Sialon powders were synthesized using aluminium dross, fly ash and carbon black as main starting materials by the C-Al compound reduction and nitridation process. The effects of different factors on the phase of products were studied, such as the compositions of raw material (the proportion of Si/Al is 1.5, 1 and 0.27), the content of carbon black (10%, 17%, 22% and 27%) and heating temperature (1400,1450 and 1500℃). The results show that the relatively pure Sialon powders can be obtained at 1450 ℃; the process of reduction-nitridation is effectively accelerated by the increase of the carbon black content. When the proportion of Si/Al is about 1, the main phases of products are Si_3Al_3O_3N_5(β-Sialon,z=3) and SiAl_4O_2N_4(15R) using 17% carbon black; at 1450℃, a nearly pure Sialon powder ( the main phase is Si_3Al_3O_3N_5) can be obtained when the proportion of Si/Al is about 1.5 and the fly ash content is 80%.
