Sciencemadness Discussion Board - Separation of a US nickel

Separation of a US nickel

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I Like Dots - 18-10-2013 at 10:28

Well I dissolved a nickel in some vinegar/H2O2, then evaporated hoping to get pretty crystals. well I got some nice crystals but I noticed the crystals were either blue, or green. With 2 different shapes. Green were more "diamond" shaped, and the blue were ehhh "more dimensional". here are some pics.

I dont think they separated cleanly, but due to a slow evaporation they did separate to an extent.

bfesser - 18-10-2013 at 11:58

Try sorting them out as best you can with tweezers, then recrystallize each batch again with distilled water.

cyanureeves - 18-10-2013 at 15:22

is the ratio of blue to green crystals anywhere close to blue75% green 25%?

[Edited on 10-18-2013 by cyanureeves]

Random - 19-10-2013 at 01:39

I haven't read the whole thread but would reduction with Al of Ni and Cu chlorides work to precipitate metal powders, wash in NaOH to get rid of aluminum and then magnet to separate nickel?

m1tanker78 - 19-10-2013 at 16:26

Quote: Originally posted by Random

I haven't read the whole thread but would reduction with Al of Ni and Cu chlorides work to precipitate metal powders, wash in NaOH to get rid of aluminum and then magnet to separate nickel?

No. I personally tried this and gave up quickly. The metals are too interleaved to even mill and sort with a magnet.

I'm catching up on the latest posts since I last checked. Glad to see there still seems to be some interest on this topic.

Tank

bismuthate - 20-10-2013 at 08:11

Add a sodium thiosulfate solution to your Cu/Ni nitrate solution and heat gently. Copper sulfide should percipitate, filter and you are left with a solution of Nickel thiosulfate and sodium nitrate. Add NaOH to the soution and filter the nickel hydroxide. Add the nickel hydroxide to the acid of you choice and percipitate the nickle with aluminum.

WGTR - 20-10-2013 at 12:37

Quote: Originally posted by bismuthate

Add a sodium thiosulfate solution to your Cu/Ni nitrate solution and heat gently. Copper sulfide should percipitate, filter and you are left with a solution of Nickel thiosulfate and sodium nitrate. Add NaOH to the soution and filter the nickel hydroxide. Add the nickel hydroxide to the acid of you choice and percipitate the nickle with aluminum.

Here's a reference for you:

Analytical chemistry, Volume 1
Frederick Pearson Treadwell
Wiley, 1921

In the case of silver thiosulfate, it looks unstable unless it is quickly dissolved in excess thiosulfate, forming a soluble complex. Ag2S is precipitated on boiling in this case. CuS is precipitated upon boiling the acidified copper thiosulfate complex. I don't know the relative stability of a complex with nickel thiosulfate in the same environment. If the idea works, then it might be necessary to acidify the solution first, and then heat. Doing it the other way around might cause NiS to co-precipitate.

[Edited on 20-10-2013 by WGTR]

Zephyr - 3-11-2013 at 10:35

Quote: Originally posted by The_Davster

Drive to Canada. Go to a bank. Ask for a brick of nickels (100$ worth) Those from 1955 to 1981 are pure nickel metal.

Naturally, only f you are after the metal, and not just looking for some chemistry to do...

If you are searching for pure nickle, the Canadian quarter was pure nickle from 1999-1968.

cjevancich - 11-11-2013 at 06:24

I was actually performing this experiment over the summer, and thought I'd add a few ideas I tried:

The first was to dissolve the alloy in either nitric acid or a mixture of sulfuric or hydrochloric acid and an oxidizer. It doesn't really matter, because after this you mix the solution with sodium bicarbonate and filter it so that you can make a clean mixture of nickel and copper chloride using HCl. It is important to do this because if you just use hydrochloric acid and an oxidizer, you can't use a reduction agent reliably (oxidizer will tend to interfere).

Then after you have the clean mixture of chlorides, adding Ascorbic acid reduces the copper(II) chloride to insoluble copper(I) chloride. I didn't like this method very much though because unless you're in a vacuum or inert gas environment, it readily becomes copper(II) chloride from the atmosphere and from air entering the water you use.

Another solution I found interesting, but haven't perfected, is to use acetylsalicylic acid (Aspirin). Apparently aspirin will form copper aspirinate, but nickel will not. I discovered that adding sodium aspirinate (made by adding sodium carbonate or bicarbonate to aspirin in water) to a mixture of copper and nickel chlorides will precipitate the insoluble copper aspirinate. Adding ascorbic acid seems to precipitate any remaining aspirin from the solution, leaving you with what should be nickel chloride.

Edit: I also had the idea to try and make a saturated solution of either the chlorides or sulfates and try a recrystallization, since the copper chloride or sulfate would precipitate since it's the majority. I haven't tried it yet, but at the very least it should concentrate the nickel by removing the copper.

[Edited on 11-11-2013 by cjevancich]

m1tanker78 - 12-11-2013 at 18:45

@cjevancich:

Some more details (if available) would be nice.. Something that can be tested and maybe reproduced by others.

I believe all of your points have been raised or attempted further upthread.

Quote:

Edit: I also had the idea to try and make a saturated solution of either the chlorides or sulfates and try a recrystallization, since the copper chloride or sulfate would precipitate since it's the majority. I haven't tried it yet, but at the very least it should concentrate the nickel by removing the copper.

This I know has been done, albeit unintentionally, by Sedit and yours truly. Again, check upthread because as I recall, there was a good explanation of the common ion effect by blogfast. Copper sulfate did precipitate first but according to Sedit, his solution still contained a lot of copper. I never got around to testing my solution. Crystallization can probably be sped up by gently warming then cooling the concentrated sulfate solution repeatedly (ugh..).

