CA2054620A1 - Flotation column - Google Patents
Flotation columnInfo
- Publication number
- CA2054620A1 CA2054620A1 CA002054620A CA2054620A CA2054620A1 CA 2054620 A1 CA2054620 A1 CA 2054620A1 CA 002054620 A CA002054620 A CA 002054620A CA 2054620 A CA2054620 A CA 2054620A CA 2054620 A1 CA2054620 A1 CA 2054620A1
- Authority
- CA
- Canada
- Prior art keywords
- passageways
- flotation column
- slurry
- passageway
- froth
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Physical Water Treatments (AREA)
Abstract
ABSTRACT
This invention relates to a flotation column for separating particulate material. The column has at least two separate passageways within each of which slurry is in use separated from froth by an interface. Feed means for feeding slurry into each passageway below the interface is provided within each passageway. Bubble generating means is provided below or within the passageways and a tailings outlet is located below the bubble generating means.
This invention relates to a flotation column for separating particulate material. The column has at least two separate passageways within each of which slurry is in use separated from froth by an interface. Feed means for feeding slurry into each passageway below the interface is provided within each passageway. Bubble generating means is provided below or within the passageways and a tailings outlet is located below the bubble generating means.
Description
2~5~520 This invention relates to a flotation column and to a method of separating particulate material in a flotation column.
Large unbaffled columns are subject to severe a~ial mixing or recirculation. It has generally been assumed that such columns should be baffled by vertical baffles located wholly within the slurry phase to reduce a~ial mixing. The Applicant has found that these baffles do not prevent a~ial mi~ing from taking place and that in some instances they enhance axial mixing.
Axial mi~ing results in a reduced residence time of some of the particulate material within the column leading to a poor recovery rate. It is for this reason that flotation columns have generally only been used as clea~ers and not as roughers or scavengers.
It is an object of this invention to provide a flotation column and a method of separating 2(~ 20 particulate material which at least reduce axial mi~ing associated with prior art flotation columns.
According to a first aspect~of the invention, there is ~;rovided a flotation column for separating particulate material includes at least two separate passageways within each of which slurry is in use separated from froth by an interface, feed means within each passageway for feeding the slurry into each passageway below the interface, bubble generating means located below or within the passageways, and at least one tailings outlet below the bu'oble generating means.
In the preferred form of the invention control means is provided for controlling the positions of the interfaces.
In one form of the invention the control means may be valves for manipulating the flow of fluid or particulate material to or from the column.
The froth zones may merge to form a common froth zone.
The separate passageways may be formed by at least 2(~ S20 one baffle. The baffle may extend from above the outlet so that the passageways have a common outlet. The top of the baffle may terminate at the froth overflow zone or above at least part of the froth overflow zone.
The separate passageways may include at least one closable opening through which the passageways can communicate with one another. Circulation may take place through this opening. The circulation can be used to control the relative levels of the interfaces. The opening may be closable by a gate located in the baffle.
According to another aspect of the invention a flotation column for separating particulate material includes at least one continuous baffle which creates at least two separate passageways in each of which slurry is in use separated from froth by an interface, the top of the baffle terminating at the froth overflow zone or above at least part of the iroth overflow zone.
According to another aspect of the invention a method of separating particulate material within a flotation column having at least two separate passageways includes the step of creating a slurry phase and a froth phase within each passageway, with the phases in each passageway being separated by an interface located within each passageway.
The method preferably includes the step of 2 ~ 5~5 2 0 controlling the positions of the interfaces within each passageway by manipulating the flow of fluid or particulate material to or from the column. In one form of the invention the position of one of the interfaces is controlled by controlling the flow of slurry from the column, and the positions of the other interfaces are controlled by allowing circulation between a closable opening between the passageways or by adjusting the performance of the bubble generating means.
The invention will now be described by way of a non-limiting e~amples with reference to the accompanying drawings in which:
igure 1 is a cross-sectional side view of a flotation column according to the invention; and igure 2 is a perspective view of part of a ~lotation column according to another form of the invention; and igure 3 is a cross-sectional side view on line III - III of the flotation column shown in figure 2; and 2~ S20 igure 4 is a graph showing the ef~ect of the interface position relative to the ba~fles on the residence time distribution.
Re~erring to ~igure 1, a flotation column 10 includes a baffle 12 which divides part of the column 10 into two separate passageways 14 and 16.
The passageways have a common tailings outlet 18 and a common ~roth overflow 20. The outlet 18 is provided with a valve 19.
Each passageway has a slurry phase 22 separated from a froth phase 24 by an interface 26.
Furthermore, each passageway has its own slurry supply 28 which can be controlled by a valve 30.
