US3816306A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Copper etchant effluent treatment
Assignee: Individual
•
Filing: 1973-04-13
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Granted: 1974-06-11
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Expires: 1993-04-13
Abstract
Abstract The copper content of aqueous effluent containing the rinsings from the etching of copper containing substrates is reduced to less than about 5 ppm., by the steps of: (a) adjusting the pH of the effluent to no more than about 4.; (b) providing in the effluent, while vigorously agitating, hydrogen peroxide and a water soluble compound such as calcium chloride; and (c) adding to the reaction mixture as required an alkaline material such as lime or a water soluble salt of carbonic acid, in an amount effective to adjust the pH to at least about 8.
Inventors
- 👤 C Roy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 10:15
CPC Classifications
C; C02; C02F; C02F9/00; C02F1/00; C02F1/72; C02F1/722; C02F1/66; C02F1/68; C02F1/683; C02F1/70; C02F1/705; C02F2101/00; C02F2101/10; C02F2101/20; C02F2209/00; C02F2209/06; Y; Y10; Y10S; Y10S210/00; Y10S210/902; Y10S210/911; Y10S210/912
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
30 words
A process as in claim 1 wherein the pH in step a) is adjusted by the addition of sulfuric acid, and wherein the salt in step c) is sodium carbonate.
Claim 2
Dependent Claim
15 words
A process as in claim 2 wherein said alkaline material includes sodium hydroxide or lime.
Claim 3
Dependent Claim
28 words
A process as in claim 1 wherein the pH in step a) is adjusted to about 2-3 and the pH in step c) is adjusted to about 9-11.
Claim 4
Dependent Claim
14 words
A process as in claim 1 wherein steps a) and b) are effected simultaneously.
Claim 5
Dependent Claim
41 words
A process as in claim 1 wherein hydrogen peroxide is added to the effluent in step b) before the water soluble compound is added, and the hydrogen peroxide addition is paced by the pH adjustment of step a) or step c).
Claim 6
Dependent Claim
18 words
A process as in claim 1 wherein all of said steps are effected in a single reaction zone.
Claim 7
Dependent Claim
76 words
A process as in claim 1 wherein the pH adjustment of step a) and the provision of hydrogen peroxide are effected in a first reaction zone, the water soluble compound addition is effected in a second reaction zone, and the pH adjustment of step c) is effected in a third reaction zone, and wherein the flow of reaction mixture is continuous from a source of said effluent sequentially through said reaction zones to a settling zone.
Claim 8
Dependent Claim
40 words
A process as in claim 8 wherein said settling zone is separated from said third reaction zone by a fourth zone comprising a precipitation and digestion zone, and the flow from said fourth zone to said settling zone is continuous.
Claim 9
Dependent Claim
14 words
A process as in claim 8 wherein said water soluble compound is calcium chloride.
Claim 10
Dependent Claim
38 words
A process as in claim 1 wherein the water soluble compound is a water soluble salt of an alkali metal, an alkaline earth metal, or metals of Groups IIB, IIIA, IVA, VIIB and VIII of the Periodic Table.
Claim 11
Dependent Claim
41 words
A process as in claim 1 wherein the water soluble compound is a water soluble salt of calcium, sodium, potassium, aluminum, magnesium, iron or manganese, and the alkaline material is lime, sodium carbonate, or a mixture of lime and sodium carbonate.
Claim 12
Dependent Claim
34 words
A process as in claim 1 wherein the water soluble compound is lime, said lime being added in an amount effective to adjust the reaction mixture to a pH of at least about 8.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-06-10 | 1977-12-10 | 1978-06-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-06-10 | 1981-12-10 | 1982-06-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-06-10 | 1985-12-10 | 1986-06-11 | $7700.00 | Window Closed / Lapsed |