Oscilllator
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separation of nickel nitrate and copper nitrate
I want to get some nickel nitrate for the production of nickel hydrazine nitrate, and I figured the best way to get this would be to react nickel
metal with nitric acid.
Nickel metal is available where I live in the form of silver coins. The problem is that the coins are 75%copper and 25% nickel.
If I react nitric acid with the coins, then all i would need to do is to separate the nickel nitrate from the copper nitrate. Therein lies the
problem.
I thought I could isolate the two by evaporating the solution and then heating the copper nitrate until it decomposes. I could then dissolve the
nickel nitrate in water and filter off the copper oxide, to yield a nickel nitrate solution.
The problem is that nickel nitrate boils at 137 degrees, and is carcinogenic to boot.
Is there any other way to separate a solution of the two mixtures, or is the described way my best shot?
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Hexavalent
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Looking at the solubilities in water, I don't think you'll get too good of a separation, however look around for solubility data for other solvents -
its unlikely you'll find a common one that's suitable, but you never know.
Personally, if I needed nickel (II) nitrate I'd either buy it or some precursors from eBay -
http://www.ebay.co.uk/itm/Nickel-Chloride-400-grams-in-HDPE-...
You could take this, add a stoichiometric amount of sodium carbonate to precipitate nickel carbonate and then dissolve this in nitric acid to yield
the nitrate salt. Yes, it takes longer, but is easier and safer both to prepare and purify.
Also, are you sure it isn't illegal to dissolve coins/currency where you live?
"Success is going from failure to failure without loss of enthusiasm." Winston Churchill
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tetrahedron
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the separation of Cu and Ni has been discussed a lot on this forum. you can try precipitating the Cu from a solution of the mixed salts using
electrodeposited Cu/Ni powder in excess of the 3:1 stoichiometric ratio.
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Vargouille
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Nickel will react with hydrochloric acid, due to an E0 of -0.28 V, while copper does not, due to a higher E0 of 0.34. If the coin is a layer of nickel deposited on copper, then
it'll react fairly well.
[Edited on 22-10-2012 by Vargouille]
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phlogiston
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| Quote: | | Nickel metal is available where I live in the form of silver coins |
. The problem is that the coins are
75%copper and 25% nickel.
Why are these called silver coins then?
You could also extract a little Ni from discarded NiCd or NiMH batteries, but you would have to be careful given the toxicity and potential for
energetic reactions.
-----
"If a rocket goes up, who cares where it comes down, that's not my concern said Wernher von Braun" - Tom Lehrer |
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AJKOER
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Here is an extract from an old recipe from "Hand-book of chemistry", Volume 5, page 357 by Leopold Gmelin that mentions some of the steps noted above
to separate out Nickel:
"5. Proust heats roasted copper-nickel with dilute sulphuric acid, and adds carbonate of potash to the filtered solution, to precipitate arseniate of
ferric oxide, till iron can no longer be detected in the liquid by ferrocyanide of potassium. The liquid is then filtered again, and sulphuretted
hydrogen passed through it, to precipitate arsenic, copper, and bismuth, till it is so far saturated as to retain the odour of the gas after being
kept for 24 hours in a closed vessel. The liquid, once more filtered and then evaporated, yields crystals chiefly consisting of sulphate of
nickel-oxide and potash, while the cobalt-salt, for the most part, remains in solution; the former is repeatedly dissolved and recrystallized to free
it from adhering cobalt-salt, and its solution afterwards treated with carbonate of potash, which precipitates the nickel in the form of carbonate."
Also, per page 355:
"The copper-nickel or the cobalt-speiss is generally roasted in a state of powder (at a gentle heat at first, to prevent it from baking together),
whereby the greater part of the arsenic is removed, the nickel oxidated, and a saving of nitric acid thus effected. Since, however, the roasting
process leaves a portion of the arsenic combined in the form of arsenic acid with the oxide of nickel, the roasted ore must be several times
intimately mixed with charcoal dust and again roasted, as long as vapours of arsenic continue to be evolved. Erdmann moistens the roasted cobalt
speiss with water and places it in a cellar till it is converted into hydrate; it is thereby rendered more easily soluble.
