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Title: Extracting metals directly from metal oxides

Abstract

A method of extracting metals directly from metal oxides by exposing the oxide to a supercritical fluid solvent containing a chelating agent is described. Preferably, the metal is an actinide or a lanthanide. More preferably, the metal is uranium, thorium or plutonium. The chelating agent forms chelates that are soluble in the supercritical fluid, thereby allowing direct removal of the metal from the metal oxide. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of {beta}-diketones, halogenated {beta}-diketones, phosphinic acids, halogenated phosphinic acids, carboxylic acids, halogenated carboxylic acids, and mixtures thereof. In especially preferred embodiments, at least one of the chelating agents is fluorinated. The method provides an environmentally benign process for removing metals from metal oxides without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the metal recovered, to provide an economic, efficient process. 4 figs.

Inventors:
; ;
Issue Date:
Research Org.:
Univ. of Iowa, Iowa City, IA (United States)
OSTI Identifier:
441851
Patent Number(s):
5,606,724
Application Number:
PAN: 8-552,941
Assignee:
Idaho Research Foundation, Inc., Moscow, ID (United States)
DOE Contract Number:  
FG02-91ER75679
Resource Type:
Patent
Resource Relation:
Other Information: PBD: 25 Feb 1997
Country of Publication:
United States
Language:
English
Subject:
05 NUCLEAR FUELS; URANIUM; PLUTONIUM; THORIUM; SUPERCRITICAL GAS EXTRACTION; URANIUM OXIDES; PLUTONIUM OXIDES; THORIUM OXIDES; CHELATING AGENTS; CARBON DIOXIDE; SPENT FUELS; REPROCESSING

Citation Formats

Wai, C M, Smart, N G, and Phelps, C. Extracting metals directly from metal oxides. United States: N. p., 1997. Web.
Wai, C M, Smart, N G, & Phelps, C. Extracting metals directly from metal oxides. United States.
Wai, C M, Smart, N G, and Phelps, C. Tue . "Extracting metals directly from metal oxides". United States.
@article{osti_441851,
title = {Extracting metals directly from metal oxides},
author = {Wai, C M and Smart, N G and Phelps, C},
abstractNote = {A method of extracting metals directly from metal oxides by exposing the oxide to a supercritical fluid solvent containing a chelating agent is described. Preferably, the metal is an actinide or a lanthanide. More preferably, the metal is uranium, thorium or plutonium. The chelating agent forms chelates that are soluble in the supercritical fluid, thereby allowing direct removal of the metal from the metal oxide. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is selected from the group consisting of {beta}-diketones, halogenated {beta}-diketones, phosphinic acids, halogenated phosphinic acids, carboxylic acids, halogenated carboxylic acids, and mixtures thereof. In especially preferred embodiments, at least one of the chelating agents is fluorinated. The method provides an environmentally benign process for removing metals from metal oxides without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the metal recovered, to provide an economic, efficient process. 4 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1997},
month = {2}
}