[jrfrost]

Hello!

Imagine a bucket filled with small pieces (9mm-bullet size) of Aluminium, Brass and Copper. Now I would like to separate Al from Brass and Cu.
The simplest and most boring way. Go piece by piece and throw it in one bucket named Al and another one named Brass/Cu.
I don't like boring, I like fun!
My first thought was some cool liquid (throw everyting in it and Al will float). But it took me about 5 sec to run into the whole density-problem-s#*$. Al ~ 2.7 , Cu ~ 9 and Brass ~ 8.5. I can't find any liquid with density above 2.7 except mercury (13.5) and it's to high and far to dangerous to handle.

Is it even possible? Any ideas?

[Borek]

In any liquid with non-zero viscosity they will fall with different speeds.