US3923689A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Removal of iron contaminants from porous materials
Assignee: Zeneca Inc
•
Filing: 1972-11-29
•
Granted: 1975-12-02
•
Expires: 1992-11-29
Abstract
Abstract A method is disclosed for removing iron contaminants from porous materials, such as active carbon. The method involves treating the porous material with an acidic solution containing a suitable reducing agent.
Inventors
- 👤 Clifton William Broughton
- 👤 Joseph Tucker Truemper
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 10:24
CPC Classifications
B; B01; B01J; B01J37/00; B01J37/06; B01J20/00; B01J20/02; B01J20/10; B01J20/16; B01J20/18; B01J20/186; B01J21/00; B01J21/18; B01J37/16; C; C01; C01B; C01B32/00; C01B32/30; C01B32/354; C01B32/378
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
63 words
IN A METHOD FOR REMOVING IRON FROM A POROUS CARBONACEOUS MATERIAL WHEREIN THE POROUS CARBONACEOUS MATERIAL IS TREATED WITH AN ACIDIC SOLUTION, THE IMPROVEMENT COMPRISING INCLUDING IN SAID SOLUTION A REDUCING AGENT SELECTED FROM THE GROUP CONSISTING OF HYDRAZINE, THIOSULFATES, SULFITES, NITRITES, AND HYDROXYL AMINE, PROVIDED THAT THE AMOUNTS OF ACID AND REDUCING AGENT IN SAID SOLUTION ARE SUFFICIENT TO SOLUBILIZED THE IRON.
Claim 2
Dependent Claim
63 words
IN A METHOD FOR REMOVING IRON FROM A POROUS CARBONACEOUS MATERIAL WHEREIN THE POROUS CARBONACEOUS MATERIAL IS TREATED WITH AN ACIDIC SOLUTION, THE IMPROVEMENT COMPRISING INCLUDING IN SAID SOLUTION A REDUCING AGENT SELECTED FROM THE GROUP CONSISTING OF HYDRAZINE, THIOSULFATES, SULFITES, NITRITES, AND HYDROXYL AMINE, PROVIDED THAT THE AMOUNTS OF ACID AND REDUCING AGENT IN SAID SOLUTION ARE SUFFICIENT TO SOLUBILIZED THE IRON.
Claim 3
Dependent Claim
14 words
A method, as claimed in claim 1, wherein the porous material is active carbon.
Claim 4
Dependent Claim
13 words
A method, as claimed in claim 1, wherein the reducing agent is hydrazine.
Claim 5
Dependent Claim
24 words
A method, as claimed in claim 1, wherein the acidic solution has a pH in the range of from about 1 to about 2.5.
Claim 6
Dependent Claim
17 words
A method, as claimed in claim 4, wherein the acidic solution has a pH of about 2.
Claim 7
Dependent Claim
19 words
A method, as claimed in claim 1, wherein the porous material has previously been treated with an acidic solution.
Claim 8
Dependent Claim
25 words
A method, as claimed in claim 1, wherein the acidic solution is heated to a temperature of from about 60* C. to about 80* C.
References Cited (Backward Citations)
US3018288A
Cited
US3312697A
Cited
US2912470A
Cited
US3168485A
Cited
DE1147925B
Cited
US3576767A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-01 | 1979-06-02 | 1979-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-01 | 1983-06-02 | 1983-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-01 | 1987-06-02 | 1987-12-02 | $7700.00 | Window Closed / Lapsed |