Sciencemadness Discussion Board

Ni from coins

menchaca - 18-3-2003 at 16:05

i hope you arent tired of my and my continius questions but how cani get NI from the coins?

Well i dont need it as a metal i just need to separte it from the other metal as Cu,Fe,Co..etc

i supused it could be attaked with acids but im not sure about how separate Ni++ from the other ions

thanks a lot for your patience

madscientist - 18-3-2003 at 18:26

I've actually made efforts at isolating nickel from American nickels (which are made from a 25% Ni, 75% Cu alloy).

The first experiment was placing nickels in 37% HCl solution, as Ni metal reacts with HCl while Cu metal does not. After a week, I merely had a pale greenish solution. The reaction obviously was proceeding ridiculously slow. A few days later, a crack mysteriously developed in the beaker, and the contents leaked out. So that was the end of that experiment. The next experiment involved adding nickels to a solution of 27.5% H<sub>2</sub>O<sub>2</sub> and H<sub>2</sub>SO<sub>4</sub>. Bubbles streamed from the coins, and the solution soon turned blue-green. I left it on the lab bench unattended for about an hour. Upon my return, I found blue-green solution strewn everywhere - all over the bench, my notes, the wall, and the floor. I donned my chemical warfare suit (nickel salts are very toxic!) and spent an hour cleaning up the mess. I moved onto dissolving nickels in 70% HNO<sub>3</sub>. At the initial reaction temperature of -10C, essentially nothing was happening. Upon gentle warming, though, the reaction started, billowing NO<sub>2</sub> for several minutes, yielding blue-green crystals and solution. I then realized that aqua regia would be a good way to lower the amount of valuable 70% HNO<sub>3</sub> I would have to use, and so gave that a whirl. Six nickels (30g) were added to a solution composed of 13mL 70% HNO<sub>3</sub> and 50mL 37% HCl. As with dissolving in straight HNO<sub>3</sub>, the reaction proceeded exceedingly slowly until it was gently warmed (all of these experiments were being done outside, in -20C weather). The reaction was very exothermic and likely would have begun boiling violently had it not been for the cooling effect of the cold weather. A blue-green foam formed as the temperature rose past 50C. At 90C, the temperature leveled off, the blue-green foamed vanished suddenly, and a solution which appeared almost brownish remained. I boiled down the solution (leaving brownish crystals), added water (became blue-green), and then boiled for at least an hour with 17.1g Cu metal (to convert soluble cupric salts to insoluble cuprous saIts). After filtration, the copper wire weighed 16.5g, meaning that very little cupric salt was converted to cuprous salt. I soon learned that the reason for this trouble was the fact that nitrate ions were in solution, destabilizing cuprous cations. Cuprous nitrate is soluble, so it decomposes quickly in aqueous solution; cuprous chloride is not soluble, so it doesn't decompose in aqueous solution (at an appreciable rate, that is). I then boiled 44mL concentrated H<sub>2</sub>SO<sub>4</sub> with 10 nickels until all of the H<sub>2</sub>SO<sub>4</sub> was gone. Very little of the nickels were dissolved. I proceeded to try dissolving six nickels in a solution prepared by adding 36g NaNO<sub>3</sub> to 100mL 37% HCl. The reaction proceeded similarily to the one previously mentioned, except it was considerably less exothermic - meaning it was much easier to control. I added an excess of NaOH solution, precipitating insoluble cupric hydroxide and nickelous hydroxide (small amounts of black nickelic hydroxide, the trivalent cation, were noted). The precipitate was washed with concentrated NaOH, in hope that cupric cations (which are soluble in strong alkaline solution, while nickelous/nickelic cations are not) would be washed out, leaving only the nickelous and nickelic hydroxides. The concentrated NaOH solution used for washing became only a pale blue, so I concluded that NaOH washing was not an effective method of isolating nickel.