1. Laugier dissolves the roasted copper-nickel or the speiss in nitric acid, passes sulphuretted hydrogen through the dilute acid solution till all
the arsenic, copper, bismuth, and antimony are precipitated—then falters
—precipitates all the iron, cobalt, and nickel with carbonate of soda— washes the precipitate thoroughly, and treats it first with oxalic acid and
then with ammonia, as described on page 319, repeating the solution of the nickel-oxalate in aqueous ammonia, till the liquid which stands above the
resulting precipitate no longer exhibits a rose-colour, and is almost wholly free from cobalt."
Link: http://books.google.com/books?pg=PA357&lpg=PA32&dq=h...
So the short recipe is dissolve the Ni/Cu in HNO3 then treat a dilute acid solution with H2S (or add Aluminum sulfide) precipitating out the CuS (and
Al(OH)3). After filtering, treat the solution with NaHCO3 to isolate Nickel carbonate. Wash and redissolve in HNO3.
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Oscilllator
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Quote: Originally posted by AJKOER  | Here is an extract from an old recipe from "Hand-book of chemistry", Volume 5, page 357 by Leopold Gmelin that mentions some of the steps noted above
to separate out Nickel:
"5. Proust heats roasted copper-nickel with dilute sulphuric acid, and adds carbonate of potash to the filtered solution, to precipitate arseniate of
ferric oxide, till iron can no longer be detected in the liquid by ferrocyanide of potassium. The liquid is then filtered again, and sulphuretted
hydrogen passed through it, to precipitate arsenic, copper, and bismuth, till it is so far saturated as to retain the odour of the gas after being
kept for 24 hours in a closed vessel. The liquid, once more filtered and then evaporated, yields crystals chiefly consisting of sulphate of
nickel-oxide and potash, while the cobalt-salt, for the most part, remains in solution; the former is repeatedly dissolved and recrystallized to free
it from adhering cobalt-salt, and its solution afterwards treated with carbonate of potash, which precipitates the nickel in the form of carbonate."
Also, per page 355:
"The copper-nickel or the cobalt-speiss is generally roasted in a state of powder (at a gentle heat at first, to prevent it from baking together),
whereby the greater part of the arsenic is removed, the nickel oxidated, and a saving of nitric acid thus effected. Since, however, the roasting
process leaves a portion of the arsenic combined in the form of arsenic acid with the oxide of nickel, the roasted ore must be several times
intimately mixed with charcoal dust and again roasted, as long as vapours of arsenic continue to be evolved. Erdmann moistens the roasted cobalt
speiss with water and places it in a cellar till it is converted into hydrate; it is thereby rendered more easily soluble.
1. Laugier dissolves the roasted copper-nickel or the speiss in nitric acid, passes sulphuretted hydrogen through the dilute acid solution till all
the arsenic, copper, bismuth, and antimony are precipitated—then falters
—precipitates all the iron, cobalt, and nickel with carbonate of soda— washes the precipitate thoroughly, and treats it first with oxalic acid and
then with ammonia, as described on page 319, repeating the solution of the nickel-oxalate in aqueous ammonia, till the liquid which stands above the
resulting precipitate no longer exhibits a rose-colour, and is almost wholly free from cobalt."
Link: http://books.google.com/books?pg=PA357&lpg=PA32&dq=h...
So the short recipe is dissolve the Ni/Cu in HNO3 then treat a dilute acid solution with H2S (or add Aluminum sulfide) precipitating out the CuS (and
Al(OH)3). After filtering, treat the solution with NaHCO3 to isolate Nickel carbonate. Wash and redissolve in HNO3.