Quote:

Run a stream of acytelene through the solution of copper/nickel nitrate then filter the solution.
Be warned this makes copper acetylide, a sensitive explosive.

I'm still holding out hope for a simple-ish way to quantify the proportion of metals in solution (for analysis, not bulk separation). Bismuthate's acetylene idea sounds good right about now and is reported and demonstrated to work with copper chloride as well.

Tank

WGTR - 12-11-2013 at 20:59

I use a scanning electron microscope (SEM) to quantize things around here, but why not precipitate out the respective sulfides, and
weigh those? Nickel and copper ions can be separated quite distinctly in this way.

woelen - 13-11-2013 at 01:54

Removed some crap from Ph.D.Chemist user.

cyanureeves - 17-11-2013 at 07:25

i just dissolved some nickels in both hydrochloric acid and nitric acid and ran a stream of acetylene from my bottle.the nitrated cupronickel solution has not reacted as i wanted with acetylene as nothing happened.the hydrochloric acid solution however looks promising because i ran acetylene through it and also nothing but when i added ammonium hydroxide,the magic happened.i added ammonium hydroxide from ace hardware and it just disappeared into the hydrochloric solution so i added more and just when i thought it was going to drop the hydroxides it turned blood red.i went this route after watching the youtube video how to make copper acetylene.i added acetylene to the blood red solution and it has not settled yet. the hydrochloric solution was made by dissolving nickels with 5volts in Hcl acid and removing the copper sponge so the red is what little copper is in solution.i do not know how much nickel is in solution or in the removed sponge nor do i know if nickel will also drop as a hydroxide or remain in solution.i plan to nickel plate with whatever is in solution because if it all precipitates i will be back to square one again with 0 for 0.

[Edited on 11-17-2013 by cyanureeves]

[Edited on 11-17-2013 by cyanureeves]

plante1999 - 17-11-2013 at 07:34

Acetylene separation, very very promising, although extremely unsafe in larger quantity.

Here is a rough idea:
Electrolysing Cupronickel in ammonium chloride solution, adding ammonia and copper powder. Wait a few day and precipitate the copper I with acetylene, filter the nickel solution and destroy the copper acetylide with strong hydrochloric acid. The nickle solution could be reduced to elemental nickel probably.

cyanureeves - 17-11-2013 at 10:45

it has been a couple of hours now since the acetylene was bubbled through the Hcl acid solution and alot of red precipitate has developed and has occupied half of the reaction flask.i now have half red precipitate and half blue solution which i wishfully think is the nickel ammonia complex.the nitric solution did not work in the same manner because i added ammonium hydroxide to it and as all you here would probably guess,i got nickel and copper hydroxide.RATS! Big Effing rats says johnny!

m1tanker78 - 17-11-2013 at 12:57

Interesting experiment @cyanureeves. From what you say, I deduce that the solution should be only slightly acidic (near neutral?) while bubbling acetylene. Is that correct?

The only potential drawback I can think of at the moment is the addition of NH4 ions. It may not hinder anything, just something to keep in mind if one wants a more refined product later..

I'm interested to know what you find after filtering off the copper acetylide (don't let it dry out completely). If possible, leave one part for plating, another for dropping with aluminum, and another for.... whatever. lol More acetylene --> more precipitate? This would indicate incomplete saturation/reaction on the first round.

Tank

blogfast25 - 17-11-2013 at 13:04

CR:

The nickel ammonia complex is a very specific colour, I wouldn't describe it as blue, more a kind of light purple. But Cu (I) does form a diammine complex and believe it's blue (like its Cu(II) counter part).

Careful with that copper (I) acetylide: explosive when dry! Shock sensitive too...

cyanureeves - 17-11-2013 at 14:39

correction

DARK purple) is what the nitrated solution looks like which did actually precipitate a jet black charcoal which i now have drying. nickel does indeed make up most of both left over blue and purple solutions because i totally nickel plated a copper penny with both solutions. i added sodium carbonate to both and added a bit of Hcl acid to make the plating solutions and both are effective. when carbon steel is immersed in the plating bath it will however draw out a little pink hue at first.adding some of the ammoniated solutions give more nickel power but will add alot of soot that has to be rubbed off and then exposes the shiny nickel. i have two coffee filters full of the precipitates drying but the red stuff is way,way more.seems every darn by product is volatile,from farts to bombs.i'll be careful. @ tank, yes indeed i have some unadultered solution and it was exactly what i had in mind(mo gas) i didnt check the acidity i just went by color, you cant miss it!it turns red before your eyes in a fraction of a second.one thing to note is that both precipitates are hard to clean off and messy as hell!

[Edited on 11-17-2013 by cyanureeves]

[Edited on 11-17-2013 by cyanureeves]

blogfast25 - 18-11-2013 at 05:40

Quote: Originally posted by cyanureeves

i have two coffee filters full of the precipitates drying but the red stuff is way,way more.