And that's as far as I've gotten. Right now, I think the best method would be dissolving the coins in NaNO<sub>3</sub>/HCl solution, precipitating insoluble hydroxides with addition of NaOH solution; converting to chlorides with HCl, then boiling with Cu metal, precipitating insoluble cuprous chloride; then finally filtering out the insoluble cuprous chloride, leaving a solution of nickel chloride.

Darkfire - 18-3-2003 at 18:41

Whats so great about nickle?

CTR

Organikum - 18-3-2003 at 21:32

Yes you can extract the nickel electrolytically from the coins, also the actual US nickles are a bad source. There are older nickle coins (canadian? ask a numismatic) which consist from quite pure Ni alone - a far better start I guess.

Start and aim all in one are special Ni welding rods for cast iron which consist of 99,98% Ni. (there is some protecting stuff covering the NI which is easy to break away).

Darkfire: Ni/Pd/Pt. Have a looka t hte periodic table and you will see. Also Ni looks nice and doesn´t rust. Most important is of course the fact that it exists. Who needs more reasons? ;)

ORG

Hotblack

Ramiel - 24-3-2003 at 21:28

If you alloy 13 moles of Nickel with two of phosphorus, and etch it with Nitric Acid, you may be surpsised to get (if you did it right) Black. Not ordinary matte black, not even metallica T-shirt black. This is the process ( recently patented ) to give a black up to 1000 times more black than any previous blacks. It is super-absorbant of light because the etching creates a 'mountanous' surface which just locks in the light.

Well, that's why I want pure Ni... I thought that was a pretty good reason.

Blind Angel - 24-3-2003 at 22:22

Hey i want more info on this procedure, it interest me a lot. Also more propertie (like if it can be used as a paint) would be appreciate.

P.S. I stille looking for my numistmatic kit, but i think canadian nickel are 75% nickel

Edit: Here are the info for all the canadian coin (now circulating) if you have a lot too much (you can send me some too you know :)):

2$: The outer ring of the two dollar coin is nickel and the inner core is aluminum bronze (92% copper, 6% aluminum, 2% nickel).

1$: The one dollar coin is made of aureate bronze plated on pure nickel.

50¢: The fifty cent coin was made of nickel from 1968 until 2000, when its composition was changed to nickel plated steel (93.15% steel, 4.75% copper, 2.1% nickel).

25¢: The twenty-five cent coin was made of nickel from 1968 until 2000, when its composition was changed to nickel plated steel (94% steel, 3.8% copper, 2.2% nickel).

10¢: The ten cent coin was made of nickel from 1968 until 2000, when its composition was changed to nickel plated steel (92% steel, 5.5% copper, 2.5% nickel).

5¢: The five cent coin was made of cupro-nickel (75% copper and 25% nickel) from 1982 until 2000, when its composition was changed to nickel plated steel (94.5% steel, 3.5% copper, 2% nickel).

1¢: Today's one cent coin, modified in 2000, is made of copper plated steel (94% steel, 1.5% nickel, 4.5% copper). From 1997 until 2000, it was made of copper plated zinc. Prior to 1997 the one cent coin was 98% copper, 1.75% zinc and .25% other metals

Here are those for the US:

1$: .885 copper .06 zinc . .035 manganese .02 nickel

50¢: clad coinage: .750 copper and .250 nickel bonded to an inner core of pure copper

25¢: clad coinage: .750 copper and .250 nickel bonded to an inner core of pure copper

10¢: clad coinage: .750 copper and .250 nickel bonded to an inner core of pure copper

5¢: .750 copper .250 nickel

1¢: 992 zinc .008 copper

Going for the euro :)
(sorry no precise quantity):

2€: Outer part: copper-nickel; inner part: three layers: nickel brass, nickel, nickel brass

1€: Outer part: nickel brass; inner part: three layers: copper-nickel, nickel, copper-nickel

50¢: Nordic gold (huh?)

