A Laboratory Micro-Flotation Method Based on Ultrasonic Pulping and Aeration

Abstract

The present invention discloses a laboratory micro flotation method based on ultrasonic pulp conditioning and aeration. The method includes mixing a powder sample with water to obtain a mixed slurry, then adding the mixed slurry into a flotation cell and replenishing water to adjust the liquid level height of the mixed slurry; adjusting the height of the horn, and turning on the ultrasonic wave to enter the ultrasonic pulp conditioning stage I; adding a collector and a regulator, and entering the ultrasonic pulp conditioning stage II; adding a foaming agent, and entering the ultrasonic pulp conditioning stage III; turning off the ultrasonic wave, adjusting the height of the horn, and turning on the ultrasonic wave to enter the ultrasonic aeration stage; turning off the ultrasonic wave, and collecting the flotation concentrate and the flotation tailings. The equipment of the present invention has no mechanical stirring device and self-suction aeration system. During the flotation process, pulp conditioning and aeration are carried out by ultrasonic waves, and no other devices need to be installed inside the flotation cell. Therefore, the flotation machine can be equipped with a flotation cell with a smaller volume, the sample consumption is greatly reduced, and micro flotation can be carried out; the techniques of ultrasonic pulp conditioning and aeration can obtain better dispersion effects and significantly reduce the flotation bubble size, thereby improving the flotation efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of laboratory micro-miniature flotation equipment, and particularly relates to a laboratory micro-flotation method based on ultrasonic pulp conditioning and aeration. Background Art

[0002] Flotation is one of the common means for the separation of fine particles and is widely used in the fields of mineral processing and sewage treatment. Through the differences in the physicochemical properties of particle surfaces, the flotation separation of particles with different properties can be achieved. Usually, the optimal process parameters for flotation between different materials are different. Therefore, it is usually necessary to determine the optimal flotation process conditions before industrial flotation. Laboratory flotation is an important method for exploring the floatability of materials and is also a necessary procedure before the industrial flotation process. Through laboratory miniaturized flotation equipment, the floatability of materials is evaluated to obtain the optimal process parameters for different flotation feedstocks, so as to guide the equipment selection, reagent selection and dosage selection in industrial flotation, etc.

[0003] At present, most domestic laboratory flotation experiments use self-aspirating mechanical agitation flotation machines. Such flotation machines have independent mechanical agitation devices and self-aspirating aeration systems. Due to the existence of mechanical agitation devices and self-aspirating aeration systems, the designed volume of laboratory flotation machines is generally large. The volume of most laboratory flotation machines is 1.5 L, and a small number can reach 0.5 L. However, in many fine material flotation experiments, due to reasons such as the high cost and difficulty in obtaining raw materials and flotation reagents, the cost of laboratory flotation exploration is relatively high. For example, in the flotation of rare earth metals, graphene, graphene oxide and other substances, the raw materials themselves have high value. If a conventional self-aspirating mechanical agitation flotation machine is used, a large amount of raw materials will be consumed in flotation, and the flotation exploration experiment will be a huge expense. In addition, in some cases, the available amount of raw materials is small or difficult to obtain, and a large-capacity flotation cell will require more flotation feedstock, resulting in the inability to carry out flotation exploration experiments.

[0004] As a commonly used external field strengthening technology, ultrasound can be used to improve the flotation effect of minerals. At present, the applications of ultrasound in flotation mainly include the removal of fine slime covering on the particle surface, the stripping of oxide films, desulfurization in the flotation process, reagent emulsification and dispersion, etc. These ultrasound application schemes are only limited to being auxiliary means in flotation and cannot independently undertake the functions of pulp conditioning and aeration in the flotation process. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a laboratory micro-flotation method based on ultrasonic pulp conditioning and aeration. During the flotation process, ultrasonic waves are used for pulp conditioning and aeration, replacing the mechanical agitation device and self-aspirating aeration system built in the flotation machine in the traditional technology, enabling the flotation machine to be equipped with a small-volume flotation cell, reducing the demand for flotation feedstock, and realizing micro-flotation.

