Extracting metals directly from metal oxides
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.
- Research Organization:
- Univ. of Iowa, Iowa City, IA (United States)
- DOE Contract Number:
- FG02-91ER75679
- Assignee:
- Idaho Research Foundation, Inc., Moscow, ID (United States)
- Patent Number(s):
- US 5,606,724/A/
- Application Number:
- PAN: 8-552,941
- OSTI ID:
- 441851
- Resource Relation:
- Other Information: PBD: 25 Feb 1997
- Country of Publication:
- United States
- Language:
- English
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