抄録
Fusion of ground natural quartz powder was carried out in propane-oxygen flames. The flow rates of propane and oxygen gases and powder feed rate were varied from 5 to 12.5 and from 25 to 62.5 Nm3/h and from 3 to 50 kg/h, respectively, but the flow rate of oxygen carrier gas at 7.5 Nm3/h was kept constant. Two types of burners were used, where a powder-feeding nozzle was placed axially at the center of burner and six nozzles were around the center of another type of burner. The vitrification ratio of about 80% was observed when the powder was treated at the condition of the gas flow rates of 5 for propane gas and 25 Nm3/h for oxygen gas, and the feed rate of powder at 20 kg/h. Small particles showed higher vitrification ratio and sphericity than large one. It was also found that high vitrification ratio was obtained using the burner with six nozzles. Small particles with some hundreds of nm in size which are generated in the flame contribute to an increase of specific surface area of products.
