US4356106A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Cerium compounds
Assignee: United Kingdom Atomic Energy Authority
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Filing: 1981-04-20
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Granted: 1982-10-26
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Expires: 2001-04-20
Abstract
Abstract The present invention relates to compounds and more particularly to cerium compounds. According to one aspect of the present invention there is provided a process for the preparation of a dispersible cerium compound which comprises heating a substantially dry cerium (IV) oxide hydrate in the presence of a deaggregating agent to cause deaggregation of aggregated crystallites in the cerium (IV) oxide hydrate and produce a dry dispersible cerium compound.
Inventors
- 👤 James L. Woodhead
- 👤 Graham Raw
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 05:41
CPC Classifications
C; C01; C01F; C01F17/00; C01F17/20; C01F17/276; C01F17/206; C01F17/224; C01F17/235; C01P; C01P2006/00; C01P2006/22
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
46 words
A process for the preparation of a dispersible cerium compound which comprises heating a substantially dry cerium (IV) oxide hydrate in the presence of a deaggregating agent to cause deaggregation of aggregated crystallites in the cerium (IV) oxide hydrate and produce a dry dispersible cerium compound.
Claim 2
Dependent Claim
46 words
A process for the preparation of a dispersible cerium compound which comprises heating a substantially dry cerium (IV) oxide hydrate in the presence of a deaggregating agent to cause deaggregation of aggregated crystallites in the cerium (IV) oxide hydrate and produce a dry dispersible cerium compound.
Claim 3
Dependent Claim
14 words
A process as claimed in claim 1 wherein the deaggregating agent comprises acid species.
Claim 4
Dependent Claim
22 words
A process as claimed in claim 2 wherein the acid species include nitrate anions, chloride anions, perchlorate anions, or any combination thereof.
Claim 5
Dependent Claim
32 words
A process as claimed in claim 2 wherein the acid species include nitrate anions and the nitrate/CeO 2 ratio in the cerium (IV) oxide hydrate is in the range 0.15 to 0.35.
Claim 6
Dependent Claim
23 words
A process as claimed in claim 1 wherein the cerium (IV) oxide hydrate is heated to a temperature in the range 200°-450° C.
Claim 7
Dependent Claim
23 words
A process as claimed in claim 5 wherein the cerium (IV) oxide hydrate is heated to a temperature in the range 300°-350° C.
Claim 8
Dependent Claim
31 words
A process as claimed in claim 1 further comprising the step of dispersing the dry dispersible cerium compound in an aqueous medium to give a colloidal dispersion of the cerium compound.
Claim 9
Dependent Claim
18 words
A process as claimed in claim 7 wherein the aqueous medium is water or an aqueous acid solution.
Claim 10
Dependent Claim
44 words
A process as claimed in claim 1 further comprising the steps of mixing the dispersible cerium compound with water at such a concentration that the dispersible cerium compound coagulates to form a slurry and separating the coagulated cerium compound from liquor of the slurry.
Claim 11
Dependent Claim
22 words
A process as claimed in claim 9 wherein the separated coagulated cerium compound is dispersed in water to form a colloidal dispersion.
Claim 12
Dependent Claim
37 words
A process for the preparation of a gel which comprises drying a sol which has been prepared by dispersing in an aqueous medium a dry dispersible cerium compound prepared by a process as claimed in claim 1.
Claim 13
Dependent Claim
14 words
A dry dispersible cerium compound prepared by a process as claimed in claim 1.
Claim 14
Dependent Claim
27 words
A dry dispersible cerium compound as claimed in claim 12 wherein nitrate anions are present and the nitrate/CeO 2 ratio is in the range 0.05 to 0.25.
Claim 15
Dependent Claim
20 words
A dry dispersible cerium compound as claimed in claim 13 wherein the nitrate/CeO 2 ratio is in the range 0.08-0.15.
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) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |