Molten Salt Oxidation (MSO) technology was developed and evaluated from the 1970's through the first half of the 1990's with excellent results for treating hazardous and radioactive wastes: activity and interest in MSO was stagnant in the late 1980's because of the availability of less expensive treatment bulk waste incineration technologies, and because of a national reluctance to continue with storage rather than treatment. The U.S. Department of Energy (DOE) has recently shown renewed interest in MSO because of its potential advantages over existing processes in treating mixed wastes.
MSO technology can be characterized as a submerged oxidation processess; the basic concept is to introduce air and wastes into a bed molten salt, oxidize the organic wastes in the molten salt, use the heat of oxidation to keep the salt molten and remove the salt for disposal or processing and recycling. The molten salt (usually sodium carbonate at 900-1000°C) provides four waste management functions: providing a heat transfer medium, catalyzing the oxidation reaction, preventing the formation of acid gases by forming stable salts and efficiently capturing ash particles and radioactive materials by the combined effects of wetting, encapsulation and dissolution. The MSO process requires no wet scrubbing system for off-gas treatment.
The process has been developed through bench-scale and pilot-scale testing, with successful destruction demonstration of a wide variety of hazardous and mixed (radioactive and hazardous) wastes including chemical warfare agents, combustible solids, halogenates solvents, polychlorinated biphenyls, plutonium-contaminated solids and uranium-contaminated solvents. This presentation will review the principles and capabilities of MSO and previous work using it to treat mixed wastes as well as describe recent results to demonstrate the process for the treatment of mixed wastes.