|Monthly Tech-Tip |
Alternate Names: Potassium Carbonate, K2CO3, Pearlash
This is the only material in ceramics that can deliver K2O in the exact amount required without bringing other oxides with it, however it is water soluble. The most common source of K2O in glazes is feldspar and normally all of the oxides that feldspar supplies are also needed in glazes (so it is rare that pure and much more expensive K2O is needed). Sometimes this is used to modify the color in glazes.
In the manufacture of frits, pearl ash can be an important source of potassium.
|Oxides||K2O - Potassium Oxide|
|Materials||Potassium Carbonate Trihydrate|
|Materials||Pearl Ash Calcined|
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.
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.
Potassium Carbonate Toxicity
|Frit Softening Point||896C M|
|Density (Specific Gravity)||2.30|