If the red stuff is copper (I) acetylide that sounds rather a lot. At the risk of sounding like a broken record, be very careful with it. I would decompose it with HCl if I were you: it has fulfilled its desired purpose but now isn't needed anymore.

cyanureeves - 18-11-2013 at 15:48

yes all i want is a nickel plating solution and have no desire for explosives but either way i did not make copper acetylide because my stuff does not deflagrate. i probably did not have strong ammonia or acetylene was not enough but anyhow the precipitates have shrunk to about 1/4 it's original mass.i have to be very careful that i do not intentionally make explosives or poisons for poison's sake.i think i owe it to all sciencemadness members that i be responsible with what i learn here and everywhere.

cyanureeves - 20-11-2013 at 16:44

update: the solution containing what i thought was mostly nickel has a crapload of copper still because reduction with aluminum proves it.i get red sponge just as if i used a battery and furthermore the untouched blue solution does not turn red with more acetylene nor with more ammonium hydroxide.at this point i am stopping until i come up with some sort of bladder to keep the copper sponge on the aluminum away from the rest of precipitates as i do the reduction.i swear explosives are the result of frustration stemming from failure and wars are all caused by copper.give nickel a chance!

bismuthate - 20-11-2013 at 17:11

Sorry it's not working. On the bright side I just realized we could percipitate 2CuI+I2 by adding KI. This seems to good to be true!

cyanureeves - 20-11-2013 at 18:41

bismuthate when i said a crapload of copper i was exagerating a bit. the acetylene dropped more copper than i have ever before.i think i should have added more ammonia or acetylene. acetylene and a bladder to filter the remaining copper will be my next attempt.the aluminum is actually turning black rather than produce more sponge. thanx for your u2u. nickel or bust!or bust,or bust,or bust!

bismuthate - 21-11-2013 at 04:04

Ok. Also after further research I found that my KI idea would not work...

but AlI3 should work to percipitate CuI.

m1tanker78 - 21-11-2013 at 17:41

Quote: Originally posted by cyanureeves

update: the solution containing what i thought was mostly nickel has a crapload of copper still because reduction with aluminum proves it.

Not so fast cyanureeves.... What was your Al source? Check about half way down page 6 of this thread..

http://www.sciencemadness.org/talk/viewthread.php?tid=16811&...

I proved that Al foil (alloy) will give deceiving results. If you have access to a more pure Al source, you could rule out the above. If you don't, then let us know how it behaves around a strong magnet, por favor.

Tank

cyanureeves - 21-11-2013 at 19:42

i will try sometime this weekend, i just dont understand this whole thing sometimes.

cyanureeves - 1-12-2013 at 17:25

<img src="http://i1190.photobucket.com/albums/z444/scarface130/DSCI1329_zpsa322e380.jpg" width="800" />you are very much in the right m1tanker78.not all the red was copper but in fact nickel as well even though it was no different in color than the copper. a strong magnet did pick up the nickel powder which was blue and not green.my next step involved using aluminum to drop both the metals but stopping when the solution looked more green than blue.hoping that copper would precipitate first i removed the aluminum along with the red sponge as it started to just pick up nickel.the nitrated solution did not precipitate anything with acetylene but in fact just precipitated hydroxides when ammonium hydroxide was introduced.why the hydrochloric acid solution in which i dissolved the nickels with 5 volts did not even fume when i added ammonium hydroxide is a mystery to me.why the hydrochloric solution did not fume or drop hydroxides is also something i did not expect.the whole thing just started to make the blue amine complex then suddenly turned rust red.the acetylene does drop quite a bit of copper enough to let me nickel plate.

[<a href="u2u.php?action=send&username=bfesser">bfesser</a>: reduced image size(s)]

[Edited on 26.1.14 by bfesser]

TheChemiKid - 25-1-2014 at 09:43

I am sorry if this has been said before, but the thread is so long it is hard to find anything. I tried method one, but the nickel just would get attracted to my magnet (It was a 1/2" x 1/2" x 1/2" Neodymium magnet). now I have an annoying powder of metals on my hands. What should I do?

cyanureeves - 26-1-2014 at 07:02

try anything chemkid but be careful with acetylene because it appears it also bonds with nickel,so does vinegar,sulfuric acid, etc. and it also drops with aluminum along with copper.you can plate out most of copper with an annode but some will remain in solution.once they are converted to their carbonates or hydroxides then they are almost impossible to separate.i think it has been suggested that molten sodium hydroxide might separate copper only like plante1999 did with chromium.good luck but dont give up entirely.

bismuthate - 21-4-2014 at 15:06

Ok so after a while I have come up with a few ways to separate the nickel and copper.
First the nickel should be dissolved in HNO3.
1Then you can add a solution of potassium ferrocyanide. After that just filter the red/brown copper ferrocyanide and you are left with a copper free solution that you can get nickel from.
2 Add KI or NaI to the solution and again filter to get your nice pretty nickel solution. (On a side note oddly enough the iodine that should nave apeared does not but remains in solution until and acid is added (this may be because I used realy impure NaI that I made from povidone iodine))
3 Add sodium chromite (which is actually rather easy to make)
4 I have heard about copper borate being made via copper sulfate and sodium tetraborate and have experimented on it but have not tested the method definitively. I can if anybody has an interest in it.
5 I found that simpley using an excess of nickel and letting it sit for a few days in nitric acid give a rather pure nickel nitrate solution.
If anybody has any interest in these tell me and I can do more research and post a procedure.

cyanureeves - 21-4-2014 at 15:26

you mean add nickel to copper/nickel nitrated solution???

[Edited on 4-21-2014 by cyanureeves]

bismuthate - 21-4-2014 at 15:32

Well I meant that I used a bunch of nickels and added them to not enough nitric acid to react with a 5th the coins.
Althogh be warned if you did this you would need to purify it after.

[Edited on 21-4-2014 by bismuthate]

m1tanker78 - 28-4-2014 at 16:07

I think a clever design for electrolysis without having to weld the coins or pieces together is in order. Without yet reading the last few pages, I got remarkably pure metal powders via electrolysis and a displacement reaction. Problem is I cheated and welded the coins together to form the anode. I'll bet a small car battery and a couple of graphite rods will make a fine 'welder' in a pinch.... never mind.

