SBRANFPOTS@aol.com on sun 4 jul 99
Folks,
I received an inquiry from someone who is interested in a substitute for rice
husk ash. Anybody have an ideas? If so, please reply directly to Bruce
Triplett <>
Thanks,
Steven Branfman
June Perry on mon 5 jul 99
Tell them to buy a product called "Clean Sweep." It can be found in
janitorial supply stores. It is made of rice hull ash.
Regards,
June
Louis H.. Katz on mon 5 jul 99
The ash of the husks of rice are nearly all silica 99%+.
I would suggest a coarse grade of ground silica as a substitute. The ash has
been suggested as a source of silica for chips (computer not corn).
Louis
cc/ btripper@aol.com
Peter Atwood on tue 6 jul 99
Steve,
Phil Rogers in his book Ash Glazes, claims that you can get a reasonable
substitute for rice husk ash by taking regular wood ash and adding 80% to
90% silica. His contention was that it could be used in this way to
duplicate the tortoiseshell effects of ancient Chinese glazes. Well, I tried
this last week and the results were pitiful. The 20 ash 80 silica
combination I used did not melt at all on the test tile when applied by
itself and over Baymore Tenmoku it came out a nasty milky white that clearly
had melted into the glaze only because of the underlying ingredients. So
it's back to the drawing board for me.
--Peter Atwood
Date: Sun, 4 Jul 1999 17:37:49 EDT
From: SBRANFPOTS@aol.com
Subject: Rice Husk Ash
----------------------------Original message----------------------------
Folks,
I received an inquiry from someone who is interested in a substitute for
rice
husk ash. Anybody have an ideas? If so, please reply directly to Bruce
Triplett <>
Thanks,
Steven Branfman
_______________________________________________________________
Get Free Email and Do More On The Web. Visit http://www.msn.com
nikom chimnok on tue 6 jul 99
Hello,
Not sure if I know what I'm talking about here or not, but I understand that
rice husk ash is an amorphous silica, not crystilline, and thus has no
quartz inversion, and melts at a lower temperature. This from James
Danisch's "Clay Materials" or something like that (I've lost the book.)
Later,
Nikom
*******************************************
At 16:42 5/7/99 EDT, you wrote:
>----------------------------Original message----------------------------
>The ash of the husks of rice are nearly all silica 99%+.
>I would suggest a coarse grade of ground silica as a substitute. The ash has
>been suggested as a source of silica for chips (computer not corn).
>Louis
>
>cc/ btripper@aol.com
>
>
Daniel Semler on fri 18 aug 06
Hi Danny,
The analyses will vary a bit, perhaps quite a bit. The only =20
analyses I've seen were from a study done in Japan for the National =20
Institute of Health. They used two types of rice husk ash, each with =20
about 93% silica, 2 or 3% K2O and the remainder made up of less than =20
1% of Al2O3, Fe2O3, MnO, MgO, CaO and traces of Na2O and TiO2. It =20
should be noted that they then leached the ash with HCL and got rid of =20
most of the traces raising the SiO2 percentage to about 96-97%. The =20
silica content is amorphous rather than crystalline in structure.
So its used as Lee pointed out in glazes. As Hank mentioned its a =20
very fine silica as you tend to get from organic sources as far as I =20
can tell. It would be a decent source of silica in glazes if you can =20
get it cheaply. I would expect its fineness to promote better melting =20
than coaser grades of silica. I see no reason why it could not be used =20
as a filler in clay bodies but you'd want to make sure you had a =20
decent supply before going far with it.
I think I found it on the web actually. The full title is =20
Quantitative Analysis of Tridymite and Cristobalite Crystallized in =20
Rice Husk Ash by Heating, by Yasushi Shinohara and Norihiko Kohyama.
Thx
D
threereeds1 on fri 18 aug 06
Maurice,
What a useful and encouraging response to Danny's
inquirery about rice hull ash.
It would be great to see more posts from you.