20¢: Nordic gold

10¢: Nordic gold

5¢: Copper-covered steel

2¢: Copper-covered steel

1¢: Copper covered steel

fiou long post, hope it help though

[Edited on 25-3-2003 by Blind Angel]

Microtek - 24-3-2003 at 23:23

NiS does not precipitate below about Ph 0.4 but CuS does, so adjust the acidity to about this level ( calculations ) and add H2S soln ( poisonous ). Cu will precipitate ( along with any Cd, Pb, Hg ) as insoluble sulfide.
The insolubles are removed by filtration, and the filtrate is basified with NaOH which precipitates Ni(OH)2.
Presumably, this could be roasted in air to form NiO and H2O.
NiO can be reduced with CO at high temps.
A rather exotic method exists for purification of the nickel: It is reacted with CO at 60 C to form Ni(CO)4 which has a boiling point of only 43 C ( and is highly poisonous ). This gas is drained off from the impurities, and heated to 200 C which reverses the reaction: Ni(CO)4 -200C-> Ni + 4 CO
Maybe you could grind down the coins and use this process....

madscientist - 25-3-2003 at 19:43

The coins are Cu/Ni alloys though; and Cu/Ni alloy requires higher pressures/temperatures for the formation of nickel carbonyl to occur. :(

Blind Angel - 25-3-2003 at 21:01

Most pre-2000 canadian coin are made from pure nickel as i saw :) there still a chance that we can get pure nickel from them. But, isn't nickel easy to obtains OTC ???

Marvin - 26-3-2003 at 08:21

Quote "Ni(CO)4 -200C-> Ni + 4 CO
Maybe you could grind down the coins and use this process...."

NononononoNONONONONO DON'T DO THIS. Not even outside.

'Highly poisonous' works well for, CO, H2S or HCN but it doesnt begin to cover how nasty nickel carbonyl is.

Acceptable levels of CO in the work place are of the order of 50ppm with lethal levels being only 1 order above this.

Acceptable levels of nickel carbonyl are of the order 0.001ppm. Odour threshold is around 1ppm.

There are no ways of handling this stuff outside a very well equipped laboratory.

If you want to remove copper from a nickel solution, add iodide, and you'll get iodine in solution, and a ppt of very sparingly soluable copper(I) iodide. A similar reaction is possible with chloride, but as copper(II) isnt a strong enough oxidising agent to make chlorine you need a reducing agent like sulphite in solution as well.

I would be inclined just to try fractional crystalisation on the mix, but getting the metals from coins is very expensive.

Darkfire - 28-3-2003 at 16:25

After you converted both the coper and nickle into compounds, would it still be posible to use the magnetic properties of Ni to seperate the metal salts?

CTR

Organikum - 29-3-2003 at 04:36

as far as I know Ni looses the magnetic properties as salt and even when very fine divided.

Marvin - 29-3-2003 at 07:58

Ferromagnetism is an unsual state requiring very ordered structure in the lattice. This usually vanishes a long time before melting and a true liquid ferromagnetic material is thought to be impossible. Very fine powders eg 1u are still ferromagnetic, and usually single domain grains, the basis for magnetic tape recording. Solutions of salts are simply too disordered to be strongly magnetic.

U.S. $0.01 penny

Cappy - 29-3-2003 at 21:33

Does anyone know what year was the last year of pure copper pennies?

I believe it was sometime in the 1950s or 60s.

Darkfire - 29-3-2003 at 22:07

Uh i think 86 or 68 but im not entirly sure... but coper is pretty useless exept for messing around with hno3.

CTR

Cappy - 29-3-2003 at 22:56

I was going to make aluminum powder for thermite by sulfating the aluminum, then replacing it with magnesium.

I figured I could instead sulfate copper, then replace with aluminum, and then magnesium, so I would end up with copper and aluminum powder. Would this add a lot of time to the process?

I thought copper powder might be useful for blue flame coloring. Will copper burn easily, or must I make copper nitrate? I don't have access to HNO3, but I have a liter of H2SO4.

