Wyndham Dennison on thu 24 apr 08
>
> Say, as and illustration only, a kilogram of glaze requires one litre of =
> water, Mass 1000 grams. So of the glazes the one with 20% Lithium Carb =
> will have 200 grams of Lith carb. Of this 15 grams will dissolve in 1000 =
> grams of water. This leaves 185 grams to contribute fluxing action to =
> the glaze. The recipe containing 2% will contribute 20 grams but the =
> water content remains constant, 1000 grams. The solubility does not =
> alter, still 15 grams/ litre. This only leaves 5 grams to contribute =
> fluxing qualities to the glaze.
>
> Now I am unsure that answers your question.
>
> Best regards,
>
> Ivor Lewis.
Ivor, you are correct as to the amt that goes into solution, but when a
bisque piece is dipped, the glazes and solution go into the piece. The
problem is that the concentration of soluble% changes with time, use and
evaporation, making it a changing %. If the glaze mentioned above were
used on 100 identical pots, the issue, for me, would be the movement of
the lithium onto the clay body by way of solution, which would seem to
flux the body and in turn influence the glaze.
As mentioned some frits also have a solubility issue but we work with
these as well as Shino glazes that use soda ash or wood ash in others.
Lithium is just a very reactive element. I used to work in a lithium
mine in Silver Peak, NV We pumped lithium chloride out of an old
submerged lake and after concentrating it through evaporation added
magnesium carb(I think) to make lithium carb then heat treated this to
get the lithium carb powder(about 1978)
Just my 2cent on it, I'd rather use spodumene(sp) if possible. BTW there
were about 100 fellows(town pop was 134) working in this little Nev town
and even at the bar(cafe, laundry) on Saturday nights it was a very
mellow place. We sometimes shoveled Lith Carb like snow into dump trucks
when a bagging machine broke or just on cleanup day. Wyndham
Hank Murrow on thu 24 apr 08
On Apr 24, 2008, at 6:49 AM, Wyndham Dennison wrote:
>> I used to work in a lithium
> mine in Silver Peak, NV We pumped lithium chloride out of an old
> submerged lake and after concentrating it through evaporation added
> magnesium carb(I think) to make lithium carb then heat treated this to
> get the lithium carb powder(about 1978)
>
Dear Wyndham;
I never knew about that operation when I had my PotShop in Venice CA
in the early sixties. We used to go out in the desert for kaolin and
feldspar and obsidian, but I wish I had known about the lithium. It
has always been my glaze 'spice' of choice!
Cheers, Hank
www.murrow.biz/hank
Ivor and Olive Lewis on fri 25 apr 08
Dear Wyndham Dennison,
I used to visit a Magnesia Factory. They extracted Magnesium chloride =
from the ocean and precipitated Magnesium carbonate by mixing with =
limestone , or for an increased yield, with Dolomite. To get refractory =
grade Magnesium oxide the precipitate was calcined at about 1400 deg C.
I understand the points you are making. The question to which I would =
like an answer relates to the reaction between Lithium Carbonate and =
free silica or silicate minerals. That is the lowest temperature at =
which this reaction can take place. I ask because the melting point of =
Lithium silicates over 1200 Deg C. This would seem to immobilise Lithium =
carbonate or oxide as an active flux.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
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