[0006] The object of the present invention is mainly achieved by the following technical solutions:

[0007] A laboratory micro flotation method based on ultrasonic pulp conditioning and aeration, comprising the following steps:

[0008] S1: Mix the powder sample with water to obtain a mixed slurry, then add it into the flotation cell, and make up water until the liquid level of the mixed slurry is 2 - 10 mm away from the top of the flotation cell;

[0009] S2: Adjust the height of the electric lifting table so that the lower end of the horn is placed at a height of 1 / 3 to 2 / 3 below the liquid level of the mixed slurry, then turn on the ultrasonic wave to enter the first stage of ultrasonic pulp conditioning, and the time of the first stage of ultrasonic pulp conditioning is 3 - 10 min;

[0010] S3: Add a collector and a regulator to the mixed slurry to enter the second stage of ultrasonic pulp conditioning, and the time of the second stage of ultrasonic pulp conditioning is 1 - 5 min;

[0011] S4: Add a foaming agent to the mixed slurry to enter the third stage of ultrasonic pulp conditioning, and the time of the third stage of ultrasonic pulp conditioning is 10 - 60 s;

[0012] S5: After the third stage of ultrasonic pulp conditioning ends, turn off the ultrasonic wave, adjust the height of the electric lifting table so that the lower end of the horn is placed 1 - 5 mm above the liquid level of the mixed slurry, then turn on the ultrasonic wave to enter the ultrasonic aeration stage, and the time of the ultrasonic aeration stage is 1 - 5 min;

[0013] S6: After the ultrasonic aeration stage ends, turn off the ultrasonic wave. The foam product in the concentrate collection tank is the flotation concentrate, and the slurry remaining in the flotation cell is the flotation tailings.

[0014] A laboratory micro flotation device based on ultrasonic pulp conditioning and aeration, which includes a flotation cell, a scale, a concentrate collection tank, an electric lifting table, an ultrasonic oscillator, a horn, a frame, a fixture, and an ultrasonic generator.

[0015] Furthermore, a scale is adhered to the outside of the flotation cell, and the flotation cell is placed on the electric lifting table and fixed by a fixture, and the other end of the fixture is vertically welded to the frame; the concentrate collection tank is placed below the overflow port of the flotation cell; the electric lifting table is fixed to the lower frame; an ultrasonic oscillator is provided above the central position of the flotation cell, the ultrasonic oscillator is embedded in the upper part of the frame and connected to the horn, and the horn can extend into the flotation cell; the ultrasonic oscillator is connected to the ultrasonic generator through a connecting wire, and its generation of ultrasonic waves can be controlled by the ultrasonic generator.

[0016] Furthermore, the flotation cell is a columnar, round-bottomed structure made of transparent glass or organic glass, with a volume of 10-500 mL. When in use, the columnar, round-bottomed flotation cell structure can make the flow field distribution in the ultrasonic pulping process more reasonable, reduce the dead angle of ultrasonic action, and fully disperse the particles; the flotation cell made of transparent glass or organic glass makes it easier to observe the liquid level of the slurry during the flotation process, and is convenient for adjusting the relative height of the amplitude rod; there is no built-in stirring and inflation mechanism in the flotation cell, and the flotation machine can be equipped with a flotation cell of smaller volume.

[0017] Furthermore, the ultrasonic vibrator generates ultrasound at a frequency of 20-50 kHz. Ultrasound in this frequency band has a stronger cavitation effect, and the disperser has a better inflation effect.

[0018] Furthermore, the ultrasonic power of the ultrasonic slurry adjustment I, ultrasonic slurry adjustment II and ultrasonic slurry adjustment III stages is 50-300W, and the slurry adjustment intensity can be changed by adjusting the ultrasonic power.

[0019] Furthermore, the ultrasonic power in the ultrasonic inflation stage is 200-1000W, and the inflation volume can be changed by adjusting the ultrasonic power.

