US3846520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sintering of sol-gel material
Assignee: Reactor Centrum Nederland
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Filing: 1972-05-17
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Granted: 1974-11-05
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Expires: 1992-05-17
Abstract
Abstract The invention relates to an economic method for sintering spherical sol-gel material. Spherical hexavalent oxidic uranium material, such as A.D.U. or UO3-hydrate, is converted into nuclear fuel of high density by means of a sinter stage, which consists in heating-up and cooling at a rate of 10* - 65* C/min. The sinter stage may be preceded by a preheating stage. Whereas the starting material may contain finely divided carbon. Previously only spherical sol-gel material of tetravalent uranium and pressed compacts of ceramic uranium dioxide powder where sintered with the above heating rates. Tetravalent uranium material has disadvantages with respect to hexavalent uranium material.
Inventors
- 👤 E Bruijn
- 👤 R Rooy
- 👤 F Hamburg
- 👤 J Kanij
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:56
CPC Classifications
G; G21; G21C; G21C3/00; G21C3/42; G21C3/58; G21C3/62; G21C3/623; Y; Y02; Y02E; Y02E30/00; Y02E30/30
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
111 words
A METHOD FOR THE CONVERSION OF SPHERICAL SOL-GEL FISSILE MATERIAL INTO SPHERICAL OXIDIC, CARBIDIC OR CARBONITRIDIC NUCLEAR FUEL MATERIAL, BY MEANS OF A SINTERING STEP, COMPRISING HEATING THE SOL-GEL SPHERES TO THE SINTERING TEMPERATURE AND COOLING FROM THE SINTERING TEMPERATURE AT RESPECTIVELY HEATING AND COOLING RATES RANGING BETWEEN 10* AND 65*C/MINUTE, THE SOL-GEL MATERIAL BEING A COMPOSITION PREPARED BY SOLIDIFICATION THROUGH THE ACTION OF ONE OR MORE OF THE FACTORS HEAT, DEHYDRATION, HYDROLYSIS BY THE ACTION OF FREE AMMONIA, OR OF AMMONIA FORMED BY THE DECOMPOSITION OF AN AMMONIADONOR ON A GLOBULAR AQUEOUS METALLIFEROUS AQUEOUS PHASE, SELECTED FROM THE GROUP CONSISTING OF METAL HYDROXIDE SOLS, METAL SALT SOLUTIONS OR MIXTURES THEREOF.
Claim 2
Independent Claim
111 words
A METHOD FOR THE CONVERSION OF SPHERICAL SOL-GEL FISSILE MATERIAL INTO SPHERICAL OXIDIC, CARBIDIC OR CARBONITRIDIC NUCLEAR FUEL MATERIAL, BY MEANS OF A SINTERING STEP, COMPRISING HEATING THE SOL-GEL SPHERES TO THE SINTERING TEMPERATURE AND COOLING FROM THE SINTERING TEMPERATURE AT RESPECTIVELY HEATING AND COOLING RATES RANGING BETWEEN 10* AND 65*C/MINUTE, THE SOL-GEL MATERIAL BEING A COMPOSITION PREPARED BY SOLIDIFICATION THROUGH THE ACTION OF ONE OR MORE OF THE FACTORS HEAT, DEHYDRATION, HYDROLYSIS BY THE ACTION OF FREE AMMONIA, OR OF AMMONIA FORMED BY THE DECOMPOSITION OF AN AMMONIADONOR ON A GLOBULAR AQUEOUS METALLIFEROUS AQUEOUS PHASE, SELECTED FROM THE GROUP CONSISTING OF METAL HYDROXIDE SOLS, METAL SALT SOLUTIONS OR MIXTURES THEREOF.
Claim 3
Dependent Claim
16 words
A method according to claim 1 wherein the sol-gel material consists of spheres of ammonium diuranate.
Claim 4
Dependent Claim
19 words
A method as in claim 1 wherein the sintering is carried out in the presence of a reducing gas.
Claim 5
Dependent Claim
25 words
A method as in claim 3 wherein the gas is a dry oxygen-free gass and wherein the same gas is present during heating and cooling.
Claim 6
Dependent Claim
17 words
A method as in claim 1 wherein sintering is effected at temperatures ranging between 1,200* and 1,700*C.
Claim 7
Dependent Claim
16 words
A method as in claim 1 wherein the maximum sintering temperature lies between 1,600* and 1,700*C.
Claim 8
Dependent Claim
18 words
A method as in claim 1 wherein the sintering stage is preceded by calcination in an oxygenous atmosphere.
Claim 9
Dependent Claim
18 words
A method as in claim 7 wherein calcination is effected at a temperature of from 300* to 650*C.
Claim 10
Dependent Claim
38 words
A method as in claim 7 wherein calcination is effected in an oven in which the material is heated at a heating rate not exceeding 200*C/hour from room temperature to a temperature that lies between 300* and 650*C.
Claim 11
Dependent Claim
23 words
A method as in claim 1 wherein the sintering stage is preceded by a preheating stage in a reducing gas or in vacuo.
Claim 12
Dependent Claim
12 words
Sintered fragments and globules prepared according to the method of claim 1.
Claim 13
Independent Claim
50 words
A method for the conversion of spherical uranium-containing, hydroxide-like gel particles to spherical oxidic particles comprising heating the gel particles to a sintering temperature of between 1,200* C and 1,700* C and cooling the resulting oxidic particles, the heating and cooling being carried out at rates between 10*C/minute and 65*C/minute.
Claim 14
Independent Claim
50 words
A method for the conversion of spherical uranium-containing, hydroxide-like gel particles to spherical oxidic particles comprising heating the gel particles to a sintering temperature of between 1,200* C and 1,700* C and cooling the resulting oxidic particles, the heating and cooling being carried out at rates between 10*C/minute and 65*C/minute.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-04 | 1978-05-06 | 1978-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-04 | 1982-05-06 | 1982-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-04 | 1986-05-06 | 1986-11-05 | $7700.00 | Window Closed / Lapsed |