Peter Atwood on mon 11 jan 99
Hi folks,
Here's a question for the clayart collective.
I have been making batches of the ^10 glaze known as
"moonlight" for the past few months and have been very
happy with the results. Over my white stoneware body
I get a subtle almost pastel variation of colors with
sprinkles of titanium crystals that look like fields of
flowers. On a darker, orangy body I get a dark purply
blue with sprinkles of rusty orange iron crystals. Both
are gorgeous. Recently I have been adding small amounts
of cobalt and copper carb to vary the color and deepen the
blues a bit. This glaze was my best seller this past fall.
It has powdered illmenite as one of the ingredients.
I've seen the recent posts on powdered illmenite and
the possibility that there could be a shortage- whether
or not this is true I don't know. Anyhow, I just picked up
5 lbs of it from Sheffield Pottery (my favorite supplier)
because we are running low on the old product at the studio
and I did not want to be caught with my pants down if indeed
there turned out to be a shortage.
Well, when I got the new bag back home I opened it up
and sure enough, there is a major difference in appearance
compared to the old stuff. The new is definitely a fine
dark gray powder and looks a lot like a very dark rutile.
The old powdered illmenite is a fine black sand. We also have
a jar of granular illmenite at the studio which is a coarse
and heavy black sand.
I'm wondering, Is the old material really two grades of
granular illmenite? If so, then I suppose this new powdered
substance will have a substantial effect on my glaze perhaps
a very good effect but different.
Any comments about differences in these products or light and
dark rutiles would be most welcome.
Thanks,
--Peter Atwood
fountainman@hotmail.com
______________________________________________________
Get Your Private, Free Email at http://www.hotmail.com
David Hewitt on tue 12 jan 99
In message , Peter Atwood writes
>----------------------------Original message----------------------------
>snip
>Well, when I got the new bag back home I opened it up
>and sure enough, there is a major difference in appearance
>compared to the old stuff. The new is definitely a fine
>dark gray powder and looks a lot like a very dark rutile.
>The old powdered illmenite is a fine black sand. We also have
>a jar of granular illmenite at the studio which is a coarse
>and heavy black sand.
I have experienced similar colour / appearance variation with Rutile and
would also be interested in knowing more about the source of these
materials and how better to specify what one wants when repeating an
order. I feel sure that Tom Buck could help here.
>
>I'm wondering, Is the old material really two grades of
>granular illmenite? If so, then I suppose this new powdered
>substance will have a substantial effect on my glaze perhaps
>a very good effect but different.
I have certainly found that different colour / /appearance Rutile makes
a difference to the glaze - in my case not a beneficial difference.
>
>Any comments about differences in these products or light and
>dark rutiles would be most welcome.
>
>Thanks,
>
>--Peter Atwood
>
>fountainman@hotmail.com
>
>______________________________________________________
>Get Your Private, Free Email at http://www.hotmail.com
>
--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP6 1DQ, UK. Tel:- +44 (0) 1633 420647
FAX:- +44 (0) 870 1617274
Own Web site http://www.dhpot.demon.co.uk
IMC Web site http://digitalfire.com/education/people/hewitt.htm
Harry Verkooyen on wed 13 jan 99
-------Yes sir-rey, it makes a big differences. The grandular stuff makes
spots in the glaze and the fine gives a range of color from beige to bluish,
purply beige. I use an illimite glaze over browns to spice them up.
Michelle
-----Oorspronkelijk bericht-----
Van: David Hewitt
Aan: CLAYART@LSV.UKY.EDU
Datum: woensdag 13 januari 1999 2:28
Onderwerp: Re: illmenite question
----------------------------Original message----------------------------
In message , Peter Atwood writes
>----------------------------Original message----------------------------
>snip
>Well, when I got the new bag back home I opened it up
>and sure enough, there is a major difference in appearance
>compared to the old stuff. The new is definitely a fine
>dark gray powder and looks a lot like a very dark rutile.
>The old powdered illmenite is a fine black sand. We also have
>a jar of granular illmenite at the studio which is a coarse
>and heavy black sand.
I have experienced similar colour / appearance variation with Rutile and
would also be interested in knowing more about the source of these
materials and how better to specify what one wants when repeating an
order. I feel sure that Tom Buck could help here.
>
>I'm wondering, Is the old material really two grades of
>granular illmenite? If so, then I suppose this new powdered
>substance will have a substantial effect on my glaze perhaps
>a very good effect but different.
I have certainly found that different colour / /appearance Rutile makes
a difference to the glaze - in my case not a beneficial difference.
>
>Any comments about differences in these products or light and
>dark rutiles would be most welcome.
