What does rutile do in glazes?
Rutile is that unbelievably beautiful glaze additive that produces colors ranging from light and dark blue, to tan, gold, yellow, and even purple. It also produces a range of crystal formations. It seems to behave however it chooses, depending on the glaze base and the firing conditions.
What is rutile flour?
Description: The mineral is obtained from beach sands and usually contains about 95-97% titanium dioxide with impurities such as iron oxide, chromium oxide and silica. In the high lead rutile glazes it usually constitutes about 10 -15% of the glaze recipe.
What is the formula of rutile?
Rutile is a titanium oxide of formula TiO2. It is a member of the oxides and hydroxides group. Rutile is the most common titanium oxide, but there are two other polymorphs: anatase, which is tetragonal, and brookite, which is orthorhombic.
What is rutile made of?
Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer polymorphs of TiO2 are known, including anatase, akaogiite, and brookite.
What do you use rutile for?
Rutile is a commercially important titanium mineral, although most titanium dioxide is produced from ilmenite. Rutile has minor uses in porcelain and glass manufacture as a colouring agent and in making some steels and copper alloys.
Where does rutile come from?
The top rutile-producing countries include Australia, South Africa, and Ukraine. Rutile is also mined from apatite veins in the Gjerstadvatnet and Vegårshei regions of Norway.
What is rutile in ceramics?
However in nature rutile is always contaminated by other minerals (especially iron but also things like tantalum, niobium, chromium and tin, the analysis provided here is obviously a simplification). In ceramics, the term ‘rutile’ is generally understood to refer to the brown powder into which these minerals are ground.
Is pure rutile powder the same as pure titanium dioxide?
Pure rutile powder, although its color makes it appear to be a crude ground mineral, normally contains 95%+ titanium dioxide. However this does not mean that you can use a 95% titanium:5% iron mix and get the same result in a ceramic glaze (obviously line blending would be needed to match the amount of iron).
Why is rutile used as an opacifier?
Even in small amounts, rutile tends to matte the surface of leaded glazes. As an opacifier rutile is economical compared with pure titanium and it is employed where white shades are not required.
Is rutile a variegator or colorant?
In ceramic glazes rutile is more often considered a variegator than a colorant. As little as 2% can impart significant effects in stoneware glazes. It is normally used in combination with a wide range of metal oxide and stain colorants to produce surfaces that are much more visually interesting.