Method and apparatus for dissociating metals from metal compounds extracted into supercritical fluids

Patent · Sat Jan 01 00:00:00 EST 2000

OSTI ID:873305

Wai, Chien M ^[1]; Hunt, Fred H ^[1]; Smart, Neil G ^[2]; Lin, Yuehe ^[3]

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1. Moscow, ID
2. Workington, GB
3. Richland, WA

A method for dissociating metal-ligand complexes in a supercritical fluid by treating the metal-ligand complex with heat and/or reducing or oxidizing agents is described. Once the metal-ligand complex is dissociated, the resulting metal and/or metal oxide form fine particles of substantially uniform size. In preferred embodiments, the solvent is supercritical carbon dioxide and the ligand is a .beta.-diketone such as hexafluoroacetylacetone or dibutyldiacetate. In other preferred embodiments, the metals in the metal-ligand complex are copper, silver, gold, tungsten, titanium, tantalum, tin, or mixtures thereof. In preferred embodiments, the reducing agent is hydrogen. The method provides an efficient process for dissociating metal-ligand complexes and produces easily-collected metal particles free from hydrocarbon solvent impurities. The ligand and the supercritical fluid can be regenerated to provide an economic, efficient process.

• Research Organization: Idaho National Laboratory (INL), Idaho Falls, ID (United States)
• DOE Contract Number: AC07-94ID13223
• Assignee: Idaho Research Foundation, Inc. (Moscow, ID)
• Patent Number(s): US 6132491
• OSTI ID: 873305
• Country of Publication: United States
• Language: English

Related Subjects

method
apparatus
dissociating
metals
metal
compounds
extracted
supercritical
fluids
metal-ligand
complexes
fluid
treating
complex
heat
reducing
oxidizing
agents
described
dissociated
resulting
oxide
form
fine
particles
substantially
uniform
size
preferred
embodiments
solvent
carbon
dioxide
ligand
beta
-diketone
hexafluoroacetylacetone
dibutyldiacetate
copper
silver
gold
tungsten
titanium
tantalum
mixtures
agent
hydrogen
provides
efficient
process
produces
easily-collected
free
hydrocarbon
impurities
regenerated
provide
economic
metal particle
supercritical carbon
fine particles
preferred embodiments
metal compound
metal particles
metal compounds
supercritical fluid
carbon dioxide
metal oxide
preferred embodiment
substantially uniform
reducing agent
method provides
oxidizing agent
efficient process
method provide
uniform size
resulting metal
metal-ligand complex
fine particle
hydrocarbon solvent
supercritical fluids
form fine
oxide form
oxidizing agen
ligand complex
/75/210/