US4074865A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of recovering platinum group metal values from a used washcoated catalyst
Assignee: Johnson Matthey PLC
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Filing: 1974-09-06
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Granted: 1978-02-21
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Expires: 1994-09-06
Abstract
Abstract This invention relates to the recovery of metallic values from materials such as catalysts containing or supporting the values. The method comprises removing a layer or layers and a catalyst support including a quantity of the metallic value and thereafter chemically or otherwise separating the value therefrom.
Inventors
- 👤 Alan Gibbon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:31
CPC Classifications
C; C22; C22B; C22B11/00; C22B11/02; C22B11/021; C22B11/026; C22B7/00; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
84 words
A method of recovering platinum group metal values from a used washcoated catalyst comprising a catalyst support having a catalytic washcoat thereon including platinum group metal, said method comprising grinding the catalyst to obtain fines which are less than 10 μm and tails which are greater than 10 μm, at least 40-55% of the ground catalyst being -400 mesh and the fines containing most of the platinum group metal values, and separating the fines from the tails using a cut point of 10 μm.
Claim 2
Independent Claim
84 words
A method of recovering platinum group metal values from a used washcoated catalyst comprising a catalyst support having a catalytic washcoat thereon including platinum group metal, said method comprising grinding the catalyst to obtain fines which are less than 10 μm and tails which are greater than 10 μm, at least 40-55% of the ground catalyst being -400 mesh and the fines containing most of the platinum group metal values, and separating the fines from the tails using a cut point of 10 μm.
Claim 3
Dependent Claim
21 words
A method according to claim 1 wherein the said fines and tail are separated from each other by wet gravity separation.
Claim 4
Dependent Claim
21 words
A method according to claim 1 wherein the said fines and tails are separated from each other by dry air classification.
Claim 5
Dependent Claim
22 words
The method of claim 1 wherein the size of essentially all of the particles in the tails is greater than 30 μm.
Claim 6
Dependent Claim
20 words
The method of claim 4 wherein the support is cordierite and the washcoat is alumina containing a platinum group metal.
Claim 7
Dependent Claim
20 words
The method of claim 1 wherein the tails are ground again to give more fines containing platinum group metal values.
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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) | 1981-02-20 | 1981-08-22 | 1982-02-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-20 | 1985-08-22 | 1986-02-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-20 | 1989-08-22 | 1990-02-21 | $7700.00 | Window Closed / Lapsed |