posted on 2024-11-16, 08:29authored byXiang Li, Guangqing ZhangGuangqing Zhang, Kai Tang, Oleg Ostrovski, Ragnar Tronstad
Synthesis of silicon carbide (SiC) by carbothermal reduction of quartz in a CH4-H2-Ar gas mixture was investigated in a laboratory fixed-bed reactor in the temperature range of 1573 K to 1823 K (1300 °C to 1550 °C). The reduction process was monitored by an infrared gas analyser, and the reduction products were characterized by LECO, XRD, and SEM. A mixture of quartz-graphite powders with C/SiO2 molar ratio of 2 was pressed into pellets and used for reduction experiments. The reduction was completed within 2 hours under the conditions of temperature at or above 1773 K (1500 °C), methane content of 0.5 to 2 vol pct, and hydrogen content ≥70 vol pct. Methane partially substituted carbon as a reductant in the SiC synthesis and enhanced the reduction kinetics significantly. An increase in the methane content above 2 vol pct caused excessive carbon deposition which had a detrimental effect on the reaction rate. Hydrogen content in the gas mixture above 70 vol pct effectively suppressed the cracking of methane.
Funding
Fundamentals of an Innovative Technology for Solar Silicon Production
Li, X., Zhang, G., Tang, K., Ostrovski, O. & Tronstad, R. (2015). Carbothermal reduction of quartz in methane-hydrogen-argon gas mixture. Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science, 46 (5), 2384-2393.
Journal title
Metallurgical and Materials Transactions B: Process Metallurgy and Materials Processing Science