|Monthly Tech-Tip |
Alternate Names: Tri-Calcium Phos, Tribasic Calcium Phosphate, Synthetic Bone Ash, Calcium Orthophosphate, TCP
Also known as Synthetic Bone Ash, Calcium Orthophosphate, TCP. A white, odorless, tasteless very small particle size powder that is stable in air, insoluble in alcohol and very slightly soluble in water. In ceramics it is used as a substitute for bone ash in glazes and bodies since its chemistry is similar.
However brand name materials do not match the theoretical chemistry here and they can have an LOI of up to 10%. Often Ca rather than CaO content is quoted. There are normally ppm amounts of heavy metals, arsenic, fluoride.
CAS1306-06-5 is Hydroxyapatite (HAP), 7758-87-4 is Tricalcium Phosphate (TCP). These have different Ca/P molar ratios: 1.67 vs 1.5.
Calcium phosphate makes up most of the bones and teeth. Companies doing use 3D printing of medical grades of TCP and HAP for orthopedic, spinal and cranial implants and bone substitutes, they generate porous yet strong products. They are biocompatible, bioactive, osseointegating.
Although they are calling it Tricalcium Phosphate, it is actually Hydroxyapatite.
Bone Ash Calcined
Tricalcium Phosphate, F.C.C.
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.
Opacifiers are powders that turn transparent glazes opaque by various chemical and physical mechanisms (and combinations of mechanisms).
Tricalcium phosphate at Wikipedia
|Oxides||P2O5 - Phosphorus Pentoxide|
|Frit Softening Point||1670C|
|Density (Specific Gravity)||3.18|
|Glaze Opacifier||Tricalcium phosphate has been used as an opacifier (to replace tin oxide) to give similar color, texture, and brilliance in leadless sanitaryware glazes above cone 8. Does not produce opacity at lower temperatures.|
|By Tony Hansen|
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