US4670244A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for reducing metal ions in aqueous solutions
Assignee: Hoechst AG
•
Filing: 1985-10-01
•
Granted: 1987-06-02
•
Expires: 2005-10-01
Abstract
Abstract Metal ions are reduced from a higher to a lower oxidation stage using ferrophosphorus as the reductant.
Inventors
- 👤 Wouter Roos
- 👤 Bernardus J. Damman
- 👤 Arie Lagendijk
- 👤 Dieter Steidl
- 👤 Raban VON Schenck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:59
CPC Classifications
C; C01; C01G; C01G49/00; C01G1/00; C01G31/00; C01G37/00; C01G43/00
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
30 words
A process for reducing metal ions from a higher to a lower oxidation stage by means of a reductant in an aqueous solution, which comprises using ferrophosphorus as the reductant.
Claim 2
Dependent Claim
30 words
A process for reducing metal ions from a higher to a lower oxidation stage by means of a reductant in an aqueous solution, which comprises using ferrophosphorus as the reductant.
Claim 3
Dependent Claim
22 words
The process as claimed in claim 1, wherein the ferrophosphorus substantially consists of particles having a size of less than 100 μm.
Claim 4
Dependent Claim
22 words
The process as claimed in claim 2, wherein the ferrophosphorus substantially consists of particles having a size of less than 10 μm.
Claim 5
Dependent Claim
19 words
The process as claimed in claim 1, wherein the reduction is effected at a temperature higher than 60° C.
Claim 6
Dependent Claim
19 words
The process as claimed in claim 1, wherein the reduction is effected in an acid, alkaline or neutral medium.
References Cited (Backward Citations)
US1633621A
Cited
US2127450A
Cited
US3294680A
Cited
US3421845A
Cited
US3536619A
Cited
US3857704A
Cited
US3770630A
Cited
US3901805A
Cited
JPS5122262A
Cited
US4053562A
Cited
US4108769A
Cited
US4146575A
Cited
US4147757A
Cited
US4159309A
Cited
JPS5451972A
Cited
US4374805A
Cited
US4394360A
Cited
US4490336A
Cited
JPS5889987A
Cited
US4485078A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-06-01 | 1990-12-01 | 1991-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-06-01 | 1994-12-01 | 1995-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-06-01 | 1998-12-01 | 1999-06-02 | $7700.00 | Window Closed / Lapsed |