US3905556A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for recovery of metals from scrap
Assignee: Air Products and Chemicals Inc
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Filing: 1974-08-14
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Granted: 1975-09-16
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Expires: 1994-08-14
Abstract
Abstract Small pieces of scrap containing a mixture of metals obtained from previous fragmentation by crushing of the scrap in hammer mills or the like and from which at least a major portion of ferrous materials has been removed to provide such mixture rich in ductile metals, is subjected to further size reduction in a granulating chopper. The chopped product is classified by screening into several cuts of different size and each cut separately subjected to further dry separation into components differing in density to recover the individual metal components. In a preferred embodiment, prior to charging to the granulating chopper, the pieces of scrap from the last crushing operation preceding, are subject to air separation so as to remove selectively therefrom heavy particles, such as nuggets or the like, likely otherwise to damage the chopper blades. The light fraction from the air separation may optionally be subjected to magnetic separation to remove any remaining ferrous materials released by the crushing and/or air separation, from its encapsulation or occlusion in diamagnetic covering materials.
Inventors
- 👤 David J Drage
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:48
CPC Classifications
C; C22; C22B; C22B7/00; C22B7/005; B; B02; B02C; B02C23/00; B02C23/08; B02C23/14; B02C23/18; B02C23/20; B03; B03B; B03B9/00; B03B9/06; B03B9/061; Y; Y02; Y02P; Y02P10/00; Y02P10/20; Y02W; Y02W30/00; Y02W30/50; Y02W30/52; Y02W30/82; Y10; Y10S; Y10S241/00; Y10S241/38
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
135 words
A METHOD OF RECOVERING INDIVIDUAL COMPONENTS FROM A PREVIOUSLY COMMUNITED SCRAP FROM WHICH THE ORIGINAL CENTENT OF FERROUS METAL COMPONENTS HAS BEEN AT LEAST LARGELY REMOVED, THE STEPS OF: A. SUBJECTING SMALL PIECES OF SUCH SCRAP TO A CHOPPING OPERATION TO REDUCE THE PIECES TO SMALLER AND MORE UNIFORMLY SIZED PARTICLES: B. SCREENING SAID PARTICLES TO OBTAIN A NUMBER OF INDIVIDUAL STREAMS RANGING IN PARTICLE SIZE FROM FINE TO COARSE, EACH SAID STREAM BEING OF NARROW SIZE DISTRIBUTION RANGE: C. AND SUBJECTING EACH SUCH STREAM SEPARATELY TO DENSITY SEPARATION BY PNEUMATIC FLUIDIZATION TO SEPARATE EACH SAID STREAM INTO FRACTIONS OF DIFFERENT DENSITY: AT LEAST ONE OF SAID SEPARATED FRACTIONS BEING COMPOSED OF MATERIALS OF LOWER DENSITY THAN ALUMINUM AND AT LEAST ONE OTHER OF SAID SEPARATED FRACTIONS INCLUDING NON-FERROUS METALS HIGHER IN DENSITY THAN ALUMINUM.
Claim 2
Independent Claim
135 words
A METHOD OF RECOVERING INDIVIDUAL COMPONENTS FROM A PREVIOUSLY COMMUNITED SCRAP FROM WHICH THE ORIGINAL CENTENT OF FERROUS METAL COMPONENTS HAS BEEN AT LEAST LARGELY REMOVED, THE STEPS OF: A. SUBJECTING SMALL PIECES OF SUCH SCRAP TO A CHOPPING OPERATION TO REDUCE THE PIECES TO SMALLER AND MORE UNIFORMLY SIZED PARTICLES: B. SCREENING SAID PARTICLES TO OBTAIN A NUMBER OF INDIVIDUAL STREAMS RANGING IN PARTICLE SIZE FROM FINE TO COARSE, EACH SAID STREAM BEING OF NARROW SIZE DISTRIBUTION RANGE: C. AND SUBJECTING EACH SUCH STREAM SEPARATELY TO DENSITY SEPARATION BY PNEUMATIC FLUIDIZATION TO SEPARATE EACH SAID STREAM INTO FRACTIONS OF DIFFERENT DENSITY: AT LEAST ONE OF SAID SEPARATED FRACTIONS BEING COMPOSED OF MATERIALS OF LOWER DENSITY THAN ALUMINUM AND AT LEAST ONE OTHER OF SAID SEPARATED FRACTIONS INCLUDING NON-FERROUS METALS HIGHER IN DENSITY THAN ALUMINUM.
Claim 3
Dependent Claim
20 words
The method as defined in claim 1 wherein by said density separation a fraction consisting essentially of aluminum is isolated.
Claim 4
Dependent Claim
35 words
The method as defined in claim 1 wherein said separated fraction higher in density than aluminum is further subjected to density classification by stratification in air and a cut rich in copper is isolated therefrom.
Claim 5
Dependent Claim
39 words
The method as defined in claim 1 wherein prior to being subjected to said chopping operation, the small pieces of comminuted scrap are subjected to air separation for removal of large pieces likely to cause damage to chopping blades.
Claim 6
Dependent Claim
45 words
The method as defined in claim 4, wherein after removal of said large pieces by air separation, the remainder of said scrap is subjected to magnetic separation for removal therefrom of ferrous components and the remaining non-magnetic portion only subjected to the defined chopping operation.
