US3216792A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydrometallurgical process
Assignee: North American Coal Corp
•
Filing: 1962-05-28
•
Granted: 1965-11-09
•
Expires: 1982-05-28
Abstract
No abstract record available.
Inventors
- 👤 Udy Tessa
- 👤 Murray C Udy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:19
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/68; C01F7/74; C01F7/743; C01F7/02; C01F7/20; C01F7/26
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
132 words
IN A PROCESS FOR PRODUCING NEUTRAL ALUMINUM SULFATE HYDRATE FROM PARTICULATE ALUMINA-BEARING SILICEOUS MATERIAL CONTAINING IRON IMPURITIES, THE STEPS THAT COMPRISE: SUBJECTING SUCH ALUMINA-BEARING MATERIAL TO THE LEACHING ACTION OF HOT SULFURIC ACID AT A TEMPERATURE OF FROM 100*C. TO THE BOILING POINT OF SAID ACID; SAID ACID AT THE START OF SAID LEACHING ACTION BEING AT A CONCENTRATION OF BETWEEN 40-80 PERCENT H2SO4 BY WEIGHT AND BEING EMPLOYED IN AN AMOUNT EQUAL TO AT LEAST TWICE THE NORMAL STOICHIOMETRIC REQUIREMENTS TO PRODUCE A PREGNANT LIQUOR CONTAINING ALUMINUM SULFATE, AND A SOLID RESIDUE COMPRISING SILICA CONTAINING A MAJOR PORTION OF THE IRON IMPURITIES PRESENT IN SAID MATERIAL; SEPARATING SAID PREGNANT LIQUOR FROM SAID SOLID RESIDUE WHILE HOT; PROVIDING A H2SO4 CONCENTRATION IN SAID PREGNANT LIQUOR OF BETWEEN 30-46 PERCENT BY WEIGHT THEREOF;
Claim 2
Dependent Claim
132 words
IN A PROCESS FOR PRODUCING NEUTRAL ALUMINUM SULFATE HYDRATE FROM PARTICULATE ALUMINA-BEARING SILICEOUS MATERIAL CONTAINING IRON IMPURITIES, THE STEPS THAT COMPRISE: SUBJECTING SUCH ALUMINA-BEARING MATERIAL TO THE LEACHING ACTION OF HOT SULFURIC ACID AT A TEMPERATURE OF FROM 100*C. TO THE BOILING POINT OF SAID ACID; SAID ACID AT THE START OF SAID LEACHING ACTION BEING AT A CONCENTRATION OF BETWEEN 40-80 PERCENT H2SO4 BY WEIGHT AND BEING EMPLOYED IN AN AMOUNT EQUAL TO AT LEAST TWICE THE NORMAL STOICHIOMETRIC REQUIREMENTS TO PRODUCE A PREGNANT LIQUOR CONTAINING ALUMINUM SULFATE, AND A SOLID RESIDUE COMPRISING SILICA CONTAINING A MAJOR PORTION OF THE IRON IMPURITIES PRESENT IN SAID MATERIAL; SEPARATING SAID PREGNANT LIQUOR FROM SAID SOLID RESIDUE WHILE HOT; PROVIDING A H2SO4 CONCENTRATION IN SAID PREGNANT LIQUOR OF BETWEEN 30-46 PERCENT BY WEIGHT THEREOF;
References Cited (Backward Citations)
US2476979A
Cited
US3078146A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-11-08 | 1969-05-10 | 1969-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-11-08 | 1973-05-10 | 1973-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-11-08 | 1977-05-10 | 1977-11-09 | $7700.00 | Window Closed / Lapsed |