Plaster of Paris
What is
plaster of Paris?
Plaster of Paris is also known as POP.
The chemical name of plaster of Paris is calcium sulphate hemihydrate and
chemical formula is CaSO4.1/2H2O. Plaster of Paris is very important product
which is obtained from gypsum. Gypsum is very much available in Nigeria. Gypsum
is also used by different industries for numerous applications. Before we
understand the plaster of Paris, we need to understand gypsum.
Now let’s talk about gypsum. Gypsum is also
known as alabaster. Gypsum is type of sedimentary rock. Gypsum can show various
colors white, brown, yellow, grey and pink. Gypsum is show in various colors
because its nature is impurity. Gypsum is a major and very important raw
material of plaster of Paris. Pure gypsum is a white crystalline mineral. It
consists of hydrated calcium sulphate. The chemical formula of gypsum is CaSO4.2H2O.
The first gypsum was found in Paris.
Now let’s get information about plaster of
Paris. Plaster of Paris is made up with raw materials. Gypsum is one of the raw
materials which is very important raw material. If we heat pure gypsum on
temperature 107 degree Celsius to 130 degree Celsius. Then it loses its water
and convert into plaster of Paris. The methods of preparing plaster of Paris
are given blow:
collection,
selection, washing, drying, crushing, screening, calcination and storing
Plaster
of Paris is manufactured by impure gypsum for commercial uses. Impurities of
gypsum are iron, silicates, carbonates, lime, etc. The chemical reaction of
plaster of Paris is shown in equation:
CaSO4.2H2O
+ Heat → CaSO4. ½H2O + 1½H2O
Properties
of plaster of Paris
1. Plaster of Paris is a powder. It is
white in color. If we heat it on high flam then it is converted into calcium sulphate which is very hard.
2. If we react plaster of Paris with
water then it releases a lot of energy. After that it is converted into solid. It is called
freezing of plaster of Paris.
3. Plaster of Paris is nonflammable.
Uses of
plaster of Paris
1. Surgeons use the plaster of Paris for
plaster.
2. Plaster of Paris is use for preparing
models and molds.
3. Plaster of Paris is also use for
making toys and statues.