The Calcination Process
The production of the lime consists
on the calcination
of the limestone, to a temperature above 900º C.
The calcium carbonate breaks down by the heat according
to the following equation:
The reaction of dissociation of
the limestone is characterized
by the fact that it takes place in a front of decomposition
area), in which the still non-dissociated nucleus of
CaCO3 and the shell of CaO
that has been formed are in contact. This front of
from the periphery towards the center at a certain
speed. Simultaneously there is a transfer of heat from
the exterior towards the nucleus and
a detachment of CO2 towards the exterior.
Nowadays, the calcination of
limestone is carried out fundamentally
in regenerative kilns with parallel current that, opposed
counter-current classic ones, allow to preheat
and to recover
the combustion gases. They are ovens of double pot,
in alternative operation.
This technology allows an optimization of the energy
© Caleras de San Cucao, S.A.