Dave wrote:
>
>
> Since the blue crystals are mostly Copper Sulfate, another option
> might be to electroplate out the Copper. Of course, something
> will have to be dissolved into the solution to bind to the sulfate
> ions, but that can be a metal which isn't as toxic as Copper (Iron?).
>
> I'll leave further discussion of this up to the chemists.
>
> For additional speculation, would it be possible to electroplate
> out the Copper from used Ferric Chloride solution (e.g., Copper
> Chloride), and replace it with Iron, thus possibly regenerating the
> Ferric Chloride?
>
> Dave
I think people have tried this . I don't think its that easy. Plating
copper out is one thing, but converting the solution back to its
original state is another, Somehow Fe(+2) must go back to Fe(+3).
Often these reclaiming processes are only worthwhile on large scale.
As for sulfate based etchant (ammonium persulfate, sodium persulfate,
peroxide-sulfuric), yes, possible. For copper refining they use lead
sheet for anode material (positive, where oxygen gas evolves) and copper
sheet for cathode (negative, where copper metal deposits).
Again not worth the effort for a few liters of solution.
There is one chemistry that is cable of recycling and etching
simultaneous, see
http://www.elo-chem.com/index.php?subid=2It is alkaline ammonium copper sulfate. Needs heating, and smells.