BENEFICIATION
Silica gives the
magic of glass
By Eamonn Ryan | Photos by PFG
When silica sand from a nearby quarry is unloaded by tipper truck at PFG’s Springs factory, it drops
into a silo before being combined by a mixer with other raw materials; it later emerges as flat glass
of varying thicknesses.
T
he float glass manufacturing
process used at PFG was
patented by Sir Alistair
Pilkington in 1959 and is
still used throughout the world today
having taken flat glass technology to a
revolutionary new level.
The process ensures glass gains its
lustrous finish and perfect flatness by
floating on a bath of molten tin in a
chemically controlled atmosphere. The
ribbon of glass is then cooled slowly
or annealed to relieve internal stresses
in the glass as it moves through the
annealing and strain point. The glass is
then automatically cut and stacked, ready
to be packed for distribution to local and
international customers.
The PFG facility at Springs has two
large plants, one for building glass and the
other for automotive glass. PFG produces
clear glass used in buildings, which is then
delivered to distributers or third-party
processors that add value to the basic
glass for such uses as toughening, mirrors,
laminated, tinted glass and double glazing.
28_QUARRY SA| MARCH/APRIL 2019
One of two large plants at PFG’s facility at Springs – one for building glass and the other for
automotive glass.
www.quarryonline.co.za