JP7245415B2 - Floss bubble diameter measuring device, flotation machine using the same, and froth bubble diameter measuring method - Google Patents

Description

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

Flotation is known as a method for separating valuable components in minerals from other components when recovering valuable components contained in minerals. As described in Patent Document 1, this ore flotation is obtained by mixing pulverized minerals with a liquid such as water to form a slurry and blowing air into the slurry. Then, among the pulverized materials, the pulverized materials having high affinity with air float, so that the pulverized materials that float and the other pulverized materials can be separated. In flotation, multiple reagents such as foaming agents and collectors are added to the slurry in order to float the pulverized material together with air. The pulverized material containing is floated with air.

In this flotation, depending on the amount of air blown into the slurry, the ability to separate pulverized materials into those that float and those that do not (that is, pulverized materials that settle) changes. For example, when the amount of air blown into the slurry is increased, the pulverized material containing the desired valuable component tends to float and the recoverability improves, but the other pulverized material also tends to float. Therefore, when the amount of air blown into the slurry increases, the amount of impurities contained in the collected pulverized material increases. Therefore, it is necessary to appropriately control the amount of air blown into the slurry in order to improve the recoverability of the pulverized material containing the desired valuable component and to increase the quality of the pulverized material collected.

Quality and recovery rate are determined by adjustment of reagents and air amount, etc. Currently, as an index, qualitative judgment is made by visually observing the size of floating froth bubbles.

JP 2013-180289 A

However, in the conventional qualitative judgment by visual observation, the error of judgment by the operator is large, and adjustment of reagents, adjustment of air amount, etc. cannot be performed appropriately. For this reason, it is difficult to perform 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 inline, and digitizes it in real time, a flotation machine using the same, and a froth bubble diameter measuring method. do.

In order to achieve the above object, a froth bubble diameter measuring device according to an aspect of the present invention is provided above a flotation tank, and includes a light source that irradiates light from above onto the slurry stored in the flotation tank. ,
imaging means for imaging the slurry from above;
Arithmetic processing means for calculating a froth bubble diameter of froth bubbles included in the image captured by the imaging means.

According to the present invention, since the froth bubble diameter can be measured quantitatively, it is possible to adjust reagents and air amounts in real time with higher precision than qualitative judgment by visual observation.

BRIEF DESCRIPTION OF THE DRAWINGS It is the schematic which shows the structure of the froth bubble diameter measuring device which concerns on embodiment of this invention, and a flotation machine. FIG. 10 is a diagram for explaining why the top of the floss bubble shines whiter than the peripheral portion; It is the figure which showed an example of the image which imaged floss bubble from upper direction. FIG. 12 shows a correlation between the reflected light size of the floss bubble and the actual size of the floss bubble. FIG. 2 is a flow diagram showing an example of a processing flow of a froth bubble diameter measuring method according to an embodiment of the present invention;

BEST MODE FOR CARRYING OUT THE 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 configuration of a floss bubble diameter measuring device and a flotation machine according to an embodiment of the present invention. A flotation machine 100 according to an embodiment of the present invention includes a flotation tank 10 , a stirrer 20 , an air supply shaft 30 , and a froth bubble diameter measuring device 80 . Also, the froth 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 section 71 and a storage section 72 . The area scan camera 60 and the computer 70 may be connected by a connection cord 61, for example. As a related component of the flotation machine 100 , ore slurry 40 is stored in the flotation tank 10 .

The flotation tank 10 is slurry storage means for storing a liquid ore slurry 40 containing pulverized materials to be ore beneficiation. Since the pulverized material is a useful metal to be processed or concentrated, the ore slurry 40 is stored in the flotation tank 10 and then subjected to flotation. Therefore, although not shown in FIG. 1, the flotation tank 10 has an extraction port for extracting useful metals at the top of the flotation tank 10, and a discharge port for discharging tailings that are not subject to useful metals. may be provided.

The agitating blade 20 is froth bubble refining means for refining 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 rising, thereby reducing the diameter of the froth bubbles. By reducing the froth bubble diameter, the collision efficiency with the ore particles in the ore slurry 40 can be increased.

