US3834529A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Device and method of density measurement and control of flotation systems
Assignee: Dow Chemical Co
•
Filing: 1972-01-20
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Granted: 1974-09-10
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Expires: 1992-01-20
Abstract
Abstract Two open-end tubes are vertically immersed, open-end down at substantially the same level, one near the place of entrance of a liquid in process in a series of treating vessels and the other near the outlet of the liquid whereby densities of the liquid at the respective locations are measured by means of a suitable pneumatic assembly, the density values are translated to and recorded as a pneumatic pressure differential and the pneumatic pressure differential is either (1) automatically converted to and recorded in meaningful values and the indicated adjustments manually made to restore and tend to maintain the optimum density differential, or (2) directed to an optimizer whereby optimum adjustments are automatically made to restore and tend to maintain a maximum density differential. Where a fluctuating level of liquid exists, two probes immersed at different depths to define a fixed stratum may be used in cooperation to obtain one density value.
Inventors
- 👤 P Hart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 07:25
CPC Classifications
B; B03; B03B; B03B13/00; B03B13/005
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
161 words
In the recovery of mineral values from an ore slurry employing flotation principles wherein conditioning agents are admixed with water and pulverulent ore to make a treated slurry and said slurry is subjected to flotation by passing air upwardly through the agitated slurry in successive connected cells whereby the mineral sOught to be recovered is collected in a froth which is overflowed and recovered from the thus provided overflow, the improvement comprising: continuously measuring the density values of at least two of said cells, continuously converting the density values to a pressure differential which is proportional to the differential of density values; causing a pneumatic impulse in accordance with variations in the pressure differential to be relayed to a continuous registering instrument to provide a continuous pressure differential record which is calibrated to show density differential; adjusting at least one additive of the flotation process in accordance with the recorded density differential to tend to maintain said differential at a maximum.
Claim 2
Dependent Claim
161 words
In the recovery of mineral values from an ore slurry employing flotation principles wherein conditioning agents are admixed with water and pulverulent ore to make a treated slurry and said slurry is subjected to flotation by passing air upwardly through the agitated slurry in successive connected cells whereby the mineral sOught to be recovered is collected in a froth which is overflowed and recovered from the thus provided overflow, the improvement comprising: continuously measuring the density values of at least two of said cells, continuously converting the density values to a pressure differential which is proportional to the differential of density values; causing a pneumatic impulse in accordance with variations in the pressure differential to be relayed to a continuous registering instrument to provide a continuous pressure differential record which is calibrated to show density differential; adjusting at least one additive of the flotation process in accordance with the recorded density differential to tend to maintain said differential at a maximum.
Claim 3
Dependent Claim
46 words
The method according to claim 1 wherein the electrical potential (EMF) value of the slurry prior to its being subjected to flotation is continuously recorded so that, for purposes of process control, said electrical potential can be adjusted in accordance with changes in said density differential.
Claim 4
Dependent Claim
88 words
a tube extending from the upper end of each of said probes leading to opposite sides of a closed bi-chambered pressure-sensitive instrument, the chambers being formed by a dividing flexible membrane, thereby providing entrapped substantially dead gas in each probe-tube chamber combination, the pressure of which increases or decreases directly in response to the density of the liquid at the level of the lower end of each of said probes and deflects said membrane in accordance with the pressure differential and therefore in accordance with the density differential;
Claim 5
Dependent Claim
88 words
a tube extending from the upper end of each of said probes leading to opposite sides of a closed bi-chambered pressure-sensitive instrument, the chambers being formed by a dividing flexible membrane, thereby providing entrapped substantially dead gas in each probe-tube chamber combination, the pressure of which increases or decreases directly in response to the density of the liquid at the level of the lower end of each of said probes and deflects said membrane in accordance with the pressure differential and therefore in accordance with the density differential;
Claim 6
Dependent Claim
31 words
means for continuously measuring the electrical potential (EMF) of the ore slurry at a location prior to the first flotation stage and means for recording and adjusting said electrical potential; and
Claim 7
Dependent Claim
31 words
means for continuously measuring the electrical potential (EMF) of the ore slurry at a location prior to the first flotation stage and means for recording and adjusting said electrical potential; and
Claim 8
Dependent Claim
16 words
The method according to claim 2 wherein the electrical potential (EMF) is calibrated into pH values.
Claim 9
Dependent Claim
50 words
a peak-seeking optimizer responsive to the pressure differential provided by said pressure-sensitive instrument and which adjusts the said eleCtrical potential (EMF) of the slurry at said location prior to the first flotation stage at the optimum necessary to maintain the pressure differential (and thus the ore recovery) at a maximum.
Claim 10
Dependent Claim
50 words
a peak-seeking optimizer responsive to the pressure differential provided by said pressure-sensitive instrument and which adjusts the said eleCtrical potential (EMF) of the slurry at said location prior to the first flotation stage at the optimum necessary to maintain the pressure differential (and thus the ore recovery) at a maximum.
Claim 11
Dependent Claim
41 words
The method according to claim 1 wherein a pneumatic impulse in accordance with said pressure differential, as controlled and determined by said density differential, is continuously sent to an optimizer which automatically seeks the maximum density differential which is continuously recorded.
Claim 12
Dependent Claim
40 words
The method according to claim 4 wherein said maximum density differential is continuously converted to pH values and such values used to guide the amount of an ingredient which, when admixed with the slurry, modifies the electrical potential (EMF) thereof.
Claim 13
Dependent Claim
70 words
The method according to claim 4 wherein a series of pneumatic impulses provided by said optimizer are sent to the feed control of an ingredient which modifies the electrical potential (EMF) in the slurry and increases or decreases the rate of said feed to cause the potential to trend at predetermined time intervals in the direction of maximum density differential in the slurry bath in the two cells being measured.
Claim 14
Dependent Claim
69 words
The method according to claim 6 wherein the optimum positive-negative potential differential in the slurry bath is recorded as well as automatic adjustment made of the rate of feed of a positive-negative modifying ingredient to continue to modify that rate to one which gives maximum density differential between the density of the slurry at or near the beginning and that at or near the end of the flotation operation.
Claim 15
Independent Claim
16 words
An apparatus for continuously measuring, recording and controlling an ore flotation process which comprises in combination:
Claim 16
Independent Claim
16 words
An apparatus for continuously measuring, recording and controlling an ore flotation process which comprises in combination:
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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) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |