Jim Tabor on thu 28 mar 02
I would appreciate information from anyone with any experience with
ceramic grade uranium that can inform me about the material. I
understand it was a ceramic colorant used in the US before 1947 and have
seen it listed in some older books.
What risks are associated with this form of uranium. Where is there info
about it? How do you dispose of it? I have a small amount to get rid of
and missed the semi annual hazardous waste drop last weekend because I
went back to KC to see more NCECA shows and did not know of the drop off
date until today. Help!
jt
Edouard Bastarache on fri 29 mar 02
Nowadays most stains/pigments containing uranium (if available) would
be made using the depleted type with less emission of alpha particles but
still
radioactive.
DEPLETED URANIUM
Uranium :
1-Uranium is a silver-white, lustrous, dense, natural, weakly radioactiv=
e
element. It is ubiquitous throughout the natural environment, and is foun=
d
in varying but small amounts in rocks, soils, water, air, plants, animals
and in all human beings.
2- On average, approximately 90 =B5g (micrograms) of uranium exist in the
human body from normal intakes of water, food and air. About 66% is found=
in
the skeleton, 16% in the liver, 8% in the kidneys and 10% in other tissue=
s.
3- Natural uranium consists of a mixture of three radioactive isotopes wh=
ich
are identified by the mass numbers 238U(99.27% by mass), 235U(0.72%) and
234U(0.0054%).
4- Uranium is used primarily in nuclear power plants. However, most react=
ors
require uranium in which the 235U content is enriched from 0.72% to about
3%.
Depleted uranium :
1- The uranium remaining after removal of the enriched fraction contains
about 99.8% 238U, 0.25% of 235U and 0.001% 234U by mass; this is referred=
to
as depleted uranium or DU.
2- DU is weakly radioactive and a radiation dose from it would be about 6=
0%
of that from purified natural uranium with the same mass.
3- The behaviour of uranium and DU in the body is identical radiologicall=
y
and chemically.
4- Spent uranium fuel from nuclear reactors is sometimes reprocessed in
plants used for natural uranium enrichment. Some reactor-created
radio-isotopes can consequently contaminate the reprocessing equipment an=
d
the DU. Under these conditions another uranium isotope, 236U, may be pres=
ent
in the DU together with very small amounts of the transuranic elements
plutonium, americium and neptunium and the fission product technetium-99.
However, on the basis of the concentrations of these radio-isotopes found=
in
DU, the increase in radiation dose from uptake by the human body would be
less than 1%.
Applications of depleted uranium :
1- The main civilian uses of DU include counterweights in aircraft,
radiation shields in medical radiation therapy machines and containers fo=
r
the transport of radioactive materials.
2- Due to its high density, about twice that of lead, and other propertie=
s,
DU is used in munitions designed to penetrate armour plate and for
protection of military vehicles such as tanks.
Exposure to uranium and depleted uranium :
1- The average annual intakes of uranium by adults are estimated to be 46=
0
=B5g from ingestion and 0.59 =B5g from inhalation.
2- Under most circumstances, use of DU will make a negligible contributio=
n
to the overall natural background levels of uranium in the environment. T=
he
greatest potential for DU exposure will follow a conflict where DU muniti=
ons
are used.
3- A recent United Nations Environment Programme (UNEP) report giving fi=
eld
measurements taken around selected impact sites in Kosovo (Federal Republ=
ic
of Yugoslavia) indicates that contamination by DU in the environment was
localized to a few tens of metres around impact sites. Contamination by D=
U
dusts to local vegetation and water supplies was found to be extremely lo=
w.
Thus, the possibility of significant exposure to the local populations wa=
s
found to be very low.
4- However, levels of DU may be significantly raised over background leve=
ls
in close proximity to DU contaminating events. Over the days and years
following such an event, the contamination will become dispersed into the
wider natural environment. People living or working in affected areas can
inhale dusts and can consume contaminated food and drinking water.
5- There is a possibility that people near an aircraft crash may be expo=
sed
to DU dusts if counterweights were to combust on impact. Significant
exposure to people from this situation would be rare. Exposures to clean-=
up
and emergency workers following aircraft accidents are possible, but norm=
al
occupational protection measures would prevent any significant exposure
occurring.
DU exposure pathways :
1- Individuals can be exposed to DU in the same way they are routinely
exposed to natural uranium, i.e. through inhalation, ingestion, dermal
contact or injury (e.g. embedded fragments).
