US3676337A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for magnetic separation
Assignee: Massachusetts Institute of Technology
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Filing: 1970-07-09
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Granted: 1972-07-11
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Expires: 1990-07-09
Abstract
Abstract Process for separating colloidal and sub-colloidal ceramic magnetic components and paramagnetic components from a slurry (or other carrier) by passing the slurry through a column containing a magnetic material, as a magnetic grade stainless steel wool. The steel wool is subjected to a d-c magnetic field sufficient in magnitude to effect magnetization to saturation and above and provides a large number of regions of very high magnetic field and magnetic field gradient along the paths of travel of the slurry to attract and retain the magnetic components. It has been found that in order to provide removal of such components on an industrial scale at the high throughput rates required, a background field in the wool of at least about 12,000 gauss is required to overcome the forces of turbulence or the like in the slurry.
Inventors
- 👤 Henry H Kolm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 12:20
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/72; B; B03; B03C; B03C1/00; B03C1/02; B03C1/025; B03C1/027; B03C1/031; B03C1/032; B03C1/033; B03C1/0332; B03C1/0335; B03C1/0337; B03C1/034; G01N27/74; B03C2201/00; B03C2201/18
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
38 words
A process as claimed in claim 1 that comprises, removing the background field and applying a low intensity a-c magnetic field to the material, gradually reducing the a-c field to zero, and flushing said components from the wool.
Claim 2
Dependent Claim
69 words
A process as claimed in claiM 1 and including the further steps of compressing the wool to a density sufficiently high to provide a large collection area per unit volume for the retention of said components and adjusting the background field in said volume to separate said components according to size and/or magnetic susceptibility by the imposition of the background field and the magnetic field gradient upon each component.
Claim 3
Dependent Claim
44 words
A process as claimed in claim 1 and including the further step of adjusting the background field in said volume to separate said components according to size and/or magnetic susceptibility by the imposition of the background field and magnetic field gradient upon each component.
Claim 4
Dependent Claim
217 words
A process for separating colloidal paramagnetic components from a fluid carrier, that comprises, passing the carrier and components through a substantial volume of ferromagnetic corrosion resistant wool material that contains a plurality of paths therethrough along which the carrier and components can travel, the wool being placed within the central opening of a coil which when energized is adapted to provide a substantially uniform background magnetic field in the volume occupied by the wool material substantially parallel to the fluid flow and of an average strength at least adequate to magnetize the wool to saturation and above, energizing the coil to provide said background magnetic field, said background field being substantially stronger than required to magnetize the magnetic wool material throughout said volume to saturation and strong enough to magnetize paramagnetic components in the carrier, the magnetic field thereby induced in the saturated strands of said wool leaving the wool at a large number of regions and passing into the space adjacent the strands along said paths to provide a large number of regions of very high magnetic background field and magnetic field gradient within said volume, the background field in said space and the field gradient in said space being sufficiently high in relation to the size of the components to attract and retain said components.
Claim 5
Dependent Claim
165 words
A process for separating colloidal paramagnetic components from a fluid carrier, that comprises, passing the carrier and components through a substantial volume of ferromagnetic corrosion resistant wool material that contains a plurality of paths therethrough along which the carrier and components can travel, establishing a substantially uniform background field in said volume, substantially parallel to the fluid flow, substantially stronger than required to magnetize the magnetic wool material throughout said volume to saturation and strong enough to magnetize paramagnetic components in the carrier, the magnetic flux thereby induced in the saturated strands of said wool leaving the wool at a large number of regions and passing into the space adjacent the strands along said paths to provide a large number of regions of very high magnetic background field and magnetic field gradient within said volume, the background field in said space and the field gradient in said space being sufficiently high in relation to the size of the components to attract and retain said components.
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) | 1975-07-11 | 1976-01-10 | 1976-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-07-11 | 1980-01-10 | 1980-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-07-11 | 1984-01-10 | 1984-07-11 | $7700.00 | Window Closed / Lapsed |