Abstract: Using tire semicoke and silica sand as raw materials, silicon carbide whiskers were prepared by the carbothermal reduction method. X-ray diffraction (XRD) and scanning electron microscope (SEM) were used to analyze the phase composition and morphology of the prepared product, and the influence laws of reaction temperature (1 300 ℃ to 1 500 ℃), reaction time (120 min to 300 min), heating procedure and semicoke particle size on the synthesis of silicon carbide whiskers were explored. The results show that the whisker growth is best when the temperature is controlled at about 1 350 ℃, and the heating method that first rises to 1 500 ℃ for nucleation and then drops to 1 350 ℃ for holding growth. The particle size of the raw material simultaneously affects the formation rate of silicon carbide. And the whisker as the semicoke particle size decreases, the yield and quality of silicon carbide whiskers increase first and then decrease. When the tire semicoke particle size is 100 mesh to 120 mesh (150 μm to 120 μm), the reaction temperature is 1 350 ℃, and the reaction time is 240 min, under the best conditions, the prepared whiskers have a diameter of 50 nm to 120 nm and a length of 50 μm to 80 μm, with uniform distribution and high yield 95.36%.

Key words: tire semicoke, carbothermal reduction, silicon carbide whisker, heating procedure, generation mechanism