YT2095 - 19-10-2006 at 01:26
I`m trying to get a reasonable sample of Ni metal for my element collection, I have 15ml of near saturated Nickel Nitrate.
now I see it as I have 3 choices basicly.
1) Displacement reaction with another metal such as Mg.
2) a Thermit reaction with the Oxide.
3) Plating out.
the problems I can see with each is that a displacement reaction and magneticaly harvested often gives a powder that doesn`t represent the true
qualities of Ni 9it would look crap in a vial).
there`s also not really enough for a decent thermit reaction although a nugget would look good.
plating gives a very nice result, but everytime I plate to a carbon electrode, although it`s easy enough to cut and peel off afterwards, it always
leaves black carbon deposits on the reverse side.
also with an MP of 1728k I`de have no way of melting/casting it.
anyone have any advice or alternative methods to get a reasonable sample?
not_important - 19-10-2006 at 02:28
Displacement using a metal only a bit higher in the electromotive series, and not too concentrated of a solution, can give fairly smooth deposits or
"trees" which look nice. Iron is a little above nickel, might be worth a try.
Plating - try making an electrode from graphite rubbed on a piece of plastic that has been roughend with fine sandpaper. After plating the Ni layer
should peel off, and can be buffed to remove any graphite.
The "readily available chemicals list" gives three ceramics supplies in the UK that carry nickel compounds. The carbonate, sulfate, and oxides are all
commonly used, which should give you the option of going for plating or Goldschmidt for a lump of nickel.
YT2095 - 19-10-2006 at 02:57
well I`ve diluted a portion 1:10 so it`s a little like green moutwash color, and as luck would have it I made a nugget of reasonably pure iron via a
thermit reaction a few weeks ago, there is a distinct color change around the iron now and tiny bubbles have formed around it, it seems to be going
well.
with the rest I`ve diluted that 1:3 and am now passing a current through it using carbon anode and graphite (pencil lead) as the cathode, as it`s much
smoother.
oddly there`s no plating and both A and K fizz with sufficient current, there`s not even a Hint of any metal being produced.
I`m thinking it might be an idea to scrap this nitrate and make the hydroxide, and then dissolve that in H2SO4 to make the sulphate, perhaps that
would be a better electrolyte for plating?
if nothing else, at least I`ve learned the Nickel Nitrate makes a lousey electro-plating soln 
woelen - 19-10-2006 at 03:30
IIRC the best solution for electroplating nickel is a mix of nickel sulphate and nickel chloride. I would precipitate the nitrate with carbonate or
hydroxide, and then rinse the precipitate and dissolve in a mix of HCl and dilute H2SO4.
YT2095 - 19-10-2006 at 06:11
well I`ve done that, and now there is a strong smell of Cl2, both the anode And the cathode are fizzing equaly, although the anode bubbles form a type
of "Raft" with a slight brown color (probably off the Carbon) although it`s not being corroded as anodes Normaly do. the cathode has a seemingly equal
volume of bubbles but White no brown crap.
if I up the current to a feirce bubble then black matter comes off the cathode, however it doesn`t seem to be strongly attracted to a magnet in any
noticable way that Ni metal would be.
if I didn`t know better, I`de think this thing was making Nickel Chlorate LOL
eitherway, it`s a Nil result.
not_important - 19-10-2006 at 06:13
To back woelen up :
The Watts nickel bath that is used in this process can be described as follows:
280 g L-1 NiSO4.6H2O, 40 g L-1 NiCl2.6H2O, enough boric acid to buffer the pH at about 4 (note, this compound does not introduce a significant
population of ions). The density of nickel is 8.9 g cm-3 and the current efficiency for plating is virtually 100%.
The nickel chloride is used to corrode nickel anodes, if you are using inert anodes then the NiCl2 can be greatly reduced or eliminated.
Another bath uses around 375 g/L of nickel sulfamate and boric acid to pH 4.
Also see
http://www.inco.com/customercentre/nickelplating/science/pdf...
YT2095 - 19-10-2006 at 06:38
I don`t distrust Woelen or his advice (we are good friends), however I can only state my findings, and it didn`t work here at all.
it is noteworthy to also state that I used No Boric acid (I have no sulphamate of Nickel, I only have the acid itself) and yes I did use inert
electrodes.
I think what I shall do now, is filter off this soln from the crap, and then put a chunk of Mg in the vessel and shelve it for a few months in the
"Long term" section.
and then basicly I`ll just have to start a new batch whilst the long term project does it`s thing.
at least that way I get my Nickel Back ))
there`s a joke in there somewhere...
woelen - 19-10-2006 at 11:37
The solution of NiCl2/NiSO4 must not contain too many cations besides the nickel ions. So, if there is a lot of acid in the solution as well, or a lot
of sodium ions, then part of the current is used for making H2 at the cathode. This totally spoils the plating process. The white crap you mention
probably is finely divided Ni(OH)2, which looks white in the otherwise green solution.
If you want more nickel to experiment with, then try to obtain some NiO from an eBay seller or a ceramics shop. This stuff dissolves in acid quite
well (requires some heating) and is cheap (right now, there is a buy now item on eBay for GBP 4.99, 250 grams of NiO).
Mr. Wizard - 19-10-2006 at 16:19
See the link below for Raney Nickel:
http://en.wikipedia.org/wiki/Raney_nickel
Maybe you can get your Nickel back by making the Aluminum concentration high enough to dissolve in NaOH, releasing the Nickel. Be careful, it's
supposed to be pyroforic. They also have a nice phase diagram.
There was a method of welding that used a sheet of material consisting of many alternating thin layers of Nickel and Aluminum, only a few (?) atoms
thick. The very thin leaf of material was placed between the two metal objects to be welded and the exposed edge of the layered material was ignited.
The very fast reaction forming the Nickel/ Aluminum alloy welded the two metal objects together. Think of the applications, you could weld an engine
together, and not use any bolts. ;-)