US4072501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of producing homogeneous mixed metal oxides and metal-metal oxide mixtures
Assignee: United States Department of Energy
•
Filing: 1977-04-13
•
Granted: 1978-02-07
•
Expires: 1997-04-13
Abstract
Abstract Metal powders, metal oxide powders, and mixtures thereof of controlled particle size are provided by reacting an aqueous solution containing dissolved metal values with excess urea. Upon heating, urea reacts with water from the solution leaving a molten urea solution containing the metal values. The molten urea solution is heated to above about 180 DEG C. whereupon metal values precipitate homogeneously as a powder. The powder is reduced to metal or calcined to form oxide particles. One or more metal oxides in a mixture can be selectively reduced to produce metal particles or a mixture of metal and metal oxide particles.
Inventors
- 👤 Thomas C. Quinby
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 19:33
CPC Classifications
C; C22; C22C; C22C1/00; C22C1/10; C22C1/1026; B; B22; B22F; B22F5/00; B22F9/00; B22F9/16; B22F9/18; B22F9/20; B22F9/22; G; G21; G21F; G21F9/00; G21F9/04; G21F9/06; G21F9/14; G21F9/28; G21F9/30; G21F9/301; G21F9/302
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
97 words
A method of preparing particulate metal or metal oxide of controlled particle size comprising: a. contacting an aqueous solution containing dissolved metal values with excess urea at a temperature sufficient to cause urea to react with water in said aqueous solution to provide a molten urea solution containing said metal values; b. heating said molten urea solution containing metal values to cause said metal values to precipitate forming a mixture containing precipitated metal values; c. heating said mixture containing precipitated metal values to evaporate volatile material from said mixture, leaving a dry powder containing said metal values.
Claim 2
Independent Claim
97 words
A method of preparing particulate metal or metal oxide of controlled particle size comprising: a. contacting an aqueous solution containing dissolved metal values with excess urea at a temperature sufficient to cause urea to react with water in said aqueous solution to provide a molten urea solution containing said metal values; b. heating said molten urea solution containing metal values to cause said metal values to precipitate forming a mixture containing precipitated metal values; c. heating said mixture containing precipitated metal values to evaporate volatile material from said mixture, leaving a dry powder containing said metal values.
Claim 3
Dependent Claim
15 words
The method of claim 1 comprising calcining said dry powder to provide particulate metal oxide.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein said dry powder containing said metal values has an average particle size less than 15 microns.
Claim 5
Dependent Claim
27 words
The method of claim 2 wherein said aqueous solution contains values of more than one metal, whereby said particulate metal oxide is a mixture of metal oxides.
Claim 6
Dependent Claim
42 words
The method of claim 4 wherein said metal values are precipitated homogeneously from said molten urea solution and said particulate metal oxide is a homogeneous mixture of metal oxides, said mixture having a composition variance of less than ± 1 wt. %.
Claim 7
Dependent Claim
21 words
The method of claim 4 further comprising, after said calcining step, reducing at least one of said metal oxides to metal.
Claim 8
Dependent Claim
27 words
The method of claim 4 further comprising, after said calcining step, selectively reducing at least one of said metal oxides to provide a metal-metal oxide powder mixture.
Claim 9
Dependent Claim
20 words
The method of claim 4 in which said aqueous solution contains radioactive metal values and values of a non-radioactive metal.
Claim 10
Dependent Claim
39 words
The method of claim 7 in which said aqueous solution contains radioactive metal values and values of a non-radioactive metal and said non-radioactive metal oxide is reduced to provide a powder mixture containing radioactive metal oxides and non-radioactive metal.
Claim 11
Dependent Claim
22 words
The method of claim 9 in which said aqueous solution contains radioactive fission product values from the reprocessing of irradiated nuclear fuel.
References Cited (Backward Citations)
CA525200A
Cited
US3862908A
Cited
US3778380A
Cited
US3669632A
Cited
US4010242A
Cited
US3962114A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-02-06 | 1981-08-08 | 1982-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-06 | 1985-08-08 | 1986-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-06 | 1989-08-08 | 1990-02-07 | $7700.00 | Window Closed / Lapsed |