US4544463A
Expired / Lapsed
US
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Method for producing equiaxed iron or iron alloy particles
Assignee: Olin Corp
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Filing: 1984-01-12
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Granted: 1985-10-01
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Expires: 2004-01-12
Abstract
Abstract A method is disclosed for producing iron or iron alloy particles. A metal or metal alloy strip having fine particles of iron or alloy distributed throughout is provided. The metal strip is selectively dissolved without substantial dissolving of the iron or iron alloy particles in order to recover the particles.
Inventors
- 👤 Michael J. Pryor
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:52
CPC Classifications
C; C25; C25F; C25F5/00; B; B22; B22F; B22F1/00; B22F1/06; B22F1/062; B22F9/00; B22F9/16; C25F3/00; C25F3/02; G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/706; G11B5/70605; H; H01; H01F; H01F1/00; H01F1/01; H01F1/03; H01F1/032; H01F1/04; H01F1/06
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
141 words
A method of producing substantially equiaxed iron or iron alloy particles, comprising the steps of: providing a melt including a base metal consisting essentially of copper, transition metal additions of less than about 10% by weight to enhance magnetic performance, and above about 20% by weight of iron; rapidly solidifying said melt into a copper or copper alloy strip having distributed therein fine, substantially equiaxed particles of iron or iron alloy; and selectively dissolving said copper or copper alloy without substantial dissolving of said iron or iron alloy particles to recover said substantially equiaxed particles, said step of dissolving including immersing said copper or copper alloy strip in an electrolytic solution selected from the group consisting of alkaline metal sulfates so that the iron or iron alloy particles are passivated while permitting electrolytic dissolution of the copper or copper alloy strip.
Claim 2
Independent Claim
141 words
A method of producing substantially equiaxed iron or iron alloy particles, comprising the steps of: providing a melt including a base metal consisting essentially of copper, transition metal additions of less than about 10% by weight to enhance magnetic performance, and above about 20% by weight of iron; rapidly solidifying said melt into a copper or copper alloy strip having distributed therein fine, substantially equiaxed particles of iron or iron alloy; and selectively dissolving said copper or copper alloy without substantial dissolving of said iron or iron alloy particles to recover said substantially equiaxed particles, said step of dissolving including immersing said copper or copper alloy strip in an electrolytic solution selected from the group consisting of alkaline metal sulfates so that the iron or iron alloy particles are passivated while permitting electrolytic dissolution of the copper or copper alloy strip.
Claim 3
Dependent Claim
12 words
The method of claim 1 wherein said electrolytic solution is sodium sulfate.
Claim 4
Dependent Claim
19 words
The method of claim 2 wherein the concentration of sodium sulfate is between about 0.05 to about 4.0 normal.
Claim 5
Dependent Claim
78 words
The method of claim 3 further including the steps of: passing any electric current through said electrolytic solution between a counter electrode and a working electrode, said working electrode further being in electrical contact with said copper or copper alloy; maintaining the potential of said metal or metal alloy at a substantially constant value between about 0.0 and 1.5 volts SHE ; and depositing said copper on said counter electrode to free the iron or iron alloy particles.
Claim 6
Dependent Claim
19 words
The method of claim 1 wherein said step of dissolving further includes collecting said iron or iron alloy particles.
Claim 7
Dependent Claim
19 words
The method of claim 5 further including the step of separating said iron or iron alloy particles by size.
Claim 8
Dependent Claim
16 words
The method of claim 5 further including the step of preventing corrosion of the collected particles.
Claim 9
Dependent Claim
42 words
The method of claim 7 wherein the step of preventing corrosion includes the step of washing the collected particles in water containing an oxidizing corrosion inhibitor selected from the group consisting essentially of sodium chromate, sodium nitrite, sodium tungstate and sodium molybdate.
Claim 10
Dependent Claim
18 words
The method of claim 8 further including the step of rapidly drying said particles after the washing step.
Claim 11
Dependent Claim
20 words
The method of claim 7 wherein the step of preventing corrosion includes deaerating said electrolytic medium with an inert gas.
Claim 12
Dependent Claim
11 words
The method of claim 10 wherein said inert gas is nitrogen.
Claim 13
Dependent Claim
32 words
The method of claim 7 wherein the step of preventing corrosion includes applying a metal coating to the particles having a thickness in the range of about 100 to about 500 microinches.
Claim 14
Dependent Claim
11 words
The method of claim 12 wherein said coating is essentially copper.
Claim 15
Dependent Claim
11 words
The method of claim 12 wherein said coating is essentially cobalt.
References Cited (Backward Citations)
US1787139A
Cited
US1735405A
Cited
US2301492A
Cited
US2436244A
Cited
US2622063A
Cited
US2463190A
Cited
US2974104A
Cited
US2999777A
Cited
US3556962A
Cited
US4120758A
Cited
US4140597A
Cited
US4274865A
Cited
US4161434A
Cited
US4290799A
Cited
US4264419A
Cited
US4360377A
Cited
US4487815A
Cited
US4461685A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-09-30 | 1989-04-01 | 1989-10-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-09-30 | 1993-04-01 | 1993-10-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-09-30 | 1997-04-01 | 1997-10-01 | $7700.00 | Window Closed / Lapsed |