I'm thinking along the lines of a titanium wire cage tumbler filled with alloy coins/pieces. Apply gentle current (see upthread for specs) and clean copper sponge from cathode periodically. After some time, you'll hold quite a bit of copper powder and if desired, you can drop out relatively pure nickel powder with pure aluminum (again, see upthread).

I do like that people are thinking of and at times trying other ways to make this alloy divorce..

Tank

jiexiang88 - 17-11-2015 at 00:04

Forgive me if this was already posted, but I do not have time to go through all 10 pages of this thread

CrossxD - 4-2-2016 at 10:58

is nickel borate soluble in water?

Fulmen - 3-11-2016 at 11:00

I might be onto a workable solution to this. I started by dissolving some cupronickel coins in a HCl/NaNO3-mixture. I then tried precipitation with NH3, and while a green precipitate formed I was unable to separate this out in any way. Gravity filtering just clogged the paper while it passed right through when vacuum filtering. No surprise there. So I figured I'd give the acetate route a try, copper acetate should be less soluble than nickel, giving me at least partial separation.

So I acidified the solution (now containing copper, nickel, chlorides, nitrates and ammonia), but got no crystallisation even with cooling.I figured it needed to be more concentrated, so I started to boil it down. After reducing it to appr. 1/2 the volume I suddenly got a pale green precipitate again, accompanied by a strong acetic acid smell. And this time the precipitate was much coarser and easily filtered.

I guess the acetate simply boiled off, increasing the pH to the point where the nickel hydroxide would form again. But the slow hot process seems to promote crystal growth much better than the direct precipitation did.

DraconicAcid - 3-11-2016 at 12:07

Quote: Originally posted by Fulmen

I then tried precipitation with NH3, and while a green precipitate formed I was unable to separate this out in any way. Gravity filtering just clogged the paper while it passed right through when vacuum filtering. No surprise there.

Nickel hydroxide is awful to try to filter, in my experience. But if you had a high concentration of nickel, you should have gotten Ni(NH3)6Cl2, which is much less soluble than the copper complex Cu(NH3)4Cl2. That might be a way to separate them.

Fulmen - 3-11-2016 at 12:37

Metal hydroxides can be a real pain, I've tried copper oxide this way before and it's a complete mess.

My "discovery" seems related to the ammonia/ammonium carbonate leach for copper. In this process an ammonia/ammoniacal carbonate complex is generated, in the subsequent boil the ammonia is driven off and malachite (Cu2CO3(OH)2) precipitates. And this precipitate is a dense, fine powder rather than the amorphous gel obtained by direct precipitation.

I'm not completely sure if the precipitate is nickel hydroxide yet, but it's the most likely culprit. I guess I could do a silver nitrate test for chlorides, any other suggestions?

Update: The separation of copper and nickel seem to be quite good. I can add a fair amount of ammonia to the supernatant liquid (dark green) without any more precipitation, an excess produces a blue solution indicating a copper amino complex.

[Edited on 3-11-16 by Fulmen]

m1tanker78 - 3-11-2016 at 20:16

Fulmen, your precipitate could be copper hydroxychloride rather than nickel hydroxide. There is theoretical as well as experimental evidence for this a few pages back in this thread.

Fulmen - 4-11-2016 at 02:53

You could be right. I dissolved the precipitate in sulfuric acid, and the result was a blue-green color that doesn't match either copper or nickel. So it doesn't look good for separation this way.

CrossxD - 5-11-2016 at 09:13

Today I tried to separete them by reduction by reducing sugars.
I made solution of glucose-fructose, than dissolved in that solution sodium carbonate and than citric acid and let it on about pH 9,than I mixed it with my Cu/Ni solution and heated up.
Brick like red solid precipitated

I hope it will be good for u 2

Fulmen - 6-11-2016 at 02:50

But did you get a precipitate that could be filtered? I tired adding some acid-hydrolyzed sugar, and I did get a brown precipitate but nothing that allowed for separation.

Extraction the cheapest way

symboom - 6-11-2016 at 02:50

It seems turning to organic chemistry for the solution is the simplest way

Materials:
Nickels
Acetic acid
Hydrogen peroxide
Asprin
Sodium bicarbonate

starting with nickels desolve in vinegar and hydrogen peroxide mixture
Nickel acetate and copper acetate is formed

Prepare sodium aspirnate
From sodium bicarbonate and aspirin excess asprin to prevent nickel from percipitating

Mixing solutions copper is percipitated while sodium acetate is formed

Possibilities
In sol.
Sodium acetate
Acetic acid
Aspirin
Hydrogen peroxide
Nickel acetate/asprinate

Copper aspirinate is insouble filter off
Nickel aspernate is soluble stays in solution
Precipitate nickel carbonate by adding more sodium bicarbonate

[Edited on 6-11-2016 by symboom]

[Edited on 6-11-2016 by symboom]

[Edited on 6-11-2016 by symboom]

zwt - 6-11-2016 at 06:14

Quote: Originally posted by symboom

Copper aspirinate is insouble filter off
Nickel aspernate is soluble stays in solution

Ingenious!
Almost as much as when it was suggested 3 years ago, in this thread.
...and 5 years before that, in another thread.
One wonders why a repeatable procedure, based on this principle and with things like actual measurements, hasn't been posted yet.
Could it be that this doesn't work nearly as well in practice as it does in theory? When I experimented with this some months ago, that's what my results implied.

Fulmen - 6-11-2016 at 07:29

Getting an insoluble precipitate isn't enough, it also needs to be coarse enough to allow filtration.

Fulmen - 8-11-2016 at 08:50

The ammonia seems to be a fairly selective, it readily complexes the copper without dissolving the nickel. Even with enough ammonia to dissolve filter paper the green precipitate was unaffected while the supernatant liquid stayed blue. Filtration is a major pain, although boiling the suspension seems to cause some slight flocculation. It will probably need several days of standing/decanting, but it's worth a shot.

