Analysis of Material Recovery in Plasma Arc Melting of Solid Wastes: A Computational Study

Processing hazardous solid wastes in a DC arc melter offers several advantages over other competitive methods, including the ability to vary the mixture chemistry independently of the energy input. This decoupling allows the melter to be operated in conditions that enhance material recovery while continuing to provide robust waste destruction. This paper describes the use of a previously developed model to investigate the effect of chlorinated additives on metal volatilization in batch melters. Chlorinated species are shown to vary in their effectiveness as an additive; the potential to simultaneously treat solid wastes and chlorinated organics is also confirmed. At low additive levels the amount of chlorine, regardless of molecular form, determines the volatilization level, with a linear relationship between chlorine feed amount and volatilization. At high additive levels, CCl₄ becomes increasingly more effective as an additive, causing greater volatilization by a preferred set of species, while NaCl volatilizes almost completely without reacting, rendering it an ineffective additive.