RogueRose
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Seperating Cu & Ni salts - chlorides & sulfates (& possibly nitrates)
So I wanted to isolate some Ni to do some electroplating and to have some pure nickel but the only source I had was an alloy of Ni/Cu, so I dissolved
some of it in HCl and some in H2SO4 and now have a mix of the metal salts.
I've looked at the different solvents that can be used and when it comes to the sulfates, Cu doesn’t' dissolve in any form (anhydrous to hydrates)
in ethanol, but the Ni sulfate heptahydrate does dissolve in ethanol (how much , IDK) but there is no listing of how much of the salt dissolves in any
alcohol or water, so it's tough to see what method is best.
Another idea would be to use electrolysis to pull the nickel or copper out of the solution and deposit on an anode but IDK if that can be done with
the 2 salts present.
Now for the chlorides, it says that the Nickel chloride is soluble in ethanol (methanol not mentioned...) but CuCl isn't soluble at all but I'm always
confused as to what copper chloride is present, CuCl or CuCl2 (as CuCl2 IS very soluble in ethanol, so if CuCl2 is present then this method won't
work).
Now I don't have any HNO3 (yet) but the salts Cu(NO3)2 is not soluble in ethyl acetate while nickel nitrate may be (not listed). So I've thought this
may be a method to separate down the road if I can find a good source of ethyl acetate (why so darn hard to find!!!)
What would be a good method for separating these salts or even plating out the specific metals independently?
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Akhil jain
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Actually this method is very expensive since it requires a large amount if hydrogen sulphide
The method is :
Take the solution to it add dil HCl . Now bubble H2S gas until you stop getting a precipitate.
What will happen here all the Cu++ ions would precipitate as CuS while nickel won't be precipitated as NiS due to common ion effect.
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JJay
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CuCl2 is soluble in acetone. I don't know if NiCl2 is soluble in acetone, but I can't find any data indicating that it is.
Electrolysis is probably an effective method to separate them, although there might be issues with precipitation of CuCl.
Lead, hydrogen, and stannous chloride can be oxidized by CuCl2 but not by NiCl2.
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crystal grower
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Not sure how well this would work but maybe it will be useful:
Add more Ni/Cu alloy to the chloride solution and copper should drop out (due to different electropotential) while more nickel is being oxidised .
That should leave you with relatively pure nickel chloride solution.
[Edited on 31-3-2018 by crystal grower]
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CobaltChloride
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http://www.sciencemadness.org/talk/viewthread.php?tid=81185 I suggest looking at this thread I began. There are some good separating methods
presented here by other sciencemadness members.
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LearnedAmateur
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Crystal grower is onto something here, since nickel is more reactive it will displace copper ions from solution. If you know the specific percentages
in the alloy, you’ll be able to calculate how much alloy-acid ratio you’ll need and then subsequent recrystallisations should eliminate the
impurities.
In chemistry, sometimes the solution is the problem.
It’s been a while, but I’m not dead! Updated 7/1/2020. Shout out to Aga, we got along well.
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ninhydric1
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Quote: Originally posted by LearnedAmateur  | | Crystal grower is onto something here, since nickel is more reactive it will displace copper ions from solution. If you know the specific percentages
in the alloy, you’ll be able to calculate how much alloy-acid ratio you’ll need and then subsequent recrystallisations should eliminate the
impurities. |
This is almost exactly what I did when I was using electrolysis to separate nickel and copper from US nickels. By allowing some of the coins to sit in
the copper/nickel aqueous solution after the initial electrolysis for a few days, most of the copper plated out of solution (which could be scraped
off the coins), leaving a relatively clean, aqueous nickel solution. I used acetic acid + sodium acetate as the electrolyte but a stronger acid may
work better.
The philosophy of one century is the common sense of the next.
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RogueRose
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I'll look into adding Ni/Cu and seeing if the Cu drops out. I'm not sure what the concentration currently is of the solution so I'll have to measure
out a volume, evaporate it and weigh the contents, which should give me the total amount dissolved in the solution (by multiplying by total volume).
