Abstract: The physical and chemical characteristics of wet fly ash from coal gangue-fired power plant in shaanxi were studied by using chemical analysis, laser sizer, XRD, SEM and other techniques. The experimental results showed that the wet gangue fly ash has anomalous particles with 20-70 μm. The chemical composition contains mainly SiO_2,Al_2O_3 and Fe_2O_3 with more than 70% content. It has lower calcium content and higher ignition loss, meeting the national standard of Ⅲ grade of fly ash. Fly ash consists of porous amorphous phase, carbon grain and a small amount mineral crystal which dominated by quartz, mullite and hematite. In filling and supporting of coal mine, the wet fly ash can be activated by combining with physical and chemical activation and adopting special techniques further.

Key words: wet fly ash%physical and chemical properties%activity