Comment from a German specialist in a thread about this from 2017:
Die nicht recykelbaren Reste wie Lebensmittelreste, Farbauftrag oder irgendwelche Etiketten verbrennen in der Schmelze und treiben oben auf dem flüssigen Metall als Schlacke, die einfach abgeschöpft und entsorgt werden kann.
Translation:
The non-recyclable residues, such as food scraps, paint coatings or labels burn off in the melt and float to the top of the molten metal as slags, which can simply be skimmed off and disposed of.
Comment from a German specialist in a thread about this from 2017:
Translation:
I was a process engineer in an aluminum plant. While I didn’t directly work in remelt, this is correct as I understand it.
20:1 is the net energy usage for new aluminum smelting:recycling.
Recycle your metals please.
https://m.youtube.com/shorts/f5-Ljn7GX_8
This short explains the German mindset about recycling. The only difference is that in Germany, the letter would be laminated.
Yeah, contaminants aren’t a big deal with metal recycling.
I’m not saying we shouldn’t recycle, we of course should. But most local recycling plants don’t have that capability.
And the biggest problem are plastics - glass and metal materials are much more forgiving.