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Sounds good. I can make aluminium sulfide by reaction of aluminium powder ad sulfur right? I have both.
also @Vargouille, that actually might be a better method, since it requires fewer steps. However my coins are an alloy of copper and nickel, not
nickel plated copper. I'll give it a shot anyway, ad post the results 
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tetrahedron
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| Quote: Originally posted by Oscilllator | | @Vargouille, that actually might be a better method, since it requires fewer steps. However my coins are an alloy of copper and nickel, not nickel
plated copper. I'll give it a shot anyway, ad post the results
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that method is not hasslefree if your source is an alloy: the Cu will protect the Ni. Moreover, the potentials are so close that if you try
electrolysis (the Cu should plate out preferentially) you'll get quite an impure product at any reasonable current.
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m1tanker78
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| Quote: Originally posted by tetrahedron |
[...] the potentials are so close that if you try electrolysis (the Cu should plate out preferentially) you'll get quite an impure product at any
reasonable current. |
I would disagree. Here I demonstrated otherwise. The problem is having to tack the coins together to form an anode of sufficient surface area to be practical. Both
products (nickel and copper powders) were very clean and free of the opposite metal if caution was taken. Copper plates out as sponge. Nickel must be
displaced from solution by aluminum or other more reactive metal.
Tank
Chemical CURIOSITY KILLED THE CATalyst.
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AJKOER
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Oscillator:
Please research the Al/S reaction, a well known flash powder/thermite reaction for tips on what not to do. Here is a text from Wikipedia:
"Aluminium sulfide is readily prepared by ignition of the elements
2 Al + 3 S → Al2S3
This reaction is extremely exothermic and it is not necessary or desirable to heat the whole mass of the sulfur-aluminium mixture; (except possibly
for very small amounts of reactants). The product will be created in a fused form; it reaches a temperature greater than 1100 °C and may melt its way
through steel. The cooled product is very hard."
Also, I would use an excess of Al well mixed with the Sulfur to reduce the formation of Aluminum polysulfide.
Be prepared to store the product in a sealed vessel or use the product quickly as it reacts with moisture to release H2S. Generally speaking, work
with Hydrogen sulfide in an open area (away from neighbors) as H2S is also quite toxic and an insidious poison (will deaden ones sense of smell
enabling a lethal exposure which is not immediate evident - a walking dead in effect).
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tetrahedron
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| Quote: Originally posted by m1tanker78 | | Quote: Originally posted by tetrahedron |
[...] the potentials are so close that if you try electrolysis (the Cu should plate out preferentially) you'll get quite an impure product at any
reasonable current. |
I would disagree. Here I demonstrated otherwise. The problem is having to tack the coins together to form an anode of sufficient surface area to be practical. Both
products (nickel and copper powders) were very clean and free of the opposite metal if caution was taken. Copper plates out as sponge. Nickel must be
displaced from solution by aluminum or other more reactive metal. |
congratulations. i obviously wasn't updated on that thread. i tried the same procedure myself a while ago, but didn't quite manage to remove all the
Cu2+. i'll reply in that thread with the details.
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Random
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| Quote: Originally posted by Oscilllator | | Quote: Originally posted by AJKOER | Here is an extract from an old recipe from "Hand-book of chemistry", Volume 5, page 357 by Leopold Gmelin that mentions some of the steps noted above
to separate out Nickel:
"5. Proust heats roasted copper-nickel with dilute sulphuric acid, and adds carbonate of potash to the filtered solution, to precipitate arseniate of
ferric oxide, till iron can no longer be detected in the liquid by ferrocyanide of potassium. The liquid is then filtered again, and sulphuretted
hydrogen passed through it, to precipitate arsenic, copper, and bismuth, till it is so far saturated as to retain the odour of the gas after being
kept for 24 hours in a closed vessel. The liquid, once more filtered and then evaporated, yields crystals chiefly consisting of sulphate of
nickel-oxide and potash, while the cobalt-salt, for the most part, remains in solution; the former is repeatedly dissolved and recrystallized to free
it from adhering cobalt-salt, and its solution afterwards treated with carbonate of potash, which precipitates the nickel in the form of carbonate."
