In 2018, the European Union recorded 61.8 million metric tons of plastic refuse to have been produced with only 9.4 million metric tons was recycled. This accounts for a huge amount of plastic waste that requires attention. Magnetic density separation is one technique for separating plastic materials using magnetic fields. The technique, however, is not very effective.
An initiative for this involved study of flow of plastic particle mixes in wind tunnels to assess the effect of tumult on the separation method.
In fact, plastic is a versatile material that is used for a wide spectrum of applications in the society. Plastic is used in food packaging to increase the shelf life and in a large number of health products such as the ones to manage spread of diseases such as COVID-19.
Nonetheless, several plastics are single use that have issues related to their recycling and separation from other wastes. This requires new techniques to improve the recycling of plastic waste.
Magnetic density separation is one such technique to address this. The technique uses a ferrofluid that produces a vertical mass density descent if a magnetic field exists. In other words, the apparent mass density of the fluid increases as the separation process moves from the top to the bottom of the fluid.
With the addition of plastic particles to the ferrofluid, the various particles move to a position where the evident mass density of the ferrofluid is about the same as that of plastic particles. Consequently, separated plastic can be reused for higher value products, and this significantly increases the economic viability of recycling.
The separation process occurs in the magnetic density separator wherein at the end the horizontal plates remove the particle mixtures at varying heights.