US4142951A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Brine electrolysis using bonded asbestos diaphragms
Assignee: CHEMTECH ROYALTY ASSOCIATES LP
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Filing: 1977-12-20
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Granted: 1979-03-06
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Expires: 1997-12-20
Abstract
Abstract The electrolysis of brine in electrolytic chlor-alkali diaphragm cells is performed using polymeric fluorocarbon-bonded mixtures of chrysotile asbestos and crocidolite asbestos as the diaphragm material. These diaphragms are particularly effective in permitting operation of the cells at low pH, thereby extending the life of graphite anodes.
Inventors
- 👤 Richard N. Beaver
- 👤 Charles W. Becker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 05:41
CPC Classifications
C; C25; C25B; C25B1/00; C25B1/01; C25B1/34; C25B1/46; C25B13/00; C25B13/04; C25B13/05; C25B13/06; C25B13/08
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
78 words
In a process for electrolyzing brine in chlor-alkali diaphragm cells employing graphite anodes, the improvement comprising operating at a low anolyte pH of less than 1.5 thereby extending the operating life of the graphite anodes, said operation at a low ph of less than 1.5 being made operationally feasible by employing as the diaphragm material a vacuum-drawn polymeric fluorocarbon-bonded mixture of crocidolite/chrysotile asbestos fibers, said crocidolite/chrysotile being in a weight ratio range of about 33/67 to about 80/20.
Claim 2
Dependent Claim
78 words
In a process for electrolyzing brine in chlor-alkali diaphragm cells employing graphite anodes, the improvement comprising operating at a low anolyte pH of less than 1.5 thereby extending the operating life of the graphite anodes, said operation at a low ph of less than 1.5 being made operationally feasible by employing as the diaphragm material a vacuum-drawn polymeric fluorocarbon-bonded mixture of crocidolite/chrysotile asbestos fibers, said crocidolite/chrysotile being in a weight ratio range of about 33/67 to about 80/20.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the ratio of crocidolite/chrysotile asbestos is in the range of about 40/60 to about 75/25.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein the ratio of crocidolite/chrysotile asbestos is about 50/50.
Claim 5
Dependent Claim
32 words
The process of claim 1 wherein the amount of polymeric fluorocarbon in the bonded asbestos diaphragm is in the range of about 5 parts to 100 parts per hundred parts of asbestos.
Claim 6
Dependent Claim
32 words
The process of claim 1 wherein the amount of polymeric fluorocarbon in the bonded asbestos diaphragm is in the range of about 10 to about 50 parts per hundred parts of asbestos.
Claim 7
Dependent Claim
32 words
The process of claim 1 wherein the amount of polymeric fluorocarbon in the bonded asbestos diaphragm is in the range of about 15 to about 40 parts per hundred parts of asbestos.
Claim 8
Dependent Claim
18 words
The process of claim 1 wherein the pH is in the range of about 0.5 to about 1.5.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-03-05 | 1982-09-04 | 1983-03-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-03-05 | 1986-09-04 | 1987-03-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-03-05 | 1990-09-04 | 1991-03-06 | $7700.00 | Window Closed / Lapsed |