US3922330A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Separation and purification of platinum group metals and gold
Assignee: Swarsab Mining Exploration and Development Co Ltd
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Filing: 1973-08-02
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Granted: 1975-11-25
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Expires: 1993-08-02
Abstract
Abstract A method of separating palladium from a mixture of PGMs which contains palladium and at least one other PGM, the method comprising the formation in solution of the amine complexes of the metals present with the metals being in a reduced state and precipitating out the palladium by means of dimethylglyoxime provided that where platinum is present the precipitation is effected at a pH of about 4.0 in the presence of an ammonia absorber.
Inventors
- 👤 Willem Hubert Pittie
- 👤 Gerhardus Overbeek
- 👤 Kingsley Ferguson Doig
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 18:45
CPC Classifications
C; C01; C01G; C01G55/00; C01G55/001; C22; C22B; C22B11/00; C22B11/04; C22B3/00; C22B3/20; C22B3/26; C22B3/30; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
81 words
IN A METHOD FOR SEPARATING PALLADIUM FROM A MIXTURE OF PGMS (PLATINUM GROUP METALS), WHICH CONTAINS PALLADIUM AND AT LEAST ONE OTHER PGM, BY PRECIPITATING THE PALLADIUM WITH DIMETHYLGLYOXIME FROM A SOLUTION OF THE MIXTURE, THE IMPROVEMENT WHEREIN (A) THE SOLUTION IS THAT OF AMMINE COMPLEXES (FORMED IN SOLUTION) OF THE METALS AND (B) SAID METALS ARE IN A REDUCED STATE; WITH THE PROVISO THAT SAID SOLUTION IS BUFFERED AT A PH OF ABOUT 4.0 WHEN PLATINUM VALUES ARE CONTANED THEREIN
Claim 2
Dependent Claim
81 words
IN A METHOD FOR SEPARATING PALLADIUM FROM A MIXTURE OF PGMS (PLATINUM GROUP METALS), WHICH CONTAINS PALLADIUM AND AT LEAST ONE OTHER PGM, BY PRECIPITATING THE PALLADIUM WITH DIMETHYLGLYOXIME FROM A SOLUTION OF THE MIXTURE, THE IMPROVEMENT WHEREIN (A) THE SOLUTION IS THAT OF AMMINE COMPLEXES (FORMED IN SOLUTION) OF THE METALS AND (B) SAID METALS ARE IN A REDUCED STATE; WITH THE PROVISO THAT SAID SOLUTION IS BUFFERED AT A PH OF ABOUT 4.0 WHEN PLATINUM VALUES ARE CONTANED THEREIN
Claim 3
Dependent Claim
47 words
A method which comprises (a) reducing PGMs, including palladium, and gold in an initial mixture thereof, thus precipitating gold from the mixture, (b) forming amine complexes of the PGMs (c) separating precipitated gold values from PGM values and (d) thereafter precipitating the palladium according to claim 1.
Claim 4
Dependent Claim
35 words
A method as claimed in claim 2 which comprises reducing the PGMs and gold by boiling the initial mixture in a solution of hydrogen peroxide in nitric acid medium prior to forming the amine complexes.
Claim 5
Dependent Claim
26 words
A method as claimed in claim 2 in which the PGMs and gold in the initial mixture are in the form of their nitroso chloride complexes.
Claim 6
Dependent Claim
36 words
A method as claimed in claim 4 which comprises evaporating to dryness a mixture of chloride complexes of the PGMs and gold with nitric acid to obtain the nitroso chloride complexes of the PGMs and gold.
Claim 7
Dependent Claim
29 words
A method as claimed in claim 1 which comprises adding excess ammonium hydroxide to a solution of the metals to form the amine complexes of the PGMs and gold.
Claim 8
Dependent Claim
21 words
A method as claimed in claim 6 which comprises boiling off excess ammonia subsequent to the formation of the amine complexes.
Claim 9
Dependent Claim
25 words
A method as claimed in claim 1 wherein a reagent which combines with free ammonia is present in the solution while precipitating palladium with dimethylglyoxime.
Claim 10
Dependent Claim
41 words
A method as claimed in claim 8 which comprises precipitating palladium with a slurry of dimethylglyoxime and acetic acid, the latter constituting the reagent which combines with free ammonia and also one which buffers the solution to a pH of 4.
Claim 11
Dependent Claim
24 words
A method as claimed in claim 1 which furhter comprises dissolving thus-precipitated palladium and precipitating thus-dissolved palladium according to the method of claim 1.
Claim 12
Dependent Claim
18 words
A method as claimed in claim 1 in which the mixture of PGMs comprises predominantly palladium and platinum.
Claim 13
Dependent Claim
15 words
A method according to claim 1 wherein platinum is present in the mixture of PGMs.
Claim 14
Dependent Claim
66 words
A method according to claim 1 wherein the mixture is essentially free from gold and the method comprises removing any excess ammonia from the solution of amine complexes, cooling the resulting solution, filtering out any thus-obtained insolubles to produce a filtrate, adding dimethylglyoxime to the filtrate, maintaining the resulting filtrate at an elevated temperature under agitation, cooling the thus-treated filtrate and separating precipitated palladium values therefrom.
Claim 15
Dependent Claim
64 words
A method according to claim 1 which comprises (a) preparing a solution of a mixture of PGM values, including palladium values, in which the values are in amine complex form and the metals are in a reduced state, (b) buffering the solution at a pH of about 4.0 when it contains platinum values, and (c) precipitating the palladium values from the solution with dimethylglyoxime.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-11-24 | 1979-05-26 | 1979-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-11-24 | 1983-05-26 | 1983-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-11-24 | 1987-05-26 | 1987-11-25 | $7700.00 | Window Closed / Lapsed |