Darkfire - 30-3-2003 at 09:16

I think most copper salt will color flame to some degree, some better than other. If you plan on coloring your thermite, i think copper makes better color at lower temps.

CTR

Marvin - 30-3-2003 at 14:18

I dont know of any blues offhand that use copper powder, I'm not convinced it would work well. The species your after is CuCl, so low temperature flames with an easily decomposed copper salt and a chlorine donor. Most of the cheep blues I know of use a chlorate or perchlorate salt, with ammonium perchlorate being the best, a chlorine donor like PVC, and copper carbonate.

Adding sodium carbonate to copper sulpate would get you this, but it would leave so much sodium impurity in the carbonate as to render it totally useless. Potassium carbonate woiuld work well if you can get it, maybe someone can point out a method I havnt thought of.

Adding iron or magnesium to copper sulphate solution would certainly get you copper powder, but I'm not convinced aluminium powder would react at all, and making aluminium powder by adding magnesium to aluminium sulphate definatly wont work in solution.

You cant ppt aluminium or magnesium in water solutions, you just get the hydroxides. Thermite will almost certainly work with magnesium powder, but I'm not sure how well, or if there are any additional dangers.

If you want copper metal, tubing from a scrap yard or a plumbing shop is potentially a lot cheaper.

[Edited on 30-3-2003 by Marvin]

menchaca - 30-3-2003 at 14:48

i´ve think in a way to obtaim CuCO3 im not sure if it works but...

you take CuSO4 and heat it strongly you will get CuO, you take this and add to this acetic acid or vineager(does it write so?)
you ill get copper acetate if you let it cristalicve dry the cristals and heat it you should get CuCO3 and acetone, acetone evaporates and CuCO3 precipites


copper acetate +heat-->copper sulphate +acetone

i think there will easir wayis to get it but this i think this give you relativily pure copper carbonate

menchaca - 30-3-2003 at 14:53

i think that i could have done it easier:

copper carbonate is unsoluble wile copper sulphate ,sodium sulphate and sodium carbonate isn´t , so you take

CuSO4+Na2CO3--->Na2SO4(sol.)+CuCO3(unsol.)

Cappy - 30-3-2003 at 15:26

Quote:
Originally posted by Marvin
Adding iron or magnesium to copper sulphate solution would certainly get you copper powder, but I'm not convinced aluminium powder would react at all, and making aluminium powder by adding magnesium to aluminium sulphate definatly wont work in solution.

You cant ppt aluminium or magnesium in water solutions, you just get the hydroxides. Thermite will almost certainly work with magnesium powder, but I'm not sure how well, or if there are any additional dangers.


[Edited on 30-3-2003 by Marvin]


Check out http://www.webelements.com/webelements/elements/text/Al/chem...

"Aluminium metal dissolves readily in dilute sulphuric acid to form solutions containing the aquated Al(III) ion together with hydrogen gas, H2. The corresponding reactions with dilute hydrochloric acid also give the aquated Al(III) ion. Concentrated nitric acid passivates aluminium metal.

2Al(s) + 3H2SO4(aq) 2Al3+(aq) + 2SO42-(aq) + 3H2(g)"

I don't see why Al wouldn't be precipitated by the more reactive Mg (single-replacement reaction).

I'd like to see if Mg/Fe2O3 thermite would be more energetic than Al/Fe3O3, but I don't have an easy way to make fine Mg powder. I'm assuming sandpaper would just polish Mg.

[Edited on 30-3-2003 by Cappy]

Organikum - 31-3-2003 at 05:44

As a source for copper don´t take tubes or sheet from the scrapyard as this are usually alloys.
Use copper from some old high quality electrostuff, the wires, instead as these are very pure copper - in transformers for example


I had just some ugly experiences in using plumbing coppertube for a tube furnace experiment where copper was required.

