In situ vitrification: A new process for waste remediation
In situ vitrification is a thermal treatment process that converts contaminated soil into a chemically inert, stable glass and crystalline product. A square array of four electrodes are inserted into the ground to the desired treatment depth. Because the soil is not electrically conductive once the moisture has been driven off, a conductive mixture of flaked graphite and glass frit is placed among the electrodes to act as the starter path. An electrical potential is applied to the electrodes, which establishes an electrical current in the starter path. The resultant power heats the starter path and surrounding soil up to 3600/sup 0/F, well above the normal fusion temperature of soil of between 2000 and 2500/sup 0/F. The graphite starter path is eventually consumed by oxidation, and the current is transferred to the molten soil, which is now electrically conductive. As the vitrified zone grows, it incorporates nonvolatile elements and destroys organic components by pyrolysis. The pyrolyzed byproducts migrate to the surface of the vitrified zone, where they combust in the presence of oxygen. A hood placed over the processing area provides confinement for the combustion gases, and the gases are drawn into the off-gas treatment system. 8 refs., 7 figs., 2 tabs.
- Research Organization:
- Pacific Northwest Lab., Richland, WA (USA)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 5750355
- Report Number(s):
- PNL-SA-14066; CONF-870941-1; ON: DE88001963
- Resource Relation:
- Conference: 2. international conference on new frontiers for hazardous waste management, Pittsburgh, PA, USA, 27 Sep 1987; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
54 ENVIRONMENTAL SCIENCES
HAZARDOUS MATERIALS
GROUND DISPOSAL
IN-SITU PROCESSING
PERFORMANCE TESTING
RADIOACTIVE WASTES
SOILS
VITRIFICATION
BACKFILLING
COST ESTIMATION
LEACHING
OFF-GAS SYSTEMS
PORTABLE EQUIPMENT
PYROLYSIS
REMEDIAL ACTION
TECHNOLOGY ASSESSMENT
CHEMICAL REACTIONS
DECOMPOSITION
DISSOLUTION
EQUIPMENT
MANAGEMENT
MATERIALS
PROCESSING
RADIOACTIVE MATERIALS
SEPARATION PROCESSES
TESTING
THERMOCHEMICAL PROCESSES
WASTE DISPOSAL
WASTE MANAGEMENT
WASTES
052001* - Nuclear Fuels- Waste Processing
053000 - Nuclear Fuels- Environmental Aspects
510300 - Environment
Terrestrial- Radioactive Materials Monitoring & Transport- (-1989)
510200 - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)
052002 - Nuclear Fuels- Waste Disposal & Storage