Could you design a machine to detect the metal with high enough confidence you could "filter" the contamination out?<p>If this was separation of precious metal from gangue you'd use flocculation or flotation after grinding.
I have so many questions<p>Why?<p>How did the metal get there?<p>Is metal a common contaminant in these sorts of things?<p>Why (I’m not complaining) is this on HN?