US4177059A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of yttrium
Assignee: Johnson Matthey PLC
•
Filing: 1978-07-05
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Granted: 1979-12-04
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Expires: 1998-07-05
Abstract
Abstract This invention relates to refining yttrium. Known methods of refining yttrium involve the use of expensive crucibles made from tantalum or tungsten which are only available in relatively small sizes. According to the present invention there is provided a process for the production of yttrium metal and alloys thereof in which calcium (metal) and yttrium fluoride are reacted together by use of a submerged electric arc in a molten slag.
Inventors
- 👤 Joseph G. Day
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 03:38
CPC Classifications
C; C22; C22B; C22B59/00; C22C; C22C28/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
47 words
A process for the production of yttrium metal and alloys thereof in which calcium metal and yttrium fluoride are reacted together by the use of electric resistance heating in a molten slag which contains the calcium metal, the yttrium fluoride and a preponderant amount of calcium fluoride.
Claim 2
Dependent Claim
47 words
A process for the production of yttrium metal and alloys thereof in which calcium metal and yttrium fluoride are reacted together by the use of electric resistance heating in a molten slag which contains the calcium metal, the yttrium fluoride and a preponderant amount of calcium fluoride.
Claim 3
Dependent Claim
18 words
A process as claimed in claim 1 or 2 carried out in a crucible lined with calcium fluoride.
Claim 4
Dependent Claim
19 words
A process as claimed in claim 1, 2 in which the arc is passed between tungsten or carbon electrodes.
Claim 5
Dependent Claim
18 words
A process as claimed in claims 1, or 2 in which iron is added to the molten slag.
Claim 6
Dependent Claim
19 words
A process as claimed in claim 1, 2 in which iron is added by way of consumable iron electrodes.
Claim 7
Dependent Claim
22 words
A process as claimed in claim 5 in which the consumable electrode is an iron tube containing calcium (metal) and yttrium fluoride.
References Cited (Backward Citations)
US3009807A
Cited
US3264093A
Cited
US3150964A
Cited
US3980468A
Cited
US3873307A
Cited
US3953579A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-12-03 | 1983-06-04 | 1983-12-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-12-03 | 1987-06-04 | 1987-12-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-12-03 | 1991-06-04 | 1991-12-04 | $7700.00 | Window Closed / Lapsed |