US3876747A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation and purification of iridium
Assignee: SWARSAB MINING
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Filing: 1973-08-02
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Granted: 1975-04-08
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Expires: 1993-08-02
Abstract
Abstract A method of separating iridium from at least one other metal of the group nsisting of platinum, palladium, ruthenium, rhodium and gold comprising converting the PGMs and gold in a solution thereof to lower oxidation states by treating the solution with hydrogen peroxide in acid medium at elevated temperature, adjusting the pH of the solution to approximately pH 9, separating the precipitate to leave iridium and platinum in solution, thereafter converting the platinum and iridium to their highest valency states by the action of sodium bromate in acid medium at elevated temperature and adjusting the pH of the solution to between about 6.5 and 7.5 to precipitate iridium and leave platinum in solution.
Inventors
- 👤 Willem Hubert Pittie
- 👤 Gerhardus Overbeek
- 👤 Kingsley Ferguson Doig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 14:36
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/04
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
118 words
A METHOD OF SEPARATING IRIDIUM FROM AT LEAST ONE OTHER METAL SELECTED FROM THE GROUP CONSISTING OF PLATINUM, PALLADIUM, RUTHENIUM, RHODIUM AND GOLD COMPRISING CONVERTING THE AT LEAST ONE OTHER METAL: IN A SOLUTION THEREOF TO LOWER OXIDATION STATES BY TREATING THE SOLUTION WITH HYDROGEN PEROXIDE IN ACID MEDIUM AT ELEVATED TEMPERATURE, ADJUSTING THE PH OF THE SOLUTION TO APPROXIMATELY PH6, SEPARATING ANY PRECIPITATE AND THUS LEAVING IRIDIUM AND ANY PLATINUM IN SOLUTION, THEREAFTER CONVERTING THE PLATINUM AND IRIDIUM TO THEIR HIGHEST VALENCY STATES BY CONTACTING THEM WITH SODIUM BROMATE IN ACID MEDIUM AT ELEVATED TEMPERATURE AND THEN ADJUSTING THE PH OF THE SOLUTION TO BETWEEN ABOUT 6.5 AND 7.5 TO PRECIPITATE IRIDIUM AND LEAVE PLATINUM IN SOLUTION.
Claim 2
Independent Claim
118 words
A METHOD OF SEPARATING IRIDIUM FROM AT LEAST ONE OTHER METAL SELECTED FROM THE GROUP CONSISTING OF PLATINUM, PALLADIUM, RUTHENIUM, RHODIUM AND GOLD COMPRISING CONVERTING THE AT LEAST ONE OTHER METAL: IN A SOLUTION THEREOF TO LOWER OXIDATION STATES BY TREATING THE SOLUTION WITH HYDROGEN PEROXIDE IN ACID MEDIUM AT ELEVATED TEMPERATURE, ADJUSTING THE PH OF THE SOLUTION TO APPROXIMATELY PH6, SEPARATING ANY PRECIPITATE AND THUS LEAVING IRIDIUM AND ANY PLATINUM IN SOLUTION, THEREAFTER CONVERTING THE PLATINUM AND IRIDIUM TO THEIR HIGHEST VALENCY STATES BY CONTACTING THEM WITH SODIUM BROMATE IN ACID MEDIUM AT ELEVATED TEMPERATURE AND THEN ADJUSTING THE PH OF THE SOLUTION TO BETWEEN ABOUT 6.5 AND 7.5 TO PRECIPITATE IRIDIUM AND LEAVE PLATINUM IN SOLUTION.
Claim 3
Dependent Claim
21 words
A method as claimed in claim 1 in which the iridium is mixed with minor amounts of other PGMs and gold.
Claim 4
Dependent Claim
29 words
A method as claimed in claim 2 in which the iridium is contained in residue from an aqua regia leach step performed on a mixture of PGMs and gold.
Claim 5
Dependent Claim
24 words
A method as claimed in claim 3 in which the residue is treated for removal of rhodium therefrom prior to treatment with hydrogen peroxide.
Claim 6
Dependent Claim
22 words
A method as claimed in claim 1 in which the pH of the solution is increased by the use of sodium hydroxide.
Claim 7
Dependent Claim
21 words
A method as claimed in claim 1 in which the treatment with hydrogen peroxide is carried out in hydrochloric acid medium.
References Cited (Backward Citations)
US2714555A
Cited
US3024084A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-04-07 | 1978-10-07 | 1979-04-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-04-07 | 1982-10-07 | 1983-04-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-04-07 | 1986-10-07 | 1987-04-08 | $7700.00 | Window Closed / Lapsed |