US2755172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Selective replacement of metal sulfides
Assignee: Chemical Construction Corp
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Filing: 1953-09-11
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Granted: 1956-07-17
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Expires: 1973-09-11
Abstract
No abstract record available.
Inventors
- 👤 Patrick J Mcgauley
- 👤 Felix A Schaufelberger
- 👤 Edward S Roherts
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 13:20
CPC Classifications
C; C22; C22B; C22B3/00; C22B3/20; C22B3/44; C22B15/00; C22B15/0063; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
141 words
IN A PROCESS OF SEPARATING THEREFROM AS ITS SULFIDE AT LEAST ONE NON-FERROUS METAL CONTENT OF AN AQUEOUS SOLUTION CONTAINING A PLURALITY OF NON-FERROUS METAL SULFATES, THE COMPOSITION OF WHICH SOLUTION PRECLUDES EFFECTIVE SEPARATION BY FRACTIONAL CRYSTALLIZATION, THE IMPROVEMENT WHICH COMPRISES THE STEPS OF: TREATING SAID SOLUTION UNDER ACIDIC CONDITIONS IN THE PRESENCE OF FREE ACID WITH ABOUT A STOICHIOMETRIC EQUIVALENT AT LEAST ONE SOLID METAL SULFIDE THE SOLUBILITY OF WHICH IS GREATER THAN THE LEAST SOLUBLE SULFIDE OF ANY NON-FERROUS METAL THE SULFATE OF WHICH IS DISSOLVED IN SAID SOLUTION AND WITH A REDUCING AGENT IN SUFFICIENT AMOUNT TO INSURE SUBSTANTIALLY NO OXIDATION OF SULFIDE IONS TO ELEMENTAL SULFUR; CONTINUING THE TREATMENT AT FROM ABOUT 250* -450* F., UNTIL PRECIPITATION OF SAID METAL HAVING SAID LEAST SOLUBLE METAL SULFIDE SUBSTANTIALLY CEASES; AND REMOVING RESULTANT REPLACED SULFIDE PRECIPITATED BY SAID TREATMENT.
Claim 2
Dependent Claim
141 words
IN A PROCESS OF SEPARATING THEREFROM AS ITS SULFIDE AT LEAST ONE NON-FERROUS METAL CONTENT OF AN AQUEOUS SOLUTION CONTAINING A PLURALITY OF NON-FERROUS METAL SULFATES, THE COMPOSITION OF WHICH SOLUTION PRECLUDES EFFECTIVE SEPARATION BY FRACTIONAL CRYSTALLIZATION, THE IMPROVEMENT WHICH COMPRISES THE STEPS OF: TREATING SAID SOLUTION UNDER ACIDIC CONDITIONS IN THE PRESENCE OF FREE ACID WITH ABOUT A STOICHIOMETRIC EQUIVALENT AT LEAST ONE SOLID METAL SULFIDE THE SOLUBILITY OF WHICH IS GREATER THAN THE LEAST SOLUBLE SULFIDE OF ANY NON-FERROUS METAL THE SULFATE OF WHICH IS DISSOLVED IN SAID SOLUTION AND WITH A REDUCING AGENT IN SUFFICIENT AMOUNT TO INSURE SUBSTANTIALLY NO OXIDATION OF SULFIDE IONS TO ELEMENTAL SULFUR; CONTINUING THE TREATMENT AT FROM ABOUT 250* -450* F., UNTIL PRECIPITATION OF SAID METAL HAVING SAID LEAST SOLUBLE METAL SULFIDE SUBSTANTIALLY CEASES; AND REMOVING RESULTANT REPLACED SULFIDE PRECIPITATED BY SAID TREATMENT.
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) | 1959-07-17 | 1960-01-16 | 1960-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-07-17 | 1964-01-16 | 1964-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-07-17 | 1968-01-16 | 1968-07-17 | $7700.00 | Window Closed / Lapsed |