Patent US4740488A successfully refreshed from Google Patents.
US4740488A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Modified clay sorbents
Assignee: BOARD OF REGENTS ACTING FOR AND ON BEHALF OF UNIVERSITY OF MICHIGAN A CORP OF MICHIGAN
•
Filing: 1985-11-25
•
Granted: 1988-04-26
•
Expires: 2005-11-25
Abstract
Abstract Modified clay is a general purpose sorbent for the removal of trace organic pollutants from process effluent streams. An expandible smectite clay, such as montmorillonite, is placed in an aqueous suspension to expand the layers. The expanded clay is then treated with an excess of a solution of hydroxy-aluminum, in particular, a hydroxy-aluminum solution having an OH - /Al ratio of about 2.54 and a pH in the vicinity of 4.5. The weight of clay to volume of hydroxy-aluminum solution may vary from about 1:10 and 1:25. The treated clay is filtered, washed, dried, and powdered by techniques well known in the art, and then the entire treatment sequence is repeated. The modified, powdered clay removes organic pollutants from industrial effluent in the ppb-ppq range. In particular, the modified clay is useful in removing traces of PCBs and Dioxin.
Inventors
- 👤 H. Scott Fogler
- 👤 Kerran R. Srinivasan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 01:25
CPC Classifications
B; B01; B01J; B01J20/00; B01J20/02; B01J20/10; B01J20/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
59 words
A pillared clay composition formed by a process comprising the steps of: swelling an expandible clay with a solvent; contacting the swollen clay with an aqueous solution of hydroxy-aluminum to produce a mixture; filtering said mixture to produce a filter cake; drying said filter cake; powdering said filter cake; and repeating said steps of contacting, filtering, drying, and powdering.
Claim 2
Dependent Claim
59 words
A pillared clay composition formed by a process comprising the steps of: swelling an expandible clay with a solvent; contacting the swollen clay with an aqueous solution of hydroxy-aluminum to produce a mixture; filtering said mixture to produce a filter cake; drying said filter cake; powdering said filter cake; and repeating said steps of contacting, filtering, drying, and powdering.
Claim 3
Dependent Claim
14 words
The pillared clay composition of claim 1 wherein said expandible clay is a smectite.
Claim 4
Dependent Claim
12 words
The pillared clay composition of claim 2 wherein said smectite is montmorillonite.
Claim 5
Dependent Claim
12 words
The pillared clay composition of claim 1 wherein said solvent is water.
Claim 6
Dependent Claim
25 words
The pillared clay composition of claim 1 wherein said aqueous solution of hydroxy-aluminum has an OH - /Al ratio of approximately between 2.0 to 3.1.
Claim 7
Dependent Claim
16 words
The pillared clay composition of claim 5 wherein said OH - /Al ratio is approximately 2.54.
Claim 8
Dependent Claim
23 words
The pillared clay composition of claim 5 wherein said aqueous solution has a pH in the range of approximately between 3.6 and 5.4.
Claim 9
Dependent Claim
13 words
The pillared clay composition of claim 7 wherein said pH is approximately 4.5.
Claim 10
Independent Claim
84 words
A method of preparing a composition for removing organic trace components from industrial effluents, the method comprising: forming a swollen montmorillonite; contacting said swollen montmorillonite with an aqueous solution of hydroxy-aluminum, said solution having an OH - /Al ratio of approximately 2.54 and a pH of approximately 4.5 to produce a mixture; filtering said mixture to produce a filter cake; washing said filter cake; drying said filter cake; powdering said filter cake; and repeating said steps of forming, contacting, filtering, washing, drying, and powdering.
Claim 11
Independent Claim
84 words
A method of preparing a composition for removing organic trace components from industrial effluents, the method comprising: forming a swollen montmorillonite; contacting said swollen montmorillonite with an aqueous solution of hydroxy-aluminum, said solution having an OH - /Al ratio of approximately 2.54 and a pH of approximately 4.5 to produce a mixture; filtering said mixture to produce a filter cake; washing said filter cake; drying said filter cake; powdering said filter cake; and repeating said steps of forming, contacting, filtering, washing, drying, and powdering.
References Cited (Backward Citations)
DE143894C
Cited
US2408207A
Cited
US3487928A
Cited
US4060480A
Cited
US4033764A
Cited
US4040990A
Cited
US4176090A
Cited
US4363749A
Cited
US4216188A
Cited
JPS53101847A
Cited
US4238364A
Cited
US4248739A
Cited
US4267055A
Cited
US4271043A
Cited
US4367163A
Cited
US4436832A
Cited
US4452910A
Cited
US4549966A
Cited
US4436645A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-04-26 | 1991-10-26 | 1992-04-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-04-26 | 1995-10-26 | 1996-04-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-04-26 | 1999-10-26 | 2000-04-26 | $7700.00 | Window Closed / Lapsed |