US4247391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Froth flotation cell and method of operation
Assignee: Edward L Bateman Ltd
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Filing: 1979-03-09
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Granted: 1981-01-27
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Expires: 1999-03-09
Abstract
Abstract Coarse particles of up to 3 mm are floated in a cylindrical froth flotation cell in which the agitation impeller has a cover preventing fluid from being drawn in above. Air is supplied from a ring around the periphery of the cell and situated above the cover. Baffles project radially inwardly up to a short distance from the top. Froth is allowed to overflow around the periphery of the cell. The opposed inlet and outlet are disposed respectively below the level and at the level of the impeller. The arrangement is such that the liquid below the layer of froth is substantially quiescent.
Inventors
- 👤 Philip J. D. Lloyd
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:04
CPC Classifications
B; B03; B03D; B03D1/00; B03D1/14; B03D1/1412; B03D1/1493; B03D1/16; B03D1/22; B03D1/24; B03D1/245
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
124 words
A method of recovering coarse particles from pulp by froth flotation, comprising establishing a quantity of said pulp in a froth flotation tank, agitating said pulp by means of an agitator disposed centrally of and at a low level in said tank, baffling the pulp flow at a central location of said tank above said agitator, injecting air bubbles into the tank about the periphery of the tank inwardly toward the body of pulp in the tank at a level above the level of said baffling, collecting froth from an upper portion of said tank, and introducing pulp into the tank and withdrawing from the tank pulp from which coarse particles have been removed, at levels no higher than the level of said agitator.
Claim 2
Independent Claim
124 words
A method of recovering coarse particles from pulp by froth flotation, comprising establishing a quantity of said pulp in a froth flotation tank, agitating said pulp by means of an agitator disposed centrally of and at a low level in said tank, baffling the pulp flow at a central location of said tank above said agitator, injecting air bubbles into the tank about the periphery of the tank inwardly toward the body of pulp in the tank at a level above the level of said baffling, collecting froth from an upper portion of said tank, and introducing pulp into the tank and withdrawing from the tank pulp from which coarse particles have been removed, at levels no higher than the level of said agitator.
Claim 3
Dependent Claim
90 words
A froth flotation cell comprising a tank, a driven impeller disposed centrally of and at a low level in the tank, a cover above the impeller to minimize entry of fluid from above, a series of injection points for compressed air about the periphery of the tank directed toward the interior of the tank and higher than the level of the cover, and an inlet to the tank and an outlet from the tank disposed at levels no higher than the impeller and disposed on opposite sides of the tank.
Claim 4
Dependent Claim
90 words
A froth flotation cell comprising a tank, a driven impeller disposed centrally of and at a low level in the tank, a cover above the impeller to minimize entry of fluid from above, a series of injection points for compressed air about the periphery of the tank directed toward the interior of the tank and higher than the level of the cover, and an inlet to the tank and an outlet from the tank disposed at levels no higher than the impeller and disposed on opposite sides of the tank.
Claim 5
Dependent Claim
86 words
A froth flotation cell comprising a tank, a driven impeller disposed centrally of and at a low level in the tank, a cover above the impeller to minimize entry of fluid from above, a series of injection points for compressed air about the periphery of the tank directed toward the interior of the tank and higher than the level of the cover, the tank being cylindrical about a vertical axis, and means to withdraw froth from around the entire perimeter of the top of the tank.
Claim 6
Dependent Claim
86 words
A froth flotation cell comprising a tank, a driven impeller disposed centrally of and at a low level in the tank, a cover above the impeller to minimize entry of fluid from above, a series of injection points for compressed air about the periphery of the tank directed toward the interior of the tank and higher than the level of the cover, the tank being cylindrical about a vertical axis, and means to withdraw froth from around the entire perimeter of the top of the tank.
Claim 7
Dependent Claim
85 words
A froth flotation cell comprising a tank, a driven impeller disposed centrally of and at a low level in the tank, a cover above the impeller to minimize entry of fluid from above, a series of injection points for compressed air about the periphery of the tank directed toward the interior of the tank and higher than the level of the cover, the tank being cylindrical about a vertical axis, and a series of radially extending baffles projecting inwardly from the periphery of the tank.
Claim 8
Dependent Claim
85 words
A froth flotation cell comprising a tank, a driven impeller disposed centrally of and at a low level in the tank, a cover above the impeller to minimize entry of fluid from above, a series of injection points for compressed air about the periphery of the tank directed toward the interior of the tank and higher than the level of the cover, the tank being cylindrical about a vertical axis, and a series of radially extending baffles projecting inwardly from the periphery of the tank.
Claim 9
Dependent Claim
60 words
A cell as claimed in claim 4, in which the upper parts of the baffles are inclined to the vertical at an angle of 10 to 45 degrees, the direction of inclination being so chosen that, when viewed from above, these inclined sections of the baffles spiral downwardly in the same direction as the direction of rotation of the impeller.
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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) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |