CARBONATE DE BARYUM
BARIUM CARBONATE
CARBAR
Molar formula:
CO2Ba
Molar mass: 197
BARIUM CARBONATE
In the masses: the barium carbonate is used for the chemical binding of soluble sulfates.
The binding of the hardly soluble barium sulfate prevents discolorations (efflorescence).
In glazes: is used in stoneware glazes to modify the basic rib of the glaze.
Allows to develop a turquoise blue hue in the presence of copper oxide and a purplish hue with manganese.
To be handled with care.
Used in ceramic bodies in quantities of 2.5% approx. to avoid efflorescence of soluble salts.
It is also used as a flux in high temperature glazes and to produce matt or semi-matt surfaces at terracotta temperatures.
Used in casting slips at low levels to preventscumming (up to 0.5%).
Used in hightemperature glazes as a flux and produces matt and semi-matt surfaces atearthenware temperatures.
At higher temperatures it can make a distinctiveturquoise with copper.
In bodies it seems to impart better translucency but canlead to weakness and excessive shrinkage.