Emission spectroscopy studies of volatile species produced by plasma arc vitrification of a mixed waste surrogate

Emission spectroscopy has been used to characterize the time histories of volatile species produced by the plasma hearth vitrification of a Savannah River mixed waste surrogate. Relationships have been sought between emission intensity (and hence concentration) of gas-phase species present and operational parameters (melt surface temperature, torch current, torch height). Boiling of the molten glass in the vicinity of the plasma arc attachment area appears to contribute significantly to the volatilization of species in this test. This suggests that operational procedures that minimize boiling can reduce the concentration of toxic species emitted to the off gas system and hence to the environment. These results demonstrate the utility of emission spectroscopy as a monitor of volatile species and provide the foundation for future work to verify and extend the results of this investigation