Also, per page 355:
"The copper-nickel or the cobalt-speiss is generally roasted in a state of powder (at a gentle heat at first, to prevent it from baking together),
whereby the greater part of the arsenic is removed, the nickel oxidated, and a saving of nitric acid thus effected. Since, however, the roasting
process leaves a portion of the arsenic combined in the form of arsenic acid with the oxide of nickel, the roasted ore must be several times
intimately mixed with charcoal dust and again roasted, as long as vapours of arsenic continue to be evolved. Erdmann moistens the roasted cobalt
speiss with water and places it in a cellar till it is converted into hydrate; it is thereby rendered more easily soluble.
1. Laugier dissolves the roasted copper-nickel or the speiss in nitric acid, passes sulphuretted hydrogen through the dilute acid solution till all
the arsenic, copper, bismuth, and antimony are precipitated—then falters
—precipitates all the iron, cobalt, and nickel with carbonate of soda— washes the precipitate thoroughly, and treats it first with oxalic acid and
then with ammonia, as described on page 319, repeating the solution of the nickel-oxalate in aqueous ammonia, till the liquid which stands above the
resulting precipitate no longer exhibits a rose-colour, and is almost wholly free from cobalt."
Link: http://books.google.com/books?pg=PA357&lpg=PA32&dq=h...
So the short recipe is dissolve the Ni/Cu in HNO3 then treat a dilute acid solution with H2S (or add Aluminum sulfide) precipitating out the CuS (and
Al(OH)3). After filtering, treat the solution with NaHCO3 to isolate Nickel carbonate. Wash and redissolve in HNO3.
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Sounds good. I can make aluminium sulfide by reaction of aluminium powder ad sulfur right? I have both.
also @Vargouille, that actually might be a better method, since it requires fewer steps. However my coins are an alloy of copper and nickel, not
nickel plated copper. I'll give it a shot anyway, ad post the results
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a member here almost died from h2s, had to inject himself with nitrites
i wouldnt mess with h2s
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Oscilllator
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Alright, I tried to dissolve a couple 5-cent coins in HCl, and over a period of 6 hours or so, the solution turned light green. however, the solution
remained highly acidic, indicative of a passivating layer 
Instead of going through the process of making nitric acid, could I instead mix concentrated sulfuric acid and potassium nitrate, and then add the
coins? I know this has the same effect as nitric acid when nitrating cellulose, and so it might work here.
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Vargouille
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It will, but then you'll have competing solubility equilibria between the nitrates and the sulphates.
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bbartlog
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| Quote: Originally posted by Oscilllator | Alright, I tried to dissolve a couple 5-cent coins in HCl, and over a period of 6 hours or so, the solution turned light green. however, the solution
remained highly acidic, indicative of a passivating layer
Instead of going through the process of making nitric acid, could I instead mix concentrated sulfuric acid and potassium nitrate, and then add the
coins? I know this has the same effect as nitric acid when nitrating cellulose, and so it might work here. |
The problem is not a passivating layer; HCl takes that right off (in the case of Cu/Ni, anyway). The problem is that HCl is not an oxidizing acid.
Something else, whether air or H2O2 or whatever, has to oxidize the copper or nickel before the HCl will react with it.
I expect that your KNO3/H2SO4 bath would dissolve the coins, but think ahead - you'll have a fairly messy solution at that point,
copper/nickel/potassium sulfate/nitrate(..sulfite/nitrite?), maybe with a bit of NO2 contamination. Depending on what you're trying to do, the workup
may be difficult. You could add some hydrogen peroxide to your HCl instead to allow it to attack the metal; seems like a cleaner solution.
The less you bet, the more you lose when you win.
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Oscilllator
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| Quote: Originally posted by bbartlog | | Quote: Originally posted by Oscilllator | Alright, I tried to dissolve a couple 5-cent coins in HCl, and over a period of 6 hours or so, the solution turned light green. however, the solution
remained highly acidic, indicative of a passivating layer
Instead of going through the process of making nitric acid, could I instead mix concentrated sulfuric acid and potassium nitrate, and then add the
coins? I know this has the same effect as nitric acid when nitrating cellulose, and so it might work here. |
The problem is not a passivating layer; HCl takes that right off (in the case of Cu/Ni, anyway). The problem is that HCl is not an oxidizing acid.
