|Monthly Tech-Tip |
|Dry M.O.R. (50% Silica)||332C|
-Antimony oxide is used as an opacifier in low fire glazes and porcelain enamel (mainly leadless but it has been replaced to an extent by titania). Antimony is easily reducible; thus an oxidizing agent like potassium nitrate may be required to prevent it from going into solution and losing its opacifying power and affecting color.
-It is not useful in glazes over cone 1 due to volatilization.
-Antimony can be used as a yellow body stain in combination with rutile or titanium.
-Antimony will bleach the surface of low fire red-burning clay to a buff color to produce variegated coloration.
-The glass industry uses antimony as a decolorizing and fining agent to clarify glasses and as a stabilizing agent in the production of emerald green glass.
-Antimony has a low thermal expansion and reduces crazing.
|Temperatures||Antimony volatilizes (1100C+-)|
|Glaze Color||It can give a yellowish color if the glaze contains lead, this is a result of the precipitation of yellow lead antimonate (known as Naples yellow).|
|Glaze Opacifier||Antimony works to a limited extent as an opacifier to cone 1.|