Be well,
Tom King
----- Original Message -----
From: "Maurice Weitman"
To:
Sent: Friday, August 18, 2006 10:17 AM
Subject: Re: Rice Husk Ash
> At 03:54 -0400 on 8/18/06, Danny Floyd wrote:
>>Hi guys
>>Im kind of a newbie, more to Clayart than pottery, so I hope someone can
>>help. I d like to know why rice husk ash is used in pottery. I know its
>>made by burning of the outer bit of rice but not what it does. Why use it
>>in glazes? And can it be mixed with clay to make the pots? Does anyone
>>knwo
>>what its made of so I can try to use it in glaze calculations (Im trying
>>to
>>learn!) What can it be subbed with? Any info would be really great
>>
>>Thankyou in advance to anyone who can help
>
> Hello, Danny, and welcome to clayart.
>
> In time, you'll likely learn that one of the real benefits of clayart
> is its archives, but I'll hasten that and make the introduction here.
>
> At the bottom of each clayart message, you'll find the web address
> for the archives:
>
>>You may look at the archives for the list or change your subscription
>>settings from http://www.ceramics.org/clayart/
>
> I did a search in the archives for "rice husk" and came up with 33
> matches, at least one answers your question directly.
>
> Here's the web address for the search itself:
>
> (http://lsv.ceramics.org/scripts/wa.exe?S2=CLAYART&L=CLAYART&q=rice+husk&s=&f=&a=&b=)
>
> and this is the address for one of the pertinent messages:
>
> (http://lsv.ceramics.org/scripts/wa.exe?A2=ind9805&L=CLAYART&P=R40912)
>
> Warning: browsing/searching the archives can be addictive, but it's
> mighty informative.
>
> Regards,
> Maurice
>
> ______________________________________________________________________________
> 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.
>
Danny Floyd on fri 18 aug 06
Hi guys
Im kind of a newbie, more to Clayart than pottery, so I hope someone can
help. I d like to know why rice husk ash is used in pottery. I know its
made by burning of the outer bit of rice but not what it does. Why use it
in glazes? And can it be mixed with clay to make the pots? Does anyone knwo
what its made of so I can try to use it in glaze calculations (Im trying to
learn!) What can it be subbed with? Any info would be really great
Thankyou in advance to anyone who can help
Danny
Lee Love on fri 18 aug 06
Hi Danny,
It is mostly silica, with soluables and phosphorus tainting it.
It is used in the silica saturated white Nuka glaze here in Mashiko.
Mashiko clay has a lot of silica in it, so it wouldn't make too much
sense to add ricehull ash to Mashiko clay. Why is it used? The
farmers burn it in their fields and it is easy and cheap to get, but
provides a finer silica than from sand etc.
If you check out Phil Rogers book on ash glazes, he has a nice
synthetic nuka glaze which is very close to the real thing.
--
Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
Lee Love on fri 18 aug 06
You can see examples of my version of Phil Roger's synthetic Nuka
here, also the recipe:
Nuka over Tenmoku and nuka recipe as comment:
http://public.fotki.com/togeika/pots_from_mashiko/photo#aut_0020
Seiji (Green) Nuka:
http://public.fotki.com/togeika/pots_from_mashiko/photo#tokuri
Green:
http://public.fotki.com/togeika/pots_from_mashiko/photo#sage
Henko, Seki Nami Jiro glaze base, seiji nuka, resist, Mashiko Kaki.
The green freaks some people out (see archives.) Actually,
there is so much silica in any Nuka glaze that some don't consider it
function.
Typically, nuka is used over other glazes and is most often
used on the outside of large pots for decorative splashes.
--
Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
Maurice Weitman on fri 18 aug 06
At 03:54 -0400 on 8/18/06, Danny Floyd wrote:
>Hi guys
>Im kind of a newbie, more to Clayart than pottery, so I hope someone can
>help. I d like to know why rice husk ash is used in pottery. I know its
>made by burning of the outer bit of rice but not what it does. Why use it
>in glazes? And can it be mixed with clay to make the pots? Does anyone knwo
>what its made of so I can try to use it in glaze calculations (Im trying to
>learn!) What can it be subbed with? Any info would be really great
>
>Thankyou in advance to anyone who can help
Hello, Danny, and welcome to clayart.
In time, you'll likely learn that one of the real benefits of clayart
is its archives, but I'll hasten that and make the introduction here.
At the bottom of each clayart message, you'll find the web address
for the archives:
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
I did a search in the archives for "rice husk" and came up with 33
matches, at least one answers your question directly.
