Zinc in copper anode

[Ayham Hafez]

I was trying to melt gold plated connectors into anodes to process them in copper refining cell, while melting I noticed that a lot of zinc been oxidized and make a lot of smoke so I wait some time then pour the anode, I got yellowish anode with lot of zinc oxide powder that not melted because zinc oxide melting point is above 1900 c, even using some soda ash and borax but they are not appeared after pouring because of zinc oxide powder.

I don't have xrf analysis access but I think zinc content in the anode will be about 10 to 15 percent supposing I started with 30% zinc material in the connectors.

I read some articles about zinc impurity in copper refining cell, what I understand is using voltage less than 0.76 v will not make zinc plate on cathode but zinc will be dissolved in the electrolyte like iron.

Anyone has experience what exactly will happen with processing high zinc content in copper anode? Will it damage the electrolyte? In general how we can get rid of zinc from brass thermally without getting a lot of smoke, any special fluxes used?

 

[Shark]

Zinc in the electrolyte will make it have a white cloudy look. You will also see some slowing in deposition of your copper. Removing the zinc before pouring is the best way to deal with it. As for fluxing, I can't be much help there. There are ways to clean your electrolyte at times a filter bag will do a pretty good job.

 

[Martijn]

if you put a condensor ring on your furnace fume outlet, you can capture all the zinc, leaving copper in stead of brass.
zinc evaporates as a gas above 900 or 1000 degrees C, not sure exactly, but here is a video explaining the process:
https://www.google.nl/url?sa=t&rct=...usg=AOvVaw3l8iod8zFTcMDKPXvlYz8m&opi=89978449

that makes smelting brass a concern if you don't capture the zinc. Pollution of the air, fume fever...

 

[Ayham Hafez]

Zinc in the electrolyte will make it have a white cloudy look. You will also see some slowing in deposition of your copper. Removing the zinc before pouring is the best way to deal with it. As for fluxing, I can't be much help there. There are ways to clean your electrolyte at times a filter bag will do a pretty good job.

Am using filter anode bags + filter bag on suction tube attached to out chemical filter which also make filtration, am not worry about solution clouds because of my several filtration steps, but what does zinc do in the electrolyte? Will it just slow copper deposition?

Another thing I thought about is to rise the voltage upper than zinc plating voltage so I got zinc plated with copper on the cathode, since connectors has no silver so no silver will be dissolved in the electrolyte, what do you think?

 

[Martijn]

sorry wrong video, this one i meant:

 

[Ayham Hafez]

if you put a condensor ring on your furnace fume outlet, you can capture all the zinc, leaving copper in stead of brass.
zinc evaporates as a gas above 900 or 1000 degrees C, not sure exactly, but here is a video explaining the process:
https://www.google.nl/url?sa=t&rct=j&q=&esrc=s&source=video&cd=&cad=rja&uact=8&ved=2ahUKEwjKirHDi7SKAxXX_rsIHXUcNcs4ChC3AnoECAkQAg&url=https://www.youtube.com/watch?v=d9N7VDMOw5o&usg=AOvVaw3l8iod8zFTcMDKPXvlYz8m&opi=89978449

that makes smelting brass a concern if you don't capture the zinc. Pollution of the air, fume fever...

That's really amazing method, for future brass material will try to build a simple condenser, but for now I have 7 anodes about 75kg and remelting them will take time and effort so trying to find a way to refine them as they are with minimum lost

 

[Martijn]

That's really amazing method, for future brass material will try to build a simple condenser, but for now I have 7 anodes about 75kg and remelting them will take time and effort so trying to find a way to refine them as they are with minimum lost

If you can get the zinc out, it will have a huge positive effect on your electrolyte's longevity and quality of deposited copper.

 

[Shark]

If your filters are working the zinc shouldn't affect deposition of the copper. Smelting it out would be the fastest improvement. Filtering is good, but does have limits such changing out the filters, and less life span of the electrolyte.