Preparation of SiC from carbonaceous vanadium-bearing stone coal via carbothermal reduction method

Abstract

In the present study, silicon carbide (SiC) was prepared via carbothermal reduction method using carbonaceous vanadium-bearing stone coal at 1400 °C. Compared to other reported raw materials, SiC was prepared at a relatively low the reaction temperature. The effects of temperature, duration and vanadium catalysis on the process of SiC preparation were investigated, and the kinetics of SiC nucleation and growth were analyzed. The results indicate that the SiC conversion of samples with 0 wt% and 2 wt% V2O3 additions reached to 68.9 wt% and 80.7 wt% at 1450 °C for 5 h. It was observed that the reduction of vanadium oxides resulted in the formation of vanadium carbide (VC), which played an important role in catalyzing the nucleation of SiC and accelerating its growth. The mechanism of SiC nucleation and growth is consistent with the Johnson-Mehl-Avrami-Erofeev-Kolmogorov (JMAEK) model, and the apparent activation energy values of the carbothermal reduction reaction are 213.17 kJ/mol and 109.66 kJ/mol for samples with 0 wt% and 2 wt% V2O3 additions. Therefore, this method not only expanded the source of raw material but also reduced energy consumption and economic costs.