Here's the web address for the search itself:
(http://lsv.ceramics.org/scripts/wa.exe?S2=CLAYART&L=CLAYART&q=rice+husk&s=&f=&a=&b=)
and this is the address for one of the pertinent messages:
(http://lsv.ceramics.org/scripts/wa.exe?A2=ind9805&L=CLAYART&P=R40912)
Warning: browsing/searching the archives can be addictive, but it's
mighty informative.
Regards,
Maurice
Hank Murrow on fri 18 aug 06
On Aug 18, 2006, at 12:54 AM, Danny Floyd wrote:
> Hi guys
> Im kind of a newbie, more to Clayart than pottery, so I hope someone
> can
> help. I d like to know why rice husk ash is used in pottery. I know its
> made by burning of the outer bit of rice but not what it does. Why use
> it
> in glazes? And can it be mixed with clay to make the pots? Does anyone
> knwo
> what its made of so I can try to use it in glaze calculations (Im
> trying to
> learn!) What can it be subbed with? Any info would be really great
Dear Danny;
Rice husk ash is mostly colloidal silica, very finely divided, and is
mainly useful in formulating Nuka-style glazes. There is often a
significant unburned carbon content.
Cheers, Hank
www.murrow.biz/hank
John Britt on fri 18 aug 06
You can get rice hull ash from:
Industrial Minerals Co.
916-383-2811
It goes for $17.00 for 50 pounds, you pay the shipping and handling.
Hope it helps,
John Britt
www.johnbrittpottery.com
Karin Abromaitis on sat 19 aug 06
Can anyone tell me why I can find rice hull ash at the local Asian =
grocery/department store? I buy it for glaze, but have no idea why =
anyone else would. Thanks.
Karin A.
----- Original Message -----=20
From: Daniel Semler=20
To: CLAYART@LSV.CERAMICS.ORG=20
Sent: Saturday, August 19, 2006 12:46 AM
Subject: Re: Rice Husk Ash
Hi Danny,
The analyses will vary a bit, perhaps quite a bit. The only =20
analyses I've seen were from a study done in Japan for the National =20
Institute of Health. They used two types of rice husk ash, each with =20
about 93% silica, 2 or 3% K2O and the remainder made up of less than =20
1% of Al2O3, Fe2O3, MnO, MgO, CaO and traces of Na2O and TiO2. It =20
should be noted that they then leached the ash with HCL and got rid of =
=20
most of the traces raising the SiO2 percentage to about 96-97%. The =20
silica content is amorphous rather than crystalline in structure.
So its used as Lee pointed out in glazes. As Hank mentioned its a =20
very fine silica as you tend to get from organic sources as far as I =20
can tell. It would be a decent source of silica in glazes if you can =20
get it cheaply. I would expect its fineness to promote better melting =
than coaser grades of silica. I see no reason why it could not be used =
=20
as a filler in clay bodies but you'd want to make sure you had a =20
decent supply before going far with it.
I think I found it on the web actually. The full title is =20
Quantitative Analysis of Tridymite and Cristobalite Crystallized in =20
Rice Husk Ash by Heating, by Yasushi Shinohara and Norihiko Kohyama.
Thx
D
=
_________________________________________________________________________=
_____
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.
Lee Love on sun 20 aug 06
I don't think you will find it at the Asian Grocery. They do have
the rice bran, which is called nuka. It is used to make pickles and
is also an additive when cooking fresh bamboo shoots.
Someone left a link earlier of a wholeseller. In the past,
folks have bought it from custodial supply stores. It is absorbent
and is used as a sweeping compound.
On 8/19/06, Karin Abromaitis wrote:
> Can anyone tell me why I can find rice hull ash at the local Asian grocery/department store? I buy it for glaze, but have no idea why anyone else would. Thanks.
--
Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
Karin Abromaitis on sun 20 aug 06
Its really ash-says so on the label and I've made some very nice clear =
glazes with it. Just can't figure out what anybody else would use it =
for. Maybe for kimshi? I have no idea how that is made.
