Earl Krueger on tue 11 nov 03
Some months ago, as a fun exercise, I made
up 9 different clay body mixtures. They each
consisted of 100 parts of a 70/30 Kaolin/ball clay
mixture plus additions of 10, 25 and 40 parts of
Nepheline Syenite and 10, 25 and 40 parts of Silica.
I made each of these into a slurry and then dried
them out on a plaster slab to a somewhat wet
and sticky consistency. Then I got distracted by
the purchase of a wheel and they sat, wrapped
in plastic till now.
While cleaning up I ran across these and decided
to finish the experiment. One mixture in particular
was quite moist and I noticed that even though
it was stiff enough that I could make a very soft ball
of it and could even tear it into two pieces, if I let it
sit in my hand and jiggled it with a finger from my
other hand it turned into a liquid and ran through
my fingers. Really weird stuff.
My thoughts on the cause of this are that over time
Sodium ions dissolved from the NS and defloculated
the clay resulting in the thixotropy.
What say the experts? Is this a good guess or is
something else happening here?
Earl...
Bothell, WA, USA
David Beumee on wed 12 nov 03
Earl Kruger wrote:
One mixture in particular
> was quite moist and I noticed that even though
> it was stiff enough that I could make a very soft ball
> of it and could even tear it into two pieces, if I let it
> sit in my hand and jiggled it with a finger from my
> other hand it turned into a liquid and ran through
> my fingers.
The way neph sy melts in comparison to potash based spars proves its sodium
content is relatively high, likely high enough for enough leaching to occur
over time to cause the body to become highly thixotropic. By chance did the
sample in question contain 40 parts neph sy?
> Some months ago, as a fun exercise, I made
> up 9 different clay body mixtures. They each
> consisted of 100 parts of a 70/30 Kaolin/ball clay
> mixture plus additions of 10, 25 and 40 parts of
> Nepheline Syenite and 10, 25 and 40 parts of Silica.
> I made each of these into a slurry and then dried
> them out on a plaster slab to a somewhat wet
> and sticky consistency. Then I got distracted by
> the purchase of a wheel and they sat, wrapped
> in plastic till now.
>
> While cleaning up I ran across these and decided
> to finish the experiment. One mixture in particular
> was quite moist and I noticed that even though
> it was stiff enough that I could make a very soft ball
> of it and could even tear it into two pieces, if I let it
> sit in my hand and jiggled it with a finger from my
> other hand it turned into a liquid and ran through
> my fingers. Really weird stuff.
>
> My thoughts on the cause of this are that over time
> Sodium ions dissolved from the NS and defloculated
> the clay resulting in the thixotropy.
>
> What say the experts? Is this a good guess or is
> something else happening here?
>
> Earl...
> Bothell, WA, USA
>
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David Hendley on wed 12 nov 03
Yes, the soluble fluxes in the Nepheline Syeneite made
the claybody thixotrophic.
David Hendley
david@farmpots.com
http://www.farmpots.com
Wow, spellcheck does not like Nepheline, Syeneite, claybody,
or thixotrophic.
----- Original Message -----
From: "Earl Krueger"
< One mixture in particular
> was quite moist and I noticed that even though
> it was stiff enough that I could make a very soft ball
> of it and could even tear it into two pieces, if I let it
> sit in my hand and jiggled it with a finger from my
> other hand it turned into a liquid and ran through
> my fingers. Really weird stuff.
Snail Scott on wed 12 nov 03
At 11:25 PM 11/11/03 -0800, you wrote:
>...
>My thoughts on the cause of this are that over time
>Sodium ions dissolved from the NS and defloculated
>the clay resulting in the thixotropy.
I thnk you are right. -Snail
iandol on thu 13 nov 03
Dear Earl Krueger,=20
Interesting observation! I think you are on the money with your =
explanation.
Why not take a sample and treat it with Magnesium Chloride of Magnesium =
Sulphate ad see if that removes the effect.
Best regards,
Ivor Lewis. Redhill, South Australia
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