Introduction
to
the
Manufacturing
of
the
Cement
Throughout
history
,
cementing
materials
have
played
a
vital
role
.
They
were
used
widely
in
the
ancient
world
.
The
Egyptians
used
calcined
____________________
as
a
cement
.
The
Greeks
and
Romans
used
lime
made
by
heating
limestone
and
added
sand
to
make
mortar
,
with
coarser
stones
for
concrete
.
In
1845
,
it
was
made
the
first
modern
Cement
by
firing
a
mixture
of
chalk
and
clay
at
much
higher
temperatures
,
similar
to
those
used
today
.
At
these
temperatures
(
____________________
)
,
clinkering
occurs
and
minerals
form
which
are
very
reactive
and
more
strongly
cementitious
.
While
it
was
used
the
same
materials
to
make
cement
as
we
use
now
,
three
important
developments
in
the
manufacturing
process
lead
to
modern
cement
:
-
Development
of
rotary
____________________
-
Addition
of
____________________
to
control
setting
-
Use
of
ball
____________________
to
grind
____________________
and
raw
materials
The
two
other
principal
technical
developments
,
gypsum
addition
to
control
setting
and
the
use
of
ball
mills
to
grind
the
clinker
,
were
also
introduced
at
around
the
end
of
the
19th
century
.
