US5159094A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the preparation of solid iron (III) complexes
Assignee: Hampshire Chemical Corp
•
Filing: 1991-05-15
•
Granted: 1992-10-27
•
Expires: 2011-05-15
Abstract
Abstract Fe(III) complexes having high bulk density and a process for the production of the same without the generation of heavy metal-contaminated effluents are disclosed. Solid complexes of EDTANaFe and EDTAKFe having high bulk densities are formed by reaction with ferric sulfate containing low chromium levels, followed by total drying of the resulting mixture in the same processing equipment without the prior separation of the sulfate salts formed.
Inventors
- 👤 Jon C. Thunberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:01
CPC Classifications
C; C07; C07F; C07F15/00; C07F15/02; C07F15/025; Y; Y10; Y10S; Y10S71/00; Y10S71/02
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
89 words
A process for producing iron (III) complexes of alkali metal salts of EDTA, comprising: a. neutralizing free alkali present in an alkali metal salt solution of EDTA with and neutralizing free alkali in the alkali metal salt solution of EDTA with acid; b. reacting the neutralized alkali metal salt solution with ferric sulfate to form a slurry containing alkali metal sulfate. c. vacuum drying said slurry without the prior separation of said alkali metal sulfate, said reacting and vacuum drying steps being carried out in the same processing equipment.
Claim 2
Dependent Claim
89 words
A process for producing iron (III) complexes of alkali metal salts of EDTA, comprising: a. neutralizing free alkali present in an alkali metal salt solution of EDTA with and neutralizing free alkali in the alkali metal salt solution of EDTA with acid; b. reacting the neutralized alkali metal salt solution with ferric sulfate to form a slurry containing alkali metal sulfate. c. vacuum drying said slurry without the prior separation of said alkali metal sulfate, said reacting and vacuum drying steps being carried out in the same processing equipment.
Claim 3
Dependent Claim
16 words
The process of claim 1 wherein the alkali metal salt of EDTA is EDTANa 4 .
Claim 4
Dependent Claim
16 words
The process of claim 1 wherein the alkali metal salt of EDTA is EDTAK 4 .
Claim 5
Dependent Claim
14 words
The process of claim 1 wherein the neutralization is carried out with EDTA acid.
Claim 6
Dependent Claim
14 words
The process of claim 1 wherein the neutralization is carried out with sulfuric acid.
References Cited (Backward Citations)
US2534781A
Cited
US2859104A
Cited
US2891854A
Cited
US2816060A
Cited
US2906762A
Cited
US2931716A
Cited
US2943100A
Cited
US3080410A
Cited
US3150016A
Cited
US3661953A
Cited
US3753675A
Cited
US3903119A
Cited
US3981712A
Cited
US4056381A
Cited
US4130582A
Cited
US4181516A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-10-27 | 1996-04-27 | 1996-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-10-27 | 2000-04-27 | 2000-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-10-27 | 2004-04-27 | 2004-10-27 | $7700.00 | Window Closed / Lapsed |