US4173467A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for recovering valuable metals from superalloy scrap
Assignee: Haynes International Inc
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Filing: 1978-05-26
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Granted: 1979-11-06
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Expires: 1998-05-26
Abstract
Abstract Disclosed is a process for recovering valuable metals from scrap including the steps of melting the initial scrap feed, carburizing the melt, solidifying the carburized melt, and recovering the valuable metals from the resultant material by an appropriate acid leaching step.
Inventors
- 👤 Barry H. Rosof
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 07:25
CPC Classifications
C; C22; C22B; C22B7/00; C22B23/00; C22B23/04; C22B23/0407; C22B23/0446; Y; Y02; Y02P; Y02P10/00; Y02P10/20
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
166 words
A method for treating certain metal scraps which comprises: providing an initial scrap metal feed containing the combination of (a) at least one metal selected from the group consisting of nickel, cobalt or mixtures thereof, and (b) at least one refractory metal selected from the group consisting of chromium, molybdenum, tungsten and mixtures thereof, said feed comprising at least one acid resistant alloy selected from the group consisting of cobalt and nickel base alloys; melt carburizing said feed sufficiently to at least predominantly insolubilize the metals of group (b) with respect to the aqueous acid leach step below and to render the group (a) metals of said acid resistant alloy contained in said feed soluble in said acid leach step; and non-electrolytically leaching the melt carburized feed with aqueous acid leach liquor having dissolving power for the metals of group (a), whereby said metals of group (a) pass predominantly into solution in said liquor while the metals of group (b) remain predominantly as undissolved leach residue.
Claim 2
Independent Claim
166 words
A method for treating certain metal scraps which comprises: providing an initial scrap metal feed containing the combination of (a) at least one metal selected from the group consisting of nickel, cobalt or mixtures thereof, and (b) at least one refractory metal selected from the group consisting of chromium, molybdenum, tungsten and mixtures thereof, said feed comprising at least one acid resistant alloy selected from the group consisting of cobalt and nickel base alloys; melt carburizing said feed sufficiently to at least predominantly insolubilize the metals of group (b) with respect to the aqueous acid leach step below and to render the group (a) metals of said acid resistant alloy contained in said feed soluble in said acid leach step; and non-electrolytically leaching the melt carburized feed with aqueous acid leach liquor having dissolving power for the metals of group (a), whereby said metals of group (a) pass predominantly into solution in said liquor while the metals of group (b) remain predominantly as undissolved leach residue.
Claim 3
Dependent Claim
42 words
The method of claim 1 wherein said initial scrap metal feed, in the molten state, comprises a minimum of about 25 weight percent of the metal of group (a) and at least 8 weight percent of the refractory metal of group (b).
Claim 4
Dependent Claim
14 words
The method of claim 1 wherein said scrap metal feed comprises nickel base alloy.
Claim 5
Dependent Claim
13 words
The method of claim 3 wherein said nickel base alloy is a superalloy.
Claim 6
Dependent Claim
14 words
The method of claim 1 wherein said scrap metal feed comprises cobalt base alloy.
Claim 7
Dependent Claim
13 words
The method of claim 5 wherein said cobalt base alloy is a superalloy.
Claim 8
Dependent Claim
35 words
The method of claim 1 wherein said melt carburizing is undertaken to the extent that the melt carburized scrap metal feed product has a carbon content of between about 0.5 and about 6.0 weight percent.
Claim 9
Dependent Claim
22 words
The method of claim 1 wherein carbon for the carburizing step is added to said scrap metal feed prior to melting thereof.
Claim 10
Dependent Claim
49 words
The method of claim 8 wherein carbon for the carburizing step is provided by mixing a metal scrap containing insufficient carbon for carburizing thereof with another metal scrap containing excess carbon for carburizing thereof, thereby to provide a composite initial scrap metal feed containing sufficient carbon for carburizing thereof.
Claim 11
Dependent Claim
26 words
The method of claim 1 wherein, prior to the carburizing step, oxidizable metal values are removed from the initial scrap metal feed by oxidation treatment thereof.
Claim 12
Dependent Claim
20 words
The method of claim 10 wherein said oxidation treatment comprises melting the scrap metal feed and introducing molecular oxygen thereinto.
Claim 13
Dependent Claim
24 words
The method of claim 10 wherein said oxidation treatment comprises melting the scrap metal feed and slagging the molten feed with an oxidizing slag.
Claim 14
Dependent Claim
14 words
The method of claim 1 wherein said aqueous acid leach liquor is hydrochloric acid.
Claim 15
Dependent Claim
14 words
The method of claim 1 wherein said aqueous acid leach liquor is sulfuric acid.
Claim 16
Dependent Claim
22 words
The method of claim 1 wherein the leach liquor product of the leaching step is treated to recover dissolved metal values therefrom.
References Cited (Backward Citations)
US3438730A
Cited
US3649487A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-11-05 | 1983-05-07 | 1983-11-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-11-05 | 1987-05-07 | 1987-11-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-11-05 | 1991-05-07 | 1991-11-06 | $7700.00 | Window Closed / Lapsed |