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Title: Extraction of metals using supercritical fluid and chelate forming ligand

Abstract

A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated {beta}-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated {beta}-diketone and a trialkyl phosphate, or a fluorinated {beta}-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated {beta}-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process. 7 figs.

Inventors:
;
Issue Date:
Sponsoring Org.:
USDOE, Washington, DC (United States); National Science Foundation, Washington, DC (United States)
OSTI Identifier:
597116
Patent Number(s):
5730874
Application Number:
PAN: 8-253,000; CNN: Grant RII-8902065; TRN: 98:004643
Assignee:
Idaho Research Foundation, Inc., Moscow, ID (United States)
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 24 Mar 1998
Country of Publication:
United States
Language:
English
Subject:
32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION; 05 NUCLEAR FUELS; SUPERCRITICAL GAS EXTRACTION; CHELATING AGENTS; ACTINIDES; RARE EARTHS; MATERIALS RECOVERY; INDUSTRIAL WASTES; WASTE PROCESSING; CARBON DIOXIDE

Citation Formats

Wai, C M, and Laintz, K E. Extraction of metals using supercritical fluid and chelate forming ligand. United States: N. p., 1998. Web.
Wai, C M, & Laintz, K E. Extraction of metals using supercritical fluid and chelate forming ligand. United States.
Wai, C M, and Laintz, K E. Tue . "Extraction of metals using supercritical fluid and chelate forming ligand". United States.
@article{osti_597116,
title = {Extraction of metals using supercritical fluid and chelate forming ligand},
author = {Wai, C M and Laintz, K E},
abstractNote = {A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated {beta}-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated {beta}-diketone and a trialkyl phosphate, or a fluorinated {beta}-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated {beta}-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process. 7 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1998},
month = {3}
}