Fluidized bed combustion (FBC) is a promising environmentally-
friendly coal combustion process with operating temperature
of 800–900 C comparing with pulverized coal combustion. The
low temperature prohibits the nitrogen oxides (NOx) emission
[1]. The amount of FBC fly ash has, therefore, increased significantly
over the past few years owing to the rapid growth of FBC
technology [1]. The fly ash has low glassy phase material and possesses
very low pozzolanic property. Improvement on its reactivity
can be obtained from an intense grinding to reduce the particle size
[2]. In addition, it contains high amount of calcium compounds
(CaO and CaSO4) from the use of lime powder to capture SO2.
The use of FBC fly ash as a pozzolan to partially replace Portland
cement is therefore not recommended