Mechanical activation of power station fl y ash by grinding – A review

Power station fly ash has good application possibilities mainly in the construction industry, nevertheless, significant amount is landfilled due to their relatively low reactivity and heterogeneity. Hydraulic properties of fly ashes can be tailored by mechanical activation achieving a higher added value product, for example supplementary cementing materials (scms). the improved properties are higher specific surface area and desired particle size distribution (containing submicron size particles) as well as higher amount of reactive components that can be optimized by grinding. the objective of this paper is to investigate the effect of mechanical activation of fly ash by grinding on physico-chemical and minerological properties. it can be established that there are numerous techniques for mechanical activation of fly ash, e.g. planetary ball mill, vibratory mill or stirred media mill. on the other hand, most of the results reported in the literature are focusing on material related investigations, but beside this, from energetic point of view the process related evaluation has even higher importance.