Nickel oxide versis nickel carbonate

Question? I want to try some Nickel oxide or nickel carb as a colorant
in my glaze. Does anyone know the pros and cons of using one instead of the
other. I know that nickel carbonate is less expansive.

B Macdugal

On Wed, 08 Oct 2003 22:59:42 GMT, "Bruce on Earthlink"
wrote:

Question? I want to try some Nickel oxide or nickel carb as a colorant
in my glaze. Does anyone know the pros and cons of using one instead of the
other. I know that nickel carbonate is less expansive.

Nickel carb has less nickel per pound, so while it is less expensive
more nickel carb will be required than nickel oxide to get the same
effect. You'll likely find that the same dollar amount is needed to
get the same amount of nickel with either so the cost difference
probably isn't meaningful. With cobalt, the carbonate disperses
better in glazes and is less likely to cause spotting as the oxide
can. I don't know if you'll see a similar effect with nickel.

deg

fyi: there are two nickel oxides and one nickel carbonate basic
offered commercially:
nickel-3 oxide: gray-black powder, Ni2O3, density 4.84 g/mL, on
firing at 600 oC it changes to:

nickel-2 oxide: green powder, becoming yellowish on standing,
density 6.6-6.8 g/mL, on firing at 400 oC it changes to nickel-3 oxide
which reverts to nickel-2 oxide at 600 oC.

nickel carbonate basic: uncertain composition, probably
NiCO3.2Ni[OH]2.4H2O comes closest to its formula. This comes as light
green cystals or brown powder, density 2.6 g/mL. made by combining
soda ash, Na2CO3, to a solution of of nickel-2 sulfate aka sulphate.
this compound on firing above 600 oC becomes nickel-2 oxide.

ask your supplier to tell you the amount of Nickel (elemental form)
in the material you buy. it is the only way you can compare the
above compounds since their compositions are variable from time
to time.
also be aware that nickel-2 oxide may be toxic in some
fired glazes because it can be solubilized by weak (dilute)
acids ... vinegar, lemon juice, orange juice.
so do not use it in a liner glaze without careful testing and
analysis.

Tom Buck aa563 at hwcn.org -- primary address. Tom.Buck at hwcn.org
"alias" or secondary address.
tel: 905-389-2339 (westend Lake Ontario, province of Ontario, Canada).
mailing address: 373 East 43rd Street, Hamilton ON L8T 3E1 Canada

Unless it is essential, I would strongly suggest that you avoid using nickel
salts. These have been classified as confirmed human carcinogens. Their use
in industry inside the European Union is, quite rightly, very tightly
controlled.