ivor and olive lewis on thu 12 may 11
Dear David Beumee,
You tell us ..... " Our local building inspector gave me the task of
"proving" that soda firing is safe for the environment as a precursor for
granting a building permit for a small soda fired kiln here at the studio.
I'm hoping this evidence will be convincing...."
I am pleased Vince and his team were able to help but the conclusions you
are drawing from their efforts seem to me to be conjectural. Any unreacted
sodium carbonate exiting the kiln will be, at the temperatures you give,
solid and particulate in nature. The majority of Sodium carbonate entering
your kiln will, as you say, react with the hot silicate compounds in you
clay
Be certain, before you present your proposition, that you can validate your
evidence.
Note in the CRC Handbook of Chemistry gives no boiling point for Sodium
Carbonate. Only its melting point is stated. Note also that Sodium
Bi-Carbonate decomposes below the boiling point of water discharging Water
Vapour and Carbon dioxide leaving a residue of Sodium Carbonate. Of Sodium
Hydroxide Durrant says "When heated sodium hydroxide does not lose water to
yield sodium oxide; at temperatures above 1300 deg C it dissociates to a
slight extent into its constituent elements Na, O2 and H2." and "On
exposure to air sodium hydroxide first adsorbs water and becomes moist, but
subsequently the superficial solution reacts with carbon dioxide to form
sodium carbonate....".
Your nearest high school Chemistry specialist would be able to confirm or
refute the information I give you.
I think you would better satisfy your opponent if you could supply actual
analyses of kiln effluent showing that individual compounds are absent from
kiln emissions or below the levels required of industrial chemical
industries. (Have you asked what the maximum allowable emission levels are =
?
(ref P.J. Durrant, "General and Inorganic Chemistry". Longman Press, 1954)
Hope you get eventual success.
Sincerely,
Ivor Lewis,
REDHILL,
South Australia
Steve Mills on thu 12 may 11
=3D46rom my own practice with vapour glazing (admittedly not soda), another=
fa=3D
ctor, which is very helpful to your efforts, needs to be addressed, and tha=
t=3D
is dilution by air at the exit from the flue/stack which immediate and con=
s=3D
iderable.=3D20
It is worth the effort to take a lot of air samples at that point during th=
e=3D
appropriate phase in the firing.=3D20
In the past an awful lot of effort was wasted on devising complex "scrubber=
s=3D
" for flues, when it was eventually realised that their effect was effectua=
l=3D
ly minimal due to dilution.=3D20
Needless to say design and geographical location also play their part as we=
l=3D
l.=3D20
I cannot at this moment lay my hands on the appropriate articles, but I sus=
p=3D
ect they are out there waiting to be found.=3D20
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my Ipod touch
On 12 May 2011, at 07:52, ivor and olive lewis wrot=
e=3D
:
> Dear David Beumee,
>=3D20
> You tell us ..... " Our local building inspector gave me the task of
> "proving" that soda firing is safe for the environment as a precursor for
> granting a building permit for a small soda fired kiln here at the studio=
.=3D
> I'm hoping this evidence will be convincing...."
>=3D20
> I am pleased Vince and his team were able to help but the conclusions you
> are drawing from their efforts seem to me to be conjectural. Any unreacte=
d=3D
> sodium carbonate exiting the kiln will be, at the temperatures you give,
> solid and particulate in nature. The majority of Sodium carbonate enterin=
g=3D
> your kiln will, as you say, react with the hot silicate compounds in you
> clay
>=3D20
> Be certain, before you present your proposition, that you can validate yo=
u=3D
r
> evidence.
>=3D20
> Note in the CRC Handbook of Chemistry gives no boiling point for Sodium
> Carbonate. Only its melting point is stated. Note also that Sodium
> Bi-Carbonate decomposes below the boiling point of water discharging Wate=
r=3D
> Vapour and Carbon dioxide leaving a residue of Sodium Carbonate. Of Sodiu=
m=3D
> Hydroxide Durrant says "When heated sodium hydroxide does not lose water =
t=3D
o
> yield sodium oxide; at temperatures above 1300 deg C it dissociates to a
> slight extent into its constituent elements Na, O2 and H2." and "On
> exposure to air sodium hydroxide first adsorbs water and becomes moist, b=
u=3D
t
> subsequently the superficial solution reacts with carbon dioxide to form
> sodium carbonate....".
>=3D20
> Your nearest high school Chemistry specialist would be able to confirm or
> refute the information I give you.
>=3D20
> I think you would better satisfy your opponent if you could supply actual
> analyses of kiln effluent showing that individual compounds are absent fr=
o=3D
m
> kiln emissions or below the levels required of industrial chemical
> industries. (Have you asked what the maximum allowable emission levels ar=
e=3D
?
>=3D20
> (ref P.J. Durrant, "General and Inorganic Chemistry". Longman Press, 1954=
)=3D
>=3D20
> Hope you get eventual success.
>=3D20
> Sincerely,
>=3D20
> Ivor Lewis,
> REDHILL,
> South Australia
Edouard Bastarache on fri 13 may 11
Hello Steve,
years ago I asked the advice of Brnd Pfannkuche,
a German international consultant in ceramics
and editor of Neue Keramik in Berlin.
Germany is the land of salt glazing, he assured me
this technique was not hazardous.
Now, on a theoritical basis, soda firing appears even
less hazardous.
At that time this information was relayed to Clayart.
Maybe some officials in the USA do not know what
they talking about.
Go to the source where people have been involved in these
processes for centuries and get decent information...
Why having to prove a process is not hazardous when
the rest of the planet knows its not(completely stupid)
Gis,
Edouard Bastarache
Spertesperantisto
Sorel-Tracy
Quebec
http://www.flickr.com/photos/30058682@N00/
http://edouardbastarache.blogspot.com/
http://www.facebook.com/edouard.bastarache
http://blogsalbertbastarache.blogspot.com/
Steve Mills on sat 14 may 11
Dear Edouard,
Unfortunately "Salt =3D Hazard" thinking has been the default for a
looooooooong time.
In the Bristol (UK) area there was a very successful Salt Glaze pipe works
for many years, which was driven out of business by continuous demands from
the powers that be that their chimney be increased in height for "safety"
reasons, until these demands rendered the Kiln unusable because the draught
generated became uncontrollable, and the cure unaffordable!
Steve M
On 13 May 2011 19:08, Edouard Bastarache wrote:
> Hello Steve,
>
> years ago I asked the advice of Brnd Pfannkuche,
> a German international consultant in ceramics
> and editor of Neue Keramik in Berlin.
> Germany is the land of salt glazing, he assured me this technique was not
> hazardous.
> Now, on a theoritical basis, soda firing appears even less hazardous.
> At that time this information was relayed to Clayart.
> Maybe some officials in the USA do not know what they talking about.
> Go to the source where people have been involved in these
> processes for centuries and get decent information...
>
> Why having to prove a process is not hazardous when the rest of the plane=
t
> knows its not(completely stupid)
>
> Gis,
>
> Edouard Bastarache Spertesperantisto
> Sorel-Tracy
> Quebec
>
> http://www.flickr.com/photos/30058682@N00/
> http://edouardbastarache.blogspot.com/
> http://www.facebook.com/edouard.bastarache
> http://blogsalbertbastarache.blogspot.com/
>
>
>
>
>
>
| |
|
