|Monthly Tech-Tip |
Description: High boron zero silicate refractory calcia alumina frit
Although this frit is very high in boron, it is a refractory (this might be a surprise to ceramic technicians who are accustomed to the use of boron as a powerful flux). Frits of this type have been in use to stop the penetration of aluminum in refractories since 1958 (by Carborundum Co., Metaullics Inc., Ceradyne, H-W Refractories (now ANH), and AP Green, and others). The original patent holder for these frits was Kaiser Aluminum Corp.
They are about ~1% soluble after 90 min in ~25 C water. In this way they can be used in castable cements where any appreciable amount of soluble boric oxide would retard Calcium Aluminate cement almost indefinitely.
A frit is the powdered form a man-made glass. Frits are premelted, then ground to a glass. They have tightly controlled chemistries, they are available for glazes of all types.
Matrix Frit B70-A
Calcium Aluminate Cement
|Oxides||B2O3 - Boric Oxide|
|By Tony Hansen|
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