In addition each passageway has its own bubble generator 32. Each bubble generator is connected to an air supply 34, a water supply 36 and a irother supply 38.
The positlons o~ the inter~aces 26 are controlled so as to be level with one another or as close to level with one another as possible. One of the inter~ace levels is controlled by varying the tailings rate. The level of the other inter~ace is controlled by controlling one or more o~ the ~ollowing: the output from the bubble generator, 2~S~O
the slurry supply to the passageways or the circulation between the passageways through closable openings (not shown) in the baffle.
Although also not shown, probes are provided for monitoring the pressure a short distance below the interfaces. The outputs from the probes may be used automatically to vary the bubble and/or slurry feed to the passageways. Thus the interfaces can be kept level with one another automatically.
Various other methods could of course be used for sensing the interface level in each passageway.
8y ensuring that the interfaces 26 are located below the top of the baffle 12, the column is effectively divided into two individual columns.
This eliminates recirculation or a~ial mi~ing of the slurry between the two passageways.
Referring now to figures 2 and 3 in which the same numerals refer to the same parts of figure 1, the top 12.2 of the baffle 12.1 terminates at the top of the froth overflow 20.2 of the flotation column 10.1.
The applicant conducted five experiments using a flotation column in which the height of baffles relative to the position of the interfaces could be varied.
2~5'~
For each experiment a tracer (3 g of NaCl dissolved in 2~0 ml water) was inserted into the slurry supply. The tracer concentration was then measured by a conductivity probe at the tailings outlet of the column to determine the residence time distribution of the tracer within the column. In the first e~periment the interfaces were located four centimetres above the top of the baffle. In the second experiment the interfaces were level with the top of the baffle, thereafter the interfaces were 1 cm; 3,5 cm and 1 cm respectively below the top of the baffle. The gas superficial velocity (JG), which is a measure of the gas rate, was kept constant at 0.75 cm/s for each experiment except for the last e~periment where it was 0 cm/s.
The results of the experiments are shown by way of five graphs in figure 4. The top graph relates to the first experiment and the bottom graph to the fifth experiment. In figure 4, E(X) indicates the residence time distribution; t indicates time;
X = t indicates the normalised residence time;
T indicates the average residence time; and LINT -LBAFF is the difference in height between the interfaces and the baffle. The residence time distribution E(X) is defined as E(X)dX which is the ~raction of the tracer which spends a time between 2~ o X and XtdX in the column where dX is a small time increment.
The experiment showed that the residence time distribution of the tracer within the column improved as the height of the baffle was raised relative to the interfaces. The time taken for the fastest moving tracer to move from the slurry inlet to the tailings outlet increased, and the spread of the distribution was reduced as the height of the baffle was raised relative to the interfaces. Thus more particulate material passed through the column at residence times which were close to the average residence time.
The applicant believes that a substantial improvement in residence time distribution and hence column recovery can be obtained in columns in which the interfaces are located below the top of the baffles. Furthermore the applicant believes that these columns will be able to be used as roughers and scavengers.
It wili be appreciated that many modifications and/or variations of the invention are possible without departing from the spirit or scope of the invention.
Large unbaffled columns are subject to severe a~ial mixing or recirculation. It has generally been assumed that such columns should be baffled by vertical baffles located wholly within the slurry phase to reduce a~ial mixing. The Applicant has found that these baffles do not prevent a~ial mi~ing from taking place and that in some instances they enhance axial mixing.
Axial mi~ing results in a reduced residence time of some of the particulate material within the column leading to a poor recovery rate. It is for this reason that flotation columns have generally only been used as clea~ers and not as roughers or scavengers.
It is an object of this invention to provide a flotation column and a method of separating 2(~ 20 particulate material which at least reduce axial mi~ing associated with prior art flotation columns.
According to a first aspect~of the invention, there is ~;rovided a flotation column for separating particulate material includes at least two separate passageways within each of which slurry is in use separated from froth by an interface, feed means within each passageway for feeding the slurry into each passageway below the interface, bubble generating means located below or within the passageways, and at least one tailings outlet below the bu'oble generating means.
In the preferred form of the invention control means is provided for controlling the positions of the interfaces.
In one form of the invention the control means may be valves for manipulating the flow of fluid or particulate material to or from the column.
The froth zones may merge to form a common froth zone.
The separate passageways may be formed by at least 2(~ S20 one baffle. The baffle may extend from above the outlet so that the passageways have a common outlet. The top of the baffle may terminate at the froth overflow zone or above at least part of the froth overflow zone.
