THERMAL DESTRUCTION OF HIGHLY CHLORINATED MIXED WASTES WITHOUT GENERATING CORROSIVE OFF-GASES USING MOLTEN SALT OXIDATION (1,2)

A pilot-scale MSO (Molten Salt Oxidation) system was used to process 45-gallons of a halogenated mixed waste that is difficult to treat with other thermal systems. The mixed waste was a halogenated solvent that consisted mostly of methylchloroform. The 80 weight percent of waste consisting of highly corrosive chlorine was captured in the first process vessel as sodium chloride. The sodium chloride leached chrome from that process vessel and the solidified salt exhibited the toxicity characteristic for chrome as measured by TCLP (Toxicity Characteristic Leaching Procedure) testing. The operating ranges for parameters such as salt bed temperature, off-gas temperature, and feed rate that enable sustained operation were identified. At feed rates below the sustainable limit, both processing capacity and maintenance requirements increased with feed rate. Design and operational modifications to increase the sustainable feed rate limit and reduce maintenance requirements reduced both salt carryover and volumetric gas flows