2- Each of these exposure situations needs to be assessed to determine an=
y
potential health consequence.
3- The relative contribution from each of these pathways to the total DU
uptake into the body depends on the physical and chemical nature of the D=
U,
as well as the level and duration of exposure.
Intake of depleted uranium :
1- Intake by ingestion can occur if drinking water or food is contaminate=
d
by DU. In addition, the ingestion of soil by children via geophagia (the
practice of eating earth, clay, chalk, etc.) or hand-to-mouth activities =
is
also an important pathway.
2- Intake by inhalation can occur following the use of DU munitions durin=
g
or when DU deposits in the environment are re-suspended in the atmosphere=
by
wind or other forms of disturbance. Accidental inhalation may also occur =
as
a consequence of a fire in a DU storage facility, an aircraft crash, or t=
he
decontamination of vehicles from within or close to conflict areas.
3- Intake by contact exposure of DU through the skin is very low and
relatively unimportant.
4- Intake from wound contamination or embedded fragments in skin tissues
allows DU to enter the systemic circulation.
Absorption of depleted uranium :
1- Most (>95%) uranium entering the body via inhalation or ingestion is =
not
absorbed, but is eliminated via the faeces.
2- Of the uranium that is absorbed into the blood, approximately 67% wil=
l
be filtered by the kidney and excreted in the urine within 24 hours; this
amount increases to 90% within a few days.
3- Typical gut absorption rates for uranium in food and water are about 2=
%
for soluble uranium compounds and down to 0.2% for insoluble uranium
compounds.
Health effects of exposure to depleted uranium :
DU has both chemical and radiological toxicity with the two important tar=
get
organs being the kidneys and the lungs.
1- In the kidneys, the proximal tubules are considered to be the main sit=
e
of potential damage. Long-term studies of workers chronically exposed to
uranium have reported impairment of the kidneys that depended on the leve=
l
of exposure. There is also some evidence that this impairment may return =
to
normal once the source of excessive uranium exposure has been removed.
2- In a number of studies on uranium miners, an increased risk of lung
cancer has been demonstrated, but this has been attributed to exposure fr=
om
radon decay products. There is a possibility of lung tissue damage leadin=
g
to a risk of lung cancer if a high enough radiation dose results from
insoluble DU compounds remaining in the lungs over a prolonged period (ma=
ny
years).
3- Erythema (superficial inflammation of the skin) or other effects on th=
e
skin should not occur even if DU is held against the skin for prolonged
periods (weeks). There is no established data to suggest that skin cancer
results from skin contact with uranium dusts.
4- No consistent or confirmed adverse effects have been reported for the
skeleton or liver. However, few studies have been conducted.
5- No reproductive or developmental effects have been reported in humans,
but studies are limited.
6- Although uranium released from embedded fragments may accumulate in th=
e
central nervous system (CNS) tissue and some animal and human studies are
suggestive of effects on CNS function, it is difficult to draw firm
conclusions from the studies.
Maximum radiation exposure limits :
The following doses, from the International Basic Safety Standards agreed=
by
WHO in 1996, are in addition to those from normal background exposures.
1- The general public should not receive a dose of more than 1 millisieve=
rt
(mSv) in a year. In special circumstances, an effective dose of up to 5 m=
Sv
in a single year is permitted provided that the average dose over five
consecutive years does not exceed 1 mSv per year. An equivalent dose to t=
he
skin should not exceed 50 mSv in a year.
2- Occupational exposure should not exceed an effective dose of 20 mSv pe=
r
year averaged over five consecutive years or an effective dose of 50 mSv =
in
any single year. An equivalent dose to the extremities (hands and feet) o=
r
the skin should not surpass 500 mSv in a year.
Guidance on exposure based on chemical and radiological toxicity :
The World Health Organization (WHO) has guidelines for determining the
values of health-based exposure limits or tolerable intakes (TIs) for
chemical substances. The TIs given below are applicable to long-term
exposure in the general public (as opposed to workers). In single and
short-term exposures, higher exposure levels may be tolerated without
adverse effects.
1- The general public's intake via inhalation or ingestion of soluble DU
compounds should be based on a tolerable intake value of 0.5 =B5g per kg =
of
body weight per day. This leads to an air concentration of 1 =B5g/m3. For
ingestion, this would be about 11 mg/y for an average adult.
