| Gypsum is an abundant, naturally occurring mineral that is
mined or quarried for a variety of uses – predominantly for
the production of gypsum board and gypsum plaster. It is believed
that the vast worldwide deposits of gypsum ore were formed
by the precipitation of minerals and the evaporation of inland
seas some 140 million years ago! Gypsum is also produced synthetically.
One process uses the desulfurization of environmentally harmful
flue gases at fossil-fuel burning power plants to create benign
and beneficial gypsum. See information on byproduct gypsum.
Chemically, gypsum is know as hydrous calcium sulfate (CaSO4.2H2O).
The two molecules of water are chemically bound to the crystal
lattice during the crystallization process. One of the many
unique properties of gypsum is the ability to release this
water when heated (in a process called calcination) and recombine
with the water to re-form gypsum. It is fascinating to realize
that the steam plume from a gypsum board plant is water captured
by the gypsum while dinosaurs roamed the earth! The presence
of the two water molecules (accounting for approximately 21%
of the minerals weight) and high insulative properties of the
rock contribute to gypsum's use as a premier fire resistant
material.
Gypsum plaster, easily dating to 2000 B.C., has been found
in the Egyptian pyramids. The development of gypsum plaster
as a modern building material dates back to around 1835 with
more advances occurring in the late 1870's. Augustine Sackett
is given credit for the invention of what we know today as
gypsum board. Sackett's patent on plaster board or Sackett
Board dates to 1894. |
|
 |
| The gypsum industry has enjoyed tremendous growth since
the turn of the century due to refinements in manufacturing
processes, coupled with the need for high quality, low cost
buildings and houses. It is estimated that about 90% of the
interior finished surfaces of buildings are covered with
gypsum products. The gypsum industry continues to investigate
new and innovative ways to provide high quality products
and services to code officials, designers, and others.
(Reprinted with permission from the "Gypsum Association
Board Talk" magazine). |
Also visit:
and
|
|
