Patent US4304599A successfully refreshed from Google Patents.
US4304599A
Expired / Lapsed
US
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Heavy metal removal process
Assignee: Individual
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Filing: 1980-07-29
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Granted: 1981-12-08
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Expires: 2000-07-29
Abstract
Abstract A gravity fed water bath process treats waste water from spray rinses containing compounds of copper and like heavy metals. For displacing heavy metals, such as copper, the bath has a substantially pure metal with an electrode potential greater than the heavy metal contained in the rinse water. A system for controlling the pH level of the water bath treatment and for supplying acid at the beginning of the bath, and alkaline at the end of the bath provides a highly acidic pH level for the water bath and heavy metal removal chamber, and adjusts the pH level of the discharged water for satisfactory deposit in municipal sewer systems. A method for displacing the heavy metal from the compound in solution requires exposing the heavy metal compound to a substantially pure metal having an electrode potential greater than the heavy metal of the compound, in an acidic bath whose pH level is controlled. The control of the pH is accomplished by acid sensing probes connected in circuit with a valve control which injects and mixes acid in the bath of a treatment chamber.
Inventors
- 👤 Richard G. Durkee
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 15:54
CPC Classifications
C; C02; C02F; C02F9/00; C02F1/00; C02F1/008; C02F1/66; C02F1/70; C02F1/705; C22; C22B; C22B15/00; C22B15/0063; C22B15/0084; C22B15/0089; C22B15/0091; C22B15/0095; C22B3/00; C22B3/20; C22B3/44; C22B3/46; C22B7/00; C22B7/006; C02F2101/00; C02F2101/10; C02F2101/20; C02F2209/00; C02F2209/06; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
103 words
A method of reclaiming heavy metal from a heavy metal finishing process, in an aqueous solution, comprising the steps of: a. acidifying the aqueous solution to a pH less than 2 to form a solution in heavy metal salt of the acid used to acidify the solution; and b. flowing the aqueous solution containing the heavy metal in a path including a supply of substantially pure metal aluminum tailings stable in the aqueous acid solution, the metal aluminum having a relative electrode potential greater than that of the heavy metal in the aqueous solution to precipitate said heavy metal in the aqueous solution.
Claim 2
Dependent Claim
45 words
The method of claim 1 further including the step of sensing the pH of the aqueous solution during the acidifying step, and injecting acid into said aqueous solution responsive to the sensed pH to regulate the pH of the aqueous solution before the flowing step.
Claim 3
Dependent Claim
20 words
The method of claim 2 wherein the heavy metal salt is a metal sulfate, and the acid is sulfuric acid.
Claim 4
Dependent Claim
36 words
The method of claim 1 wherein the tailings are maintained by grates forming the bottom of removable boxes positioned in a reaction chamber, said boxes being adapted to be removed and inserted into the reaction chamber.
Claim 5
Dependent Claim
29 words
The method of claim 1 wherein the step of flowing, the aqueous solution flows by gravity feed over the substantially pure metal aluminum stable in the aqueous acid solution.
Claim 6
Dependent Claim
30 words
The method of claim 1 further including the step of raising the pH of the aqueous solution after the step of flowing the aqueous solution over the metal stable therein.
Claim 7
Dependent Claim
18 words
The method of claim 6 wherein the pH is raised by mixing alkaline material in said aqueous solution.
Claim 8
Dependent Claim
47 words
The method of claim 6 further including the step of sensing the pH in the aqueous solution after the flowing step, and of injecting alkaline material into said aqueous solution responsive to said sensed pH in an amount sufficient to raise the pH to at least 6.0.
Claim 9
Independent Claim
141 words
A method of purifying aqueous solutions in a process involving the etching of poisonous heavy metal salts in solutions in a rinse of the process after the etching step, comprising the steps of: a. acidifying the aqueous solution to a pH less than 2 to form in solution a heavy metal salt of the acid used to acidify the solution; b. exposing the acidic aqueous solution to a supply of aluminum metal stable in the acid aqueous solution and having a relative electrode potential greater than that of the poisonous heavy metal; c. displacing the poisonous heavy metal in metallic form by non-poisonous aluminum metallic cations of the aluminum metal stable in the acid aqueous solution and having an electrode potential greater than that of the poisonous heavy metal; and e. neutralizing the resulting aqueous solution by the injection of caustic.
Claim 10
Independent Claim
141 words
A method of purifying aqueous solutions in a process involving the etching of poisonous heavy metal salts in solutions in a rinse of the process after the etching step, comprising the steps of: a. acidifying the aqueous solution to a pH less than 2 to form in solution a heavy metal salt of the acid used to acidify the solution; b. exposing the acidic aqueous solution to a supply of aluminum metal stable in the acid aqueous solution and having a relative electrode potential greater than that of the poisonous heavy metal; c. displacing the poisonous heavy metal in metallic form by non-poisonous aluminum metallic cations of the aluminum metal stable in the acid aqueous solution and having an electrode potential greater than that of the poisonous heavy metal; and e. neutralizing the resulting aqueous solution by the injection of caustic.
Claim 11
Dependent Claim
46 words
The method of claim 9 further comprising the step of forming alum during the neutralizing step by the injection of caustic, regulating the pH by this injection of caustic to at least 6.0 preparatory to deposition of the treated aqueous solution into a public waste system.
Claim 12
Dependent Claim
45 words
The method of claim 9 further including the step of sensing the pH in the aqueous solution prior to the exposing step, and injecting acid into said aqueous solution responsive to said sensed pH to maintain the pH at a level of less than 2.
Claim 13
Dependent Claim
17 words
The method of claim 11 wherein the pH is maintained at a level of one or less.
Claim 14
Dependent Claim
45 words
The method of claim 9 further including the step of sensing the pH level in the aqueous solution after the exposing step, and injecting caustic into said aqueous solution responsive to said sensed pH, to adjust the pH to a level of at least 6.0.
Claim 15
Dependent Claim
57 words
The process of precipitating and reclaiming substantially pure metal copper in aqueous solution by exposing substantially pure metal aluminum tailings to said aqueous solution and agitating the solution at the surface of said aluminum by acidifying the solution to a pH less than 2 to prevent the formation of substantially pure metal copper plating on said aluminum.
Claim 16
Dependent Claim
48 words
The process of claim 14 wherein the copper in the aqueous solution is in the form of a copper compound, and further including the step of acidifying the aqueous solution with sulfuric acid such that the copper in solution is in the form of copper sulfate in solution.
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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) | 1984-12-07 | 1985-06-08 | 1985-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-07 | 1989-06-08 | 1989-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-07 | 1993-06-08 | 1993-12-08 | $7700.00 | Window Closed / Lapsed |