Resistance of silicon carbide refractories to the action of carbon monoxide, alkalis, and slag

The effect of alkalis, slag, and carbon monoxide on silicon carbide and nitride was studied at elevated temperatures up to 1550°C. It was established that silicon carbide is destructed most rapidly at 1200°C under the action of the investigated factors. The properties of silicon nitride virtually do not change on heating up to 1400°C in the presence of carbon monoxide; one observes a slight decrease in the nitrogen content of the system only at 1550°C and an increase in the silicon content in the 1200–1550°C range due to the dissociation of Si3N4 and the formation of Si2ON2.