Separating raw materials

Separation is where the money is

After reduction, copper is still mixed with plastics, steel with wood and aluminium with film. The purer you pull those streams apart, the higher the price per tonne. That is usually where an installation pays for itself, not at the shredder.

The techniques, in order

An overband magnet takes the iron out and is almost always the first step, because iron does damage further down the line. An eddy current separator then throws off the non-ferrous fraction, so aluminium and copper. Screen decks sort by particle size and are cheap to maintain. An air classifier separates by weight and lifts film and dust out of a heavy fraction.

Which combination you need follows from your material and from the purity your customer demands. For cable recycling the eddy current separator is the heart of the line; for wood recycling it is the screen deck with a magnet in front of it.

The order matters more than the machines

We see a line with the right machines in the wrong order more often than a line with the wrong machines. Screening before you magnetise means sending iron across your screen deck. Air classifying before you dry means damp film keeps sticking. Those choices are expensive to correct later, so we would rather draw the line properly once.

What better separation returns

Work it out on your own figures. One per cent less good material in the residue is immediately visible at a few thousand tonnes a year, and a finer screen deck is usually cheaper than a bigger shredder.