Fulmen - 9-11-2016 at 06:44

The decanting/washing of the nickel hydroxide is slow work as expected, but at least the strong color of the copper complex gives a good indication of the progress.

Recovering the copper turns out to be the easiest part. Start by adding enough sodium hydroxide to cause a slight precipitate (not important, just speeds up the process), then boil the solution. As ammonia is driven off copper hydroxide precipitates out, but in a much coarser product than you will get with the direct precipitation. It could be possible to do this with the nickel as well, but it seems to require an awful lot of ammonia to dissolve it.

m1tanker78 - 9-11-2016 at 19:14

Fulmen, what do you mean by 'the ammonia'? Provide some detail of your procedure.

Fulmen - 10-11-2016 at 02:20

I'm just throwing science at the wall to see what sticks :-)

I started by dissolving coppernickel in 30% HCl with NaNO3 added as an oxidant, then precipitated it as an hydroxide with sodium hydroxide. Adding ammonia (appr 10%) dissolves the copper as the amino complex, even with a decent excess of ammonia no nickel hydroxide seems to dissolve. The solid nickel hydroxide can then be filtered off (or separated by decanting) and dissolved in the acid of your choice.
The remaining copper can easily be recovered by boiling, this drives off the ammonia reverting the copper to it's hydroxide again. This is an effective method as it produces a much heavier precipitate than a direct reaction with say sodium hydroxide, allowing for gravity filtering without instantly clogging the filter.

Sadly I did not get a complete separation this time, after reacting the nickel hydroxide with sulfuric acid I ended up with some copper sulfate as well. This could easily be seen by the color of the crystals and was confirmed by inserting a steel wire into the liquid. Copper quickly plated out. Luckily copper sulfate is slightly less soluble in cold water, so by washing it with cold water I was able to get better separation. Now a steel wire forms a black precipitate, which I assume is nickel.

My mistake was probably that I didn't wash the precipitate with enough ammonia, I was running a bit low and the fine suspension made it time consuming to do repeated washes. Perhaps stronger ammonia would be more effective, but 10% was all I had.

Suggestions for further investigation: Dissolving both the nickel and copper hydroxide in stronger ammonia. This way one should be able to get a denser, more filter friendly nickel hydroxide, and the apparent difference in solubility should provide separation.

m1tanker78 - 12-11-2016 at 18:16

As I recall, Sedit's procedure (with ammonia) didn't include an intermediate precipitation of the metal salts. He was just adding ammonia directly to the solution of metals. What you're saying is that adding ammonia to the mixed metal hydroxides selectively complexes the copper, allowing the nickel hydroxide to be filtered or decanted.

Are you washing the hydroxides prior to adding ammonia? It seems very reasonable to assume that a slight excess of NaOH should be added to the solution of metals.

How are you testing your products?

Fulmen - 13-11-2016 at 03:58

Yes. I didn't wash the precipitate before adding the ammonia, I just let it settle enough to confirm that the supernatant liquid was clear.

"Testing" was done by color. That and by inserting a steel wire into the solution. Since Cu will plate out before Ni it should be a fairly sensitive test.

Further testing indicates that I still have some traces of Cu left. I'm still weighing my options for removing this, but it should be possible to plate it out.

Soluble nickel cyanurate insoluble copper cyanurate

symboom - 7-12-2016 at 03:02

wanting to speed things along I bought some nickel sulfate
To do some reactions with it there are numerous videos and documentation of soubility of copper but not much for nickel

copper cyanurate a insoluble purple compound forms upon the reaction of copper sulfate and sodium cyanurate

Never thought I would be glad when something doesnt react

The reaction between nickel sulfate and sodium cyanurate no percipitate forms.
This seems to be a way to separate copper from nickel.

[Edited on 7-12-2016 by symboom]

[Edited on 7-12-2016 by symboom]

PirateDocBrown - 7-12-2016 at 11:28

I did this separation many times, back when dinosaurs walked the Earth, and I was in the flower of my youth.

The metallic alloy should be solvated in an oxidizing environment, such that all Cu ends up as Cu(II) and not Cu(I). In aqueous solution, concentrated nitric acid should work perfectly. If need be, break passivation with a small amount of I2.

The classic way for separation exploits the different cation solubility in the presence of sulfide ion, which is highly dependent on pH.

Again classically, the reagent of choice is thioacetamide. This is a bit pricey for a home chemist, so any source of H2S should work, it can be easily generated from Al2S3 and water, or FeS and HCl, whichever is available. Gas supply businesses can often sell lecture bottles of the stuff, as well.

Cupric sulfide precipitates out nicely, even at low pH, whereas the solution must be made quite alkaline for NiS to do so.

CuS should also be an easily filterable product. A hot solution should fall through even a fluted paper filter in a conical funnel, leaving behind only CuS.

Reduce the sulfides by roasting in air, and then crucible heating with powdered carbon will yield the metallic elements. A melt in the case of copper, sponge for nickel.

[Edited on 12/7/16 by PirateDocBrown]

[Edited on 12/7/16 by PirateDocBrown]

[Edited on 12/7/16 by PirateDocBrown]

aga - 7-12-2016 at 13:21

Hello, and Welcome to ScienceMadness !

Quote: Originally posted by PirateDocBrown

I did this separation many times, back when dinosaurs walked the Earth, and I was in the flower of my youth.

The metallic alloy should be solvated in an oxidizing environment, such that all Cu ends up as Cu(II) and not Cu(I). In aqueous solution, concentrated nitric acid should work perfectly. If need be, break passivation with a small amount of I2.