Had to plate the "copper" electrolytically with copper.
Hehe.
shit. :o

Marvin - 31-3-2003 at 14:21

In terms of electrochemical series, both aluminium and magnesium should react with water. Any attempt to reduce salts of these metals will yeild hydrogen instead, and hydroxides of the metal(s) involved. If that is, you can get it to react at all. Anything that dissolves aluminium, has to dissolve or disrupt the oxide/hydroxide coating to react at a reasonable rate.

Here copper water pipe seems to be pure copper. Ive been told only pure copper works becuase otherwise it wouldnt bend properly, most other metals are unsuitable for contact with drinking water. Maybe where you are they use something else. As anything you get from a scrap yard, a crude chemical assay should be done to check.

Theoretic - 16-11-2003 at 08:46

You could dissolve the coins in molten NH4NO3, heat untill all of the residual AN decomposes, then heat further untill nitrates have been converted to oxides, toss the lot into molten NaOH, which would dissolve Fe and Cu oxides, leaving NiO to settle to the bottom. Then you could reduce NiO with Al and dissolve in NaOH any excess Al. ;)

unionised - 16-11-2003 at 15:09

An interesting approach to a study of the stabillity of molten NH4NO3 in the presence of heavy metals. Please let me know if you are going to do it so I can be sure to be out of the way.;)
I think the idea of dissolving it in acid (electrolytic oxidation in HCl with an innert anode would be neat) and ppt the Cu as CuI is about the easiest.
Dissolving the coins in hot H2SO4(aq) and adding ammonium sulphate would precipitate the Ni as the sparingly soluble double salt but I don't know how well this would separate it form the Cu.

[Edited on 16-11-2003 by unionised]

Theoretic - 17-11-2003 at 05:20

"An interesting approach to a study of the stabillity of molten NH4NO3 in the presence of heavy metals. Please let me know if you are going to do it so I can be sure to be out of the way."
WELL, my chemistry book says that molten AN can be used to extract metal oxides like ZnO or MgO out of their ores and gives an example equation:
2NH4NO3 + CuO => Cu(NO3)2 + 2NH3 + H2O
Or for the reaction with the metals themselves: "analogous to nitric acid":
Cu + 3NH4NO3 => Cu(NO3)2 + N2 + 2NH3 +3H2O.
On second thoughts... If you are right and my chemistry book and me are wrong, then Cu - containing thermites are nice detonators of AN! ;)

madscientist - 17-11-2003 at 08:40

I would be wary when considering mixing molten ammonium nitrate with copper and nickel, as ammonium nitrate tends to complex with the salts of copper and nickel to form primary explosives.

[Edited on 17-11-2003 by madscientist]

Hermes_Trismegistus - 28-11-2003 at 02:31

fascinating conversation guys!

but....maybe......

....http://www.onlinemetals.com/

Hermes_Trismegistus - 28-11-2003 at 02:32

also

what is patent # for BLACK HOLE BLACK

I had read about it in an unrelated publication and I too am VERY curious!:o

BromicAcid - 17-12-2003 at 18:16

I forget the exact specifications but nickel can be extracted from copper by fusing with sulfur and sodium hydroxide (at high heat of course, it is fusing) The copper sulfide is soluble in the molten hydroxide whereas the nickel is not, upon cooling there are two distinct layers, I believe the upper is nickel sulfide and the bottom the mixture of copper sulfide and sodium hydroxide, and such. If anyone is interested give me a holler and I'll get the specifics.

Also as a side question, does anyone have any experience with nickel electroforming?

Tacho - 18-12-2003 at 09:56

A description of the process:

http://www.newscientist.com/news/news.jsp?id=ns99993356

It seems that you can deposit the proper nickel alloy by immertion "for five hours in a solution of nickel sulphate and sodium hypophosphite"

Of course, the devil lies in the details.

unionised - 18-12-2003 at 12:15

Here is a place to start
http://yarchive.net/metal/electroless_nickel.html

Tacho - 19-12-2003 at 09:15

It seems that the electroless deposited nickel is perfect for super black.

I am very interested in depositing nickel in non-conductive surfaces. I intend to give it a try soon, but I cold not get sodium hypophosphite, only magnesium hypophosphite.

