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Title: TUCS/phosphate mineralization of actinides

Conference ·
OSTI ID:527210
 [1]
  1. Argonne National Lab., IL (United States)

This program has as its objective the development of a new technology that combines cation exchange and mineralization to reduce the concentration of heavy metals (in particular actinides) in groundwaters. The treatment regimen must be compatible with the groundwater and soil, potentially using groundwater/soil components to aid in the immobilization process. The delivery system (probably a water-soluble chelating agent) should first concentrate the radionuclides then release the precipitating anion, which forms thermodynamically stable mineral phases, either with the target metal ions alone or in combination with matrix cations. This approach should generate thermodynamically stable mineral phases resistant to weathering. The chelating agent should decompose spontaneously with time, release the mineralizing agent, and leave a residue that does not interfere with mineral formation. For the actinides, the ideal compound probably will release phosphate, as actinide phosphate mineral phases are among the least soluble species for these metals. The most promising means of delivering the precipitant would be to use a water-soluble, hydrolytically unstable complexant that functions in the initial stages as a cation exchanger to concentrate the metal ions. As it decomposes, the chelating agent releases phosphate to foster formation of crystalline mineral phases. Because it involves only the application of inexpensive reagents, the method of phosphate mineralization promises to be an economical alternative for in situ immobilization of radionuclides (actinides in particular). The method relies on the inherent (thermodynamic) stability of actinide mineral phases.

Research Organization:
Science, Inc., Anaheim, CA (United States)
OSTI ID:
527210
Report Number(s):
PNNL-SA-28461-Rev.1; CONF-970148-Rev.1; ON: DE97052111; TRN: 97:015053
Resource Relation:
Conference: Efficient Separations and Processing (ESP) Crosscutting Program FY 1997 technical exchange meeting, Gaithersburg, MD (United States), 28-30 Jan 1997; Other Information: PBD: [1997]; Related Information: Is Part Of Proceedings of the efficient separations and processing crosscutting program 1997 technical exchange meeting; Gephart, J.M. [ed.]; PB: 211 p.
Country of Publication:
United States
Language:
English