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 TIN OXIDEtin oxide ceramic grade manufacturer
STANNIC
OXIDE [SnO2 ,CAS RN: 18282-10-5]:
a white powder compound; not soluble in
water, soluble in concentrated sulfuric acid(h2so4) the reaction between tin (sn) and
concentrated nitric acid (hno3) at high temperatures; used as a polishing agent for
glass, metals, and metallic dental restorations, and as a catalyst also known
as flowers of tin; meta stannic acid; stannic anhydride; tin dioxide; tin oxide; tin
peroxide Stannic oxide
Tin(IV) oxide
Flowers of tin
Cassiterite.
Tin
oxide is the most effective
opacifier of all. One or two percent will opacify a glaze and improve its gloss.
Normally about five percent of tin oxide added to a glaze will completely
opacify it.
For polishing purpose, tin oxide provide the marble
or granite with much
luster.
The fully oxidized state of tin
metal. It is a very white powder of low density. Although tin metal melts at a
very low temperature, the oxide form is quite refractory.
-Tin oxide has
been used primarily as an opacifier in amounts of 5-15% in all types of glazes
for many centuries. The amount required varies according to the glaze
composition and temperature. The mechanism of the opacity depends on the white
tin particles being in suspension in the molten glass. At higher temperatures,
these particles will start to dissolve and opacity will begin to be
compromised.
-Like zirconium oxide, larger amounts of tin in lower
temperature glazes have a refractory effect, stiffening the melt and increasing
the incidence of pinholing and crawling.
-Tin oxide white is considered a
softer white than that produced by the very popular and much cheaper zirconium
opacifiers.
-One peril with tin oxide SnO2 is that it reacts very strongly with
minute amounts of chrome to produce pink colors. If volatile chromium is
flashing in the kiln atmosphere from other glazes, the white color will be
lost.
-Other opacifiers include zirconium oxide (gives a harsher glassy
white), calcium phosphate (problems with off-coloring to greys), cerium oxide
(restricted to low temperatures), antimony (dissolves in some glazes and gives
yellows with lead), and titanium dioxide (discolors if any iron oxide is
present).
Stannic oxide is derived from tin. Widely known and used, tin comprises
about 0.001 percent of the earth's crust. It is sometimes found alone, but
generally is found as the oxide in the mineral cassiterite. Tin mines exist in
England, Spain, Indonesia, Thailand, Zaire, Nigeria and China. Significant
amounts of tin is also obtained through recycling. Tin is nontoxic, ductile,
malleable, adheres to various metals and has a relatively low melting point.
These properties lend to its usefulness as a rust-proofing material on iron,
low-grade steels, copper, and copper alloys.
Historical Background
Tin is a metal long known and used throughout the
world. It was known in ancient times--think Bronze Age--as a component of bronze
which it forms in combination with copper. Tin has broad uses in industry,
including food preservation and canning,
Stannic Oxide
Tin forms two series of
compounds, termed stannous and stannic. One of the most important compounds
commercially is stannic oxide, which is useful as a catalyst in industrial
processing, in ceramics and as a polishing powder for steel.
If you believe you have a use
for stannic oxide, contact us. We will be happy to discuss and help you
implement your
application.
FROM ANSWERS.COM
('stan·ik
'äk'sid)
(inorganic chemistry) SnO2 A white powder; insoluble in water,
soluble in concentrated sulfuric acid; melts at 1127°C; used in ceramic glazes
and colors, special glasses, putty, and cosmetics, and as a catalyst. Also known
as flowers of tin; stannic acid; stannic anhydride; tin dioxide; tin oxide; tin
peroxide.
Tin
Oxide ( SnO2 )
Stannic Oxide – Properties and Applications |
Background |
|
Tin oxide (SnO2) is also known as stannic
oxide. It can be found naturally as the mineral cassiterite.
It is typically a white to off-white and sometime grey
crystalline solid. |
Key
Properties |
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Density (g/cm3) |
6.90-7.00 |
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Melting Point (°C) |
1630 |
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Applications |
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Tin oxide is most commonly used in glazes where it acts as
an opacifier where it is typically added in the range of 5-10%. When used
correctly it will produce an opaque, glossy glaze. If used in excess a
dull/matt glaze can result. Potters have used tin oxide as an opacifier
for hundreds of years.
The addition of larger amounts of tin oxide to lower
temperature glazes can increase its refractoriness, i.e. the molten glaze
will have an increased viscosity increasing the possibility of pinholing
and crawling.
The use of tin oxide is diminishing, with many potters
moving towards the use of zircon, which is a cheaper alternative. However,
twice as much zircon is required to produce the same degree of opacity
when compared to tin oxide. |
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