2- It would be appropriate to reduce the TI for intake of insoluble DU
compounds to 0.5 =B5g per kg of body weight per day so that compatibility=
is
achieved with the public radiation dose limit. When the solubility
characteristics of the uranium species are not known, which is often the
case in exposure to depleted uranium, it would be prudent to apply the mo=
re
stringent tolerable intakes, i.e., 0.5 =B5g per kg of body weight per day=
for
oral exposure.
3- Uranium compounds with low absorption are markedly less nephrotoxic, a=
nd
a tolerable intake via ingestion of 5 =B5g per kg of body weight per day =
is
applicable.
Monitoring and treatment of exposed individuals :
1- For the general population, neither civilian nor military use of DU is
likely to produce exposures to DU much above normal background levels
produced by uranium. Therefore, an exposure assessment for DU will normal=
ly
not be required.
2- When an individual is suspected of being exposed to DU at a level
significantly above the normal background level, an assessment of DU
exposure may be required. This is best achieved by analysis of daily urin=
e
excretion. The amount of DU in the urine is determined from the 235U:238U
ratio, obtained using sensitive mass spectrometric techniques. Faecal
measurement can give useful information on intake if samples are collecte=
d
soon after exposure (a few days).
3- External radiation measurements over the chest, using a whole-body
radiation monitor for determining the amount of DU in the lungs, have
limited application since they require specialist facilities and can only
assess relatively large amounts of DU in the lungs.
4- There are no specific means to decrease the absorption of uranium fro=
m
the gastrointestinal tract or lungs, or increase its excretion. Thus,
general methods appropriate to heavy metal poisoning could be applied.
Similarly, there is no specific treatment for uranium poisoning and the
patient should be treated based on the symptoms observed. Dialysis may be
helpful in extreme cases of kidney damage.
Recommendations :
1- Levels of contamination in food and drinking water could rise in affec=
ted
areas after some years and should be monitored where it is considered tha=
t
there is a reasonable possibility of significant quantities of DU enterin=
g
the ground water or food chain.
2- Where possible, clean-up operations in impact zones should be undertak=
en
where there are substantial numbers of radioactive projectiles remaining =
and
where qualified experts deem contamination levels to be unacceptable. If
very high concentrations of DU dust or metal fragments are present, then
areas may need to be cordoned off until removal can be accomplished.
Disposal of DU should come under appropriate national or international
recommendations for use of radioactive materials.
3- Young children could receive greater exposure to DU when playing in or
near DU impact sites. Typical hand-to-mouth activity could lead to high D=
U
ingestion from contaminated soil.
Necessary preventative measures should be taken.
4- Individuals who believe they have had excessive intakes of DU should
consult their medical practitioner for an examination and treatment of an=
y
symptoms. General screening or monitoring for possible DU related health
effects in populations living in conflict areas where DU was used is not
called for.
As for its safe disposal, check with local authorities.
Later,
Edouard Bastarache
Irreductible Quebecois
Indomitable Quebeker
Sorel-Tracy
Quebec
edouardb@sorel-tracy.qc.ca
http://sorel-tracy.qc.ca/~edouardb/
http://perso.wanadoo.fr/smart2000/index.htm
Reference: The WHO, Depleted Uranium, Fact Sheet N=B0 257, Revised April =
2001
Jim Tabor on fri 29 mar 02
Thank you Edouard. The fact sheet is very helpful to calm my fears. I will check
with my neighbor who is a geologist and chemical engineer to see if he has a
device to determine how hot the material is. I will keep the material in a remote
area until I can find someone suitable to take it. The Gov. Waste Mrg. Div. for
radiation is looking into it for me.
I appreciate the information,
jt
Edouard Bastarache wrote:
> Nowadays most stains/pigments containing uranium (if available) would
> be made using the depleted type with less emission of alpha particles but
> still
> radioactive.
>
> DEPLETED URANIUM
>
> Uranium :
> 1-Uranium is a silver-white, lustrous, dense, natural, weakly radioactive
> element. It is ubiquitous throughout the natural environment, and is found
> in varying but small amounts in rocks, soils, water, air, plants, animals
> and in all human beings.
>
> 2- On average, approximately 90 µg (micrograms) of uranium exist in the
> human body from normal intakes of water, food and air. About 66% is found in
> the skeleton, 16% in the liver, 8% in the kidneys and 10% in other tissues.
>
> 3- Natural uranium consists of a mixture of three radioactive isotopes which
> are identified by the mass numbers 238U(99.27% by mass), 235U(0.72%) and
> 234U(0.0054%).
