Hi!

I plan on some experiments with a modified method i saw here for PCB-plating with copper to make the holes conductive.
Now the question:
What if my metal is not 100% pure but has some impurities in it? Does it still only "transfer" the copper and leaves the impurities as slag behind?
I think it should be this way, since a similar approach gets used in refining metals to a very high purity; but i am unsure...

Lets say i do:
Follow the basic recipe (with smaller ammounts!) @ http://www.thinktink.com/stack/volumes/voliii/consumbl/cplatmix.htm and use copper sulfide.
I think the trick now is that only copper-ions get disolved in the copper sulfide and nothing else. Those ions become plated to the other pole and thus i get purest copper plated to it?