Abstract :
The present experimental study investigates
the feasibility of geopolymer synthesis from low Ca
electric arc ferronickel slags. Additives used include
kaolinite, sodium silicate, sodium hydroxide and water.
The effect of the main factors considered (heating
temperature, heating time and aging period) as well as
of their interactions on the final compressive strength of
the geopolymers produced was studied through a 23
factorial design. The experimental results and the
variance analysis have shown that only aging period
has a statistically very significant and positive effect on
the final compressive strength while the effect of the
other factors as well as of their interactions were either
less significant or negligible. Identification of new
phases formed in order to elucidate geopolymerisation
mechanisms was carried out by XRD and FTIR.
Sodalite, maghemite, thermonatrite, trona and calcite
are the major phases identified. The structural integrity
of the produced geopolymers was studied by subjecting
them to accelerated freeze–thaw cycles. Finally, the
durability of the produced geopolymers when immersed
in various aquatic and acidic solutions was investigated
