US3847762A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process using silicate treated asbestos diaphragms for electrolytic cells
Assignee: PPG Industries Inc
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Filing: 1973-03-21
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Granted: 1974-11-12
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Expires: 1993-03-21
Abstract
Abstract A diaphragm is disclosed for electrolytic cells, for example, chlor-alkali cells. The diaphragm is characterized in that it has been treated with a water-soluble silicate on the anolyte side. Also disclosed is an electrolytic cell process using such a diaphragm, and a method for preparing such a diaphragm.
Inventors
- 👤 F Strain
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 00:30
CPC Classifications
D; D21; D21J; D21J7/00; C; C25; C25B; C25B13/00; C25B13/04; C25B13/05; C25B13/06
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
86 words
IN A METHOD OF CONDUCTING ELECTROLYSIS IN A DIAPHRAGM CELL WHEREIN A SODIUM CHLORIDE BRINE IS FED INTO THE ANOLYTE CHAMBER OF SAID CELL AND THE ELECTROLYE WITHIN SAID ANOLYTE CHAMBER PASSES THROUGH A DIAPHRAGM OF SAID CELL TO A CATHOLYTE CHAMBER WHEREBY A PRODUCT CONTAINING SODIUM HYDROXIDE AND SODIUM CHLORIDE IS RECOVERED FROM SAID CATHOLYTE CHAMBER, THE IMPROVEMENT WHICH COMPRISES: DEPOSITING ON AN ELECTROLYTE PERMEABLE ASBESTOS MAT 0.01 TO 5.0 GRAMS PER SQUARE FOOT OF DIAPHRAGM OF A WATER SOLUBLE SILICATE HAVING THE EMPIRICAL FORMULA
Claim 2
Dependent Claim
86 words
IN A METHOD OF CONDUCTING ELECTROLYSIS IN A DIAPHRAGM CELL WHEREIN A SODIUM CHLORIDE BRINE IS FED INTO THE ANOLYTE CHAMBER OF SAID CELL AND THE ELECTROLYE WITHIN SAID ANOLYTE CHAMBER PASSES THROUGH A DIAPHRAGM OF SAID CELL TO A CATHOLYTE CHAMBER WHEREBY A PRODUCT CONTAINING SODIUM HYDROXIDE AND SODIUM CHLORIDE IS RECOVERED FROM SAID CATHOLYTE CHAMBER, THE IMPROVEMENT WHICH COMPRISES: DEPOSITING ON AN ELECTROLYTE PERMEABLE ASBESTOS MAT 0.01 TO 5.0 GRAMS PER SQUARE FOOT OF DIAPHRAGM OF A WATER SOLUBLE SILICATE HAVING THE EMPIRICAL FORMULA
Claim 3
Dependent Claim
19 words
The method of claim 1 wherein the ratio of m to n is from about 1:2 to about 1:4.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein the amount of deposited silicate is from about 0.5 to about 2.0 grams per square foot.
Claim 5
Independent Claim
81 words
A method of lengthening the life of a chlor-alkali cell asbestos diaphragm comprising: depositing a silicate having the formula (Me2O)m(SiO2)n where Me is chosen from the group consisting of lithium, sodium, and potassium, and the ratio of m to n is from about 1:1 to about 1:10 to depth of at least 0.08 inch on one surface of said diaphragm; and contacting said diaphragm with an aqueous acidic media whereby to convert said silicate to an amorphous, anolyte resistant, hydrated silica.
Claim 6
Independent Claim
81 words
A method of lengthening the life of a chlor-alkali cell asbestos diaphragm comprising: depositing a silicate having the formula (Me2O)m(SiO2)n where Me is chosen from the group consisting of lithium, sodium, and potassium, and the ratio of m to n is from about 1:1 to about 1:10 to depth of at least 0.08 inch on one surface of said diaphragm; and contacting said diaphragm with an aqueous acidic media whereby to convert said silicate to an amorphous, anolyte resistant, hydrated silica.
Claim 7
Dependent Claim
19 words
The method of claim 4 wherein the ratio of m to n is from about 1:2 to about 1:4.
Claim 8
Dependent Claim
25 words
The method of claim 4 wherein from about 0.01 to about 5.0 grams of silicate per square foot of diaphragm are deposited on the diaphragm.
References Cited (Backward Citations)
GB190105016A
Cited
US723398A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-11-11 | 1978-05-13 | 1978-11-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-11-11 | 1982-05-13 | 1982-11-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-11-11 | 1986-05-13 | 1986-11-12 | $7700.00 | Window Closed / Lapsed |