Question

What is Calcination Gypsum?

Answer 1

Calcination: The process in which solids are heated to a very high temperature to remove any volatile substance present and also to oxidize a substance is called Calcination.

Calcination of Gypsum:

• When the gypsum is heated in a controlled environment, it partially loses its water of crystalization and converts into plaster or stucco is called Calcinated Gypsum.

Heating of Gypsum:

• When the water of crystallization is removed from Gypsum (${\mathrm{CaSO}}_4.2{\mathrm{H}}_2\mathrm{O}$), a Hemihydrate Gypsum or Calcined Gypsum (${\mathrm{CaSO}}_4.\frac{1}{2}{\mathrm{H}}_2\mathrm{O}$) is produced.
  $$\begin{gathered} {\mathrm{CaSO}}_4.2{\mathrm{H}}_2\mathrm{O}\left(\mathrm{s}\right)\stackrel{∆}{\to }{\mathrm{CaSO}}_4.\frac{1}{2}{\mathrm{H}}_2\mathrm{O}\left(\mathrm{aq}\right)+\frac{3}{2}{\mathrm{H}}_2\mathrm{O}\left(\mathrm{l}\right) \\ \mathrm{Gypsum}\mathrm{Calcinated}\mathrm{Gypsum} \end{gathered}$$

Uses of calcinated gypsum:

• Used in making casts and patterns for molds and statues.
• Used as the cement in ornamental casting and for making decorative materials.
• Used as a fireproofing material and for making chalks.
• Used in hospitals for immobilizing the affected part in case of bone fracture or sprain.