search  current discussion  categories  glazes - specific colors 

blue face powder

updated sat 24 apr 04

 

Ivor and Olive Lewis on fri 23 apr 04


Dear Tony,
Interesting condiments if you have the stomach for that sort of thing.
Now what are talking about. Do you mean "Trialings". Or do you mean
"Tailings".
If it is the latter from your abandoned mine then take care. IF it is
just mine waste, could be anything but those boys were always loathe
to throw good paydirt away. I know, I worked for the Deloro Team in
the UK. If it is the residue from flotation or other beneficiation
then it may be pure dirt and full of nasties.
Usual process is to roast the ore to get rid of Sulphur and Arsenic.
Oxidation is essential. Then they dissolve in an acid and follow up
with electrolysis to throw down the pure metal.
I made my own Cobalt oxide back in 1957. Took the pure metal powder,
dissolved it in strong Nitric acid then roasted the cobalt nitrate.
Made my first glaze, half clay / half red lead with a pinch of my own
Cobalt oxide.
Cobalt Ores from Cobalt and Deloro were Cobalt Arseno Sulphides.
Quaint sort of mixture which might give a low melting point glaze. Not
sure about Arsenic as a ceramic additive. It is a Glass Former so you
might get Phase Separation in Silicate melts. Gives glaze an
opalescence. Sounds good, a blue opalescent glaze, could have
fantastic character.
If your tests are throwing out a mauve then you may have some Titanium
oxide from somewhere. Could be in your Granite.
Hey man, this Dingo talks "Strine"
All the best.
Ivor Lewis. Redhill, South Australia


----- Original Message -----
From: "clennell"
To:
Sent: Thursday, 22 April 2004 10:01
Subject: Dessert Toppings- Ivor


> Dear Ivor: You're my rock man next to Hank and Steve h who must
have left
> Dodge chased by a Clayarter that has been putting bone ash on their
morning
> cereal.
> I put liberal quantities of beautiful purple cobalt carb and a
sprinkle of
> cobalt oxide on my favourite Ben and Jerry's Cherry Garcia ice
cream. The
> taste is chalky but the presentation is FABULOUS!
> I have just been given a large supply of "raw cobalt" trailings from
a very
> old and closed mine in Cobalt, Ontario. The colour is grey which
ain't great
> for presentation but the taste is similiar.
> I loaded up a granite, limestone glaze with 3% raw cobalt expecting
a
> Mels'Mother in law blue on the test tile. The colour was in fact a
very
> light subtle mauve.
> My question is this- do they chemically remove cobalt from the rock
and if
> so how is this done? Please repy in the Queen's English so I can
understand
> what you're telling me.
> Thanks ya ol bag of dirt- that's a compliment!
> cheers,
> Tony
>
> Tony and Sheila Clennell
> Sour Cherry Pottery
> 4545 King Street
> Beamsville, Ontario
> CANADA L0R 1B1
> http://www.sourcherrypottery.com
>
>
______________________________________________________________________
________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your
subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.