ZHANG Shu-Hui Zhi-Qiang KANG Qing LU XUE Xiang-xin HUANG Da-wei
College of Metallurgy and Energy, Hebei Polytechnic University College of Resources and Environment, Hebei Polytechnic University College of Metallurgy and Energy, Hebei Polytechnic University School of Materials and Metallurgy, Northeastern University
Abstract： Based on thermodynamic analysis, Si3N4 powder was prepared by carbothermal reduction-nutridation from iron ore tailing. The phase composition and microstructure of sintered products were investigated by XRD and SEM techniques. The influences of synthesis temperature and N2 flow on the reaction process were also studied. The results show that Si3N4 phase in the products rises with increasing of synthesis temperature and reaches the maximum portion at 1450℃, which is assumed to be the optimal synthesis temperature. And Si3N4 crystal mostly exists as equiaxedly columnar or shot rod-like b-Si3N4. The increase of N2 flow is favorable to the reduction-nutridation process, and the optimal flow rate of N2 is 600 mL/min. Volatilization of SiO results in obvious mass loss of the tested samples.