>
>Thanks,
>
>--Peter Atwood
>
>fountainman@hotmail.com
>
>______________________________________________________
>Get Your Private, Free Email at http://www.hotmail.com
>
--
David Hewitt
David Hewitt Pottery ,
7 Fairfield Road, Caerleon, Newport,
South Wales, NP6 1DQ, UK. Tel:- +44 (0) 1633 420647
FAX:- +44 (0) 870 1617274
Own Web site http://www.dhpot.demon.co.uk
IMC Web site http://digitalfire.com/education/people/hewitt.htm
Tom Wirt on thu 14 jan 99
Hi Peter.
One of the things we discovered about illmenite when we went through some
problems about a year ago, is that illmenite is prepared in at least 3
different screens. 325 mesh, 200 mesh Also called milled, and 100 mesh
granular. They each have widely varying responses in the glaze, especially
Moonlight which we also use. Only the 325 mesh works (we last got it from
Mile-Hi in Denver). I suspect you need the fine grind to disperse the
titania. At the larger meshes the glaze went more iron green/brown.
Tom Wirt,
Ian Hodgson on tue 19 jan 99
Just spoke to my daughter, who is a mineral sands metallurgist. Ilmenite
consists of TiO2 and Fe2O3. It can also contain traces of chromium. The
proportion of iron oxide can vary - up to about 5 to 6% seems to be regarded
as generally acceptable variation. This would explain the variation in
glazes using ilmenite from different sources.
Ian Hodgson
Canberra
> -----Original Message-----
> From: Harry Verkooyen [SMTP:hvia@wxs.nl]
> Sent: Thursday, January 14, 1999 8:27 AM
> To: CLAYART@LSV.UKY.EDU
> Subject: Re: illmenite question
>
> ----------------------------Original message----------------------------
> -------Yes sir-rey, it makes a big differences. The grandular stuff
> makes
> spots in the glaze and the fine gives a range of color from beige to
> bluish,
> purply beige. I use an illimite glaze over browns to spice them up.
> Michelle
> -----Oorspronkelijk bericht-----
> Van: David Hewitt
> Aan: CLAYART@LSV.UKY.EDU
> Datum: woensdag 13 januari 1999 2:28
> Onderwerp: Re: illmenite question
>
>
> ----------------------------Original message----------------------------
> In message , Peter Atwood writes
> >----------------------------Original message----------------------------
> >snip
> >Well, when I got the new bag back home I opened it up
> >and sure enough, there is a major difference in appearance
> >compared to the old stuff. The new is definitely a fine
> >dark gray powder and looks a lot like a very dark rutile.
> >The old powdered illmenite is a fine black sand. We also have
> >a jar of granular illmenite at the studio which is a coarse
> >and heavy black sand.
> I have experienced similar colour / appearance variation with Rutile and
> would also be interested in knowing more about the source of these
> materials and how better to specify what one wants when repeating an
> order. I feel sure that Tom Buck could help here.
> >
> >I'm wondering, Is the old material really two grades of
> >granular illmenite? If so, then I suppose this new powdered
> >substance will have a substantial effect on my glaze perhaps
> >a very good effect but different.
> I have certainly found that different colour / /appearance Rutile makes
> a difference to the glaze - in my case not a beneficial difference.
> >
> >Any comments about differences in these products or light and
> >dark rutiles would be most welcome.
> >
> >Thanks,
> >
> >--Peter Atwood
> >
> >fountainman@hotmail.com
> >
> >______________________________________________________
> >Get Your Private, Free Email at http://www.hotmail.com
> >
>
> --
> David Hewitt
> David Hewitt Pottery ,
> 7 Fairfield Road, Caerleon, Newport,
> South Wales, NP6 1DQ, UK. Tel:- +44 (0) 1633 420647
> FAX:- +44 (0) 870 1617274
> Own Web site http://www.dhpot.demon.co.uk
> IMC Web site http://digitalfire.com/education/people/hewitt.htm
Tom Buck on thu 21 jan 99
Since you (David Hewitt) suggested I report on ilmenite (crude TiO2.FeO) I
checked on some reference tomes in our local library.
Two countries, Australia and Canada, mine and ship a large share
of the world's trade in ilmenite. For example, USA regularly imports 500
million kilograms from Australia, and 200+ million kilograms from Canada.
Both countries also ship a product called "titanium slag" a byproduct of
processing crude ilmenite to separate the iron oxide from the titanium
oxide.
World trade in rutile is quite small these days, although
Australia is still a major supplier, perhaps 5 million kilograms yearly.
Most local rutile comes from plants that process ilmenite for production
of high-white titanium IV oxide ("dioxide"); the rutile is an intermediate
product recovered during processing.
Depending on where individual potters live, they could be
supplied with Aussie or Cdn ilmenite and these two are surely quite
different in physical form, and would also vary with time as new bulk
shipments arrive.