The separate passageways may include at least one closable opening through which the passageways can communicate with one another. Circulation may take place through this opening. The circulation can be used to control the relative levels of the interfaces. The opening may be closable by a gate located in the baffle.
According to another aspect of the invention a flotation column for separating particulate material includes at least one continuous baffle which creates at least two separate passageways in each of which slurry is in use separated from froth by an interface, the top of the baffle terminating at the froth overflow zone or above at least part of the iroth overflow zone.
According to another aspect of the invention a method of separating particulate material within a flotation column having at least two separate passageways includes the step of creating a slurry phase and a froth phase within each passageway, with the phases in each passageway being separated by an interface located within each passageway.
The method preferably includes the step of 2 ~ 5~5 2 0 controlling the positions of the interfaces within each passageway by manipulating the flow of fluid or particulate material to or from the column. In one form of the invention the position of one of the interfaces is controlled by controlling the flow of slurry from the column, and the positions of the other interfaces are controlled by allowing circulation between a closable opening between the passageways or by adjusting the performance of the bubble generating means.
The invention will now be described by way of a non-limiting e~amples with reference to the accompanying drawings in which:
igure 1 is a cross-sectional side view of a flotation column according to the invention; and igure 2 is a perspective view of part of a ~lotation column according to another form of the invention; and igure 3 is a cross-sectional side view on line III - III of the flotation column shown in figure 2; and 2~ S20 igure 4 is a graph showing the ef~ect of the interface position relative to the ba~fles on the residence time distribution.
Re~erring to ~igure 1, a flotation column 10 includes a baffle 12 which divides part of the column 10 into two separate passageways 14 and 16.
The passageways have a common tailings outlet 18 and a common ~roth overflow 20. The outlet 18 is provided with a valve 19.
Each passageway has a slurry phase 22 separated from a froth phase 24 by an interface 26.
Furthermore, each passageway has its own slurry supply 28 which can be controlled by a valve 30.
In addition each passageway has its own bubble generator 32. Each bubble generator is connected to an air supply 34, a water supply 36 and a irother supply 38.
The positlons o~ the inter~aces 26 are controlled so as to be level with one another or as close to level with one another as possible. One of the inter~ace levels is controlled by varying the tailings rate. The level of the other inter~ace is controlled by controlling one or more o~ the ~ollowing: the output from the bubble generator, 2~S~O
the slurry supply to the passageways or the circulation between the passageways through closable openings (not shown) in the baffle.
Although also not shown, probes are provided for monitoring the pressure a short distance below the interfaces. The outputs from the probes may be used automatically to vary the bubble and/or slurry feed to the passageways. Thus the interfaces can be kept level with one another automatically.
Various other methods could of course be used for sensing the interface level in each passageway.
8y ensuring that the interfaces 26 are located below the top of the baffle 12, the column is effectively divided into two individual columns.
This eliminates recirculation or a~ial mi~ing of the slurry between the two passageways.
Referring now to figures 2 and 3 in which the same numerals refer to the same parts of figure 1, the top 12.2 of the baffle 12.1 terminates at the top of the froth overflow 20.2 of the flotation column 10.1.
The applicant conducted five experiments using a flotation column in which the height of baffles relative to the position of the interfaces could be varied.
2~5'~
For each experiment a tracer (3 g of NaCl dissolved in 2~0 ml water) was inserted into the slurry supply. The tracer concentration was then measured by a conductivity probe at the tailings outlet of the column to determine the residence time distribution of the tracer within the column. In the first e~periment the interfaces were located four centimetres above the top of the baffle. In the second experiment the interfaces were level with the top of the baffle, thereafter the interfaces were 1 cm; 3,5 cm and 1 cm respectively below the top of the baffle. The gas superficial velocity (JG), which is a measure of the gas rate, was kept constant at 0.75 cm/s for each experiment except for the last e~periment where it was 0 cm/s.
The results of the experiments are shown by way of five graphs in figure 4. The top graph relates to the first experiment and the bottom graph to the fifth experiment. In figure 4, E(X) indicates the residence time distribution; t indicates time;
X = t indicates the normalised residence time;
T indicates the average residence time; and LINT -LBAFF is the difference in height between the interfaces and the baffle. The residence time distribution E(X) is defined as E(X)dX which is the ~raction of the tracer which spends a time between 2~ o X and XtdX in the column where dX is a small time increment.
The experiment showed that the residence time distribution of the tracer within the column improved as the height of the baffle was raised relative to the interfaces. The time taken for the fastest moving tracer to move from the slurry inlet to the tailings outlet increased, and the spread of the distribution was reduced as the height of the baffle was raised relative to the interfaces. Thus more particulate material passed through the column at residence times which were close to the average residence time.
