Patent US4089678A successfully refreshed from Google Patents.
US4089678A
Expired / Lapsed
US
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Method and product for protecting molten magnesium
Assignee: Individual
•
Filing: 1977-02-07
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Granted: 1978-05-16
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Expires: 1997-02-07
Abstract
Abstract An improved process and product for supplying a protective atmosphere of carbon dioxide plus a minor percentage of sulfur hexafluoride (CO 2 /SF 6 ) by means of a solid agent consisting of solidified CO 2 and SF 6 which by sublimation in the presence of molten magnesium and its alloys provides a protective atmosphere of desired composition. This solid agent is used for maintaining a protective atmosphere within a covered vessel containing molten magnesium or its alloys. It is also used for purging a crucible and for flushing the air from a mold cavity prior to the pouring of the molten metal. The amount and the composition of the solid agent can be adjusted to provide the desired composition of protective atmosphere for a wide variety of situations involving molten magnesium.
Inventors
- 👤 Joseph D. Hanawalt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:40
CPC Classifications
C; C22; C22B; C22B9/00; C22B9/006; C22B26/00; C22B26/20; C22B26/22; Y; Y02; Y02P; Y02P10/00; Y02P10/10; Y02P10/146
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
46 words
A reaction inhibiting agent for forming a protective atmosphere over molten magnesium by sublimation, comprising a solidified solution consisting of carbon dioxide having dissolved therein a proportion of sulfur hexafluoride lying within the range of two tenths of one percent to three percent of the total.
Claim 2
Dependent Claim
46 words
A reaction inhibiting agent for forming a protective atmosphere over molten magnesium by sublimation, comprising a solidified solution consisting of carbon dioxide having dissolved therein a proportion of sulfur hexafluoride lying within the range of two tenths of one percent to three percent of the total.
Claim 3
Dependent Claim
37 words
A reaction inhibiting agent for forming a protective atmosphere over molten magnesium by sublimation comprising a solidifid solution consisting of carbon dioxide having dissolved therein a proportion of sulfur hexafluoride adequate to inhibit oxidation of the magnesium.
Claim 4
Dependent Claim
37 words
A reaction inhibiting agent for forming a protective atmosphere over molten magnesium by sublimation comprising a solidifid solution consisting of carbon dioxide having dissolved therein a proportion of sulfur hexafluoride adequate to inhibit oxidation of the magnesium.
Claim 5
Dependent Claim
31 words
A protective agent for molten magnesium and its alloys composed of a mixture of solidified carbon dioxide and a proportion of solidified sulfur hexafluoride adequate to inhibit oxidation of the magnesium.
Claim 6
Dependent Claim
31 words
A protective agent for molten magnesium and its alloys composed of a mixture of solidified carbon dioxide and a proportion of solidified sulfur hexafluoride adequate to inhibit oxidation of the magnesium.
Claim 7
Dependent Claim
28 words
A protective agent as defined in claim 3 which provides an atmosphere of carbon dioxide and sulfur hexafluoride in the volumetric ratio carbon dioxide/sulfur hexafluoride of about 100:1.
Claim 8
Dependent Claim
53 words
A solid agent as in claim 3 wherein the mixture is comprised of discrete particles of solidified carbon dioxide and separate discrete particles of solidified sulfur hexafluoride, whereby the ratio of carbon dioxide/sulfur hexafluoride gas given off by sublimation can be varied by varying the relative proportions of the particles in the mixture.
Claim 9
Dependent Claim
27 words
A solid agent as in claim 3 wherein the proportion of solid sulfur hexafluoride lies within the range of two tenths of one percent to three percent.
Claim 10
Dependent Claim
65 words
A process of protecting molten magnesium from oxidation attack which comprises placing an agent comprising solidified sulfur hexafluoride in such quantities and in such proximity to the magnesium as to cause sublimation of the sulfur hexafluoride at a rate which furnishes a protective atmosphere above the magnesium consisting of a proportion of not more than a few tenths percent of sulfur hexafluoride mixed with air.
Claim 11
Dependent Claim
65 words
A process of protecting molten magnesium from oxidation attack which comprises placing an agent comprising solidified sulfur hexafluoride in such quantities and in such proximity to the magnesium as to cause sublimation of the sulfur hexafluoride at a rate which furnishes a protective atmosphere above the magnesium consisting of a proportion of not more than a few tenths percent of sulfur hexafluoride mixed with air.
Claim 12
Dependent Claim
25 words
A process as defined in claim 6 wherein the agent is placed in a pervious support disposed above the exposed surface of the molten magnesium.
Claim 13
Dependent Claim
34 words
A process as defined in claim 6 wherein the agent is placed in a heat-resistant support having heat insulating material incorporated therein and disposed in floating relationship on the surface of the molten magnesium.
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) | 1981-05-15 | 1981-11-14 | 1982-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-15 | 1985-11-14 | 1986-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-15 | 1989-11-14 | 1990-05-16 | $7700.00 | Window Closed / Lapsed |