[0020] Beneficial effects of the present invention: The present invention proposes a laboratory micro-flotation method based on ultrasonic slurry adjustment and aeration, which realizes slurry dispersion and flotation aeration respectively through the same ultrasonic device. Compared with the prior art, the flotation equipment described in the present invention has no mechanical stirring device and self-aspiration aeration system, and adopts the cavitation effect and mechanical effect of ultrasound to realize slurry adjustment and aeration, thereby replacing the complex aeration system and stirring system in common laboratory flotation equipment. When the amplitude transformer is extended into the mixed slurry, ultrasonic slurry adjustment is turned on, and the special structure of the flotation cell cooperates with the ultrasonic effect to obtain a better flow field distribution, and the particles and reagents are more fully dispersed; when the amplitude transformer is adjusted to above the liquid surface of the mixed slurry, the ultrasound will break up the air above the liquid surface, and inject tiny bubbles into the water to float the concentrate. During the entire flotation process, ultrasound can independently perform the pulping and aeration functions of the flotation process, and the equipment is simple in structure. No other devices are required in the flotation cell. Therefore, the flotation machine can be equipped with a flotation cell of extremely small volume, and the sample consumption can be greatly reduced, thereby realizing micro-flotation. The use of ultrasonic pulping and aeration technology can obtain better particle dispersion effect and significantly reduce the size of flotation bubbles, thereby improving flotation efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a schematic diagram of the structure of the device of the present invention.

[0022] In the figure, 1-flotation tank, 2-scale, 3-overflow port, 4-concentrate collecting tank, 5-electric lifting platform, 6-ultrasonic vibrator, 7-amplifier, 8-frame, 9-fixer, 10-connecting line, 11-ultrasonic generator. Detailed implementation manners

[0023] The present invention will be further described below with reference to the accompanying drawings.

[0024] As Figure 1 shown, a micro flotation device for laboratory use based on ultrasonic pulp mixing and aeration includes a flotation cell (1), a scale (2), an overflow port (3), a concentrate collection tank (4), an electric lifting table (5), an ultrasonic vibrator (6), a horn (7), a frame (8), a fixture (9), a connecting wire (10) and an ultrasonic generator (11).

[0025] According to Figure 1 shown, the scale (2) is adhered to the outside of the flotation cell (1), and the flotation cell (1) is placed on the electric lifting table (5) and fixed by the fixture (9), and the other end of the fixture (9) is vertically welded to the frame (8); the concentrate collection tank (4) is placed below the overflow port (3) of the flotation cell (1); the electric lifting table (5) is fixed to the lower frame (8); an ultrasonic vibrator (6) is provided above the center of the flotation cell (1), the ultrasonic vibrator (6) is embedded in the upper part of the frame (8) and connected to the horn (7), and the horn can extend into the flotation cell (1); the ultrasonic vibrator (6) is connected to the ultrasonic generator (11) through the connecting wire (10), and the generation of ultrasonic waves can be controlled by the ultrasonic generator (11).

[0026] According to Figure 1 shown, the flotation cell (1) has a columnar and round-bottom structure, and the material is transparent glass or plexiglass, and the volume is 10 - 500 mL.

[0027] According to Figure 1 shown, the ultrasonic frequency generated by the ultrasonic vibrator (6) is 20 - 50 kHz.

[0028] A laboratory micro flotation method based on ultrasonic pulp mixing and aeration includes the following steps:

[0029] S1: Mix the powder sample with water to obtain a mixed slurry, then add it to the flotation cell, and make up water until the liquid level of the mixed slurry is 2 - 10 mm away from the top of the flotation cell;

[0030] S2: Adjust the height of the electric lifting table so that the lower end of the horn is placed at a height of 1 / 3 to 2 / 3 below the liquid level of the mixed slurry, and then turn on the ultrasonic wave to enter the ultrasonic pulp mixing stage I, and the time of the ultrasonic pulp mixing stage I is 3 - 10 min;

[0031] S3: Add a collector and a regulator to the mixed slurry to enter the ultrasonic pulp mixing stage II, and the time of the ultrasonic pulp mixing stage II is 1 - 5 min;

[0032] S4: Add a foaming agent to the mixed slurry and enter the third stage of ultrasonic pulp conditioning. The time for the third stage of ultrasonic pulp conditioning is 10 - 60 s;

[0033] S5: After the third stage of ultrasonic pulp conditioning ends, turn off the ultrasonic wave. Adjust the height of the electric lifting table so that the lower end of the horn is placed 1 - 5 mm above the liquid surface of the mixed slurry. Then turn on the ultrasonic wave and enter the ultrasonic aeration stage. The time for the ultrasonic aeration stage is 1 - 5 min;

[0034] S6: After the ultrasonic aeration stage ends, turn off the ultrasonic wave. The foam product in the concentrate collection tank is the flotation concentrate, and the slurry remaining in the flotation cell is the flotation tailings.