Something else, whether air or H2O2 or whatever, has to oxidize the copper or nickel before the HCl will react with it.
I expect that your KNO3/H2SO4 bath would dissolve the coins, but think ahead - you'll have a fairly messy solution at that point,
copper/nickel/potassium sulfate/nitrate(..sulfite/nitrite?), maybe with a bit of NO2 contamination. Depending on what you're trying to do, the workup
may be difficult. You could add some hydrogen peroxide to your HCl instead to allow it to attack the metal; seems like a cleaner solution.
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I'm afraid I dont have any hydrogen peroxide 
I did find an old thread that precipitated the copper chloride using sulfur dioxide. Might try that when I can
Here is the thread:http://www.sciencemadness.org/talk/viewthread.php?tid=8269
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MikeSomething
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I've been trying to do a similar thing: separating US nickel coins, which are 75% Cu/25% Ni. My first attempt was to put an excess of coins in 70%
(15.8M) HNO3, hoping that the slightly more electropositive nickel (1.91) would force the copper (1.90) out of solution. It seemed to work, and I left
the covered solution sitting for a few weeks. It wasn't a priority, so I would check on it periodically. It seemed to grow increasingly green, and
there was a fine, dark precipitate at the bottom of the beaker. I assumed that was copper.
I finally got around to playing with it last night. It's since been decanted, filtered, evaporated, filtered some more, diluted (with diH20),
filtered, and evaporated. With very slow heating, I ended up with about 0mL of very thick syrup that would fluctuate from crystallized at 65°F to
thick liquid at 75°F.
This afternoon, I began to warm the liquid again, intending to heat it for 20-30 seconds to drive off a bit of moisture and then desiccate it.
Naturally, the wife calls with a computer problem. 50mL of thick nitrate solution in the bottom of a 1000 mL beaker was placed in a heavy aluminum pot
I use as a mantle/heat distributor. 20 or 30 minutes (and a few OhShit!OhShit!OhShit!s) later I now have a hard black oxide on the bottom of the
beaker. I have no idea how much is nickel oxide vs copper oxide. Nickel nitrate decomposes at about 200°C; copper nitrate decomposes at 256°C. I'm
quite sure I exceeded both of those.
But there's good news! In looking for potential separating solvents, I found that nickel oxide is soluble in ammonium hydroxide, but copper oxide is
not. I have some 28% ammonium hydroxide, so that's the next step. If it works, this might be the definitive way to separate US nickel coins....for
about $1 a piece. 
Part 2: If this combined nitrates were heated to about 210°C, in theory, only the nickel nitrate would decompose, making it insoluble in water. The
cooled mixture could then be diluted, filtered, and washed.
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bfesser
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Column chromatography using a cation exchange resin. You should even be able to visualize two green/blue bands separating on the column during
elution.
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DraconicAcid
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Add iodide- the copper will precipitate as CuI (I2 will also be produced), and nickel will remain in solution.
Please remember: "Filtrate" is not a verb.
Write up your lab reports the way your instructor wants them, not the way your ex-instructor wants them.
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Oscilllator
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Thanks for the advice, although since then I have bought some nickel electrodes (as a source of pure nickel),made some nitric acid and am now the
proud owner of ~50g of emerald green nickel nitrate .
However when reacting the nitric acid with the nickel nitrate, I noticed a passivating layer formed which prevented all of the nitric acid reacting
with the nickel. As a result my nickel nitrate smells like nitric acid and is therefore presumably highly acidic. Is there any way I can remove such a
passivating layer in the future and/or remove the nitric acid from my nickel nitrate?
I should be able to remove the nitric acid from my existing nickel nitrate by dissolving it in a fairly large amound of water and boiling it down. The
nitric acid should boil out before the water does, leaving me with plain nickel nitrate.
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