Ivor and Olive Lewis on wed 31 mar 04
Dear Friends,
A kaolin of super purity is being tested by Dr. C. Madivate at =
Universidade Eduardo Mondiane in Mozambique. (Source; Interceram Jan =
2004, Vol 52, No 1.pp 4-6 )=20
Called Muiane Kaolin it has a rational analysis of Clay 94.47%; =
K-Felspar 4.10%; Quartz 0.78% with Fe2O3 at 0.02% and TiO2 of 0.01% with =
other trace elements in the same low range.
Nothing has been said to indicate if this will be exported but it is one =
of those materials which could be of great value in making glazes, =
especially Blue Celadon because of the low TiO2 fraction.
Best regards,
Ivor Lewis. Redhill, South Australia
Craig Martell on wed 31 mar 04
Ivor wrote:
>A kaolin of super purity is being tested by Dr. C. Madivate at
>Universidade Eduardo Mondiane in Mozambique. (Source; Interceram Jan 2004,
>Vol 52, No 1.pp 4-6 )
>Nothing has been said to indicate if this will be exported but it is one
>of those materials which could be of great value in making glazes,
>especially Blue Celadon because of the low TiO2 fraction.
Hello Ivor:
Great, another white primary kaolin from somewhere other than my own back
yard, with no plans to export. Well, it's at least good to know that there
are some other primary deposits around, other than just Cornwall.
Several years ago a guy at one of the local art centers asked me to give a
presentation debunking the myth that porcelain was a rare, special type of
claybody and ware. I said, "Sure, I'll do that!" But the talk that I gave
was not quite what he had in mind when I got around to the topic of the
extreme rarity of true, primary china clays. All the kaolins we have
access to here in North America are secondary kaolins with more Fe And TiO2
than we would like. Geological processes hold none of us in favor. We
have what we have.
As far as the Blue Celadons go, I've found that it's better to formulate
them with zero kaolin. There's so much K Feldspar in the ones that I've
done that the alumina molecular equivalent is close to 0.5, so clay isn't
needed. I suspend them with additions of macaloid and I ball mill these
glazes enough to homogenize the particle sizes and this aids suspension.
thanx for letting us know about the kaolin, Craig Martell Hopewell, Oregon
ps...I haven't forgotten about copying the Jim Robinson articles for
you. I'm just very slow and sort of busy
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