Copper Ingots sticking to Magnet.

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gaurav_347

Well-known member
Joined
Nov 17, 2013
Messages
169
All,

I have come across some copper ingots which are getting attracted to magnet. The copper ingots were made from copper fines and fractions. Is there any way to remove the ferrous metals while remelting the ingots by addition of fluxes? I have got these scraps for free. Apparently the smelter didn't remove the magnetics before smelting the copper fines.

Thanking you,
Gaurav
 
You can try to melt it with a flux containing an oxidizer which can react with the iron (and to a much smaller extent some copper) and put the iron into the flux as an oxide. (Potassium nitrate is an effective oxygen source) The trouble is it is in ingot form so the contact between the copper, iron, and flux is greatly limited to the surface area of the bars. And once it is molten it is the contact made at the surface of the melt where the flux contacts the top of the metal pool.

This may help, but as Goran suggested the best bet is oxygen sparging because that method allows contact with the O2 in the pool of molten metal, more contact = more reaction = less iron remaining in the metal.

Do you suspect there is some precious metal value, or are you doing this just to get the copper?
 
Thanks to both of you for your valued inputs. I am only doing this to get the copper. There are no precious metals involved.

Regards,
Gaurav
 
In order to remove the sulfide from silver sulfide contained in photo silver chip, I have always added a few lengths of rebar to the melt. Some of the iron combines with the sulfide and this iron sulfide goes into the slag, leaving a fairly pure molten silver. I'm wondering if the iron in the Cu bars would work similarly by adding some sodium sulfide to the melt? It may be necessary to analyze the iron content and add a stoichemetric amount of NaS. Another possibility would be to add a little excess of NaS and then use rebar to pick up the excess sulfide. I have no idea whether or not this would work.

Just a thought.
 
Interesting approach Chris, the copper will be molten before the sodium sulfide so it may give enough contact time with bars for the contained iron to react and form a salt with the sulfide.

But Oh My God, what a smell it would give off! Still with a good hood it is worth a try. If you were making a habit of this technique I would recommend a scrubber, before your neighbors do!
 
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