>
> 4- Uranium is used primarily in nuclear power plants. However, most reactors
> require uranium in which the 235U content is enriched from 0.72% to about
> 3%.
>
> Depleted uranium :
> 1- The uranium remaining after removal of the enriched fraction contains
> about 99.8% 238U, 0.25% of 235U and 0.001% 234U by mass; this is referred to
> as depleted uranium or DU.
>
> 2- DU is weakly radioactive and a radiation dose from it would be about 60%
> of that from purified natural uranium with the same mass.
>
> 3- The behaviour of uranium and DU in the body is identical radiologically
> and chemically.
>
> 4- Spent uranium fuel from nuclear reactors is sometimes reprocessed in
> plants used for natural uranium enrichment. Some reactor-created
> radio-isotopes can consequently contaminate the reprocessing equipment and
> the DU. Under these conditions another uranium isotope, 236U, may be present
> in the DU together with very small amounts of the transuranic elements
> plutonium, americium and neptunium and the fission product technetium-99.
> However, on the basis of the concentrations of these radio-isotopes found in
> DU, the increase in radiation dose from uptake by the human body would be
> less than 1%.
>
> Applications of depleted uranium :
> 1- The main civilian uses of DU include counterweights in aircraft,
> radiation shields in medical radiation therapy machines and containers for
> the transport of radioactive materials.
>
> 2- Due to its high density, about twice that of lead, and other properties,
> DU is used in munitions designed to penetrate armour plate and for
> protection of military vehicles such as tanks.
>
> Exposure to uranium and depleted uranium :
> 1- The average annual intakes of uranium by adults are estimated to be 460
> µg from ingestion and 0.59 µg from inhalation.
>
> 2- Under most circumstances, use of DU will make a negligible contribution
> to the overall natural background levels of uranium in the environment. The
> greatest potential for DU exposure will follow a conflict where DU munitions
> are used.
>
> 3- A recent United Nations Environment Programme (UNEP) report giving field
> measurements taken around selected impact sites in Kosovo (Federal Republic
> of Yugoslavia) indicates that contamination by DU in the environment was
> localized to a few tens of metres around impact sites. Contamination by DU
> dusts to local vegetation and water supplies was found to be extremely low.
> Thus, the possibility of significant exposure to the local populations was
> found to be very low.
>
> 4- However, levels of DU may be significantly raised over background levels
> in close proximity to DU contaminating events. Over the days and years
> following such an event, the contamination will become dispersed into the
> wider natural environment. People living or working in affected areas can
> inhale dusts and can consume contaminated food and drinking water.
>
> 5- There is a possibility that people near an aircraft crash may be exposed
> to DU dusts if counterweights were to combust on impact. Significant
> exposure to people from this situation would be rare. Exposures to clean-up
> and emergency workers following aircraft accidents are possible, but normal
> occupational protection measures would prevent any significant exposure
> occurring.
>
> DU exposure pathways :
> 1- Individuals can be exposed to DU in the same way they are routinely
> exposed to natural uranium, i.e. through inhalation, ingestion, dermal
> contact or injury (e.g. embedded fragments).
>
> 2- Each of these exposure situations needs to be assessed to determine any
> potential health consequence.
> 3- The relative contribution from each of these pathways to the total DU
> uptake into the body depends on the physical and chemical nature of the DU,
> as well as the level and duration of exposure.
>
> Intake of depleted uranium :
> 1- Intake by ingestion can occur if drinking water or food is contaminated
> by DU. In addition, the ingestion of soil by children via geophagia (the
> practice of eating earth, clay, chalk, etc.) or hand-to-mouth activities is
> also an important pathway.
>
> 2- Intake by inhalation can occur following the use of DU munitions during
> or when DU deposits in the environment are re-suspended in the atmosphere by
> wind or other forms of disturbance. Accidental inhalation may also occur as
> a consequence of a fire in a DU storage facility, an aircraft crash, or the
> decontamination of vehicles from within or close to conflict areas.
>
> 3- Intake by contact exposure of DU through the skin is very low and
> relatively unimportant.
>
> 4- Intake from wound contamination or embedded fragments in skin tissues
> allows DU to enter the systemic circulation.
>
> Absorption of depleted uranium :
> 1- Most (>95%) uranium entering the body via inhalation or ingestion is not
> absorbed, but is eliminated via the faeces.
>
> 2- Of the uranium that is absorbed into the blood, approximately 67% will
> be filtered by the kidney and excreted in the urine within 24 hours; this
> amount increases to 90% within a few days.
>
> 3- Typical gut absorption rates for uranium in food and water are about 2%
> for soluble uranium compounds and down to 0.2% for insoluble uranium
> compounds.
>
> Health effects of exposure to depleted uranium :
> DU has both chemical and radiological toxicity with the two important target
> organs being the kidneys and the lungs.
> 1- In the kidneys, the proximal tubules are considered to be the main site
> of potential damage. Long-term studies of workers chronically exposed to
> uranium have reported impairment of the kidneys that depended on the level
> of exposure. There is also some evidence that this impairment may return to
> normal once the source of excessive uranium exposure has been removed.
>
> 2- In a number of studies on uranium miners, an increased risk of lung
> cancer has been demonstrated, but this has been attributed to exposure from
> radon decay products. There is a possibility of lung tissue damage leading
> to a risk of lung cancer if a high enough radiation dose results from
> insoluble DU compounds remaining in the lungs over a prolonged period (many
> years).
>
> 3- Erythema (superficial inflammation of the skin) or other effects on the
> skin should not occur even if DU is held against the skin for prolonged
> periods (weeks). There is no established data to suggest that skin cancer
> results from skin contact with uranium dusts.
>
> 4- No consistent or confirmed adverse effects have been reported for the
> skeleton or liver. However, few studies have been conducted.
>
> 5- No reproductive or developmental effects have been reported in humans,
> but studies are limited.
>
> 6- Although uranium released from embedded fragments may accumulate in the
> central nervous system (CNS) tissue and some animal and human studies are
> suggestive of effects on CNS function, it is difficult to draw firm
> conclusions from the studies.
>
> Maximum radiation exposure limits :
> The following doses, from the International Basic Safety Standards agreed by
> WHO in 1996, are in addition to those from normal background exposures.
> 1- The general public should not receive a dose of more than 1 millisievert
> (mSv) in a year. In special circumstances, an effective dose of up to 5 mSv
> in a single year is permitted provided that the average dose over five
> consecutive years does not exceed 1 mSv per year. An equivalent dose to the
> skin should not exceed 50 mSv in a year.
>
> 2- Occupational exposure should not exceed an effective dose of 20 mSv per
> year averaged over five consecutive years or an effective dose of 50 mSv in
> any single year. An equivalent dose to the extremities (hands and feet) or
> the skin should not surpass 500 mSv in a year.
>
> Guidance on exposure based on chemical and radiological toxicity :
> The World Health Organization (WHO) has guidelines for determining the
> values of health-based exposure limits or tolerable intakes (TIs) for
> chemical substances. The TIs given below are applicable to long-term
> exposure in the general public (as opposed to workers). In single and
> short-term exposures, higher exposure levels may be tolerated without
> adverse effects.
>
> 1- The general public's intake via inhalation or ingestion of soluble DU
> compounds should be based on a tolerable intake value of 0.5 µg per kg of
> body weight per day. This leads to an air concentration of 1 µg/m3. For
> ingestion, this would be about 11 mg/y for an average adult.
>
> 2- It would be appropriate to reduce the TI for intake of insoluble DU
> compounds to 0.5 µg per kg of body weight per day so that compatibility is
> achieved with the public radiation dose limit. When the solubility
> characteristics of the uranium species are not known, which is often the
> case in exposure to depleted uranium, it would be prudent to apply the more
> stringent tolerable intakes, i.e., 0.5 µg per kg of body weight per day for
> oral exposure.
>
> 3- Uranium compounds with low absorption are markedly less nephrotoxic, and
> a tolerable intake via ingestion of 5 µg per kg of body weight per day is
> applicable.
>
> Monitoring and treatment of exposed individuals :
> 1- For the general population, neither civilian nor military use of DU is
> likely to produce exposures to DU much above normal background levels
> produced by uranium. Therefore, an exposure assessment for DU will normally
> not be required.
>
> 2- When an individual is suspected of being exposed to DU at a level
> significantly above the normal background level, an assessment of DU
> exposure may be required. This is best achieved by analysis of daily urine
> excretion. The amount of DU in the urine is determined from the 235U:238U
> ratio, obtained using sensitive mass spectrometric techniques. Faecal
> measurement can give useful information on intake if samples are collected
> soon after exposure (a few days).
>
> 3- External radiation measurements over the chest, using a whole-body
> radiation monitor for determining the amount of DU in the lungs, have
> limited application since they require specialist facilities and can only
> assess relatively large amounts of DU in the lungs.
