US4474649A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of thiourea addition of electrolytic solutions useful for copper refining
Assignee: Asarco LLC
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Filing: 1983-07-19
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Granted: 1984-10-02
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Expires: 2003-07-19
Abstract
Abstract A process for precise controlling of thiourea concentrations in a copper sulfate, sulfuric acid solution used in copper refining has permitted improvements in tankhouse current efficiencies and the quality of the refined copper deposited on the cathodes.
Inventors
- 👤 Martin Goffman
- 👤 Thomas L. Jordan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 10:48
CPC Classifications
C; C25; C25C; C25C1/00; C25C1/12
Claims Analysis
Total Claims: 24
Claim 1
Independent Claim
85 words
A method for the electrolytic refining of copper comprising: creating in a suitable container means having inlet and outlet stream, a copper refining electrolyte comprising an aqueous solution of sulfuric acid and copper sulfate of effective strength, the solution including small amounts by weight of addition agents, one of which is thiourea; adding a sufficient amount of thiourea to the inlet stream to maintain the outlet stream concentration of thiourea at a value at least above trace concentrations; and electrorefining copper in the container means.
Claim 2
Independent Claim
85 words
A method for the electrolytic refining of copper comprising: creating in a suitable container means having inlet and outlet stream, a copper refining electrolyte comprising an aqueous solution of sulfuric acid and copper sulfate of effective strength, the solution including small amounts by weight of addition agents, one of which is thiourea; adding a sufficient amount of thiourea to the inlet stream to maintain the outlet stream concentration of thiourea at a value at least above trace concentrations; and electrorefining copper in the container means.
Claim 3
Dependent Claim
27 words
A method as in claim 1 wherein the maximum concentration of thiourea in the outlet stream is a value above which cathode deposited copper contamination becomes significant.
Claim 4
Dependent Claim
18 words
A method as in claim 1 wherein the outlet stream concentration of thiourea is between about 100-5000 ppb.
Claim 5
Dependent Claim
21 words
A method as in claim 1 wherein the outlet stream concentration of thiourea is periodically measured with an effective measuring means.
Claim 6
Dependent Claim
14 words
A method as in claim 1 wherein the container is a copper refining tankhouse.
Claim 7
Independent Claim
91 words
A method for the elctrolytic refining of copper comprising: creating in a suitable container means having inlet and outlet streams, a copper refining electrolyte comprising an aqueous solution of sulfuric acid and copper sulfate of effective strength, the solution including small amounts by weight of addition agents, one of which is thiourea; adding a sufficient amount of thiourea to the inlet stream to maintain the outlet stream concentration of thiourea as measured by differential pulse polarography at a value at least above trace concentrations; and electrorefining copper in the container means.
Claim 8
Independent Claim
91 words
A method for the elctrolytic refining of copper comprising: creating in a suitable container means having inlet and outlet streams, a copper refining electrolyte comprising an aqueous solution of sulfuric acid and copper sulfate of effective strength, the solution including small amounts by weight of addition agents, one of which is thiourea; adding a sufficient amount of thiourea to the inlet stream to maintain the outlet stream concentration of thiourea as measured by differential pulse polarography at a value at least above trace concentrations; and electrorefining copper in the container means.
Claim 9
Dependent Claim
27 words
A method as in claim 6 wherein the maximum concentration of thiourea in the outlet stream is a value above which cathode deposited copper contamination becomes significant.
Claim 10
Dependent Claim
19 words
A method as in claim 6 wherein the outlet stream concentration of thiourea is at least about 100 ppb.
Claim 11
Dependent Claim
18 words
A method as in claim 6 wherein the outlet stream concentration of thiourea is between about 100-5000 ppb.
Claim 12
Dependent Claim
14 words
A method as in claim 6 wherein the container is a copper refining tankhouse.
Claim 13
Independent Claim
105 words
An apparatus for carrying out an electrolytic refining process to produce a copper product comprising: (a) a container having inlet and outlet means for holding the electrolyte, anode and cathode components; (b) feeding means for adding thiourea to the electrolyte; (c) circulating means for adding and removing electrolyte to and from the container; (d) measuring means associated with the outlet means to determine the concentration of the thiourea in the electrolyte; (e) means to compare the measured thiourea concentration with a predetermined value; and (f) means to control the thiourea feeding means to maintain the thiourea concentration in the outlet means at the predetermined value.