I presume that, if it is soluble, the reducing power of the hypophosphite ion will be enough to make a deposit. I will use an alkaline bath, with ammonium chloride and nickel chloride.

BTW, doing searches on hypophosphites, I found that they are soon to be controlled chemicals in the US.

A very comprehensive study about electroless nickel is here:
http://www.ias.ac.in/sadhana/Pdf2003JunAug/Pe1104.pdf

Tacho - 20-12-2003 at 08:51

I tried a solution of 3 parts nickel chloride, 3 parts magnesium hypophosphite, 10 parts ammonium chloride, and 50 parts water. The exact amounts don’t seem to be crucial. I used a glass flask and heated it to 90ºC. Inside I put a Cu wire and a wood rod. After 1 hour, nothing had happened. I tossed in a solder wire, because it has Sn, and Uncle Al said in sci.chem that you have to prepare the surface using Sn ions. Whatever.

I left the reaction unatended for a couple of hours and when I came back, all the water had boiled away. I didn’t use any thermostat.

There was shiny nickel in the Cu wire, there was powdered nickel on the wood rod, there was NO nickel in the glass surface and there was nickel on the solder wire. Filling the flask again with water I noticed there was also flat nickel flakes floating about, just a few.

I put the Cu wire in dilute nitric acid. It reacted and eventually peeled off, but at no moment it became black. I guess the alkaline bath, using ammonium chloride, doesn’t deposit phosphorus enough.

I wonder how can I prepare a ceramic surface to be plated this way.

unionised - 20-12-2003 at 14:59

I might look into silvering the surface (search on amateur telescope making) and then nickel plating that. Slightly ironic to start the process of making something black by coating it with silver.

nodrog19 - 23-6-2008 at 18:05

the penny was changed in 1983

Porous Nickel

jarynth - 3-10-2008 at 05:15

As a follow up to my Castner cell experiments, I tried to take advantage of nickel's and copper's different resistance to oxidation in hot alkali. As often mentioned in the electrolytical sodium thread, a Ni anode in molten NaOH won't corrode, whereas Cu immediately starts getting oxidized, as evidenced by the blue tinge diffusing from the anode. This principle should allow us to extract the Cu from suitable coins if these are used as anodes in the NaOH melt (unless the presence of Cu makes Ni more vulnerable) and obtain a sort of Ni sponge.

Unfortunately, I didn't have the patience to melt NaOH again so I just took as the electrolyte a concentrated aqueous solution of NaOH instead. This did NOT work as desired. However, a large worn (= previously used in other experiments) 75/25 Cu/Ni coin regained its shine. The electrolysis probably removed the metallic salt and oxide residues on the surface. After the experiment, the coin actually looked rather greyish, kinda like pure nickel, but this could be due to the sandpapering done before the electrolysis.

Circulating coins made of pure nickel

pantone159 - 3-10-2008 at 07:02

A number of circulating coins are 'pure' nickel. (I might be off by 1 or so on some of the dates, I don't have my notes with me right now):

Most Canadian nickels before 1982 (some exceptions during WW2/Korean War)
Most Canadian 10/25/50 cent from 1968-1999.
Many Netherlands and France coins (no Euro coins though), e.g. 1/2 Fr and 1 Fr are Ni I think.

I am interested in a more complete list, as I collect elements, and these coins are cheap and so fun and easy to collect.

As far as copper cents, US cents before 1982 are 95% Cu, those after 1982 are Zn, 1982 goes either way. To distinguish, weigh them, Cu cents weigh c. 3.1 g, Zn cents weigh 2.5 g.
Canadian cents were 98% Cu until more recently, maybe the late 90's, I don't remember for sure. I think a lot of older UK coins are close to pure Cu as well.

woelen - 3-10-2008 at 09:27

Dutch pre-euro coins were 99.5% nickel with a little other stuff mixed in (IIRC tin, and some metalloid elements). The coins which were nickel are
- 10 cents, 1948 and later (dubbeltje)
- 25 cents, 1948 and later (kwartje)
- 1 guilder, 1969 and later (gulden)
- 2.5 guilders, 1969 and later (rijksdaalder)

We also had 1 cent and 5 cents coins. There were made of pure copper, starting from 1948.

