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Fulmen
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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.
We're not banging rocks together here. We know how to put a man back together.
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symboom
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Soluble nickel cyanurate insoluble copper cyanurate
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]
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PirateDocBrown
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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]
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aga
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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]
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DraconicAcid
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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]
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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PirateDocBrown
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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]
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aga
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| 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.
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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.
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PirateDocBrown
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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]
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symboom
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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]
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symboom
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Update ammonium pbosphate was added to nickel sulfate
And copper sulfate the nickel no precipitate forms
with copper sulfate forms copper phosphate precipitate
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CrossxD
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how aboutmake from Cu and Ni sufates and copper sulfate is not soluble in ethanol and nickel sulfate is
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symboom
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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
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CharlieA
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A lot of solubility data, including nickel compounds, can be found at:
https://en.wikipedia.org/wiki/Solubility_table#N
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fusso
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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
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ninhydric1
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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.
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 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)
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symboom
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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]
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fusso
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| 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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