|Monthly Tech-Tip |
Alternate Names: Boracic acid, Orthoboric Acid, Hydrous Boric Oxide
Boric acid is a crystalline water soluble boron mineral. It is white in appearance and can be used as granules or as a powder. Both forms are stable under normal conditions, free-flowing, and easily handled by means of air or mechanical conveying. In solution, they are mildly acidic.
Boric Acids are used as the B2O3 source in the formulation frit. Fast fire frits for tiles find this material especially useful (compared to the deca and pentahydrate forms) because of their requirement for low sodium levels.
It is currently produced at Bandirma Boric Acid plant in Turkey and at Rio Tinto Borax. Depending on the particle size, the product is classified as "Granular" and "Powder".
Boric oxide can be used in sintering to initiate the bonding process, even with pure silica (and it doesn't volatilize).
The water solubility of ceramic materials is an important consideration to their usability in the process. Glazes are suspensions of insert powders, solubles present problems to this system.
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.
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.
|Materials||Disodium Octaborate Tetrahydrate|
Optibor Data Sheet
Boric Acid Data Sheet
|Oxides||B2O3 - Boric Oxide|
|Frit Softening Point||577C|
|Density (Specific Gravity)||1.50|