Page 219 - Encyclopedia of Chemical Compounds 3 Vols

CALCIUM SULFATE

Interesting Facts

• Calcium sulfate has been of Paris is made) exist
used in China for more near the city of Paris,
than 2,000 years to France. These deposits
thicken soy milk in the were long mined to obtain
production of tofu. the hemihydrate form of
calcium sulfate.
• One reason that calcium
sulfate hemihydrate is • Ancient Romans used
called plaster of Paris is plaster of Paris to cast
that large deposits of copies of Greek statues.
gypsum (from which plaster

The anhydrous form of calcium sulfate also has a number
of practical applications, the most important of which are in
the manufacture of cement and as a filler in the production
of paper. A filler adds body to paper, making it firmer,
brighter, and easier to write, draw, and print on. Soluble
anhydrite is used as a desiccant, which is a material that
removes water from other substances. It is usually sold under
Ò
the trade name of Drierite .
The primary use of calcium hemihydrate is, of course, in
the production of plaster of Paris. Plaster of Paris has a
number of important applications, such as:
• In the construction of arts and crafts projects, such as
masks, ceramics, and pottery;
• For the production of plaster casts used to immobilize
broken bones;
• As a building material in the manufacture of stucco,
drywall, division panels, ceiling tablets, plaster board,
and wall plaster.
Some other important applications of calcium sulfate
include:
• As a firming agent in foods such as canned vegetables,
soft-serve ice cream, regular ice cream, frostings, and
gelatins;
• As an additive to animal feeds to provide the calcium
and sulfate that animals need in their diets;

168 CHEMICAL COMPOUNDS