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Ceramic Rutile

Formula: TiO2
Alternate Names: Calcined Rutile, Light Rutile, Rutile Ceramic

OxideAnalysisFormula
TiO296.09%245.336
Al2O30.50%1.000
SiO20.80%2.715
Cr2O30.20%0.268
Fe2O30.50%0.638
V2O50.70%0.785
ZrO1.20%2.284
Oxide Weight20397.96
Formula Weight20397.96
If this formula is not unified correctly please contact us.

This is a much lighter color than raw rutile (because it is calcined). It is the recommended type for use in ceramic glazes since it will not produce gases of decomposition. See Rutile topic for much more information.

The theoretical chemistry is TiO2, but of course no mineral deposit has this. We have shown the chemistry of a commercial material whose original container bags are labelled "Weld Rod Titanate" (used in making welding rods).


6% rutile is too much in this cone 6 oxidation glaze

6% rutile is too much in this cone 6 oxidation glaze

Rutile variegates glaze surfaces. But it also opacifies at higher percentages. The blue effect is a product of crystallization that occurs during cooling, it is thus dependent on a slower cooling cycle, especially above 1400C. This is GA6-C Alberta Slip glaze with 4, 5 and 6% rutile. At 6% the rutile crystallization has advanced to the point of completely opacifying the glaze. At 5% the blue is still strong, even on a buff burning body. The loss of color occurs suddenly, somewhere between 5 and 6 percent. Rutile chemistry varies from batch to batch. The blue develops differently on different bodies. So do you want to play "at the edge", with 5% in the glaze, in view of these other factors and the finicky firing curve needed. Change in any of which could push it into the blueless zone?

Variegation and phase separation with about 5% rutile

Variegation and phase separation with about 5% rutile

The glaze is a dolomite matte fired to cone 10R. High fire reduction is among the best processes to exploit the variegating magic of rutile.

How much rutile can a glaze take before it becomes unstable?

How much rutile can a glaze take before it becomes unstable?

The 80:20 base Alberta slip base becomes oatmeal when over saturated with rutile or titanium (left:6% rutile, 3% titanium; right:4% rutile, 2% titanium right). That oatmeal effect is actually the excess titanium crystallizing out of solution in the melt as the kiln cools. Although the visual effects can be interesting, the micro-crystalline surface is often susceptible to cutlery marking and leaching. This is because the crystals are not as stable or durable as the glass of the glaze.

Blisters in a reduction fired rutile glaze

Blisters in a reduction fired rutile glaze

This is a common problem with these glazes. The visual effect is very compelling but also punishing! Potters experiment with higher bisque firing and soaking during bisque. They try cleaner clay bodies. They employ long hold periods at temperature in the glaze firing. But the problem persists. The solution is actually simpler. These glazes have a high melt fluidity and enough surface tension to hold a bubble static during soaks at temperature (no matter how long you hold it). It is better to cool the kiln somewhat (perhaps 100F) and soak at that temperature. Why? Because the increasing viscosity of the melt overcomes the surface tension that maintains the bubbles. You may need to cool more or less than 100 degrees, but start with that.

An original container bag of ceramic rutile

An original container bag of ceramic rutile

The primary use of this material is obvious. It is not ceramics. But this bag is marked at "ceramic grade", likely a reference to its fine particle size. This bag is very small, ceramic rutile is very dense.

Out Bound Links

In Bound Links


By Tony Hansen

XML for Import into INSIGHT

<?xml version="1.0" encoding="UTF-8"?> <material name="Ceramic Rutile" descrip="" searchkey="Calcined Rutile, Light Rutile, Rutile Ceramic" loi="0.00" casnumber="98084-96-9"> <oxides> <oxide symbol="TiO2" name="Titanium Dioxide, Titania" status="" percent="96.090" tolerance=""/> <oxide symbol="Al2O3" name="Aluminum Oxide, Alumina" status="" percent="0.500" tolerance=""/> <oxide symbol="SiO2" name="Silicon Dioxide, Silica" status="" percent="0.800" tolerance=""/> <oxide symbol="Cr2O3" name="Chrome Oxide" status="" percent="0.200" tolerance=""/> <oxide symbol="Fe2O3" name="Iron Oxide, Ferric Oxide" status="" percent="0.500" tolerance=""/> <oxide symbol="V2O5" name="Vanadium Pentoxide" status="" percent="0.700" tolerance=""/> <oxide symbol="ZrO" name="Zirconium Oxide, Zirconia" status="" percent="1.200" tolerance=""/> </oxides> </material>


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