US4632778A
Expired / Lapsed
US
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Procedure for ceramizing radioactive wastes
Assignee: Imatran Voima Oy
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Filing: 1983-04-26
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Granted: 1986-12-30
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Expires: 2003-04-26
Abstract
Abstract The present invention concerns a procedure for transforming radioactive wastes into ceramics. From the radioactive waste solution, the waste is bound to an inorganic ion exchanger either with batch equilibration or in columns. After the waste has been bound to the ion exchanger, it is transformed into ceramics by admixing it to tile clay or to another ceramizing material and by firing the mixture to a tile. This yields an extremely low soluble and mechanically durable ultimate disposal product of the nuclear waste. The ceramizing procedure is applicable with any inorganic ion exchanger.
Inventors
- 👤 Jukka K. Lehto
- 👤 Jorma K. Miettinen
- 👤 Olli Heinonen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 17:54
CPC Classifications
G; G21; G21F; G21F9/00; G21F9/28; G21F9/30; G21F9/301; G21F9/302; G21F9/04; G21F9/06; G21F9/12
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
135 words
Method of transforming radioactive waste into ceramic, which comprises the steps of first mixing a waste from radioactive waste solution with an inorganic ion exchanger selected from the group consisting of titanates, niobates, zirconates, and zirconium dioxides, and mixtures thereof, after said first mixing is completed, mixing the resulting inorganic ion exchanger loaded with the waste with a ceramizing material selected from the group consisting of red clay, kaolin, montmorillonite, feldspar, illite, and quartz, and mixtures thereof, adding water to the thus-formed mixture, to form a further mixture thereof, forming shaped tiles of the thus-formed further mixture, drying said tiles, and firing the thus-dried, shaped tiles in a kiln, without pressing of the same, at a temperature at which ceramic formation takes place, whereby shaped, ceramic tiles of radioactive waste are formed for subsequent disposal.
Claim 2
Dependent Claim
135 words
Method of transforming radioactive waste into ceramic, which comprises the steps of first mixing a waste from radioactive waste solution with an inorganic ion exchanger selected from the group consisting of titanates, niobates, zirconates, and zirconium dioxides, and mixtures thereof, after said first mixing is completed, mixing the resulting inorganic ion exchanger loaded with the waste with a ceramizing material selected from the group consisting of red clay, kaolin, montmorillonite, feldspar, illite, and quartz, and mixtures thereof, adding water to the thus-formed mixture, to form a further mixture thereof, forming shaped tiles of the thus-formed further mixture, drying said tiles, and firing the thus-dried, shaped tiles in a kiln, without pressing of the same, at a temperature at which ceramic formation takes place, whereby shaped, ceramic tiles of radioactive waste are formed for subsequent disposal.
Claim 3
Dependent Claim
12 words
The method of claim 1, wherein the shaped bodies are dried overnight.
Claim 4
Dependent Claim
28 words
The method of claim 2, wherein the drying of said shaped bodies is at a temperature of about 150° C. for at least four hours after drying overnight.
Claim 5
Dependent Claim
27 words
The method of claim 1, wherein the temperature of firing in said kiln is at a temperature of about 1020°-1060° C. for about four to ten hours.
Claim 6
Dependent Claim
25 words
The method of claim 4, comprising the additional step of raising the temperature of the kiln at a rate of about 100° C. per hour.
Claim 7
Dependent Claim
26 words
The method according to claim 4, comprising the additional step of cooling the thus-shaped ceramic bodies within the kiln, at the cooling rate of the kiln.
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) | 1989-12-29 | 1990-06-30 | 1990-12-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-12-29 | 1994-06-30 | 1994-12-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-12-29 | 1998-06-30 | 1998-12-30 | $7700.00 | Window Closed / Lapsed |