Abstract:In order to study the influence of ammonium salt on the physical and chemical properties of fly ash (FA) and enhance the application of denitrified fly ash in the cement industry, different proportions of ammonium bisulfate (ABS) (0.6%, 1.0%, 2.0%, 3.0%) were added to the fly ash, and the ammonium salt was adhered to the fly ash particles through high-temperature melting. The variations of fineness, specific surface area, particle size distribution, microscopic morphology and pore structure of FA under different ABS contents were investigated, and the fluidity and pozzolanic activity of FA were tested. The results indicated that the incorporation and adhesion of ABS increased the 45 μm and 85 μm sieve residues, particle size and pore size of fly ash, reduced the specific surface area and total pore volume of fly ash, but did not significantly affect the particle morphology of fly ash. The adhesion of ABS increased the angle of repose of FA, reduced its fluidity, and slightly decreased the pozzolanic activity (<5%).