Digitalfire Ceramic Materials Database

Logged in as Level 2 access: Logout


You should always be testing. But it is wasted without an audit trail. Document your lifetime of recipes, firing schedules, test results, pictures and much more in a private account at insight-live.com. It is the future, the next step after desktop Digitalfire Insight.

Watch the video, learn more or sign-up at http://insight-live.com.

Strontium Carbonate

Formula: SrCO3 or SrO.CO2
Alternate Names: Strontianite

OxideAnalysisFormula
SrO70.20%1.000
CO229.80
Oxide Weight103.60
Formula Weight147.58
Enter the formula and formula weight directly into the Insight MDT dialog (since it records materials as formulas).
Enter the analysis into an Insight recipe and enter the LOI using Override Calculated LOI (in the Calc menu). It will calculate the formula.
DENS - Density (Specific Gravity) 3.6
HMOH - Hardness (Moh) 3.6
MLPT - Melting Point (MP) 723C D
BDLB - Bulk Density lbs/cu. ft. (Packed) 105

Strontium Carbonate is a slightly soluble source of SrO used in glazes.

There is disagreement about when it decomposes (data sheets vary from 1075-1100C, one even indicates 1340C) as follows:

SrCO3 -> SrO + CO2

The 'Ceramic Industry Materials Handbook' states that it starts to disassociate as early as 800C in a purely oxidizing atmosphere, whereas a CO2 atmosphere might delay break-down until around 1220C. This information is supported by the fact that when the more stable calcium and barium carbonate are added to bodies, pinholing and blistering are greater than bodies containing strontium. Wikipedia says it melts and decomposes at the same time, 1100C.

Strontium carbonate is often recommended as a substitute for barium to produce matte glazes. Use about 75% as much and test first to make sure color response is the same. However strontium is not a substitute for barium as a precipitator of soluble salts in clay bodies because it combines with SO4-- ions in the water to form a compound that is not nearly as insoluble as BaSO4.

Viscous zirconium silicate glazes can be smoothed with the addition of strontium carbonate.

Strontium is considered a safe material. Some people confuse SrO with Strontium 90, an isotope released from atomic reactions; they are not the same thing.

Strontium carbonate produces gases as it decomposes and these can cause pinholes or blisters in glazes. There are many strontium frits available and incorporating one of them to source the SrO instead of raw strontium carbonate is a classic application of ceramic chemistry calculations. The resultant glaze will be more fusible and will have better clarity and fewer defects. Strontium frits have become much more common of late and are useful to producing brilliant transparent glazes without having a high expansion (like those based on Na2O and K2O). Please read the information about the oxide SrO to fully appreciate the value of SrO frits, not just as alternatives to this material, but as excellent ways to produce brilliant glazes.


Out Bound Links

In Bound Links


Pictures

Strontium carbonate fired at 1800F and then allowed to rehydrate in the air for two days. I fractures in a manner similar to calcium carbonate.


By Tony Hansen

XML for Import into INSIGHT

<?xml version="1.0" encoding="UTF-8"?> <material name="Strontium Carbonate" descrip="" searchkey="Strontianite" loi="0.00" casnumber="1633-05-2"> <oxides> <oxide symbol="SrO" name="Strontium Oxide, Strontia" status="U" percent="70.200" tolerance=""/> </oxides> <volatiles> <volatile symbol="CO2" name="Carbon Dioxide" percent="29.800" tolerance=""/> </volatiles> </material>


Feedback, Suggestions

Your email address

Subject

Your Name

Message


Copyright 2003, 2008 http://digitalfire.com, All Rights Reserved
Get a free INSIGHT software trial

INSIGHT is ceramic chemistry
calculation software that runs on
Windows, Mac and Linux and talks
to this web site. ()