If you use a lot of ilmenite and wish to avoid retesting new
material, it may be best to buy several bags, enough to last a production
potter for say 2-3 years. Then you'd do a new series of tests when new
bags arrive. For most of us, however, a 25-kg bag would be sufficient.
Is this enough for you, David, or do you wish me to probe further?
Best regards. Tom.
Tom Buck ) tel: 905-389-2339 & snailmail: 373 East
43rd St. Hamilton ON L8T 3E1 Canada (westend Lake Ontario, province of
Ontario, Canada).
Edouard Bastarache on sun 24 jan 99
Hello Tom,
sorry to disagree again. I made a phone call to Andri Marchesseault,
a chemical engineer with QIT-Quebec Iron & Titanium.
He says that "natural rutile" exists as such in beach sands of many
countries,
the richest being in Australia, South Africa and Florida.In Australia this
kind
of rutile contains 92% Tio2.
"Synthetic rutile" is as you said obtained in the process of refining
ilmenite.
Here at their plant in Tracy Quebec it contains 96% Tio2.
As for ilmenite deposits the concentrations in Tio2 vary from 37% to 60%,
60% being from a mine in Madacascar.
Till our next argument on ilmenite(heheehe) best of luck,
Edouard Bastarache
edouardb@sorel-tracy.qc.ca
http://www.sorel-tracy.qc.ca/~edouardb/
-----Message d'origine-----
De : Tom Buck
@ : CLAYART@LSV.UKY.EDU
Date : 22 janvier, 1999 08:30
Objet : Re: illmenite question
----------------------------Original message----------------------------
Since you (David Hewitt) suggested I report on ilmenite (crude TiO2.FeO) I
checked on some reference tomes in our local library.
Two countries, Australia and Canada, mine and ship a large share
of the world's trade in ilmenite. For example, USA regularly imports 500
million kilograms from Australia, and 200+ million kilograms from Canada.
Both countries also ship a product called "titanium slag" a byproduct of
processing crude ilmenite to separate the iron oxide from the titanium
oxide.
World trade in rutile is quite small these days, although
Australia is still a major supplier, perhaps 5 million kilograms yearly.
Most local rutile comes from plants that process ilmenite for production
of high-white titanium IV oxide ("dioxide"); the rutile is an intermediate
product recovered during processing.
Depending on where individual potters live, they could be
supplied with Aussie or Cdn ilmenite and these two are surely quite
different in physical form, and would also vary with time as new bulk
shipments arrive.
If you use a lot of ilmenite and wish to avoid retesting new
material, it may be best to buy several bags, enough to last a production
potter for say 2-3 years. Then you'd do a new series of tests when new
bags arrive. For most of us, however, a 25-kg bag would be sufficient.
Is this enough for you, David, or do you wish me to probe further?
Best regards. Tom.
Tom Buck ) tel: 905-389-2339 & snailmail: 373 East
43rd St. Hamilton ON L8T 3E1 Canada (westend Lake Ontario, province of
Ontario, Canada).
Cheryl Tall on mon 25 jan 99
> ----------------------------snip----------------------------
> He says that "natural rutile" exists as such in beach sands of many
> countries,
> the richest being in Australia, South Africa and Florida.In Australia this
> kind
> of rutile contains 92% Tio2.
> ---------------------------snip-----------------------------
Dear Edouard:
I live in Florida close to the beach, and I also use rutile in my glazes and
slips. How does one extract the rutile from the beach sand? I would like to
incorporate this natural material into my glazes.
Thanks,
Cheryl Tall
chryltal@belsouth.net
>
>
>
Edouard Bastarache on tue 26 jan 99
Hello Cheryl,
i dont know how but i know the deposit is owned by Dupont And i dont know
where the deposit is. I will get back to my engineer friend this week and
try to find the location.If i find the location i will notify the list.
Later,
Edouard Bastarache
edouardb@sorel-tracy.qc.ca
http://www.sorel-tracy.qc.ca/~edouardb/
-----Message d'origine-----
De : Cheryl Tall
@ : CLAYART@LSV.UKY.EDU
Date : 25 janvier, 1999 20:45
Objet : Re: illmenite question
>----------------------------Original message----------------------------
>
>
>
>> ----------------------------snip----------------------------
>> He says that "natural rutile" exists as such in beach sands of many
>> countries,
>> the richest being in Australia, South Africa and Florida.In Australia
this
>> kind
>> of rutile contains 92% Tio2.
>> ---------------------------snip-----------------------------
>
>Dear Edouard:
>
>I live in Florida close to the beach, and I also use rutile in my glazes
and
>slips. How does one extract the rutile from the beach sand? I would like
to
>incorporate this natural material into my glazes.
>
>Thanks,
>Cheryl Tall
>chryltal@belsouth.net
>
>>
>>
>>
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