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Patent USRE30360E successfully refreshed from Google Patents.
USRE30360E
Expired / Lapsed
US
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Magnetic separation of particulate mixtures
Assignee: Maryland Patent Development Co Inc
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Filing: 1977-12-14
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Granted: 1980-08-05
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Expires: 1997-12-14
Abstract
Abstract Particulate mixtures of non-magnetic or paramagnetic materials are separated by selectively coating the surfaces of a component or components of the mixture with a magnetic fluid. Thereafter, the particulate mixture is subjected to a magnetic separation yielding a magnetic fluid-coated fraction and a non-magnetic fraction. The process is especially useful in mineral beneficiation wherein a mineral concentrate is recovered from its ore.
Inventors
- 👤 Roland H. Shubert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:39
CPC Classifications
B; B03; B03C; B03C1/00; B03C1/005; B03C1/01
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
133 words
A method of recovering a mineral from the gangue constituents of its ore which comprises: comminuting the ore to a size range whereat there is achieved substantial physical liberation of the mineral from the gangue constituents of the ore; rendering the surfaces of the mineral particles magnetic by selectively wetting the surfaces of said mineral particles with a magnetic fluid, said magnetic fluid comprising an ultra-stable colloidal suspension of magnetic particles in a liquid carrier, said liquid carrier being selected from the group consisting of hydrocarbons, fluorocarbons, silicone oils, water and esters, said magnetic fluid being capable of reacting with an external magnetic field and displaying the behavior of a homogeneous Newtonian liquid, and subjecting the comminuted ore to a magnetic separation whereby a magnetic concentrate comprising magnetic fluid-wetted mineral particles is recovered.
Claim 2
Independent Claim
133 words
A method of recovering a mineral from the gangue constituents of its ore which comprises: comminuting the ore to a size range whereat there is achieved substantial physical liberation of the mineral from the gangue constituents of the ore; rendering the surfaces of the mineral particles magnetic by selectively wetting the surfaces of said mineral particles with a magnetic fluid, said magnetic fluid comprising an ultra-stable colloidal suspension of magnetic particles in a liquid carrier, said liquid carrier being selected from the group consisting of hydrocarbons, fluorocarbons, silicone oils, water and esters, said magnetic fluid being capable of reacting with an external magnetic field and displaying the behavior of a homogeneous Newtonian liquid, and subjecting the comminuted ore to a magnetic separation whereby a magnetic concentrate comprising magnetic fluid-wetted mineral particles is recovered.
Claim 3
Dependent Claim
33 words
The method of claim 1 wherein the surfaces of mineral particles are not readily wet by water and wherein the surfaces of particulate gangue constituents of the ore are readily wet by water.
Claim 4
Dependent Claim
55 words
The method of claim 2 wherein the magnetic fluid is immiscible with water and wherein the mineral particles are selectively wetted with said fluid by contacting a water suspension of said comminuted ore with an amount of magnetic fluid sufficient to form a thin film on the surfaces of mineral particles contained in the ore.
Claim 5
Dependent Claim
30 words
The method of claim 3 wherein the mineral is selected from the group consisting of metal sulfides, metal oxides and carbonaceous ores and wherein the magnetic fluid is hydrocarbon base.
Claim 6
Dependent Claim
61 words
The method of claim 4 wherein the comminuted ore is subjected to a conditioning .[.steps.]. .Iadd.step .Iaddend.comprising a chemical treatment which renders the surfaces of mineral particles hydrophobic and .[.organophyllic and wherein said magnetic separation is accomplished by subjecting the magnetic fluid-treated ore to the influence of a magnetic field having a field strength in excess of 1000 gauss.]. .Iadd.organophilic. .Iaddend.
Claim 7
Dependent Claim
38 words
The method of claim 1 wherein the comminuted ore is subjected to a conditioning step to modify the surface properties of at least one constituent of the ore prior to wetting the mineral particles with said magnetic fluid.
Claim 8
Dependent Claim
25 words
The method of claim 6 wherein said conditioning step comprises a chemical treatment which renders the surfaces of mineral particles hydrophobic and .[.organophylic.]. .Iadd.organophilic. .Iaddend.
Claim 9
Dependent Claim
25 words
The method of claim 7 wherein said conditioning step is carried out in an aqueous medium and wherein said magnetic fluid is immiscible with water.
Claim 10
Dependent Claim
48 words
The method of claim 8 wherein the mineral particles are selectively wetted with said magnetic fluid by contacting a water suspension of comminuted and conditioned ore with an amount of magnetic fluid sufficient to form a thin film on the surfaces of mineral particles contained in the ore.
Claim 11
Dependent Claim
34 words
The method of claim 9 wherein the magnetic fluid is hydrocarbon base and wherein the magnetic fluid is in the form of a water emulsion when it is brought into contact with the ore.
Claim 12
Dependent Claim
26 words
The method of claim 10 wherein the magnetic separation is a wet separation whereby mineral particles wetted with magnetic fluid are recovered from the water suspension.
Claim 13
Dependent Claim
40 words
The method of claim 10 wherein the ore suspension is de-watered and dried to a free-flowing state after being contacted with the magnetic fluid and wherein the dried ore is subjected to a magnetic separation to recover a mineral concentrate.
Claim 14
Dependent Claim
19 words
The method of claim 10 wherein the ore is a copper ore and wherein said mineral comprises copper sulfide.
Claim 15
Dependent Claim
20 words
The method of claim 13 wherein said conditioning step comprises reacting the surfaces of copper sulfide particles with ferric ion.
