search  current discussion  categories  kilns & firing - salt & soda 

gil's position on salt a (fwd)

updated mon 31 mar 97


ret on sat 22 mar 97

Gil Stengel --Congratulations!

Now THAT'S the way to do research! If I get back to my farm house in
Wisconsin where I think my papers are, you will inherit the lot.

ANd I had not forgotten the people covered with barium carbonate, silica and
other schmutz in those journals. I get my best criticisms of industry from
their own publications even today.

> but no hard data on
> the breakdown of NaCl in a kiln or the emissions from said kilns. <

I know its there somewhere in its also in the older texts that I found at
that time.

> I need to do further research on this topic but I think that my
> inability to find data related to sodium vapor kiln emissions might
> be simply that this technique does not enjoy widespread industrial
> use. The resultant lack of economic incentive for such studies could
> explain the relative dearth of material in the abstracts.<

Someone must know who's still doing it. Unless all that salt-glazed-looking
stuff in the pottery barns and other outless are boron, there must be
companies that are producing the ware.

Again, good job.

Monona Rossol

Bill Walker on mon 24 mar 97

I missed the origianl "gil's position on salt" posting, but I find
myself fascinated by the discussion.

I searched the "Ceramics Abstracts" database on CD-ROM which covers
articles in ceramic engineering journals back to about 1974. There
is very little on salt glazing, and the only article that specifically
mentions pollution is in "Ceramics Monthly".

After a bit more searching, I found Division of Building Research,
CSIRO Report CT1, "Phosphates as a Substitute for Salt in Glazing"
by Tauber, Crook and Murray, 1971 (from Australia). It referenced
Parliament of the Commonwealth of Australia, (1969) - Report from
the Senate Select Committee on Air Pollution. Parliamentary Paper
No. 91. (Commonwealth Covernment Printing Office: Canbarra) which
mentioned hydrochloric acid (HCl) and salt fume as pollutants from
the salt glazing process. Parmelee's famous book also includes
iron chlorides as being present if significant iron is present in
the clay.

Someone on this list said that some chlorine gets incorporated
into the glaze, and this is very probable. It is really difficult
to detect chlorine in a glaze so people haven't really looked for
it that much.

Hope this is helpful.

Bill Walker
Alfred NY USA