Arc melter vitrification of organic and chloride containing materials

Demonstration tests for vitrifying mixed wastes and contaminated soils have been conducted using a small (800 kVA), industrial-scale, three-phase AC, graphite electrode furnace located at the Albany Research Center of the United States Bureau of Mines (USBM). The feed mixtures were non-radioactive surrogates of mixed (radioactive and hazardous), transuranic (TRU)-contaminated wastes stored and buried at the Idaho National Engineering Laboratory (INEL). The different feed mixtures included up to (a) 80 weight % combustibles, (b) 60% chlorinated and nonchlorinated hydrocarbons, (c) 27% metals, (d) 2% nitrates, and (e) 3 % metal hydroxides. Cerium was added as a nonradioactive surrogate for plutonium, a TRU element. Over 9,200 kg (20,200 lb) of the feed mixtures were vitrified at feedrates of up to 500 kg/hr (1,100 lb/hr). The furnace products including the glass, metal, offgas, and offgas solids have been analyzed to determine the fate and partitioning of metals, organics, and the TRU surrogate. Offgas emissions were efficiently controlled using an air pollution control system that included a thermal oxidizer, water-spray and air dilution cooling, cyclone and baghouse particulate removal, packed bed acid gas scrubbing, charcoal absorption, and High Efficiency Particulate-Air (HEPA) filtration.