Pulverized materials (ore particles) with metal surfaces on the surface adhere to the froth bubbles and float in the ore slurry 40, and other pulverized materials do not adhere to the froth bubbles 41 and remain on the bottom surface of the flotation tank 10. to settle. In this case, considering the balance between the size of the pulverized material to be beneficiated and the buoyancy of the froth foam 41, it is preferable to generate the froth foam 41 having an appropriate diameter to which the pulverized material easily adheres. Therefore, a floss bubble diameter measuring device 80 is provided to measure the froth bubble diameter.

The froth 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 above.

The area scan camera 60 is imaging means for capturing an image of the ore slurry 40 from above and acquiring an image including the froth bubbles 41 . In this embodiment, an example using the area scan camera 60 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 this embodiment, it is sufficient for the area scan camera 60 to capture an image of the area illuminated by the light source 50 , and it is not necessary to capture an image of the entire surface of the flotation tank 10 .

The light source 50 is light emitting means or illumination means for illuminating the ore slurry 40 from above. Various light emitting means or illumination means can be used as long as the ore slurry 40 can be illuminated from above. By irradiating the upper surface of the ore slurry 40 with light from above, the vicinity of the top of the froth bubbles 41 existing in the ore slurry 40 shines whiter than the peripheral portion of the froth foam 41, and the top portion is brighter than the peripheral portion. shines brighter 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 base of the floss bubble.

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

FIG. 3 is a diagram showing an example of an image of such floss bubbles 41 captured from above. As shown in FIG. 3, an image is obtained in which a white shining portion (reflected light region) 42 exists in the central portion of the floss bubble 41 .

Since the size of the portion that shines white is determined by the size of the froth bubble 41 and the curvature of the froth bubble, it is conceivable that the curvature of the froth bubble 41 slightly varies depending on the composition of the ore slurry 40 . However, as shown in FIG. 2, the difference in brightness of the froth bubbles 41 depending on the position is due to the fact that the froth bubbles 41 are nearly spherical in shape. The difference is only slight and can be assumed to be approximately constant. Then, it can be said that the size of the floss bubble 41 has a correlation with the size of the portion that shines white. 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 flotation, in addition to the size and curvature of the floss bubble 41 described above. Although there is a distance from the upper surface of the bath 10 to the area scan camera 60, it can be excluded from the factors if the conditions are not 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. Note that the image from the area scan camera 60 may be transmitted via the connection cord 61 by wired communication, or may be transmitted by wireless communication.

The computer 70 includes a CPU (Central Processing Unit), a RAM (Random Access Memory), a ROM (Read Only Memory), etc., and has a structure that reads and operates a program. The computer 70 functions as arithmetic processing means for performing 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 section 71 and may have a function and structure for image processing the 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 bubble and the actual size of the froth bubble. In FIG. 4, the correlation between the size of the reflected light when the floss bubble 41 is irradiated with light and the actually measured size of the floss bubble 41 is obtained as a relational expression in advance, and the size of the floss bubble 41 is measured using this. used for That is, in FIG. 4 , the horizontal axis indicates the reflected light size of the floss bubble 41 and the vertical axis indicates the size of the floss bubble 41 . By plotting these measured values, a certain degree of correlation can be confirmed in the graph plotting the size of the white glowing portion and the size of the bubble. A regression equation can be approximated from this relationship.

In FIG. 4, the curve showing the correlation 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 such an approximate regression formula is created, it can be generally generalized and applied regardless of the composition of the ore slurry 40 . However, when it is desired 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 use an approximate regression equation with conditions more approximated by

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 floss bubble 41 by the approximate regression equation described above. Note that the approximate regression equation described in FIG. 4 is stored, for example, in 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 computation processing. should be done. Thereby, the computer 70 can obtain the size of the white shining portion 42 from the image transmitted from the area scan camera 60, and can calculate the size (diameter) of the floss bubble 41 using the approximate regression equation shown in FIG.

The light emitted from the light source 50 is desirably 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 portion 42 that shines white.

Further, the image processing section 71 may perform various image processing such as removing image noise, enhancing contrast, and facilitating arithmetic processing. For example, if a binarized image is obtained from an image obtained 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 section 71 . Note that the image processing unit 71 may be provided inside the computer 70 or may be provided as a separate body outside the computer 70 .

Since the flotation tank 10 is generally columnar and the driving part of the stirring blade 20 for cutting the supplied air and generating fine bubbles is generally arranged at the center of the upper part, the entire surface is shown from the top of the flotation tank 10. Imaging is physically difficult. However, since the state of bubbles does not depend on the location, it is possible to represent the whole by taking an image of a part. 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 depending on the application, fixing means can be provided to fix them at appropriate positions.

