During melting of soda-lime-silica glass, the volatilization of sodium species has a number of negative consequences; alteration of glass composition in the surface layer; attack on refractory; plugging of regenerators; contributions to particulate matter emissions & stack plume opacity & others. Beerkens & Kobayashi give a good summary of volatilization mechanisms & contributions to particulate matter. Concentration of sodium vapor species increases in the furnace atmosphere when a melting tank is converted from air to oxy-firing. Emissions of particulate matter are reduced because the increased concentration is offset by lower flue gas flow rate. The presence of aggressive volatile species, along with high temperature & intense radiation, makes the combustion space of a tank furnace a difficult environment for sensors.
