Three material streams for metals
After the blue PMD bag is collected from your home, it goes to one of the five brand-new sorting centres that have been built in Belgium specially for the blue bag. Most metal packaging is aluminium and steel, and the various types are separated from plastic packaging, drinks cartons and each other at the sorting centre. This is done at different points during the sorting process.
Trommels, also called drum sieves, remove smaller items. The sifted out material then goes through an eddy current separator, which removes small aluminium items. As the name suggests, this uses an eddy current: a magnetic rotor produces a rapidly changing magnetic field, pushing all the non-ferrous metals away from the rest. Crown caps, drink capsules, aluminium foil packaging (e.g. around chocolate) etc. is therefore removed from the rest of the PMD.
Packaging made of steel follows a different path: it contains iron so it is removed from the rest by means of a giant magnet. A range of metal containers that you might even use every day are made from steel: tins used for canning all kinds of foods and also the metal lids on glass jars.
Aluminium containers that are larger than small aluminium items (crown caps, drink capsules, etc.) are the last 'M' in PMD that still has to be removed from the rest at the sorting centre. These aluminium containers include drinks cans, spray cans (for whipped cream, deodorants, air fresheners, etc.), aluminium trays (for lasagne etc.), and so on. Like small aluminium items, these are removed from the rest using an eddy current separator.