Karin A
----- Original Message -----=20
From: Lee Love=20
To: CLAYART@LSV.CERAMICS.ORG=20
Sent: Sunday, August 20, 2006 11:45 AM
Subject: Re: Rice Husk Ash
I don't think you will find it at the Asian Grocery. They do have
the rice bran, which is called nuka. It is used to make pickles and
is also an additive when cooking fresh bamboo shoots.
Someone left a link earlier of a wholeseller. In the past,
folks have bought it from custodial supply stores. It is absorbent
and is used as a sweeping compound.
On 8/19/06, Karin Abromaitis =
> wrote:
> Can anyone tell me why I can find rice hull ash at the local Asian =
grocery/department store? I buy it for glaze, but have no idea why =
anyone else would. Thanks.
--
Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
=
_________________________________________________________________________=
_____
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.
Veena Raghavan on sun 20 aug 06
Hi Karin,
Could you tell us exactly what it says on the package. I would like to try to
get some on my next visit to an Asian Grocery store.
Thanks,
Veena
In a message dated 8/20/2006 9:54:47 AM Pacific Daylight Time,
Kabromaitis@MSN.COM writes:
>
> Its really ash-says so on the label and I've made some very nice clear
> glazes with it. Just can't figure out what anybody else would use it for. Maybe
> for kimshi? I have no idea how that is made.
> Karin A
VeenaRaghavan@cs.com
Lee Love on sun 20 aug 06
On 8/20/06, Karin Abromaitis wrote:
> Its really ash-says so on the label and I've made some very nice clear
>glazes with it. Just can't figure out what anybody else would use it for.
>Maybe for kimshi? I have no idea how that is made.
I don't know. I don't know of any pickles calling for this ash.
It is mostly silica.
Lee in Mashiko, Japan
Danny Floyd on mon 21 aug 06
Hi Guys,
Many thanks to you all who contributed. Ive been researching using other
sources as well, and along with your comments this is what Ive learnt so far=
1. Rice husk ash is primarily silica
2. There is no one type, and so compositions seem to vary widely
3. Chemically it is an impure source of silica
4. Structurally it is more interesting as depending on the temperature of
burning it can be noncrystalline, like opal, with higher temperatures
leading to crystal growth. Cristobalite is formed above 1000oC
5. It is a waste product of rice cultivation. The rice husks themselves are
burnt as a fuel, so I guess the ash is a waste-waste product!
6. The biggest produces are China, India and Indonesia
7. Rice Husks, i.e. before burning, also has uses including bedding for
animals and packaging material
8. Research continues to look for applications for Rice Husk Ash, with
filler in cement and concrete being the most popular. Thailand seems to be
conducting most research
Following Johns advice I called Industrial Minerals but they said they dont
stock it. A Google search found the article by Shinohara and Kohyama
recommended by Daniel - thanks its excellent. Im much happy with the
analyses they quote than another I found at Ceramic-Materials.com as Ive
previously found that website to be unreliable
Particle sizes Ive seen reported are no finer than many milled quartzes
The only references to uses in pottery I found were in glazes. Just my take
on things but depending on what type of pottery youre making using Rice
Husk Ash may help marketing, i.e. =91made with real Rice Husk Ash=92, (Thank=
s
to Hank for the reference of Nuka-style galzes but as Ive no interest in
Japanese pottery thats a blind alley for me)
I can imagine if you are in a country where theres a lot produced, like
China, India and Indonesia, it could be a cheap source of silica but I
found nothing to explain if Rice Husk Ash is bringing anything special.
Looking at the various analyses I myself cant see why subbing with quartz
or cristobalite, maybe with a slight reformulation, would not work. A
possibility is because of something related to the structure, i.e. the
grades that are noncrystaline, I could imagine this would melt quicker but
thats only speculation, but this is for one type of Rice husk Ash only
Any more info anyone has would has would be great
Thanks,
Danny
Lee Love on mon 21 aug 06
On 8/21/06, Danny Floyd wrote:
> Any more info anyone has would has would be great
They burn it in the fields here. I used Roger's synthetice back
home. Recipe here in comments:
http://public.fotki.com/togeika/pots_from_mashiko/photo#aut_0020
--
Lee in Mashiko, Japan
http://potters.blogspot.com/
"Let the beauty we love be what we do." - Rumi
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