JP2020085775A - Floss bubble diameter measurement device, flotation machine using the same, and floss bubble diameter measurement method - Google Patents

Abstract

To provide a floss bubble diameter measurement device configured to image floss bubbles, measure floss bubble diameters inline and digitize the measured diameters in real time, and to provide a flotation machine using the same and a floss bubble diameter measurement method.SOLUTION: A floss bubble diameter measurement device is provided, comprising: a light source provided above a flotation tank and configured to irradiate slurry retained in the flotation tank with light from above; image capturing means for capturing an image of the slurry from above; and arithmetic processing means configured to compute diameters of floss bubbles in the image captured by the image capturing means.SELECTED DRAWING: Figure 1

Description

The present invention relates to a floss bubble diameter measuring device, a flotation machine using the same, and a floss bubble diameter measuring method.

Floating separation is known as a method of separating valuable components in minerals from other components when recovering valuable components contained in minerals. In this flotation, as described in Patent Document 1, a pulverized product obtained by pulverizing a mineral is mixed with a liquid such as water to form a slurry, and air is blown into the slurry. Then, among the pulverized products, those having a high affinity for air float up, and thus the pulverized product that floats and the other pulverized products can be separated. Then, in flotation, a plurality of reagents such as a foaming agent and a scavenger are added to the slurry in order to float the pulverized product together with air, and a desired valuable component can be obtained by adjusting the reagent to be added. The pulverized material containing it is floated with the air.

In this flotation process, the ability to separate a pulverized product into a floating product and another product (that is, a crushed product that sediments) changes depending on the amount of air blown into the slurry. For example, when the amount of air blown into the slurry is large, a pulverized product containing a desired valuable component is likely to float and recovery is improved, but other pulverized products are also likely to be floated. Therefore, when the amount of air blown into the slurry increases, the amount of impurities contained in the recovered pulverized product increases. Therefore, it is necessary to appropriately control the amount of air blown into the slurry in order to improve the quality of the recovered pulverized product while improving the recoverability of the pulverized product containing the desired valuable component.

The quality and the actual yield are determined by adjusting the reagents and adjusting the air volume, etc., but as an index for this, the qualitative judgment is currently made by visually observing the size of the froth bubbles that have risen.

JP, 2013-180289, A

However, in the conventional qualitative judgment by visual inspection, the error of the judgment by the operator is large, and the adjustment of the reagent and the adjustment of the air amount cannot be appropriately performed. For this reason, it is difficult to make uniform adjustment, and as a result, there is a possibility that the recovery rate of the pulverized material and the quality of the recovered pulverized material may vary.

Therefore, an object of the present invention is to provide a froth bubble diameter measuring device that images the froth bubble diameter, measures it in-line, and digitizes it in real time, a flotation machine using the same, and a froth bubble diameter measuring method. To do.

In order to achieve the above object, the floss bubble diameter measuring device according to one aspect of the present invention is provided above the flotation tank, and a light source for irradiating the slurry stored in the flotation tank with light from the upper surface. ,
An image capturing means for capturing an image of the slurry from above,
Arithmetic processing means for calculating the froth bubble diameter of the froth bubbles included in the image picked up by the image pickup means.

According to the present invention, since the froth bubble diameter can be quantitatively measured, it is possible to perform the reagent adjustment and the air amount adjustment with higher accuracy and in real time as compared with the qualitative judgment by visual observation.

It is a schematic diagram showing composition of a froth bubble diameter measuring device and a flotation machine concerning an embodiment of the present invention. It is a figure for demonstrating the reason why the top of a floss bubble glows white compared with a peripheral part. It is the figure which showed an example of the image which imaged the floss bubble from the upper part. It is the figure which showed the correlation of the reflected light size of a floss bubble, and the actual size of a froth bubble. It is a flow figure showing an example of a processing flow of a floss bubble diameter measuring method concerning an embodiment of the present invention.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings.

FIG. 1 is a schematic diagram showing the configurations of a floss bubble diameter measuring device and a flotation device according to an embodiment of the present invention. The flotation machine 100 according to the embodiment of the present invention includes a flotation tank 10, an agitator 20, an air supply shaft 30, and a froth bubble diameter measuring device 80. The floss bubble diameter measuring device 80 according to the embodiment of the present invention includes a light source 50, an area scan camera 60, and a computer 70. The computer 70 may include, for example, an image processing unit 71 and a storage unit 72. The area scan camera 60 and the computer 70 may be connected by a connection cord 61, for example. Further, as a related component of the flotation machine 100, the ore slurry 40 is stored in the flotation tank 10.

The flotation tank 10 is a slurry storage means for storing a liquid ore slurry 40 containing a crushed material to be processed. Since the pulverized product is a useful metal that is the target of beneficiation or concentrate, the ore slurry 40 is stored in the flotation tank 10 to perform the flotation. Therefore, although not shown in FIG. 1, the flotation tank 10 has an extraction port for extracting useful metals at the upper part of the flotation tank 10 and an outlet for discharging tailings not targeted by useful metals. May be provided.

The stirring blade 20 is a froth bubble finer means for making fine the froth bubbles 41 generated by the air supplied from the lower end of the air supply shaft 30. The froth bubbles 41 generated at the lower end of the air supply shaft 30, that is, below the stirring blades 20, collide with the stirring blades 20 due to the rotation of the stirring blades 20 when ascending, thereby reducing the diameter of the froth bubbles. By reducing the floss bubble diameter, the collision efficiency with the ore particles in the ore slurry 40 can be increased.

The pulverized product (ore particles) whose metal surface is exposed on the surface adheres to the froth bubbles and floats in the ore slurry 40, and the other pulverized substances do not adhere to the froth bubbles 41 and the bottom surface in the flotation tank 10. Settles. In this case, it is preferable to generate the floss foam 41 having an appropriate diameter to which the pulverized material is easily attached, in consideration of the balance between the size of the pulverized material to be processed and the buoyancy of the froth foam 41. Therefore, a floss bubble diameter measuring device 80 is provided to measure the floss bubble diameter.

The floss bubble diameter measuring device 80 includes a light source 50 and an area scan camera 60 above the flotation tank 10 in order to image the froth bubbles 41 in the ore slurry 40 from the upper surface.

The area scan camera 60 is an imaging means for imaging the ore slurry 40 from the upper surface and acquiring an image including the froth bubbles 41. In the present embodiment, an example in which the area scan camera 60 is used is given, but various imaging means can be used as long as they can image a partial area or the entire area of the ore slurry 40. In the present embodiment, it is sufficient for the area scan camera 60 to be able to image the area illuminated by the light source 50, and not necessarily the entire surface of the flotation tank 10.

The light source 50 is a light emitting unit or a lighting unit for illuminating the ore slurry 40 from the upper surface. If the ore slurry 40 can be illuminated from the upper surface, various light emitting means or illumination means can be used. By irradiating the upper surface of the ore slurry 40 with light from above, the vicinity of the top of the froth bubbles 41 present in the ore slurry 40 glows whiter than the peripheral portion of the froth bubbles 41, and the top portion is the peripheral portion. Glows at a higher brightness than. That is, in the image obtained by the area scan camera 2 by irradiating the floss bubble 41 with light from the light source 50, the vicinity of the top of the floss bubble shines whiter than the foot of the floss bubble.

FIG. 2 is a diagram for explaining the reason why the top of the floss bubble 41 glows whiter than the peripheral portion. As shown in FIG. 2, when the light emitted from the light source 50 hits the floss bubble 41 and is reflected, the vicinity of the top of the floss bubble 41 is reflected upwards where the area scan camera 50 is arranged, whereas the floss bubble 41 is reflected. This is because the light that hits the skirt of 41 is reflected obliquely upward and laterally.

FIG. 3 is a diagram showing an example of an image of such a floss bubble 41 taken from above. As shown in FIG. 3, the image has a white glowing portion (reflected light area) 42 in the central portion of the froth bubble 41.

Since the size of the white glowing part is determined by the size of the floss bubble 41 and the curvature of the floss bubble 41, the curvature of the floss bubble 41 may be somewhat different depending on the composition of the ore slurry 40. However, as shown in FIG. 2, the difference in the position of the brightness of the floss bubble 41 is due to the fact that the floss bubble 41 has a substantially spherical shape, and therefore depends on the composition of the ore slurry 40. The difference is only a slight difference and can be assumed to be almost constant. Then, it can be said that the size of the floss bubble 41 has a correlation with the size of the white glowing portion. The factors that determine the size of the white glowing portion 42 include the size of the light emitting surface of the light source 50, the distance from the upper surface of the flotation tank 10 to the light source 50, and the flotation in addition to the size of the floss bubble 41 and the curvature of the bubble described above. Although there is a distance from the upper surface of the tank 10 to the area scan camera 60, they can be excluded from the factors unless the conditions are changed.

The area scan camera 60 is connected to the computer 70 via a network, and the image obtained from the area scan camera 60 is captured by the computer 70. The image from the area scan camera 60 may be transmitted by wire communication or wireless communication via the connection cord 61.

The computer 70 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), and the like, and has a structure for operating by reading a program. The computer 70 functions as an arithmetic processing unit that performs arithmetic processing for calculating the froth bubble diameter based on the image acquired from the area scan camera 60. Further, the computer 70 may include an image processing unit 71, and may have a function and structure for performing image processing on an image acquired from the area scan camera 60 as necessary.

FIG. 4 is a diagram showing the correlation between the reflected light size of the froth bubbles and the actual size of the froth bubbles. In FIG. 4, a correlation between the size of the reflected light when the floss bubble 41 is irradiated with light and the size of the actually measured floss bubble 41 is obtained as a relational expression by an experiment, and the size of the floss bubble 41 is measured. Used for. That is, in FIG. 4, the horizontal axis represents the reflected light size of the floss bubble 41, and the vertical axis represents the size of the floss bubble 41. When these measured values are plotted, a certain degree of correlation can be confirmed in the graph in which the size of the part that glows white and the size of the bubble are plotted. The regression equation can be approximated from this relationship.

In FIG. 4, the curve showing the phase relationship between the plotted points is the approximate regression equation. It can be seen that the approximate regression equation shown in FIG. 4 is not a straight line but a polynomial. Once the approximate regression equation is created, it can be generally applied regardless of the composition of the ore slurry 40. However, in order to measure the froth bubble diameter more accurately, the composition of each ore slurry 40 is measured in advance to obtain an approximate regression equation as shown in FIG. It is also possible to adopt a configuration that uses an approximate regression equation of a more approximate condition.

In this way, the computer 70 can measure the size of the white shining portion 42 of the image and calculate the size of the froth bubble 41 by the above-described approximate regression equation. The approximate regression equation described with reference to FIG. 4 is stored in, for example, the storage unit 72 in the computer 70, and the CPU refers to the approximate regression equation stored in the storage unit 72 during the arithmetic processing to perform the arithmetic processing. Should be done. Accordingly, the computer 70 can obtain the size of the white glowing portion 42 from the image transmitted from the area scan camera 60 and calculate the size (diameter) of the floss bubble 41 by using the approximate regression equation shown in FIG.

It is desirable that the light emitted from the light source 50 is surface emission that covers the imaging area and has a narrow directivity angle and is as uniform as possible. This is because the narrower the directivity angle, the easier the contrast of the part 42 that shines white becomes.

Further, the image processing unit 71 may perform various kinds of image processing for removing noise from the image and enhancing the contrast to facilitate the arithmetic processing. For example, if a binarized image is acquired from an image acquired by setting a predetermined threshold value, the size of the froth bubble 41 can be easily obtained. Such processing may be performed in the image processing unit 71. The image processing unit 71 may be provided inside the computer 70 or may be provided outside the computer 70 as a separate body.

Since the flotation tank 10 has a columnar shape and is generally provided with a drive unit of a stirring blade 20 for cutting the supply air to generate fine bubbles in the center of the upper portion, the entire surface from the upper portion of the flotation tank 10 is Imaging is physically difficult. However, since the state of bubbles does not depend on the location, it is possible to represent the whole by capturing a part of the image. Therefore, a field of view that can image a part of the upper surface of the flotation tank 10 is sufficient, and the height of the area scan camera 60 from the upper surface of the flotation tank 10 and the field of view of the lens may be determined according to the application.

In FIG. 1, the positions of the light source 50 and the area scan camera 60 are schematically shown, but fixing means can be provided and fixed at appropriate positions according to the application.

Further, in the flotation machine 100, although the constituent elements other than the flotation tank 10, the stirring blades 20, and the air supply shaft 30 are not shown, the flotation machine 100 includes various constituent elements necessary for constituting the flotation machine 100. It goes without saying that it is okay.

Next, a processing flow of the floss bubble diameter measuring method according to the embodiment of the present invention will be described. FIG. 5 is a flow chart showing an example of the processing flow of the floss bubble diameter measuring method according to the embodiment of the present invention. The constituent elements described so far are designated by the same reference numerals, and the description thereof will be omitted.

