US4537710A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of storing radioactive wastes using modified tobermorite
Assignee: United States, AS REPRESENTED BY UNITED STATED DEPARTMENT OF ENERGY
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Filing: 1983-10-31
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Granted: 1985-08-27
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Expires: 2003-10-31
Abstract
Abstract A new cation exchanger is a modified tobermorite containing aluminum isomorphously substituted for silicon and containing sodium or potassium. The exchanger is selective for lead, rubidium, cobalt and cadmium and is selective for cesium over calcium or sodium. The tobermorites are compatable with cement and are useful for the long-term fixation and storage of radioactive nuclear wastes.
Inventors
- 👤 Sridhar Komarneni
- 👤 Della M. Roy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 14:08
CPC Classifications
B; B01; B01J; B01J39/00; B01J39/02; G; G21; G21F; G21F9/00; G21F9/04; G21F9/06; G21F9/12; G21F9/28; G21F9/30; G21F9/301; G21F9/302; G21F9/304
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
119 words
A method of fixing metal ions contained in liquid low and intermediate level nuclear wastes for long-term storage comprising: contacting the liquid waste with an ion-exchange material which is a modified tobermorite containing aluminum isomorphously substituted for silicon and containing per 100 grams, about 1 to 200 milliequivalents of an alkali metal selected from the group consisting of sodium, potassium and mixtures thereof, whereby the metal ions in the liquid waste are taken up by the ion-exchange material; separating the ion-exchange material from the liquid; mixing the ion-exchange material containing the ions with portland cement to form a mixture containing up to about 40 weight percent ion-exchange material; and solidifying the mixture, thereby fixing the ions for long-term storage.
Claim 2
Independent Claim
119 words
A method of fixing metal ions contained in liquid low and intermediate level nuclear wastes for long-term storage comprising: contacting the liquid waste with an ion-exchange material which is a modified tobermorite containing aluminum isomorphously substituted for silicon and containing per 100 grams, about 1 to 200 milliequivalents of an alkali metal selected from the group consisting of sodium, potassium and mixtures thereof, whereby the metal ions in the liquid waste are taken up by the ion-exchange material; separating the ion-exchange material from the liquid; mixing the ion-exchange material containing the ions with portland cement to form a mixture containing up to about 40 weight percent ion-exchange material; and solidifying the mixture, thereby fixing the ions for long-term storage.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein the tobermorite contains from about 1 to about 15 weight percent aluminum.
Claim 4
Dependent Claim
18 words
The method of claim 2 wherein the waste solution may contain cesium, lead, rubidium, cobalt and cadmium ions.
Claim 5
Independent Claim
105 words
A method of fixing radioactive cesium for long-term storage comprising: contacting a solution containing cesium and other metal ions with a modified-tobermorite containing aluminum isomorphously substituted for silicon and containing per 100 grams, about 1 to 200 milliequivalents of an alkali metal selected from the group consisting of sodium, potassium and mixtures thereof, whereby the cesium is taken up by the modified tobermorite; separating the tobermorite containing the cesium from the liquid; mixing the tobermorite containing the cesium with portland cement to form a mixture containing up to about 40 weight percent tobermorite; and solidifying the mixture, thereby fixing the cesium ions for long-term storage.
Claim 6
Independent Claim
105 words
A method of fixing radioactive cesium for long-term storage comprising: contacting a solution containing cesium and other metal ions with a modified-tobermorite containing aluminum isomorphously substituted for silicon and containing per 100 grams, about 1 to 200 milliequivalents of an alkali metal selected from the group consisting of sodium, potassium and mixtures thereof, whereby the cesium is taken up by the modified tobermorite; separating the tobermorite containing the cesium from the liquid; mixing the tobermorite containing the cesium with portland cement to form a mixture containing up to about 40 weight percent tobermorite; and solidifying the mixture, thereby fixing the cesium ions for long-term storage.
Claim 7
Dependent Claim
18 words
The method of claim 4 wherein the tobermorite contains from about 1 to about 15 weight percent aluminum.
References Cited (Backward Citations)
US4432804A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-08-26 | 1989-02-25 | 1989-08-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-08-26 | 1993-02-25 | 1993-08-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-08-26 | 1997-02-25 | 1997-08-27 | $7700.00 | Window Closed / Lapsed |