The applicant believes that a substantial improvement in residence time distribution and hence column recovery can be obtained in columns in which the interfaces are located below the top of the baffles. Furthermore the applicant believes that these columns will be able to be used as roughers and scavengers.
It wili be appreciated that many modifications and/or variations of the invention are possible without departing from the spirit or scope of the invention.
Claims (10)
1. A flotation column for separating particulate material includes at least two separate passageways within each of which slurry is in use separated from froth by an interface, feed means within each passageway for feeding the slurry into each passageway below the interface, bubble generating means located below or within the passageways, and at least one tailings outlet below the bubble generating means.
2. The flotation column of claim 1 wherein the passageways are separated from ore another by at least one baffle.
3. The flotation column of claim 2 wherein the top of the baffle terminates at the froth overflow zone or above at least part of the froth overflow zone.
4. The flotation column of any of the above claims including control means for controlling the positions of the interfaces.
5. The flotation column of claim 4 wherein the control means includes at least one closable opening between the passageways through which opening slurry can flow between the passageways.
6. A flotation column for separating particulate material includes at least one baffle which creates at least two separate passageways in each of which slurry is in use separated from froth by an interface, the top of the baffle terminating at the froth overflow zone or above at least part of the froth overflow zone.
7. A flotation column substantially as herein described and illustrated with reference to the accompanying drawings.
8. A method of separating particulate material within a flotation column having at least two separate passageways includes the step of creating a slurry phase and a froth phase within each passageway, with the phases in each passageway being separated by an interface located within each passageway.
9. The method of claim 8 including the step of controlling the relative positions of the interfaces within each passageway by allowing recirculation of slurry between the passageways through at least one opening between the passageways.
10. A method of separating particulate material substantially as herein described.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA90/8733 | 1990-10-31 | ||
| ZA908733 | 1990-10-31 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2054620A1 true CA2054620A1 (en) | 1992-05-01 |
Family
ID=25580370
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA002054620A Abandoned CA2054620A1 (en) | 1990-10-31 | 1991-10-31 | Flotation column |
Country Status (3)
| Country | Link |
|---|---|
| AU (1) | AU648353B2 (en) |
| BR (1) | BR9104744A (en) |
| CA (1) | CA2054620A1 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7914670B2 (en) | 2004-01-09 | 2011-03-29 | Suncor Energy Inc. | Bituminous froth inline steam injection processing |
| WO2014188232A1 (en) | 2013-05-23 | 2014-11-27 | Dpsms Tecnologia E Inovação Em Mineração Ltda | Automated system of froth flotation columns with aerators injection nozzles and process |
| CN114700181A (en) * | 2021-07-22 | 2022-07-05 | 中国矿业大学 | Flotation device and method suitable for coarse slime separation |
| CN114713379A (en) * | 2021-07-22 | 2022-07-08 | 中国矿业大学 | Fluidized flotation device and method suitable for coarse particle recovery |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0146235A3 (en) * | 1983-10-21 | 1987-02-04 | The University Of Newcastle Research Associates Limited | Improved flotation method |
-
1991
- 1991-10-31 CA CA002054620A patent/CA2054620A1/en not_active Abandoned
- 1991-10-31 BR BR919104744A patent/BR9104744A/en unknown
- 1991-10-31 AU AU86900/91A patent/AU648353B2/en not_active Ceased
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7914670B2 (en) | 2004-01-09 | 2011-03-29 | Suncor Energy Inc. | Bituminous froth inline steam injection processing |
| US8685210B2 (en) | 2004-01-09 | 2014-04-01 | Suncor Energy Inc. | Bituminous froth inline steam injection processing |
| WO2014188232A1 (en) | 2013-05-23 | 2014-11-27 | Dpsms Tecnologia E Inovação Em Mineração Ltda | Automated system of froth flotation columns with aerators injection nozzles and process |
| CN114700181A (en) * | 2021-07-22 | 2022-07-05 | 中国矿业大学 | Flotation device and method suitable for coarse slime separation |
| CN114713379A (en) * | 2021-07-22 | 2022-07-08 | 中国矿业大学 | Fluidized flotation device and method suitable for coarse particle recovery |
| CN114713379B (en) * | 2021-07-22 | 2023-09-29 | 中国矿业大学 | Fluidized flotation device and method suitable for coarse particle recovery |
Also Published As
| Publication number | Publication date |
|---|---|
| AU8690091A (en) | 1992-05-14 |
| AU648353B2 (en) | 1994-04-21 |
| BR9104744A (en) | 1992-06-16 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Discontinued | ||
| FZDE | Discontinued |
Effective date: 19971031 |