Abstract：For optimizing the processing technology of by-product DR-GH during the production of electric smelting zirconia and increasing utilization value of DR-GH, the chemical composition, phase composition and particle characteristics of DR-GH were studied through particle size distribution testing, scanning electron microscope (SEM) and transmission electron microscope (TEM) observing combining with the analyzing of chemical elements and X-ray diffraction (XRD) .The results show that the DR-GH is composed of amorphous SiO₂ solid sphere and a few ZrO₂ particles.The diameter of SiO₂ primary particle is0.5～3μm, and the primary particles first aggregate to form secondary particles with strong binding force.The secondary particles agglomerate into a weakly bound SiO₂ agglomerate.The SiO₂ secondary particles can be obtained by stirring the DR-GH suspension, of which the d₉₀of DR-GH dropped from 18.551μm to 5.379μm and the d₅₀dropped from 2.582μm to 1.88μm.

Keywords：silica fume; amorphous SiO₂; particle characteristics