CN115228614A - Cold-state active oil bubble preparation device and flotation method for low-rank coal flotation - Google Patents

Abstract

The invention relates to a cold-state active oil bubble preparation device and a flotation method for low-rank coal flotation, belongs to the technical field of low-rank coal flotation, and solves the problems that in the prior art, oil bubble flotation needs heating and is poor in safety. The device comprises an active collecting agent conveying pipeline, a clear water conveying pipeline, a gas conveying pipeline and an oil bubble generator, wherein the clear water conveying pipeline, the active collecting agent conveying pipeline and the gas conveying pipeline are communicated with a feeding port of the oil bubble generator. The oil bubble generator has a simple internal structure, does not have a heating device, can generate stable active oil bubbles, and can meet the requirements of different production scales and different coal qualities in different periods.

Description

A cold-state active oil bubble preparation device and flotation method for low-rank coal flotation

technical field

The invention relates to the technical field of low-rank coal flotation, in particular to a cold-state active oil bubble preparation device and a flotation method for low-rank coal flotation.

Background technique

As an important support and industrial raw material for my country's energy, coal provides an important guarantee for social and economic development and energy security. By 2021, the country's coal output will reach 4.13 billion tons, of which low-rank coal output has accounted for more than 55% of the country's total coal output. As the main coal producing areas move westward, the output of low-rank coal will continue to increase. Therefore, the development and utilization of low-rank coal has been paid more and more attention. The degree of mechanized coal mining continues to increase, the quality of the coal mined continues to deteriorate, and the low-rank coal has a low degree of metamorphism, the coal quality is poor and brittle, and the slime content and ash content increase sharply. people pay attention. Due to the low degree of metamorphism of low-rank coal, high content of water and oxygen-containing functional groups, and developed surface pores, its flotability is poor, and clean coal is difficult to recover, resulting in waste of resources; in order to improve the recovery rate of clean coal, the amount of collectors has to be increased. However, this will lead to the high cost of slime flotation, and the subsequent treatment of slime water will be difficult, which will affect the economic benefits of coal enterprises.

The results of flotation research on various refractory minerals show that compared with conventional flotation, activated oil bubble flotation shows stronger collection capacity and selectivity, and is proved to be a more effective technical means. However, in the process of making oil bubbles and dispersing oil droplets, it is necessary to heat at high temperature to realize the gasification of oil droplets. There are a series of potential safety hazards in actual operation, which greatly limits the popularization and application of oil bubble flotation. Furthermore, due to the heating and gasification of oil droplets, water-soluble surfactants cannot be used so as not to damage the heating device.

SUMMARY OF THE INVENTION

In view of the above analysis, the embodiments of the present invention aim to provide a cold-state active oil bubble preparation device and a flotation method for low-rank coal flotation, so as to solve the problems of heating and poor safety in the existing oil bubble flotation.

In one aspect, the present invention provides a cold-state active oil bubble preparation device for low-rank coal flotation, comprising an active collector conveying pipeline, a clean water conveying pipeline, a gas conveying pipeline and an oil bubble generator, the The clean water delivery pipeline, the active collector delivery pipeline and the gas delivery pipeline are communicated with the feed inlet of the oil bubble generator.

Further, the feeding port includes a first feeding port, the fresh water conveying pipeline includes a water storage tank, and the water storage tank is communicated with the first feeding port.

Further, the active collector conveying pipeline includes a dosing box and a stirring barrel, the dosing box transports the evenly stirred surfactant into the stirring barrel, and the stirring barrel is used for stirring and mixing to add it. Internal surfactants and collectors.

Further, the feeding port includes a second feeding port, and the stirring barrel communicates with the second feeding port.

Further, the gas delivery pipeline includes an air compressor and an air storage tank, and the air compressor compresses the sucked dry air and stores it in the air storage tank.

Further, the feeding port includes a third feeding port, and the gas storage tank is communicated with the third feeding port.

On the other hand, the present invention provides a cold-state active oil bubble flotation method for low-rank coal flotation, using the above-mentioned cold-state active oil bubble preparation device, and the steps include:

Step S1: preparation of active collector, clean water and air;

Step S2: Open the solenoid valves in the clean water delivery pipeline, the active collector delivery pipeline and the gas delivery pipeline, so that the clean water, the active collector and the dry air enter the oil bubble generator;

Step S3: adjusting the openings of the flow control valves in the active collector delivery pipeline, the clean water delivery pipeline and the gas delivery pipeline until stable active oil bubbles are generated in the oil bubble generator;

Step S4: The active oil bubbles generated by the oil bubble generator are sucked into the flotation column through the air inlet of the bubble generator; the bubble generator relies on the negative pressure generated by the circulating coal slurry to inhale the active oil bubbles, and is further pulverized and mixed with the circulating slurry. Mineralize.