Claim 7
Dependent Claim
39 words
The method as defined in claim 1 wherein said screening in step (b) thereof is effected on a multi-deck screen and oversize particles retained on the uppermost screen deck are recycled to the chopping operation for further sise reduction.
Claim 8
Dependent Claim
39 words
The method as defined in claim 1 wherein said screening in step (b) is effected on a multi-deck screen to provide at least three size classified streams, each of which is subjected to the separation defined in step (c).
Claim 9
Dependent Claim
41 words
The method as defined in claim 1 wherein said screening in step (b) is effected on a multi-deck screen to provide four size classified streams, at least three of which streams are subjected separately to the separation Defined in step (c).
Claim 10
Dependent Claim
77 words
The method as defined in claim 1 wherein said dry density separation in step (c) as applied to at least one of said streams is effected in several distinct stages, at least one of said stages being applied to separate the charge thereto into fractions differing in density by more than 100% and at least one other stage subsequent thereto being applied to separate components of the charge thereto which differ in density by less than 100%.
Claim 11
Dependent Claim
83 words
The method as defined in claim 9 wherein said dry density separation as applied to a middle stream fraction from said screening in step (b) is carried out under conditions to effect separation of non-metallic components from aluminum and other ductile metals in said fraction, aluminum is next separated from remaining heavier metals, and the residual heavier metals fraction subjected to a later separation stage to separate metals therein differing in density by less than 100%, copper being recovered in said later stage.
Claim 12
Dependent Claim
52 words
The method as defined in claim 1 wherein said dry density separation in step (c) thereof as applied to at least one of said streams is carried out in stages, at least one initial stage being carried out by destoning means and a subsequent stage being carried out on a gravity table.
Claim 13
Independent Claim
223 words
The method of recovering individual components from a previously crushed scrap from whch the original content of ferrous metal components has been at least largely removed, the steps of a. subjecting the crushed scrap to air separation to remove heavy oversize pieces; b. subjecting the residual lighter fraction from step (a) to magnetic separation to remove ferrous materials freed from prior occlusion in diamagnetic coverings; c. granulating the non-magnetic fraction from step (b) by chopping and shearing the same to small size particles; d. screening the small size particles from step (c) to obtain at least three size classified individual streams each of which streams is of substantially uniform particle size, while removing dust particles from said streams, thus, providing a stream of fine particles, at least one stream of middlings, and a stream of coarse particles; e. subjecting at least the middlings and coarse streams to separation by air flotation to separate each of said streams into fractions of different density range; f. subjecting at least one fraction other than the finest fraction, to at least one additional stage of separation to separate the same into metal components differing in density and recovering one of said metal components consisting essentially of aluminum; and g. subjecting the non-aluminum portion from step (f) to further separation and recovering therefrom a cut rich in copper.
Claim 14
Independent Claim
223 words
The method of recovering individual components from a previously crushed scrap from whch the original content of ferrous metal components has been at least largely removed, the steps of a. subjecting the crushed scrap to air separation to remove heavy oversize pieces; b. subjecting the residual lighter fraction from step (a) to magnetic separation to remove ferrous materials freed from prior occlusion in diamagnetic coverings; c. granulating the non-magnetic fraction from step (b) by chopping and shearing the same to small size particles; d. screening the small size particles from step (c) to obtain at least three size classified individual streams each of which streams is of substantially uniform particle size, while removing dust particles from said streams, thus, providing a stream of fine particles, at least one stream of middlings, and a stream of coarse particles; e. subjecting at least the middlings and coarse streams to separation by air flotation to separate each of said streams into fractions of different density range; f. subjecting at least one fraction other than the finest fraction, to at least one additional stage of separation to separate the same into metal components differing in density and recovering one of said metal components consisting essentially of aluminum; and g. subjecting the non-aluminum portion from step (f) to further separation and recovering therefrom a cut rich in copper.
Claim 15
Independent Claim
120 words
An apparatus for recovering individual components from a ferrous free mixture comprising comminuted scrap, said apparatus comprising in series: a. a chopping granulator; b. a multi-decked screen for separating the chopped scrap into a plurality of size classified streams, including fine, middlings and coarse particle streams; c. means for transporting each of said streams from its discharge point at said multi-decked screen to a separate density separator for such stream; d. a density separator for at least one of said streams being a destoner; e. means for conveying the heavy fraction recovered from a destoner to a gravity table; and f. a gravity table in series with said destoner to effect further separation of components charged thereto by means (e).
Claim 16
Independent Claim
120 words
An apparatus for recovering individual components from a ferrous free mixture comprising comminuted scrap, said apparatus comprising in series: a. a chopping granulator; b. a multi-decked screen for separating the chopped scrap into a plurality of size classified streams, including fine, middlings and coarse particle streams; c. means for transporting each of said streams from its discharge point at said multi-decked screen to a separate density separator for such stream; d. a density separator for at least one of said streams being a destoner; e. means for conveying the heavy fraction recovered from a destoner to a gravity table; and f. a gravity table in series with said destoner to effect further separation of components charged thereto by means (e).
Claim 17
Dependent Claim
32 words
Apparatus as defined in claim 13 wherein an air separator is provided in advance of said chopping granulator, effective to remove oversize particles from the stream to be charged to said granulator.
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) | 1978-09-15 | 1979-03-17 | 1979-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-15 | 1983-03-17 | 1983-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-15 | 1987-03-17 | 1987-09-16 | $7700.00 | Window Closed / Lapsed |