Recent Changes - Search:

I am not a safety expert, or a chemist. Do not use this site as a primary source for safety, chemistry or disposal information.

edit

CalciumCompounds

Soluble.CalciumCompounds History

Hide minor edits - Show changes to output

March 23, 2019, at 09:23 PM by 76.248.208.245 -
Changed line 20 from:
to:
*Ulexite
Deleted line 21:
**[[https://falcon.tamucc.edu/~lkatz/articles/calcia.html|Calcia Oh Calcia]]
Added line 24:
**[[https://falcon.tamucc.edu/~lkatz/articles/calcia.html|Calcia Oh Calcia]]
February 04, 2019, at 11:49 AM by 76.248.208.245 -
Changed lines 19-20 from:
**normally made by combining or slaking the highly reactive and dangerous quicklime (Calcium Oxide) in water. This reaction can happen explosively fast. It releases a great deal of heat, often enough to convert the excess water involved into steam and blow up in your face. This can happen if you use pure calcium carbonate as wadding and is more likely to be dangerous at earthenware temperatures. At stoneware temperatures impurities seem to cause it to sinter enough to slow the react. PLEASE be careful if messing with calcining calcium carbonate. Eye and respiratory protection are a must.
to:
**normally made by combining or slaking the highly reactive and dangerous quicklime (Calcium Oxide) in water. This reaction can happen explosively fast. It releases a great deal of heat, often enough to convert the excess water involved into steam and blow up in your face. This can happen if you use pure calcium carbonate as wadding and is more likely to be dangerous at earthenware temperatures. At higher temperatures I assume that its the impurities that  usually cause it to sinter enough to slow the reaction. PLEASE be careful if messing with calcining calcium carbonate. Eye and respiratory protection are a must. 
Changed lines 22-24 from:
*[[https://falcon.tamucc.edu/~lkatz/articles/calcia.html|Calcia Oh Calcia]]
to:
**[[https://falcon.tamucc.edu/~lkatz/articles/calcia.html|Calcia Oh Calcia]]
**Gerstley bearing slips in clays seems to cause a calcium scum on the surface.
**http://louiskatz.net/LK/soph/handbuilt/r.jpg
February 04, 2019, at 11:43 AM by 76.248.208.245 -
Changed line 15 from:
**Calcium Sulphate is the chemical usually seen as scumming on ceramics. If you want it gone you can try treating your clay with small amounts of Barium Carbonate. In my soda kiln however, calcium sulphate scumming was something I looked forward to. I have considered wedging small amounts of the powder into my clay.
to:
**Calcium Sulphate is the chemical usually seen as scumming on ceramics. If you want it gone you can try treating your clay with small amounts of Barium Carbonate. In my soda kiln however, calcium sulphate scumming was something I looked forward to. I have considered wedging small amounts of the powder into my clay. I have some data to show that this would be interesting.
Changed lines 15-16 from:

*Calcium Sulphate is the chemical usually seen as scumming on ceramics. If you want it gone you can try treating your clay with small amounts of Barium Carbonate. In my soda kiln however, calcium sulphate scumming was something I looked forward to.
to:
**Calcium Sulphate is the chemical usually seen as scumming on ceramics. If you want it gone you can try treating your clay with small amounts of Barium Carbonate. In my soda kiln however, calcium sulphate scumming was something I looked forward to. I have considered wedging small amounts of the powder into my clay.
Changed lines 21-22 from:
*GerstleyBorate
to:
*GerstleyBorate
*[[https://falcon.tamucc.edu/~lkatz/articles/calcia.html|Calcia Oh Calcia]]
Changed lines 16-17 from:
Calcium Sulphate is the chemical usually seen as scumming on ceramics. If you want it gone you can try treating your clay with small amounts of Barium Carbonate. In my soda kiln however, calcium sulphate scumming was something I looked forward to.
*Calcium Hydroxide
to:
*Calcium Sulphate is the chemical usually seen as scumming on ceramics. If you want it gone you can try treating your clay with small amounts of Barium Carbonate. In my soda kiln however, calcium sulphate scumming was something I looked forward to.
*Calcium Hydroxide - Slaked Lime
**used as a cementatious binder in mortars and whitewash
**reacts with atmospheric carbon dioxide or sodium carbonate to become Calcium Carbonate (limestone)
**normally made by combining or slaking the highly reactive and dangerous quicklime (Calcium Oxide) in water. This reaction can happen explosively fast. It releases a great deal of heat, often enough to convert the excess water involved into steam and blow up in your face. This can happen if you use pure calcium carbonate as wadding and is more likely to be dangerous at earthenware temperatures. At stoneware temperatures impurities seem to cause it to sinter enough to slow the react. PLEASE be careful if messing with calcining calcium carbonate. Eye and respiratory protection are a must.
*GerstleyBorate
Added line 17:
*Calcium Hydroxide
April 25, 2016, at 10:56 PM by 76.248.208.103 -
Added lines 15-16:

Calcium Sulphate is the chemical usually seen as scumming on ceramics. If you want it gone you can try treating your clay with small amounts of Barium Carbonate. In my soda kiln however, calcium sulphate scumming was something I looked forward to.
April 24, 2016, at 04:32 PM by 64.71.89.34 -
April 24, 2016, at 04:32 PM by 64.71.89.34 -
Added lines 1-14:
*[[https://en.wikipedia.org/wiki/Calcium_chloride|Calcium Chloride - Wikipedia]]
**[=CaCl2=]
**Calcium chloride has a very high enthalpy change of solution. A considerable temperature rise accompanies its dissolution in water. The anhydrous salt is deliquescent; it can accumulate enough water in its crystal lattice to form a solution.
**Calcium chloride is used to increase the water hardness in swimming pools.
**[=Solubility in water, g/100ml at 20°C: 74.5 =]
**[[http://www.osi-univers.org/IMG/pdf/CalciumChloridHandbook-2.pdf|Calcium Chloride Handbook]]
**Melting Point_ 772–775 °C (1,422–1,427 °F)
**Boiling Paint_  1,935 °C (3,515 °F) It appears that left to its own devices this material will not decompose in our kilns. I am not sure that this is true. However when it works itself into a glassy melt we should expect that the chlorine will be expelled.
*[[https://en.wikipedia.org/wiki/Calcium_sulfate|Calcium Sulphate and related hydrates Plaster of Paris, dead burned plaster ludo etc. - Wikipedia]]
**[=Solubility 0.24 g/100ml at 20 °C (dihydrate)=]
**[[https://en.wikipedia.org/wiki/Calcium_sulfate|Read about dehydration and temperatures on Wikipedia]]
**[[https://en.wikipedia.org/wiki/Plaster#Gypsum_plaster_.28plaster_of_Paris.29|Plaster of Paris here]]
** Melting point 1,460 °C (2,660 °F; 1,730 K) (anhydrous)
** Decomposition is aided by presence of silica and alumina http://www.osti.gov/scitech/servlets/purl/7224692/ page 10 . I have always assumed that when melted in a glassy melt there is little ability to hold the sulphur dioxide and that it comes off and can be a source of bloating and pinholes. Richard Burkett suggested that decomposition can be aided by reduction of a kiln at or above 1500 F to Calcium Sulfite. The sulfite  melts at600 °C (1,112 °F; 873 K) . I am convinced that calcium sulphate is a source of gases causing pinholing and bloating.
Edit - History - Print - Recent Changes - Search
Page last modified on March 23, 2019, at 09:23 PM