Claim 16
Dependent Claim
19 words
The method of claim 10 wherein the ore is a zinc ore and wherein said mineral comprises zinc sulfide.
Claim 17
Dependent Claim
21 words
The method of claim 15 wherein said conditioning step comprises reacting the surfaces of zinc sulfide particles with a dilute acid.
Claim 18
Dependent Claim
18 words
The method of claim 10 wherein the ore is taconite and wherein said mineral comprises non-magnetic iron oxides.
Claim 19
Dependent Claim
31 words
The method of claim 17 wherein said conditioning step comprises reacting the surfaces of iron oxide particles with a material selected from the group consisting of fatty acids and sulfonic acids.
Claim 20
Dependent Claim
59 words
The method of claim 10 wherein said ore is contacted with magnetic fluid in an amount within the range of 0.01 to 10 pounds of magnetic fluid per ton of ore .[.and wherein said magnetic separation is accomplished by subjecting the magnetic fluid-treated ore to the influence of a magnetic field having a strength in excess of 1000 gauss.]..
Claim 21
Independent Claim
170 words
A method for separating .[.mixtures.]. .Iadd.a mixture .Iaddend.of particulate materials.Iadd., said mixture containing at least one component having particle surfaces readily wettable by a magnetic fluid and at least one other component having particle surfaces difficulty wettable or non-wettable by said fluid .Iaddend.which comprises .[.rendering the surfaces of at least one component of said mixture magnetic by selectively wetting the surfaces of said component with a magnetic fluid,.]. .Iadd.contacting the mixture with an amount of magnetic fluid sufficient to wet the surfaces of said readily wettable particulate component and to form a thin film thereon, .Iaddend.said magnetic fluid comprising an ultra-stable colloidal suspension of magnetic particles in a liquid carrier, said liquid carrier being selected from the group consisting of hydrocarbons, fluorocarbons, silicone oils, water and esters, said magnetic fluid being capable of reacting with an external magnetic field and displaying the behavior of a homogenous Newtonian liquid, and thereafter subjecting the mixture to a magnetic separation whereby said magnetic fluid-wetted component is separated from the remainder of the mixture.
Claim 22
Independent Claim
170 words
A method for separating .[.mixtures.]. .Iadd.a mixture .Iaddend.of particulate materials.Iadd., said mixture containing at least one component having particle surfaces readily wettable by a magnetic fluid and at least one other component having particle surfaces difficulty wettable or non-wettable by said fluid .Iaddend.which comprises .[.rendering the surfaces of at least one component of said mixture magnetic by selectively wetting the surfaces of said component with a magnetic fluid,.]. .Iadd.contacting the mixture with an amount of magnetic fluid sufficient to wet the surfaces of said readily wettable particulate component and to form a thin film thereon, .Iaddend.said magnetic fluid comprising an ultra-stable colloidal suspension of magnetic particles in a liquid carrier, said liquid carrier being selected from the group consisting of hydrocarbons, fluorocarbons, silicone oils, water and esters, said magnetic fluid being capable of reacting with an external magnetic field and displaying the behavior of a homogenous Newtonian liquid, and thereafter subjecting the mixture to a magnetic separation whereby said magnetic fluid-wetted component is separated from the remainder of the mixture.
Claim 23
Dependent Claim
38 words
The method of claim 20 wherein the mixture of particulate materials is in liquid suspension and wherein a component of the mixture is selectively wetted by contacting the liquid suspension with a magnetic fluid immiscible in said liquid.
Claim 24
Dependent Claim
40 words
The method of claim 21 wherein the mixture of particulate materials is subjected to a conditioning step to modify the surface properties of at least one consitutuent of the mixture prior to contacting the liquid suspension with the magnetic fluid.
Claim 25
Dependent Claim
30 words
The method of claim 22 wherein the magnetic fluid is emulsified in a portion of said liquid prior to contacting said liquid suspension of particulate materials with said magnetic fluid.
Claim 26
Dependent Claim
44 words
The method of claim 23 wherein the liquid is water, wherein the magnetic fluid is hydrocarbon base and wherein the conditioning step comprises reacting the particle surfaces of at least one constituent of the mixture with a substance which renders said surfaces .[.organophylic.]. .Iadd.organophilic..Iaddend.
Claim 27
Dependent Claim
27 words
The method of claim 24 wherein the magnetic separation is performed in the liquid state whereby particles wetted with magnetic fluid are recovered from the water suspension.
Claim 28
Dependent Claim
135 words
The method of claim 24 wherein the particulate suspension is de-watered and dried to a free-flowing state after being contacted with the magnetic fluid and wherein the dried particulate mixture is subjected to a magnetic separation to recover a magnetically responsive fraction comprising particles wetted with magnetic fluid. .Iadd. 27. The method of claim 5 wherein said magnetic separation is accomplished by subjecting the magnetic fluid-treated ore to the influence of a magnetic field having a field strength of about 1000 gauss. .Iaddend..Iadd. 28. The method of claim 19 wherein said magnetic separation is accomplished by subjecting the magnetic fluid-treated ore to the influence of a magnetic field having a field strength of about 1000 gauss. .Iaddend..Iadd. 29. The method of claim 20 wherein said particulate materials do not respond to a magnetic field. .Iaddend.
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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) | 1983-08-05 | 1984-02-04 | 1984-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-05 | 1988-02-04 | 1988-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-05 | 1992-02-04 | 1992-08-05 | $7700.00 | Window Closed / Lapsed |