In addition, in the flotation machine 100, components other than the flotation tank 10, the stirring blades 20, and the air supply shaft 30 are not shown, but various components necessary to configure the flotation machine 100 are provided. It goes without saying that

Next, the processing flow of the froth bubble diameter measuring method according to the embodiment of the present invention will be described. FIG. 5 is a flow diagram showing an example of the processing flow of the froth bubble diameter measuring method according to the embodiment of the present invention. The same reference numerals are given to the constituent elements that have been explained so far, and the explanation 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 portions of the floss bubbles 41 in the ore slurry 40 shine white. Note that the top portion corresponds substantially to the center of the floss bubble 41 as described with reference to FIGS.

In step S110, the area scan camera 60 captures an image of the upper surface of the ore slurry 40 and acquires an image captured from the upper surface of the ore slurry 40. FIG. The acquired image contains a floss bubble 41 with a white glowing portion 42 . The acquired image data is transmitted to the computer 70 by wired or wireless communication.

In step S120, image processing is performed on the image received by the image processing unit 71 as necessary. Image processing acquires a binarized image from the received image using a predetermined threshold, for example. Thereby, 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 necessary.

In step S130, the computer 70 performs arithmetic processing 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 an approximate regression equation that is stored in the storage unit 72 and is prepared in advance. 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, it is possible to optimize air supply conditions and agitation conditions. Such adjustment may be made by a human by looking at the measurement result of the froth bubbles, or may be made by automatic control by the computer 70 . When a human performs adjustment, the computer 70 outputs the measurement result to a display or the like. Further, 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, etc. based on the measurement results. At that time, it goes without saying that the measurement results may be output together. From this point of view, step S140 is not essential, and may be executed as needed.

As described above, according to the method for measuring the diameter of froth bubbles according to the present embodiment, the diameter of froth bubbles can be automatically measured, and further, adjustments can be made to optimize the diameter of froth bubbles as necessary. can be carried out.

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

Although the preferred embodiments of the present invention have been detailed 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.

REFERENCE SIGNS LIST 10 flotation tank 20 stirring blade 30 air supply shaft 40 ore slurry 41 froth foam 42 bright white portion (reflected light region)
50 light source 60 area scan camera 61 connection cord 70 computer 80 froth bubble diameter measuring device 100 flotation machine

Claims (4)

a light source provided above the flotation tank for irradiating the slurry stored in the flotation tank with light from above;
imaging means for imaging the slurry from above;
an arithmetic processing means for calculating a froth bubble diameter of froth bubbles present in the slurry contained in the image captured by the imaging means;
The arithmetic processing means measures the size of the white shining portion of the froth bubble included in the image, and indicates the correlation between the size of the white shining portion of the froth bubble obtained by actual measurement in advance and the size of the froth bubble. Using an approximate regression equation, calculate the froth bubble diameter from the size of the white glowing portion ,
The white shining portion is a region of reflected light reflected upward from the vicinity of the top of the froth bubble when the light is applied to the froth bubble. 2. The floss bubble diameter measuring device according to claim 1 , further comprising image processing means for removing noise from the image picked up by said imaging means and performing image processing for facilitating measurement of the size of said portion of said froth bubble that shines white. . a flotation tank for storing slurry;
A stirring means provided in the flotation tank for stirring the slurry;
A flotation machine comprising the floss bubble diameter measuring device according to claim 1 or 2 . A step of irradiating the upper surface of the slurry stored in the flotation tank with light;
imaging the upper surface of the slurry irradiated with the light;
calculating a froth bubble diameter of froth bubbles present in the slurry, which are included in the captured image;
In the step of calculating the diameter of the froth bubble, the size of the white shining portion of the froth bubble included in the image is measured, and the size of the white shining portion of the froth bubble obtained by actual measurement in advance is compared with the size of the froth bubble. Using an approximate regression formula showing a correlation, calculating the froth bubble diameter from the size of the white glowing part ,
The method for measuring the diameter of a froth bubble, wherein the portion that shines white is a region of reflected light reflected upward from the vicinity of the top of the froth bubble when the light is applied to the froth bubble.

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