Claim 14
Independent Claim
105 words
An apparatus for carrying out an electrolytic refining process to produce a copper product comprising: (a) a container having inlet and outlet means for holding the electrolyte, anode and cathode components; (b) feeding means for adding thiourea to the electrolyte; (c) circulating means for adding and removing electrolyte to and from the container; (d) measuring means associated with the outlet means to determine the concentration of the thiourea in the electrolyte; (e) means to compare the measured thiourea concentration with a predetermined value; and (f) means to control the thiourea feeding means to maintain the thiourea concentration in the outlet means at the predetermined value.
Claim 15
Dependent Claim
15 words
An apparatus as in claim 11 wherein the measuring means is a differential pulse polarograph.
Claim 16
Dependent Claim
124 words
In a method for the electrolytic refining of copper wherein a plurality of interleaved anodes of impure copper and cathodes of pure copper are disposed in a tank and immersed in an electrolyte which comprises an aqueous solution of sulfuric acid and copper sulfate of effective strength, the solution including small amounts by weight of addition agents, one of which is thiourea, said tank having both an inlet stream and outlet stream for electrolyte passing through inlet and outlet flow passage means; the improvement comprising adding a sufficient amount of thiourea to the inlet stream in order to maintain the outlet stream concentration of thiourea at a value at least above trace concentrations and below that at which cathode deposited copper contamination becomes significant.
Claim 17
Dependent Claim
124 words
In a method for the electrolytic refining of copper wherein a plurality of interleaved anodes of impure copper and cathodes of pure copper are disposed in a tank and immersed in an electrolyte which comprises an aqueous solution of sulfuric acid and copper sulfate of effective strength, the solution including small amounts by weight of addition agents, one of which is thiourea, said tank having both an inlet stream and outlet stream for electrolyte passing through inlet and outlet flow passage means; the improvement comprising adding a sufficient amount of thiourea to the inlet stream in order to maintain the outlet stream concentration of thiourea at a value at least above trace concentrations and below that at which cathode deposited copper contamination becomes significant.
Claim 18
Dependent Claim
23 words
The method of claim 13 wherein the outlet stream concentration of thiourea in the electrolyte is periodically measured with an effective measuring means.
Claim 19
Dependent Claim
14 words
The method of claim 14 wherein the measuring means is a differential pulse polarograph.
Claim 20
Dependent Claim
15 words
The method of claim 15 wherein said measuring means comprises a KNO 3 reference electrode.
Claim 21
Dependent Claim
17 words
The method of claim 13 wherein the minimum outlet stream concentration of thiourea is about 100 ppb.
Claim 22
Dependent Claim
125 words
In a method for the electrolytic refining of copper wherein a plurality of interleaved anodes of impure copper and cathodes of pure copper are disposed in a tank and immersed in an electrolyte which comprises an aqueous solution of sulfuric acid and copper sulfate of effective strength, the solution including small amounts by weight of addition agents, one of which is thiourea, said tank having both an inlet stream and outlet stream for electrolyte passing through inlet and outlet flow passage means; the improvement comprising periodically determining the amount of thiourea in the outlet stream and adjusting the addition of thiourea to the electrolyte in response thereto to provide that the amount of thiourea in the outlet stream is between about 100 to 5000 ppb.
Claim 23
Dependent Claim
125 words
In a method for the electrolytic refining of copper wherein a plurality of interleaved anodes of impure copper and cathodes of pure copper are disposed in a tank and immersed in an electrolyte which comprises an aqueous solution of sulfuric acid and copper sulfate of effective strength, the solution including small amounts by weight of addition agents, one of which is thiourea, said tank having both an inlet stream and outlet stream for electrolyte passing through inlet and outlet flow passage means; the improvement comprising periodically determining the amount of thiourea in the outlet stream and adjusting the addition of thiourea to the electrolyte in response thereto to provide that the amount of thiourea in the outlet stream is between about 100 to 5000 ppb.
Claim 24
Dependent Claim
25 words
The method of claim 13, 14, 15 or 16 wherein the range of thiourea concentrations in the outlet stream is maintained between about 100-5000 ppb.
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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) | 1987-10-02 | 1988-04-02 | 1988-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-10-02 | 1992-04-02 | 1992-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-10-02 | 1996-04-02 | 1996-10-02 | $7700.00 | Window Closed / Lapsed |