the efficiency of recycling significantly. Liquisort BV started to apply this new technique by creating joint-ventures with recyling companies that had a lot of expertise with the the day-to-day business of waste seperation. The Magnetic Density Seperation Process is now integrated into two large recyling plants in the Netherlands, processing between 8 and 18 tonnes of scrap metals per hour. The director of Liquisort expects that this technology will be diffused globally within the coming five years. In 2010, Liquisort won the Innovation award 2010 in the Recyling 2010 exhibition.
Barriers and Drivers
A main driver for seperation technology has been the recent surge in commodity prices, making elaborate seperation techniques much more cost-effective. The company has also benefitted from governmental support during the research and development phase of the product.
The launch of Liquisort technology has also met resistance due to several barriers. A main barrier still is the high cost of recycling techniques compared to primary extraction, mainly due to still very low carbon taxes or eco-innovation tax incentives. There were also technical barriers, since the system of magnets that was specially developed for this technology creates a magnetic field of constant strength in the horizontal plane. In the vertical plane, however, the magnetic field decreases exponentially in strength the further away it is from the magnetic surface. Because of this, not all current systems in the market can easily work together with this new method.
Since the technology has only just brought to the market, iti is currently hard to estimate what its eventual economic impact will be. GIven that it is widely recognized to be a superior system in waste seperation, it is expected to be diffused widely given that no new technical or market-related barriers arise. Should, as is widely expected, the cost of commodities, especially rare earth materials rise further in the coming decade, this technology should become even more interesting from an economic perspective.
An eleborate and feasible system of waste management and recycling is one of the main requirements for a sustainable economy in the future. Given that this technology could potentially deliver a big contribution to the efficiency of waste seperation, its environmental impact is also noteworthy. Again, since the technology just entered the market, it is hard to estimate what the exact impact will be. Most likely this will mean an incremental but nonetheless very useful step towards a 'cradle to cradle'economy.