The classic way for separation exploits the different cation solubility in the presence of sulfide ion, which is highly dependent on pH.

Again classically, the reagent of choice is thioacetamide. This is a bit pricey for a home chemist, so any source of H2S should work, it can be easily generated from Al2S3 and water, or FeS and HCl, whichever is available. Gas supply businesses can often sell lecture bottles of the stuff, as well.

Cupric sulfide precipitates out nicely, even at low pH, whereas the solution must be made quite alkaline for NiS to do so.

CuS should also be an easily filterable product. A hot solution should fall through even a fluted paper filter in a conical funnel, leaving behind only CuS.

Reduce the sulfides by roasting in air, and then crucible heating with powdered carbon will yield the metallic elements. A melt in the case of copper, sponge for nickel.

Your description is a bit brief for us rank Amateurs.

If you wouldn't mind, please provide more details of your process, as in Exactly how one would separate the materials, including weights, concentrations, what is a 'low' pH (1,3,5,6 ?) etc, which we'd need to be able to try it out.

It isn't often we get someone New who knows Exactly how to do something !

Looking forwards to your detailed instructions so we can all give it a try !

So exciting !

[Edited on 7-12-2016 by aga]

DraconicAcid - 7-12-2016 at 13:33

Separation as the sulphide is simple, actually- at a pH of 0, add 1 M thioacetamide and heat in a hot-water bath (near boiling) for ten minutes.

(This is from a college lab manual, for an experiment separating the metals in a mixture for identification. 2 mL of unknown is acidified with 0.5 mL 6 M HCl (to precipitate out silver, lead and/or mercury), then treated with 1 mL of 1 M thioacetamide.) This separates copper, bismuth and cadmium from the other metals such as cobalt, nickel, manganese and zinc.)

ETA: The nickel would probably precipitate at a pH of 1 or 2.

[Edited on 7-12-2016 by DraconicAcid]

PirateDocBrown - 7-12-2016 at 13:56

Since you at first dissolve the alloy in an excess of HNO3, there should already be a strongly acidic solution.

CuS will precipitate upon treatment with thioacetamide, which should be applied in slight excess of stochiometry. The reagent should be dissolved in hot water, and the treatment proceed at a similar temperature, say 80C.

If H2S gas is used, treatment should continue until no more CuS precipitate forms. Color change can provide some guidance here, as the Cu 2+ aqueous species is removed from solution, and will no longer contribute its blue color. H2S treatment would be typically done at room temperature.

If you wish to confirm the absence of the Cu(II) species, a small aliquot can be tested with a solution of potassium ferricyanide. The resulting copper species is a characteristic red color, which should make the already present Ni(II) species appear a muddy greenish brown. If no color change is observed, your copper has all been removed.

In either case, addition of a small amount of ammonium acetate can aid in making sure precipitation goes to completion.

Typically, pH would be below 2 throughout. Filtration can be best done after concentration by evaporation, then proceed while the solution is hot.

For precipitation of NiS from the filtrate, basification would be best done with concentrated ammonium hydroxide, to about pH 11.

Simple decantation should suffice.

For air roasting, the dry powder sulfides can simply be heated in an open casserole. Once fully oxidized, carbon is added in excess.

Reduction is conducted at elevated heat. The nickel crucible, in particular, should be covered to exclude air while cooling, to prevent re-oxidation.

[Edited on 12/7/16 by PirateDocBrown]

aga - 7-12-2016 at 14:30

Quote: Originally posted by PirateDocBrown

Since you at first dissolve the alloy in an excess of HNO3, there should already be a strongly acidic solution.

CuS will precipitate upon treatment with thioacetamide, which should be applied in slight excess of stochiometry. The reagent should be dissolved in hot water, and the treatment proceed at a similar temperature, say 80C.

If H2S gas is used, treatment should continue until no more CuS precipitate forms. Color change can provide some guidance here, as the Cu 2+ aqueous species is removed from solution, and will no longer contribute its blue color. H2S treatment would be typically done at room temperature.

In either case, addition of a small amount of ammonium acetate can aid in making sure precipitation goes to completion.

Typically, pH would be below 2 throughout. Filtration can be best done after concentration by evaporation, then proceed while the solution is hot.

For precipitation of NiS from the filtrate, basification would be best done with concentrated ammonium hydroxide, to about pH 11.

Simple decantation should suffice.

For air roasting, the dry powder sulfides can simply be heated in an open casserole. Once fully oxidized, carbon is added in excess.

Reduction is conducted at elevated heat. The nickel crucible, in particular, should be covered to exclude air while cooling, to prevent re-oxidation.

Wow ! THANKYOU for actually providing more specific details.

That is so Rare here these days, especially with newcomers.

Thanks again.

Please feel More welcome than earlier.

PirateDocBrown - 7-12-2016 at 18:41

Thank you for your welcome.

I have mentioned the ferricyanide spot test for cupric ion, I should also mention the preferred spot test for Ni(II).

For a small aliquot of suspected nickel solution, the sulfide anions are removed by first acidfying with an excess of HCl, boiling, then oxidized with HNO3, boiling until clear. The precipitated sulfur can be allowed to settle, removed by centrifugation, or filtered. The sample is then made strongly alkaline with NaOH, creating Ni(OH)2

Addition of dimethyl glyoxime, (CH3)2C2(NOH)2, yields a characteristic strawberry red complex precipitate.

