Patent US3657997A successfully refreshed from Google Patents.
US3657997A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Recovering metal values
Assignee: Pittsburgh Pacific Processing Co
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Filing: 1969-02-18
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Granted: 1972-04-25
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Expires: 1989-02-18
Abstract
Abstract Materials containing metal values and contaminants are subjected to a grinding operation to selectively pulverize the contaminants while minimizing grinding action on the metal values. Selective grinding is effected by controlling power input to the grinding operation. The material is ground as a pulp, and pulp density is controlled for continuous operation of the grinding mill. Pulverized contaminants are hydraulically separated from metal values in turbulators operated in parallel-flow arrangement to permit continuous discharge from the grinding mill. Underflow from turbulators passes into a rake classifier. Underflow from the classifier is dried in a hot gas blast, where separation of piggyback slimes is effected. Dried concentrate is briquetted. In a preferred embodiment, residues from grinding stainless steels are subjected to selective grinding to break away grinding wheel components bonded to the metal particles and to pulverize grinding wheel components and other contaminants while minimizing work hardening of the metal particles to avoid impairment of the ability of the metal particles to be briquetted.
Inventors
- 👤 Vincent A Vellella
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 04:54
CPC Classifications
B; B02; B02C; B02C17/00; B02C17/04; B02C19/00; B02C19/0056; B03; B03B; B03B9/00
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
25 words
The process of claim 1, including briquetting recovered metal particles, the metal particles being cohered in the briquetting by flow of metal of the particles.
Claim 2
Dependent Claim
70 words
Process for recovering metal values, comprising providing material containing metal values and contaminants, forming a pulp of the material and subjecting the material to a grinding operation in the pulp by contact with grinding rods in a rod mill, continuously feeding material to the grinding operation, continuously discharging ground material from the grinding operation, and maintaining pulp density within a range of about 45 to 55 percent solids by weight.
Claim 3
Dependent Claim
22 words
The process of claim 3, the pulp density being maintained within a range of about 45 to 55 percent solids by weight.
Claim 4
Dependent Claim
63 words
The process of claim 1, including forming a pulp of the material, the material being subjected to the grinding operation in the pulp by contact with grinding rods in a rod mill, continuously feeding material to the grinding operation, continuously discharging ground material from the grinding operation, and maintaining pulp density at a magnitude not greater than about 60 percent solids by weight.
Claim 5
Dependent Claim
35 words
The process of claim 1, the metal particles being steel particles, the power input to the grinding operation being maintained within a range of about 20 to 40 kilowatt hours per ton of material ground.
Claim 6
Dependent Claim
83 words
Process for recovering metal values, comprising providing material containing metal values and contaminants, subjecting the material to a grinding operation, maintaining power input to the grinding operation at a magnitude to pulverize the contaminants while minimizing grinding action on the metal values, separating metal values from pulverized contaminants, and recovering separated metal values, the metal values being separated from the pulverized contaminants by passing ground material from the grinding operation into an upwardly flowing liquid stream to separate light particles from heavy particles.
Claim 7
Dependent Claim
47 words
The process of claim 5, including continuously feeding material to the grinding operation, continuously discharging ground material from the grinding operation, and alternately terminating passage of ground material into the upwardly flowing liquid stream and initiating passage of ground material into a second upwardly flowing liquid stream.
Claim 8
Dependent Claim
58 words
Process for recovering metal particles from grinding residues, comprising providing grinding residues containing metal particles and nonmetallic contaminants mixed with the metal particles, subjecting the residues to a grinding operation, controlling the grinding operation to pulverize the nonmetallic contaminants while minimizing work hardening of the metal particles, separating metal particles from pulverized contaminants, and recovering separated metal particles.
Claim 9
Dependent Claim
65 words
The process of claim 8, including forming a pulp of the grinding residues, the grinding residues being subjected to the grinding operation in the pulp by contact with grinding rods in a rod mill, continuously feeding material to the grinding operation, continuously discharging ground material from the grinding operation, and maintaining pulp density at a magnitude not greater than about 60 percent solids by weight.
Claim 10
Dependent Claim
22 words
The process of claim 10, the pulp density being maintained within a range of about 45 to 55 percent solids by weight.
Claim 11
Dependent Claim
17 words
The process of claim 11, the pulp density being maintained at about 50 percent solids by weight.
Claim 12
Dependent Claim
36 words
The process of claim 8, the metal particles being steel particles, and the grinding operation being controlled by maintaining power input within a range of about 20 to 40 kilowatt hours per ton of material ground.
Claim 13
Dependent Claim
20 words
The process of claim 13, the power input being maintained at about 30 kilowatt hours per ton of material ground.
Claim 14
Dependent Claim
34 words
The process of claim 8, the metal particles being separated from the pulverized contaminants by passing ground grinding residues into an upwardly flowing liquid stream to separate light particulate material from heavy particulate material.
Claim 15
Dependent Claim
33 words
The process of claim 15, the metal particles being steel particles, and the upwardly flowing liquid stream having a rising current velocity within a range of about 15 to 35 feet per minute.
Claim 16
Dependent Claim
59 words
The Process of claim 15, including passing the heavy particles downwardly in the upwardly flowing liquid stream, and discharging heavy particles into a liquid body for settling to the bottom portion of the liquid body, removing settled heavy particles from the bottom portion of the liquid body, and overflowing slime-containing liquid from the top portion of the liquid body.
Claim 17
Dependent Claim
81 words
The process of claim 15, including continuously feeding material to the grinding operation, continuously discharging ground material from the grinding operation, passing the heavy particles downwardly in the upwardly flowing liquid stream into a storage area, holding the downwardly passed heavy particles in the storage area, and terminating passage of ground material into the upwardly flowing liquid stream, initiating passage of ground material into a second upwardly flowing liquid stream, and initiating discharge of stored heavy particles from the storage area.
Claim 18
Dependent Claim
15 words
The process of claim 8, the nonmetallic contaminants including grinding wheel abrasive and binder components.
Claim 19
Dependent Claim
18 words
The process of claim 19, a portion of the grinding wheel components being adhered to the metal particles.
Claim 20
Dependent Claim
11 words
The process of claim 19, the grinding wheel binder containing sulfur.
Claim 21
Dependent Claim
22 words
The process of claim 19, the grinding wheel abrasive including a material selected from the group consisting of alumina and silicon carbide.
Claim 22
Dependent Claim
12 words
The process of claim 8, the metal particles being alloy steel particles.
Claim 23
Dependent Claim
12 words
The process of claim 23, the metal particles being stainless steel particles.
Claim 24
Dependent Claim
49 words
The process of claim 8, the pulverized contaminants being separated from the metal particles by hydraulic classification, the separated metal particles being covered with slime, and the separated metal particles being subjected to a hot gas blast to dry the slime and separate dried slime from the metal particles.
Claim 25
Dependent Claim
25 words
The process of claim 8, including briquetting recovered metal particles, the metal particles being cohered in the briquetting by flow of metal of the particles.
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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) | 1975-04-25 | 1975-10-25 | 1976-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-04-25 | 1979-10-25 | 1980-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-04-25 | 1983-10-25 | 1984-04-25 | $7700.00 | Window Closed / Lapsed |