Patent US2556255A successfully refreshed from Google Patents.
US2556255A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Treating tungstate solutions containing as impurities one or more compounds of antimony, arsenic, or molybdenum
Assignee: Union Carbide Corp
•
Filing: 1947-03-07
•
Granted: 1951-06-12
•
Expires: 1967-03-07
Abstract
No abstract record available.
Inventors
- 👤 Michael C Carosella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:05
CPC Classifications
C; C01; C01G; C01G41/00
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
130 words
THE METHOD OF TREATING AN AQUEOUS SOLUTION CONTAINING A SOLUBLE TUNGSTATE AND, AS AN IMPURITY, AT LEAST ONE SOLUBLE THIOSALT-FORMING COMPOUND OF AN ELEMENT OF THE GROUP CONSISTING OF ANTIMONY, ARSENIC AND MOLYBDENUM, WHICH METHOD COMPRISES ADJUSTING THE PH OF SUCH SOLUTION TO BETWEEN 5 AND 8, ADDING A SOLUBLE SULFIDE IN SUBSTANTIAL EXCESS OF THE STOICHIOMETRIC PROPORTION SUFFICIENT TO RERACT WITH SUBSTANTIALLY ALL OF SAID THIOSALT-FORMING COMPOUND PRESENT IN SAID SOLUTION, ADJUSTING THE PH OF SAID SOLUTION DURING THE ADDITION OF SAID SULFIDE TO BETWEEN 8 AND 11.5, MAINTAIONING THE SOLUTION AT AN ELEVATED TEMPERATURE BELOW ITS BOILING POINT, AND ADDING A SOLUBLE ALKALINE EARTH METAL COMPOUND TO PRECIPITATE ALKALINE EARTH METAL TUNGSTATE SUBSTANTIALLY FREE SAID THIOSALT-FORMING COMPOUND WHILE MAINTAINING THE PH OF THE SOLUTION BETWEEN 8 AND 11.5
Claim 2
Independent Claim
130 words
THE METHOD OF TREATING AN AQUEOUS SOLUTION CONTAINING A SOLUBLE TUNGSTATE AND, AS AN IMPURITY, AT LEAST ONE SOLUBLE THIOSALT-FORMING COMPOUND OF AN ELEMENT OF THE GROUP CONSISTING OF ANTIMONY, ARSENIC AND MOLYBDENUM, WHICH METHOD COMPRISES ADJUSTING THE PH OF SUCH SOLUTION TO BETWEEN 5 AND 8, ADDING A SOLUBLE SULFIDE IN SUBSTANTIAL EXCESS OF THE STOICHIOMETRIC PROPORTION SUFFICIENT TO RERACT WITH SUBSTANTIALLY ALL OF SAID THIOSALT-FORMING COMPOUND PRESENT IN SAID SOLUTION, ADJUSTING THE PH OF SAID SOLUTION DURING THE ADDITION OF SAID SULFIDE TO BETWEEN 8 AND 11.5, MAINTAIONING THE SOLUTION AT AN ELEVATED TEMPERATURE BELOW ITS BOILING POINT, AND ADDING A SOLUBLE ALKALINE EARTH METAL COMPOUND TO PRECIPITATE ALKALINE EARTH METAL TUNGSTATE SUBSTANTIALLY FREE SAID THIOSALT-FORMING COMPOUND WHILE MAINTAINING THE PH OF THE SOLUTION BETWEEN 8 AND 11.5
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) | 1954-06-11 | 1954-12-11 | 1955-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-11 | 1958-12-11 | 1959-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-11 | 1962-12-11 | 1963-06-12 | $7700.00 | Window Closed / Lapsed |