[Edited on 12/8/16 by PirateDocBrown]

symboom - 8-12-2016 at 18:59

By far the easiest for me is sodium chlorocyanurate
It forms a dense copper chlorocyanurate percipitate. Sodium Chlorocyanurate is sold as chlorox bleach crystals

Conclusion what can be added to the copper and nickel salt solution to separate out copper by percipitation

H2S
SO2
Sodium metabisulfite
Aluminum sulfide
Sodium cyanurate
Sodium chlorocyanurate
Sodium aspertate
Potassium iodide
Copper powder
Sodium tetraborate

My findings
copper sulfate is mixed with
Ammonium hydroxide to form tetraminecopper sulfate then H2O2 is added
Reproducibility is odd with this one
Sometimes forms a green solution
Then slowly fades to blue
Brown percipitate or black percipitate

Because there is no data on solubility of nickel compounds many times in case anyone was wondering.
These reactions I performed

Nickel sulfate with potassium iodide
No precipitate

Nickel sulfate mixed with sodium chlorocyanurate
No percipitate formed

Nickel sulfate was mixed with sodium aspertate
No precipitate formed

Nickel sulfate mixed with magnesium citrate
no percipitate formed

Nickel sulfate mixed with potassium bitartate
no precipitated formed
___ ___ ___
Copper sulfate mixed with
Magnesium citrate no percipitate forms

Copper sulfate mixed with
Potassium bitartrate no percipitate forms
__ __ __
Copper sulfate with potassium iodide
brown iodine like solution forms percipitate of copper iodide
On the bottom somtimes it was hard to see if there was a percipitate or if it was finished aldo complicatted by the fact potassium iodide reacts with iodine to form potassium triiodide
So this reaction to separate I dont really like

Wasnt sure if certian metals would just percipitate copper metal but not be able to precipitate nickel
So I tried iron zinc and aluminum in separate respectable containers yes it was much slower in nickel sulfate
All three metals extremely slowly formed nickel metal percipitate after a day the solution still hasnt turned clear with the aluminum and zinc bubbling was only noticable on the zinc metal

Conclusion no metal will only displace copper from solution given time nickel will precipitate out after.

Side note
Copper sulfate mixed with potassium bitartrate no percipitate forms interesting if 3 percent hydrogen peroxide is added it decomposes violently and heats up

Procedures

Add sodium metabisulfite percipitate copper sulfite
Copper 1 chloride or copper 1 acetate depending which one
You used

Sulfur dioxide bubbles into the solution to percipitate copper 1 salt

Boiling copper 2 salt with copper metal powder

Add sodium cyanurate to percipitate copper cyanurate

Add sodium chlorocyanurate to percipitate copper chlorocyanurate

Aluminum sulfide to percipitate copper sulfide

Hydrogen sulfide generated by iron disulfide and an acid
Lead into the solution to produce copper sulfide
Iron disulfide can be retrieved from ultimate energizer lithium battery which goes to waste when lithium metal is extracted so its good to have a use in this

Sodium aspertate reacts with the solution to percipitate copper aspertate.

Updated reactions
Copper sulfate and nickel sulfate with sodium hypochlorite
8.25 percent chorox bottle states

Interesting reaction nickel sulfate reacts quite violently
First a dark green percipitate then the solution turns black
Then it starts to rapidly bubble not sure what the gas is

Copper sulfate with sodium hypochlorite also forms percipitate
But it is green

Calcium hypochlorite forms hardly any with nickel sulfate also forms black percipitate

Calcium hypochlorite with copper sulfate forms green percipitate

Update hydrogen peroxide added to tetraminenickel sulfate
Decomposition occurs of the hydrogen peroxide no percipitate
Once the peroxide destroys the complex signaled by it turning back from purple blueish to green adding ammonia again wont reform tetraminenickel sulfate it just causes a percipitate of nickel hydroxide to form

Hydrogen peroxide added to tetraminecopper sulfate
Brown percipitate forms at very low temperatures
Copper 1 oxide forms I deduce from that because at warm temperature the solution is black maybe from the heat generated by the reaction

Next to try is common solvents
Acetone
Methanol
Ethanol
Isopropanol

Adding copper sulfate to see its soubility
The nickel sulfate to see its solubility

*****

*Nickel sulfate with ammonia to form complex
Then add hydrogen peroxide
No precipitate

Nickel sulfate with sodium borate
Nickel sulfate with sodium silicate

Updated reaction of sodium hypochlorite
With nickel sulfate and copper sulfate

Update made sodium borate reaction of sodium hydroxide with excess boric acid to form sodium borate I wanted to make sure there was no hydroxide left to make nickel hydroxide
Solution was tested with copper sulfate percipitate forms
Nickel sulfate was combined with the sodium borate
No percipitate formed nickel borate doesnt form a precipitate

[Edited on 9-12-2016 by symboom]

symboom - 10-12-2016 at 06:48

Update ammonium pbosphate was added to nickel sulfate
And copper sulfate the nickel no precipitate forms
with copper sulfate forms copper phosphate precipitate

CrossxD - 26-12-2016 at 11:31

how aboutmake from Cu and Ni sufates and copper sulfate is not soluble in ethanol and nickel sulfate is

symboom - 29-3-2017 at 04:00

Tetramine nickel perchlorate is a good method to separate nickel from copper most procedures the copper is removed so this is interesting unfortunately ammonium perchlorate is needed

