|Monthly Tech-Tip |
Alternate Names: Calk, Calk-Stone, Barite, Barytes, BaSO4, Barium Sulphate
Barium sulfate is used as a pigment extender for coatings, plastics, rubber and chalks. Special grades are approved for pharmaceutical applications where the material is used in medical x-ray exams (it is an insoluble, inert, non-radioactive substance). The barium sulfate is more dense than the other tissues in the body making it possible to see organs and structures that cannot be seen otherwise.
On its own, barium sulphate does not decompose until after 1400C. But in the presence of silica and alumina barites decompose between 1100 and 1200 (ideal point being 1130 to 1150) with a corresponding decrease in the sulphur content. (see Metallurgical and Materials Transactions Volume 42B, August 2011)
The Use of Barium in Clay Bodies
Considerations regarding the use of barium carbonate in pottery and structural clay bodies for precipitation of soluble salts.
BARIUM and COMPOUNDS / Toxicology
Barium Sulphate Hazards at ilo.org
Barium sulphate at Wikipedia
Barite (65.7% BaO, 34.3% SO4) is the main mineral from which barium carbonate is sourced. It is mine
|Oxides||BaO - Barium Oxide, Baria|
Materials that source Na2O, K2O, Li2O, CaO, MgO and other fluxes but are not feldspars or frits. Remember that materials can be flux sources but also perform many other roles. For example, talc is a flux in high temperature glazes, but a matting agent in low temperatures ones. It can also be a flux, a filler and an expansion increaser in bodies.
Generic materials are those with no brand name. Normally they are theoretical, the chemistry portrays what a specimen would be if it had no contamination. Generic materials are helpful in educational situations where students need to study material theory (later they graduate to dealing with real world materials). They are also helpful where the chemistry of an actual material is not known. Often the accuracy of calculations is sufficient using generic materials.
|Density (Specific Gravity)||1350.00|
|Density (Specific Gravity)||4.5|
|By Tony Hansen|
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