Patent US4325792A successfully refreshed from Google Patents.
US4325792A
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Purification process
Assignee: Individual
•
Filing: 1981-03-09
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Granted: 1982-04-20
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Expires: 2001-03-09
Abstract
Abstract The use of aqueous inorganic carbonates or bicarbonates as the catholyte in the electrolytic purification of chromium plating solutions permits the cell to operate at a high capacity and a high efficiency without adversely affecting the oxidation state of the chromium ions in the solution.
Inventors
- 👤 Daniel J. Vaughan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 16:18
CPC Classifications
C; C25; C25D; C25D21/00; C25D21/16; C25D21/18; Y; Y10; Y10S; Y10S204/00; Y10S204/13
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
113 words
In the electrolytic purification of an aqueous solution of chromic acid contaminated with dissolved metallic cations by passing electric current through an electrodialysis cell comprising (a) a catholyte compartment containing a cathode and a catholyte and (b) an anolyte compartment containing an anode and an anolyte comprising a contaminated chromic acid solution the anolyte and catholyte compartments being separated by a cation-permeable membrane, the improvement comprising employing as the catholyte an aqueous solution of an inorganic carbonate or bicarbonate which forms carbon dioxide and water on contact with the anolyte, whereby a high-capacity, efficient electrodialytic purification can be carried out without adversely affecting the oxidation state of the chromium ions in the anolyte.
Claim 2
Dependent Claim
113 words
In the electrolytic purification of an aqueous solution of chromic acid contaminated with dissolved metallic cations by passing electric current through an electrodialysis cell comprising (a) a catholyte compartment containing a cathode and a catholyte and (b) an anolyte compartment containing an anode and an anolyte comprising a contaminated chromic acid solution the anolyte and catholyte compartments being separated by a cation-permeable membrane, the improvement comprising employing as the catholyte an aqueous solution of an inorganic carbonate or bicarbonate which forms carbon dioxide and water on contact with the anolyte, whereby a high-capacity, efficient electrodialytic purification can be carried out without adversely affecting the oxidation state of the chromium ions in the anolyte.
Claim 3
Dependent Claim
26 words
The purification according to claim 1 wherein the inorganic carbonate or bicarbonate is an alkali metal carbonate, an alkali metal bicarbonae, ammonium carbonate, or ammonium bicarbonate.
Claim 4
Dependent Claim
24 words
The purification according to claim 2 wherein the inorganic carbonate or bicarbonate is sodium carbonate, ammonium carbonate, sodium bicarbonate, potassium bicarbonate, or ammonium bicarbonate.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-04-19 | 1985-10-19 | 1986-04-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-04-19 | 1989-10-19 | 1990-04-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-04-19 | 1993-10-19 | 1994-04-20 | $7700.00 | Window Closed / Lapsed |