Synthesis of SiC powders by carbothermal reduction reaction using the recycling of iron ore tailings

In the present research work, SiC-based composite powders were successfully synthesized using the carbothermal reduction reaction (CTR) with high silica iron tailings (IOT) as raw materials; the anthracite culm was used as the carbon source. The effects of different sintering temperatures and carbon contents on the microstructure and phase composition of SiC powders were examined. The order of generation of reaction products during the synthesis of silicon carbide from IOT was also determined by thermodynamic analysis. The results revealed that as the CTR proceeded, the β-phase of SiC was synthesized when sintering was performed at 1500°C at a SiO₂/C molar ratio of 1:5.5 for 4 h, and the secondary crystal type was the Fe-Si compound. Thermodynamic studies showed that the presence of iron oxides in the IOT aided the synthesis of the SiC phase by CTR, a mineral phase with a high melting point, at a lower temperature. The present study thus provides significant guidance for the secondary utilization of IOT.