Fly ash is an industrial waste created when coal is burned to generate electrical power. In the present study, we used low-energy nitrogen ion implantation on fly ash to improve its surface properties. Scanning electron microscope （SEM）, fourier transform infrared spectroscopy （FTIR）, X-ray photoelectron spectroscopy （XPS） and inductively coupled plasma-atomic emission spectroscopy （ICP-AES） were used to study the changes of physical and chemical properties of fly ash after N＋ ion implantation, and the mechanism of fly ash modified by ion implantation. In the optimal implantation with energy of 5 keV and dose Of 15D0, the ion beam could effectively increase the specific surface area （approximately 150% increase） of the fly ash. Lots of scratches were generated in the surface of the fly ash after N＋ ion implantation, therefore it is good for enhancing the specific surface area. Experimental results show that the ion implantation could open the chemical bonds of Si-O, Si-A1 and Al-O, and deposit nitrogen ions on the surface of fly ash.