In FIG. 5, in step S100, the light source 50 irradiates the upper surface of the ore slurry 40 stored in the flotation tank 10 with light. As a result, the top portion of the froth bubbles 41 in the ore slurry 40 glows white. The top portion corresponds to the approximate center of the froth bubble 41, as described with reference to FIGS.

In step S110, the area scan camera 60 images the upper surface of the ore slurry 40, and acquires the image captured from the upper surface of the ore slurry 40. The acquired image includes a froth bubble 41 having a white glowing portion 42. The acquired image data is transmitted to the computer 70 by wire or wireless communication.

In step S120, image processing is performed on the image received by the image processing unit 71 as necessary. In the image processing, for example, a binarized image is acquired from the received image using a predetermined threshold value. As a result, noise is removed from the image acquired by the area scan camera 60. Note that step S120 is not essential, and may be performed as needed.

In step S130, the computer 70 performs a calculation process to calculate the froth bubble diameter. At this time, the computer 70 calculates the size of the froth bubble from the size of the reflected light using the approximate regression formula prepared in advance and stored in the storage unit 72. Thereby, the froth bubble diameter is measured.

As shown in step S140, various adjustment processes may be performed based on the measured froth bubble diameter. That is, the air supply conditions and stirring conditions can be optimized. Although such an adjustment may be made by a human being by looking at the measurement result of the froth bubbles, the computer 70 may make an automatic adjustment. When a person makes an adjustment, the computer 70 outputs the measurement result to a display or the like. When the computer 70 performs automatic adjustment, the computer 70 adjusts the output of the air supply shaft 30, the drive speed of the stirring blade 20, and the like based on the measurement result. In that case, it goes without saying that the measurement result may be output together. From this point of view, step S140 is not essential and may be executed as necessary.

As described above, according to the floss bubble diameter measuring method according to the present embodiment, it is possible to automatically measure the floss bubble diameter and further perform an adjustment so as to optimize the floss bubble diameter, if necessary, to obtain a high quality. Flotation can be done.

As described above, according to the floss diameter measuring device, the flotation machine, and the froth bubble diameter measuring method according to the present embodiment, the floss diameter can be accurately measured automatically on a uniform basis, and the quality of flotation is improved. Can be made uniform and of high quality.

Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

10 Flotation Tank 20 Stirring Blade 30 Air Supply Shaft 40 Ore Slurry 41 Floss Foam 42 White Shining Part (Reflected Light Area)
50 light source 60 area scan camera 61 connection cord 70 computer 80 floss bubble diameter measuring device 100 flotation machine

Claims (8)

A light source that is provided above the flotation tank and irradiates the slurry stored in the flotation tank with light from the upper surface,
An image pickup means for picking up an image of the slurry from above,
A floss bubble diameter measuring device, comprising: an arithmetic processing unit that calculates a froth bubble diameter of the froth bubbles included in the image captured by the image capturing unit. The floss bubble diameter measuring device according to claim 1, wherein the arithmetic processing unit calculates the floss bubble diameter based on a size of a white glowing portion of the froth bubble included in the image. The said arithmetic processing means calculates the said floss bubble diameter using the approximate regression formula obtained from the relationship between the size of the white glowing part of the froth bubble and the floss bubble diameter which were actually measured beforehand. Froth bubble diameter measuring device. 4. The image processing unit according to claim 1, further comprising an image processing unit that removes noise from the image captured by the image capturing unit and performs image processing that facilitates measurement of the size of the white glowing portion of the floss bubble. The described froth bubble diameter measuring device. A flotation tank to store the slurry,
An agitating unit provided in the flotation tank and agitating the slurry,
A flotation machine comprising the froth bubble diameter measuring device according to any one of claims 1 to 4. Irradiating the upper surface of the slurry stored in the flotation tank with light,
Imaging a top surface of the slurry irradiated with the light;
And a step of calculating the froth bubble diameter of the froth bubbles included in the captured image. The floss bubble diameter measuring method according to claim 6, wherein in the step of calculating the floss bubble diameter, the floss bubble diameter is calculated based on a size of a white glowing portion of the floss bubble included in the image. In the step of calculating the floss foam diameter, the floss foam diameter is calculated by using an approximate regression equation obtained from the relationship between the size of the white glowing portion of the floss foam and the froth foam diameter, which is obtained by actual measurement in advance. Item 7. The froth bubble diameter measuring method according to Item 7.

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