[0035] The ultrasonic power in the first stage of ultrasonic pulp conditioning, the second stage of ultrasonic pulp conditioning, and the third stage of ultrasonic pulp conditioning is 50 - 300 W.

[0036] The ultrasonic power in the ultrasonic aeration stage is 200 - 1000 W.

[0037] The present invention will be further described in conjunction with specific usage examples. Taking the coal slime flotation feed of a coal preparation plant in Shandong as a test sample, its ash content is 14.16%, and the analysis results of the chemical composition of the ash are shown in Table 1.

[0038] Table 1 Analysis results of the chemical composition of the ash of the coal slime flotation feed of a coal preparation plant in Shandong

[0039] Chemical composition <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO <![CDATA[K2O]]> MgO Others Content / % 49.45 16.26 16.21 3.49 2.70 11.90

[0040] The analysis results of the particle size composition of the coal slime flotation feed of a coal preparation plant in Shandong are shown in Table 2.

[0041] Table 2 Analysis results of the particle size composition of the coal slime flotation feed of a coal preparation plant in Shandong

[0042] Particle size grade Content / % Ash content / % +0.25mm 5.23 9.14 0.125 - 0.25mm 12.38 12.78 0.074 - 0.125mm 22.58 13.59 0.045 - 0.074mm 28.69 13.98 -0.045mm 31.12 16.68

[0043] Example 1:

[0044] The material of the flotation cell of the laboratory micro flotation equipment based on ultrasonic pulp conditioning and aeration is transparent plexiglass, and the volume is 100 mL. The frequency of the ultrasonic wave generated by the ultrasonic oscillator is 20 kHz.

[0045] In the steps of the flotation method, in step S1, add water to make the height of the liquid surface of the mixed slurry 10 mm away from the top of the flotation cell. In step S2, the time for the first stage of ultrasonic pulp conditioning is 10 min. In step S3, the time for the second stage of ultrasonic pulp conditioning is 3 min. In step S4, the time for the third stage of ultrasonic pulp conditioning is 60 s. In step S5, adjust the height of the electric lifting table so that the lower end of the horn is placed 1 mm above the liquid surface of the mixed slurry, and the time for the ultrasonic aeration stage is 3 min.

[0046] After the flotation exploration experiment, the maximum concentrate yield of the slime flotation feed in a coal preparation plant in Shandong can reach 82.31%, the concentrate ash content is 9.38%, and the tailings ash content is 35.60%.

[0047] Example 2:

[0048] The material of the flotation cell of the laboratory micro flotation equipment based on ultrasonic pulp conditioning and aeration is transparent plexiglass, and the volume is 500 mL. The frequency of the ultrasonic oscillator generating ultrasonic waves is 40 kHz.

[0049] In the steps of the flotation method, in step S1, water is added to make the liquid level height of the mixed slurry 2 mm away from the top of the flotation cell. In step S2, the time of the first stage of ultrasonic pulp conditioning is 3 min. In step S3, the time of the second stage of ultrasonic pulp conditioning is 1 min. In step S4, the time of the third stage of ultrasonic pulp conditioning is 10 s. In step S5, the height of the electric lifting table is adjusted so that the lower end of the horn is 3 mm above the liquid level of the mixed slurry, and the time of the ultrasonic aeration stage is 1 min.

[0050] After the flotation exploration experiment, the maximum concentrate yield of the slime flotation feed in a coal preparation plant in Shandong can reach 65.38%, the concentrate ash content is 8.23%, and the tailings ash content is 26.01%.

[0051] Example 3:

[0052] The material of the flotation cell of the laboratory micro flotation equipment based on ultrasonic pulp conditioning and aeration is transparent plexiglass, and the volume is 10 mL. The frequency of the ultrasonic oscillator generating ultrasonic waves is 50 kHz.