>
> 4- There are no specific means to decrease the absorption of uranium from
> the gastrointestinal tract or lungs, or increase its excretion. Thus,
> general methods appropriate to heavy metal poisoning could be applied.
> Similarly, there is no specific treatment for uranium poisoning and the
> patient should be treated based on the symptoms observed. Dialysis may be
> helpful in extreme cases of kidney damage.
>
> Recommendations :
> 1- Levels of contamination in food and drinking water could rise in affected
> areas after some years and should be monitored where it is considered that
> there is a reasonable possibility of significant quantities of DU entering
> the ground water or food chain.
>
> 2- Where possible, clean-up operations in impact zones should be undertaken
> where there are substantial numbers of radioactive projectiles remaining and
> where qualified experts deem contamination levels to be unacceptable. If
> very high concentrations of DU dust or metal fragments are present, then
> areas may need to be cordoned off until removal can be accomplished.
> Disposal of DU should come under appropriate national or international
> recommendations for use of radioactive materials.
>
> 3- Young children could receive greater exposure to DU when playing in or
> near DU impact sites. Typical hand-to-mouth activity could lead to high DU
> ingestion from contaminated soil.
> Necessary preventative measures should be taken.
>
> 4- Individuals who believe they have had excessive intakes of DU should
> consult their medical practitioner for an examination and treatment of any
> symptoms. General screening or monitoring for possible DU related health
> effects in populations living in conflict areas where DU was used is not
> called for.
>
> As for its safe disposal, check with local authorities.
>
> Later,
>
> Edouard Bastarache
> Irreductible Quebecois
> Indomitable Quebeker
> Sorel-Tracy
> Quebec
> edouardb@sorel-tracy.qc.ca
> http://sorel-tracy.qc.ca/~edouardb/
> http://perso.wanadoo.fr/smart2000/index.htm
>
> Reference: The WHO, Depleted Uranium, Fact Sheet N° 257, Revised April 2001
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
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> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
John Christie on fri 29 mar 02
Jim Tabor writes:
>I would appreciate information from anyone with any experience with
>ceramic grade uranium that can inform me about the material
Uranium oxide (depleted) produces good oranges and reds in lead glazes and
was popular at the beginning of the twentieth century when it was used in
"art" glazes, most successfully on Ruskin Ware. I have only ever used it in
low fired borax glazes (it is unstable at high temperature) with about one
half a percent of copper. It is an exciting material. Although it is not a
strong colouring oxide in a borax glaze (5% gives a pale tan yellow), it can
produce, in reduction, an attractive grey, black speckle. It also seems to
act as a catalyst in the reduced copper glaze producing much better reds and
pinks than the same glaze without the uranium. This might suggest a
potential use as a component in reduced onglaze lustre. Unfortunately it is
highly toxic - see: http://www.digitalfire.com/material/index.htm
John
www.scotpotter.com
Jim V Brooks on fri 29 mar 02
I have read a study done in Australia about this and the study indicated that
the dangers that were thought to exist, in reality, do not. It is not am
American publication.. and im not sure i can find it.. but i will look for
it.
Perhaps we can get Ms.Monona Rossol or one of our experts to bring us all up
to date on this. However, i was under the impression that it was not
available in the States.. And, im not sure we really need it anyway..
Jim........ in
Denton
j.a.velez on fri 29 mar 02
John said:
"Uranium oxide (depleted) produces good oranges and reds in lead glazes and
was popular at the beginning of the twentieth century when it was used in
"art" glazes, most successfully on Ruskin Ware."
Since this thread started it came to my mind that I had read an article
about a potter using Uranium Oxide in his glazes. I just could not recall
the name, but new he was from Texas, more specifically from San Antonio. I
could close my eyes and see these glorious glazes I had seen pictures of.
Well today, I decided to find out and in 5 minutes had my hands on the 1991
December issue of CM and there it was: Harding Black. As a matter of fact,
he also had the Chun glaze Ivor and others have been talking about. I just
re-read the article. What an inspiration. At the time of the article he
was 79 and still active. That would make him 89 now. Is he still around?
At any rate, I thought you might be interested in his work. I do not know
if he wrote about the use of Uranium in glazes.
Two by-products of the search:
1- I still might have 20+ years ahead, and if I am industrious that could be
a lot of pots.
2- I am getting old, but the "computer" is still in good order.
Regards, Jose A. Velez
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