CharlieA - 29-3-2017 at 06:43

A lot of solubility data, including nickel compounds, can be found at:

https://en.wikipedia.org/wiki/Solubility_table#N

fusso - 14-4-2018 at 11:09

here's my proposal:
1. Dissolve CuNi into HNO3 (only slight excess)
2. add excess Pb and wait until all Cu ppted
3. filter out the Cu and wash with plenty of cold DW
4. pure Cu obtained
5. add some Pb to the filtrate to ppt the last traces of Cu
6. DO NOT decant. instead filter, but add some more Pb to the filter: Pb is to prevent any Cu from reoxidizing during filtration, and filter is to remove any tiny bits of Cu that could have detached from the Pb
7. add excess NH3 to filtrate to ppt Pb(OH)2
8. filter to remove Pb(OH2)
9. add oxalic acid to Ni soln
10. filter out NiC2O4 and dry it
11. heat strongly to decomp NiC2O4 into Ni in test tube or another container, best nonmetallic ones, bubble an inert gas into container if you could (bubble CO2 into test tube/container via plastic tube before adding NiC2O4 could drive out most O2 from the NiC2O4 powder, but adding dry ice to it could contaminate it)
12. wait mixture to cool down completely
13. test for Ni metal using magnet

ninhydric1 - 14-4-2018 at 18:39

For those who don't want to deal with soluble lead compounds, tin is also an alternative to fukko's process. I might actually try this tomorrow; I dissolved some US nickels the other day.

fusso - 5-5-2018 at 16:02

Quote: Originally posted by fusso

here's my proposal:
1. Dissolve CuNi into HNO3 (only slight excess)
2. add excess Pb and wait until all Cu ppted
3. filter out the Cu and wash with plenty of cold DW
4. pure Cu obtained
5. add some Pb to the filtrate to ppt the last traces of Cu
6. DO NOT decant. instead filter, but add some more Pb to the filter: Pb is to prevent any Cu from reoxidizing during filtration, and filter is to remove any tiny bits of Cu that could have detached from the Pb
7. add excess NH3 to filtrate to ppt Pb(OH)2
8. filter to remove Pb(OH2)
9. add oxalic acid to Ni soln
10. filter out NiC2O4 and dry it
11. heat strongly to decomp NiC2O4 into Ni in test tube or another container, best nonmetallic ones, bubble an inert gas into container if you could (bubble CO2 into test tube/container via plastic tube before adding NiC2O4 could drive out most O2 from the NiC2O4 powder, but adding dry ice to it could contaminate it)
12. wait mixture to cool down completely
13. test for Ni metal using magnet

Forgotten point: filter before adding Pb/Sn to remove insoluble impurities (optional)

symboom - 15-5-2018 at 18:59

11 pages and a single displacement reaction of copper chloride reacts with tin or lead is all it takes to separate the copper from nickel

Chemicals needed

Hydrogen peroxide
Hydrochloric acid
Ammonium hydroxide
Sodium bicarbonate

Final chemicals produced
Copper powder
Tin hydroxide
Nickel carbonate
Ammonium chloride along with other small contaminates

Here is my take on it
1 dissolve the nickel coins in a mixture of Hydrochloric acid and hydrogen peroxide
Now a solution of copper chloride and nickel chloride is present

2 Tin metal is added to the solution which causes the copper to percipitate as copper powder and tin goes into solution of tin chloride

3 Copper metal is filtered
The solution now contains tin chloride and nickel chloride

4 Ammonia is added to the solution
Hexamine nickel chloride and tin hydroxide and ammonium chloride is formed

5 Tin hydroxide is filtered out
The solution now contains
Ammonium chloride and hexamine nickel chloride

6 Sodium bicarbonate is added to the solution
Forming nickel carbonate

Ammonium chloride and sodium bicarbonate
Will be left behind in solution

I think this is the cheapest way to separate the compounds
The bonus tin hydroxide reacts with hcl acid faster

The even cheaper way may be to use a cheaper acid such as acetic acid and even use lead instead but the end process would be ammonium acetate being produced lastly

Edit nickel desolves poorly if at all in peracetic acid

Edit 2
Other notes iron 3 chloride desolves nickel and copper the fastest

Which can be percipitated as iron hydroxide out along with tin hydroxide

[Edited on 16-5-2018 by symboom]

[Edited on 16-5-2018 by symboom]

fusso - 24-5-2018 at 11:59

Quote: Originally posted by symboom

11 pages and a single displacement reaction of copper chloride reacts with tin or lead is all it takes to separate the copper from nickel

Chemicals needed

Hydrogen peroxide
Hydrochloric acid
Ammonium hydroxide
Sodium bicarbonate

Final chemicals produced
Copper powder
Tin hydroxide
Nickel carbonate
Ammonium chloride along with other small contaminates

Here is my take on it
1 dissolve the nickel coins in a mixture of Hydrochloric acid and hydrogen peroxide
Now a solution of copper chloride and nickel chloride is present

2 Tin metal is added to the solution which causes the copper to percipitate as copper powder and tin goes into solution of tin chloride

3 Copper metal is filtered
The solution now contains tin chloride and nickel chloride

4 Ammonia is added to the solution
Hexamine nickel chloride and tin hydroxide and ammonium chloride is formed

5 Tin hydroxide is filtered out
The solution now contains
Ammonium chloride and hexamine nickel chloride

6 Sodium bicarbonate is added to the solution
Forming nickel carbonate

Ammonium chloride and sodium bicarbonate
Will be left behind in solution

I think this is the cheapest way to separate the compounds
The bonus tin hydroxide reacts with hcl acid faster

The even cheaper way may be to use a cheaper acid such as acetic acid and even use lead instead but the end process would be ammonium acetate being produced lastly

Edit nickel desolves poorly if at all in peracetic acid

Edit 2
Other notes iron 3 chloride desolves nickel and copper the fastest

Which can be percipitated as iron hydroxide out along with tin hydroxide

[Edited on 16-5-2018 by symboom]

[Edited on 16-5-2018 by symboom]

I prefer using as few "nonvolatile" cationic species (Sn, Na) as possible as they couldn't be driven off by heating. Also Sn2+ can reduce Cu2+ to Cu+ and u may get some Cu2O ppt.

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