In situ vitrification: An innovative thermal treatment technology
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 3600F, well above the initial melting temperature or fusion temperature of soils. The normal fusion temperature of soil ranges between 2000 and 2500F. 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.
- Research Organization:
- Pacific Northwest Lab., Richland, WA (USA)
- DOE Contract Number:
- AC06-76RL01830
- OSTI ID:
- 6287796
- Report Number(s):
- PNL-SA-14843; CONF-870695-8; ON: DE87012169
- Resource Relation:
- Conference: 80. annual meeting of the Air Pollution Control Association, New York, NY, USA, 1 Jun 1987; Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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In situ vitrification: A new process for waste remediation
In situ vitrification: Test results for a contaminated soil melting process
Related Subjects
CHEMICAL WASTES
WASTE PROCESSING
SOILS
VITRIFICATION
IN-SITU PROCESSING
METALS
ORGANIC COMPOUNDS
PYROLYSIS
REMEDIAL ACTION
CHEMICAL REACTIONS
DECOMPOSITION
ELEMENTS
MANAGEMENT
PROCESSING
THERMOCHEMICAL PROCESSES
WASTE MANAGEMENT
WASTES
510200* - Environment
Terrestrial- Chemicals Monitoring & Transport- (-1989)