Unfortunately this nice source of pure copper and nickel has gone when the euro was introduced. I am happy to have saved almost 1 kilo of dubbeltjes and kwartjes. 1 dubbeltje is 1.5 grams of nickel, one kwartje is 3 grams of nickel. So, the total value of coins is only 30..35 guilders, appr. EUR 15.

ssdd - 4-10-2008 at 12:02

This may sound a bit obvious, but at the cost of dissolving so many coils to collect the nickel would it not be a bit more economical to purchase the metal itself and not worry about purity?

United Nuclear sells Ni strips for $3 each (5in by .75in)

This is at least if you want to use the metal for other experiments, but if you just want to prove you can extract it I guess that works too....

-ssdd

woelen - 4-10-2008 at 14:51

The nickel coins from NL are very pure nickel, so there is no need to worry about that. Actually, they are a fantastic source of pure nickel. It also allows dissolving small amounts (the small coins only are 1.5 grams) and the cost of the coins probably is less than buying nickel strip from some supplier.

ssdd - 4-10-2008 at 15:24

Ah OK, I was thinking more in the terms of American coins when I had made that statement. But I could see how having coins with a much higher percentage of Ni in them would make it much more economical.

I just had this funny mental image of people taking massive amounts of Nickels and dissolving them.... :P

-ssdd

pantone159 - 4-10-2008 at 17:16

I've bought Canadian 25 cent coins at less than Ni spot before. Mainly I am just collecting them (like I collect other elements).

As for alloys like 75 Cu/25 Ni (US 5 cent coins) and similar, I agree, it is kind of silly to extract the separate metals, unless you just feel like doing it. But there are close to pure coins, for various elements.

JohnWW - 5-10-2008 at 05:49

Cupro-nickel, usually 75% Cu 25% Ni, is widely used as imitation "silver" coinage in many countries. Until about 1900, almost pure Ag was used (I have one or two such coins), then until sometime between about 1946 and 1963 alloys of about 50% Ag, 37.5% Cu, 12.5% Ni were used, and after that no Ag at all (except in special commemorative coins).

That being the case, I wonder what efficient means of separating Cu and Ni could be used on cupro-nickel. An obvious one would be the carbonyl process used for purifying Ni industrially, but generating and using large amounts of CO in a laboratory would be very dangerous.

[Edited on 6-10-08 by JohnWW]

12AX7 - 5-10-2008 at 06:50

Quote:
Originally posted by JohnWW
but generating and using large amounts of CO in a laboratory would be very dangerous.


Gnaw, CO isn't much of a pain, it's quite easy to stack charcoal, blow a mild current through it and get a billowing dark blue flame out the top, pure CO burning in air. Tap off as much as you'd like, or do it inside pyrex tubing heated with a bunsen burner.

Now generating and using large amounts of Ni(CO)5 in a laboratory would be very dangerous.

Tim

unionised - 5-10-2008 at 08:08

Quote:
Originally posted by 12AX7
Quote:
Originally posted by JohnWW
but generating and using large amounts of CO in a laboratory would be very dangerous.


Gnaw, CO isn't much of a pain, it's quite easy to stack charcoal, blow a mild current through it and get a billowing dark blue flame out the top, pure CO burning in air. Tap off as much as you'd like, or do it inside pyrex tubing heated with a bunsen burner.

Now generating and using large amounts of Ni(CO)5 in a laboratory would be very dangerous.

Tim

Dangerous, and quite tricky since it only forms the tetracarbonyl.

12AX7 - 5-10-2008 at 09:15

Oops, that's iron. http://en.wikipedia.org/wiki/Metal_carbonyl#Charge-neutral_b...