I know the metal was 60/40 Cu/Ni so the dried salts should be the same ratio as long as they are not hydrates (dried to anhydrous)
So will this only work with the solution I made with HCl and not the sulfate?
I'm still curious as to how soluble the NiCl2 is in ethanol. I hate when wiki just states it is "soluble" that could mean .5g/L or 100g/L.
Is there a reference book that shows characteristics like this in more detail than Wiki? I would think that there has to be more data than what is
available on wiki, like books available at university labs and chemical companies.
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RogueRose
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So I measured out 40ml of solution (48g) and put it in a petri dish to evap in an oven at 320F. I ended up with ~8g of brown solids. None of the
chlorides decompose anywhere near that temp so I'm sure I have the two chlorides together.
Now what I always get confused with about CuCl and CuCl2 is how to determine which will form in a solution of HCl. Both wiki's are a little confusing
when it comes to the preperation of these compounds but it says that CuCl is made by reducing CuCl2 in some manner. Now I made this solution with HCl
and H2O2 so I am guessing I have a mix of NiCl2 and CuCl2?
So if I have a 60/40 then I have a 4.8g/3.2g Cu/Ni (but some of that weight is the Cl2). Now I would need to add the alloy and the copper should
plate out and dissolve the nickel into it?
I also have a good bit of pure CuCl2 that I made before. Would it be easier to isolate pure nickel using this?
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Foeskes
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Copper sulfate decomposes to CuO and SO3 over 100 degrees below nickel sulfate if you use a kiln and a gas scrubber in theory you can do it.
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ninhydric1
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| Quote: Originally posted by RogueRose | So I measured out 40ml of solution (48g) and put it in a petri dish to evap in an oven at 320F. I ended up with ~8g of brown solids. None of the
chlorides decompose anywhere near that temp so I'm sure I have the two chlorides together.
Now what I always get confused with about CuCl and CuCl2 is how to determine which will form in a solution of HCl. Both wiki's are a little confusing
when it comes to the preperation of these compounds but it says that CuCl is made by reducing CuCl2 in some manner. Now I made this solution with HCl
and H2O2 so I am guessing I have a mix of NiCl2 and CuCl2?
So if I have a 60/40 then I have a 4.8g/3.2g Cu/Ni (but some of that weight is the Cl2). Now I would need to add the alloy and the copper should
plate out and dissolve the nickel into it?
I also have a good bit of pure CuCl2 that I made before. Would it be easier to isolate pure nickel using this? |
Because the outer layer of US nickels has a higher percentage of Ni, the plating out of copper is much faster. It might be even faster to you are able
to powderize the alloy, giving the nickel greater surface area.
The philosophy of one century is the common sense of the next.
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fusso
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| Quote: Originally posted by ninhydric1 | | Quote: Originally posted by RogueRose | So I measured out 40ml of solution (48g) and put it in a petri dish to evap in an oven at 320F. I ended up with ~8g of brown solids. None of the
chlorides decompose anywhere near that temp so I'm sure I have the two chlorides together.
Now what I always get confused with about CuCl and CuCl2 is how to determine which will form in a solution of HCl. Both wiki's are a little confusing
when it comes to the preperation of these compounds but it says that CuCl is made by reducing CuCl2 in some manner. Now I made this solution with HCl
and H2O2 so I am guessing I have a mix of NiCl2 and CuCl2?
So if I have a 60/40 then I have a 4.8g/3.2g Cu/Ni (but some of that weight is the Cl2). Now I would need to add the alloy and the copper should
plate out and dissolve the nickel into it?
I also have a good bit of pure CuCl2 that I made before. Would it be easier to isolate pure nickel using this? |
Because the outer layer of US nickels has a higher percentage of Ni, the plating out of copper is much faster. It might be even faster to you are able
to powderize the alloy, giving the nickel greater surface area. |
Isn't US nickels made of 25% Ni 75% Cu with uniform concentrations throughout the coin??
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