Further, the oil bubble generator is communicated with the air inlet of the bubble generator, and the circulation pump is arranged between the flotation column and the bubble generator.

Further, in the step 1, after the surfactant is added to the dosing box and stirred evenly, the surfactant is added to the stirring tank through the first peristaltic pump and the first liquid flow meter to mix with the collector and stir evenly.

Further, in the step 2, the solenoid valves in the fresh water delivery pipeline, the active collector delivery pipeline and the gas delivery pipeline are opened simultaneously or sequentially.

Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

(1) The oil bubble generator of the present invention has a simple internal structure and is only composed of three annular micro-pipes; no heating device, and only relying on the rapid flow and shearing of the liquid in the micro-channel to efficiently generate stable active oil bubbles; the oil bubble size, The quantity and oil film thickness can be precisely controlled by adjusting the flow rate to meet the needs of different production scales and different coal qualities in different periods.

(2) The collector of the present invention after cold foaming is uniformly dispersed in the pulp, which avoids the problem of uneven dispersion of the traditional collector by mechanical stirring, and greatly reduces the amount of the flotation collector.

(3) The cold-state active oil bubbles with controllable particle size and oil film thickness of the present invention have good flotation mineralization effect, and because of the good dispersibility of oil bubbles and the high probability of effective collision with mineral particles, the flotation effect is improved, and the flotation effect is improved. Selectivity and clean coal recovery.

In the present invention, the above technical solutions can also be combined with each other to achieve more preferred combination solutions. Additional features and advantages of the invention will be set forth in the description which follows, and some of the advantages may become apparent from the description, or may be learned by practice of the invention. The objectives and other advantages of the invention may be realized and attained by means of particularly pointed out in the description and drawings.

Description of drawings

The drawings are for the purpose of illustrating specific embodiments only and are not to be considered limiting of the invention, and like reference numerals refer to like parts throughout the drawings.

Fig. 1 is the structural representation of the active oil bubble preparation device of the present invention;

Fig. 2 is the schematic diagram of the internal structure pipeline of the oil bubble generator of the present invention and the oil bubble generation process;

Fig. 3 is the A-A sectional view of Fig. 2;

4 is a schematic structural diagram of the active oil bubble flotation device of the present invention.

Reference number:

1-oil bubble generator; 11-first microchannel; 12-second microchannel; 13-third microchannel; 14-oil bubble output pipeline; 21-dosing box; 22-mixing barrel; 23-first peristaltic pump; 24-first liquid flowmeter; 25-second peristaltic pump; 26-second liquid flowmeter; 27-first flow regulating valve; 28-first solenoid valve; 31-water storage tank; 32-first Three peristaltic pumps; 33-third liquid flow meter; 34-second flow regulating valve; 35-second solenoid valve; 41-air compressor; 42-air storage tank; 43-gas flowmeter; 44-pressure gauge; 45-the third flow regulating valve; 5-bubble generator; 6-flotation column; 7-circulation pump.

Detailed ways

The preferred embodiments of the present invention are specifically described below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention, and together with the embodiments of the present invention, are used to explain the principles of the present invention, but not to limit the scope of the present invention.

Example 1

A specific embodiment of the present invention, as shown in FIG. 1-FIG. 3, discloses a cold-state active oil bubble preparation method for low-rank coal flotation. The steps include:

Step S1: Preparation of active collector, clean water and air.

After the surfactant is added to the dosing box 21 and stirred evenly; the first peristaltic pump 23 and the first liquid flow meter 24 are added to the stirring barrel 22 and stirred evenly (in the mixture of the surfactant and the collector, the surfactant The proportion is 1-3wt%). After the first solenoid valve 28 is opened, it is conveyed to the feeding port of the second microchannel 12 through the pipeline.

It should be noted that both ionic and nonionic surfactants can be used, and anionic surfactants such as palmitic acid, sulfate, sulfonate, etc. are preferred among ionic surfactants.

A first solenoid valve 28 is provided on the active collector conveying pipeline, which is used to control the opening and closing of the output pipeline of the mixing tank 22 . The spherical float self-locking device in the dosing box 21 and the mixing barrel 22 is used to control the respective liquid level.

The water storage tank 31 communicates with the first microchannel 11 of the oil bubble generator 1 . After the second solenoid valve 35 is opened, clean water enters the oil bubble generator 1 through the feeding port of the first microchannel 11 . The liquid level in the water storage tank 31 is controlled by the spherical float self-locking device, and the second solenoid valve 35 controls the opening and closing of the output pipeline of the water storage tank 31 .

