US5543031A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for recovering indium by electrowinning and apparatus therefor
Assignee: Nippon Mining Holdings Inc
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Filing: 1995-02-10
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Granted: 1996-08-06
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Expires: 2015-02-10
Abstract
Abstract In order to recover indium, while preventing generation of chlorine gas, by a direct electrowinning method from a hydrochloric acid solution from which impurities have been removed by various chemical purification methods, an electrolysis is carried out by using an indium-containing hydrochloric acid solution as an electrolyte for a cathode compartment equipped with a cathode comprising an indium starting sheet, by using a sulfuric acid solution in an anode compartment equipped with an insoluble anode and separating the cathode compartment and the anode compartment with a diaphragm of a cation exchange material.
Inventors
- 👤 Hidenori Okamoto
- 👤 Kazuaki Takebayashi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 19:18
CPC Classifications
C; C25; C25C; C25C1/00; C25C1/22
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
74 words
A method for recovering indium for indium solution which has been purified by a channel purification method, comprising: using sulfuric acid solution as an anolyte for an anode compartment equipped with an insoluble anode, using an indium-containing hydrochloric acid solution as a catholyte for a cathode compartment, separating said cathode compartment and said anode compartment with a cation exchange membrane; and conducting an electrowinning step to recover indium from said indium-containing hydrochloric acid solution.
Claim 2
Independent Claim
74 words
A method for recovering indium for indium solution which has been purified by a channel purification method, comprising: using sulfuric acid solution as an anolyte for an anode compartment equipped with an insoluble anode, using an indium-containing hydrochloric acid solution as a catholyte for a cathode compartment, separating said cathode compartment and said anode compartment with a cation exchange membrane; and conducting an electrowinning step to recover indium from said indium-containing hydrochloric acid solution.
Claim 3
Dependent Claim
22 words
The method for recovering indium according to claim 1, wherein the sulfuric acid solution is circulated inside and outside the anode compartment.
Claim 4
Dependent Claim
52 words
The method for recovering indium according to claim 2, wherein during said conducting step, oxygen gas is generated in said anode compartment and said oxygen gas and said anolyte are circulated to a gas-liquid separation box to separate said oxygen gas from said anolyte and to lower voltage during said electrowinning step.
Claim 5
Dependent Claim
52 words
The method for recovering indium according to claim 1, wherein during said conducting step, oxygen gas is generated in said anode compartment and said oxygen gas and said anolyte are circulated to a gas-liquid separation box to separate said oxygen gas from said anolyte and to lower voltage during said electrowinning step.
Claim 6
Dependent Claim
24 words
The method for recovering indium according to claim 1, wherein the sulfuric acid concentration of the sulfuric acid solution is 10 to 180 g/L.
Claim 7
Dependent Claim
27 words
The method of claim 1 wherein a starting sheet made of a high grade of indium obtained by electrowinning or electrorefining is selected as said cathode sheet.
Claim 8
Dependent Claim
34 words
The method of claim 1 wherein a glue and a sodium lignin sulphonate are added in an amount of less than 10 g/kg of electrodeposited indium to said catholyte to minimize bubbling during electrodeposition.
Claim 9
Dependent Claim
92 words
The method of claim 1 further comprising the steps of forming said anode compartment with a top, bottom and sides to enclose said insoluble anode, at least said sides being formed of said cation exchange member and disposing said anode compartment within said cathode compartment; conducting an electrowinning step to recover indium in said cathode compartment while removing said anolyte and oxygen generated during said electrowinning step from a top of said anode compartment; and separating said oxygen from said anolyte and returning said anolyte to the bottom of said anode compartment.
Claim 10
Dependent Claim
14 words
The method of claim 1 wherein said catholyte is recirculated to said cathode compartment.
Claim 11
Independent Claim
151 words
A method for recovering indium comprising: purifying a catholyte to be used in a subsequent step for recovering indium by carrying out an electrolysis in place of a chemical purification method wherein a sulfuric acid solution is used as an anolyte for an anode compartment equipped with an insoluble anode, a hydrochloric acid solution is used as a catholyte for a cathode compartment, while separating the cathode compartment and the anode compartment with a cation exchange membrane, said electrolysis removing and recovering elements present in the catholyte more noble than indium so that indium recovered in said subsequent step is of high purity, and supplementing the cathode compartment with an indium-containing hydrochloric acid solution after said purifying step, supplementing the anode compartment with a sulfuric acid solution, and; conducting an electrowinning of indium while separating the cathode compartment and the anode compartment with a cation exchange membrane to recover said indium.
Claim 12
Independent Claim
151 words
A method for recovering indium comprising: purifying a catholyte to be used in a subsequent step for recovering indium by carrying out an electrolysis in place of a chemical purification method wherein a sulfuric acid solution is used as an anolyte for an anode compartment equipped with an insoluble anode, a hydrochloric acid solution is used as a catholyte for a cathode compartment, while separating the cathode compartment and the anode compartment with a cation exchange membrane, said electrolysis removing and recovering elements present in the catholyte more noble than indium so that indium recovered in said subsequent step is of high purity, and supplementing the cathode compartment with an indium-containing hydrochloric acid solution after said purifying step, supplementing the anode compartment with a sulfuric acid solution, and; conducting an electrowinning of indium while separating the cathode compartment and the anode compartment with a cation exchange membrane to recover said indium.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1999-08-06 | 2000-02-05 | 2000-08-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-08-06 | 2004-02-05 | 2004-08-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-08-06 | 2008-02-05 | 2008-08-06 | $7700.00 | Window Closed / Lapsed |