US3768865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the disposal of salt solutions contaminated with azide
Assignee: PPG Industries Inc
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Filing: 1972-07-13
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Granted: 1973-10-30
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Expires: 1992-07-13
Abstract
Abstract The disposal of salt solutions contaminated with azide is accomplished by depositing the solution in a subterranean cavity, maintaining the solution in the subterranean cavity until it is essentially free of azide, and pumping the essentially azide-free solution to the surface.
Inventors
- 👤 F Dehn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:53
CPC Classifications
C; C01; C01D; C01D3/00; C01D3/14; C01B; C01B21/00; C01B21/08; E; E21; E21B; E21B41/00; E21B41/005; E21B41/0057; E21B43/00; E21B43/28
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
93 words
In the method of preparing hydrazoic acid from a feed azide selected from the group consisting of alkali metal azide and alkaline earth metal azide wherein said feed azide is contacted with a feed acid to generate hydrazoic acid and a by-product salt of said feed acid contaminated with azide, the improvement comprising: a. depositing a solution of said azide contaminated by-product salt in a subterranean cavity; b. maintaining said solution in said subterranean cavity until the solution is essentially free of Azide; and c. pumping said essentially azide-free solution to the surface.
Claim 2
Dependent Claim
14 words
The method of claim 2 wherein the feed acid is a strong mineral acid.
Claim 3
Dependent Claim
12 words
The method of claim 2 wherein the feed acid is hydrochloric acid.
Claim 4
Dependent Claim
14 words
The method of claim 2 wherein said subterranean cavity is an abandoned salt well.
Claim 5
Dependent Claim
24 words
The method of claim 2 wherein the by-product salt is the same as the principal salt of the subterranean deposit containing the subterranean cavity.
Claim 6
Dependent Claim
12 words
The method of claim 6 whrein the by-product salt is sodium chloride.
Claim 7
Dependent Claim
12 words
The method of claim 6 wherein the by-product salt is potassium chloride.
Claim 8
Dependent Claim
47 words
The method of claim 6 wherein the subterranean cavity is connected to the surface of the earth by at least two wells and wherein said solution is passed down one well into the cavity and salt solution is withdrawn from said subterranean cavity through said second well.
Claim 9
Dependent Claim
11 words
The method of claim 9 wherein both wells are operating simultaneously.
Claim 10
Dependent Claim
12 words
The method of claim 9 wherein the by-product salt is sodium chloride.
Claim 11
Dependent Claim
20 words
The method of claim 9 wherein the subterranean cavity is at least 1,500 feet below the surface of the earth.
Claim 12
Dependent Claim
12 words
The method of claim 9 wherein the by-product salt is potassium chloride.
Claim 13
Dependent Claim
20 words
The method of claim 2 wherein said subterranean cavity is at least 300 feet below the surface of the earth.
Claim 14
Dependent Claim
20 words
The method of claim 2 wherein the subterranean cavity is at least 1,500 feet below the surface of the earth.
Claim 15
Dependent Claim
89 words
In the method of preparing potassium azide from sodium azide wherein the sodium azide is contacted with hydrochloric acid to generate hydrazoic acid and form by-product sodium chloride contaminated with azide and wherein said hydrazoic acid is contacted with potassium hydroxide to produce potassium azide, the improvement comprising: a. depositing a solution of said azide contaminated by-product sodium chloride in a subterranean cavity; b. maintaining said solution in said subterranean cavity until the solution is essentially free of azide; and c. pumping said essentially azide-free solution to the surface.
Claim 16
Dependent Claim
17 words
The method of claim 16 wherein said subterranean cavity is located in a subterranean sodium chloride deposit.
Claim 17
Dependent Claim
21 words
The method of claim 17 wherein said subterranean cavity is located at least 1,500 feet below the surface of the earth.
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) | 1976-10-29 | 1977-04-30 | 1977-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-10-29 | 1981-04-30 | 1981-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-10-29 | 1985-04-30 | 1985-10-30 | $7700.00 | Window Closed / Lapsed |