mintreina - 16-12-2015 at 04:51
Is it possible to extract zinc from brass alloy by electrolysis. Would electrolysis of copper (ii) sulfate solution with brass rod anode and copper
cathode work? Or any other methods to get zinc from brass?
Jechowy - 17-12-2015 at 06:01
Usually reduction of copper on cathode is much easier than reduction of zinc, so probably You would get copper on cathode. You could obtain brass on
cathode, probably with different copper to zinc ratio if You would use some complexing agent (like cyanides in industry, sodium potassium tartrate,
ammonia).
I think best way to obtain zinc from brass is to dissolve everything in nitric acid, or not oxidising acid with addition of oxidizer (H2O2 or air
agitation). Then add a lot of NaOH to dissolve zinc and precipitate Cu(OH)2, filtrate - it will be quite difficult, hence Cu(OH)2 is a gel like
precipitate. And finally electrolysis with steel anodes.
It will be much easier to obtain zinc from Zamak alloy. It is very popular alloy.
In this case You would need only sulphuric acid and lead anodes. Just dissolve piece of ZAMAK in sulphuric acid solution to make electrolyte and then
do electrolysis. Let the rest of alloy in electrolyte, but dont connect it to electrodes - it will dissolve while zinc is plated an cathode.
easier way is to buy zinc sulphate and do electrolysis with lead anodes - it is called electrowinning and it is used in zinc mining.
sorry for my english, I am not native
m1tanker78 - 17-12-2015 at 06:13
It should be possible to carry out electrolysis like you described although a copper sulfate solution would be counter-productive. Instead, begin with
dilute hydrochloric / sulfuric acid. Copper should be reduced at the cathode while zinc oxidizes and enters solution. If you employ a split cell, you
should be able to avoid some of the inevitable contamination of copper in your zinc solution.
I bet there's more to your brass stock than just copper and zinc but that's another ball game.