[0053] In the steps of the flotation method, in step S1, water is added to make the liquid level height of the mixed slurry 5 mm away from the top of the flotation cell. In step S2, the time of the first stage of ultrasonic pulp conditioning is 6 min. In step S3, the time of the second stage of ultrasonic pulp conditioning is 2 min. In step S4, the time of the third stage of ultrasonic pulp conditioning is 30 s. In step S5, the height of the electric lifting table is adjusted so that the lower end of the horn is 5 mm above the liquid level of the mixed slurry, and the time of the ultrasonic aeration stage is 5 min.

[0054] After the flotation exploration experiment, the maximum concentrate yield of the slime flotation feed in a coal preparation plant in Shandong can reach 60.17%, the concentrate ash content is 8.96%, and the tailings ash content is 22.16%.

Claims

1. A laboratory micro flotation method based on ultrasonic sizing and aeration, characterized in that It includes the following steps: S1: Mix the powder sample with water to obtain a mixed slurry, then add it into the flotation cell and make up water until the liquid level of the mixed slurry is 2 - 10 mm away from the top of the flotation cell; S2: Adjust the height of the electric lifting table so that the lower end of the horn is placed at a height of 1 / 3 to 2 / 3 below the liquid level of the mixed slurry, then turn on the ultrasonic wave to enter the first stage of ultrasonic pulp conditioning. The time of the first stage of ultrasonic pulp conditioning is 3 - 10 min; S3: Add a collector and a regulator to the mixed slurry to enter the second stage of ultrasonic pulp conditioning. The time of the second stage of ultrasonic pulp conditioning is 1 - 5 min; S4: Add a foaming agent to the mixed slurry to enter the third stage of ultrasonic pulp conditioning. The time of the third stage of ultrasonic pulp conditioning is 10 - 60 s; S5: After the third stage of ultrasonic pulp conditioning ends, turn off the ultrasonic wave, adjust the height of the electric lifting table so that the lower end of the horn is placed 1 - 5 mm above the liquid level of the mixed slurry, then turn on the ultrasonic wave to enter the ultrasonic aeration stage. The time of the ultrasonic aeration stage is 1 - 5 min; S6: After the ultrasonic aeration stage ends, turn off the ultrasonic wave. The foam product in the concentrate collection tank is the flotation concentrate, and the slurry remaining in the flotation cell is the flotation tailings; Among them, the laboratory micro - flotation method based on ultrasonic pulp conditioning and aeration is realized by the following equipment: flotation cell (1), scale (2), overflow port (3), concentrate collection tank (4), electric lifting table (5), ultrasonic vibrator (6), horn (7), frame (8), fixture (9), connecting wire (10) and ultrasonic generator (11); The scale (2) is adhered to the outside of the flotation cell (1), and the flotation cell (1) is placed on the electric lifting table (5) and fixed by the fixture (9). The other end of the fixture (9) is vertically welded to the frame (8); the concentrate collection tank (4) is placed below the overflow port (3) of the flotation cell (1); the electric lifting table (5) is fixed on the lower frame (8); above the central position of the flotation cell (1), there is an ultrasonic vibrator (6). The ultrasonic vibrator (6) is embedded in the upper part of the frame (8) and connected to the horn (7), and the horn can extend into the flotation cell (1); the ultrasonic vibrator (6) is connected to the ultrasonic generator (11) through the connecting wire (10), and its generation of ultrasonic waves can be controlled by the ultrasonic generator (11); The flotation cell (1) is of a columnar and round - bottom structure, made of transparent glass or plexiglass, and has a volume of 10 - 500 mL; The ultrasonic vibrator (6) generates ultrasonic waves with a frequency of 20 - 50 kHz.

2. The laboratory micro flotation method based on ultrasonic sizing and inflation according to claim 1, wherein The ultrasonic power in the first stage of ultrasonic pulp conditioning, the second stage of ultrasonic pulp conditioning and the third stage of ultrasonic pulp conditioning is 50 - 300 W.

3. A laboratory micro flotation method based on ultrasonic sizing and aeration according to claim 1, characterized in that The ultrasonic power in the ultrasonic aeration stage is 200 - 1000 W.

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