The air compressor 41 compresses and stores the sucked dry air in the air storage tank 42 . After the third solenoid valve (not shown in the figure) is opened, the pressurized drying air enters the oil bubble generator 1 through the feed port of the third microchannel 13 . The third solenoid valve controls the opening and closing of the output line of the air tank 42 .

Step S2: Open the solenoid valves (the second solenoid valve 35, the first solenoid valve 28 and the third solenoid valve in this embodiment) in the clean water delivery pipeline, the active collector delivery pipeline and the gas delivery pipeline, so that the Clear water, active collector, and dry air enter the oil bubble generator 1 and fill the first microchannel 11 , the second microchannel 12 and the third microchannel 13 respectively.

It should be noted that, in this step, the first solenoid valve 28 , the second solenoid valve 35 and the third solenoid valve may be opened at the same time or not at the same time, but it is necessary to ensure that no backflow occurs. A solenoid valve 28, a second solenoid valve 35 and a third solenoid valve are opened simultaneously.

Step S3: After the three micro-pipes are full, adjust the flow control valves (the first flow control valve 27, the second flow Adjust the opening of the valve 34 and the third flow control valve 45) until stable active oil bubbles are generated in the first microchannel 11;

Compared with the prior art, in the method for preparing cold active oil bubbles provided in this embodiment, the oil bubble generator includes three annular microchannels, no heating device, and only relies on the rapid flow and shearing of the liquid in the microchannels to efficiently generate stable activity. Oil bubbles; the active collector delivery pipeline, clean water delivery pipeline and gas delivery pipeline are respectively connected with the corresponding feeding ports of the three annular micro-channels of the oil bubble generator, which can produce a large adjustable range of size, and the thickness of the oil film. Easy-to-control stable active oil bubbles.

Example 2

Another specific embodiment of the present invention, as shown in Figures 1 to 3, discloses a cold-state active oil bubble preparation device (hereinafter referred to as the cold-state active oil bubble preparation device) for low-rank coal flotation, which is used for The preparation of the cold state active oil bubble of embodiment 1, comprises active collector conveying pipeline, clear water conveying pipeline, gas conveying pipeline and oil bubble generator 1, and oil bubble generator 1 comprises three coaxial microchannels , the clean water delivery pipeline, the active collector delivery pipeline and the gas delivery pipeline are respectively connected with the feed ports of the three microchannels from the outside to the inside of the oil bubble generator 1 .

Compared with the prior art, in the cold-state active oil bubble preparation device provided in this embodiment, the oil bubble generator includes three annular microchannels, without a heating device, and only relies on the rapid flow and shear of the liquid in the microchannel to efficiently generate stable activity. Oil bubbles; the active collector delivery pipeline, clean water delivery pipeline and gas delivery pipeline are respectively connected with the corresponding feeding ports of the three annular micro-channels of the oil bubble generator, which can produce a large adjustable range of size, and the thickness of the oil film. Easy-to-control stable active oil bubbles reduce the amount of flotation collectors.

As shown in FIG. 2 and FIG. 3 , the oil bubble generator 1 includes a first microchannel 11 , a second microchannel 12 and a third microchannel 13 arranged coaxially, and the second microchannel 12 is located in the first microchannel 11 and the third microchannel 13 . Between the three microchannels 13 , the inlets of the first microchannel 11 , the second microchannel 12 and the third microchannel 13 are located on the same side, and the inlets of the first microchannel 11 , the second microchannel 12 and the third microchannel 13 The discharge ports are connected, and the discharge ports of the second microchannel 12 and the third microchannel 13 are located in the first microchannel 11, and the medium flowing out from the second microchannel 12 and the third microchannel 13 merges into the first microchannel 11. inside the microchannel 11 .

In this embodiment, the clean water delivery pipeline, the active collector delivery pipeline and the gas delivery pipeline are respectively communicated with the feed ports of the first microchannel 11 , the second microchannel 12 and the third microchannel 13 . As shown in FIG. 2 , the lower end of the outlet of the first microchannel 11 is provided with an oil bubble output pipe 14 , and the medium flowing out from the outlet of the first microchannel 11 , the second microchannel 12 and the third microchannel 13 enters the The oil bubble output pipe 14, the formed oil bubble is discharged from the oil bubble output pipe 14.

The active collector conveying pipeline includes a dosing box 21 and a stirring barrel 22 . The dosing box 21 is used to stir the surfactant added into the dosing box 21 , and the surfactant stirred evenly by the dosing box 21 is transported into the stirring barrel 22 . After the collector and the surfactant in the stirring tank 22 are evenly mixed, they are transported to the feeding port of the second microchannel 12 through the pipeline.

A first peristaltic pump 23 is arranged between the dosing box 21 and the mixing barrel 22 , and the evenly stirred surfactant in the dosing box 21 is transported to the mixing barrel 22 by the power provided by the first peristaltic pump 23 .

In order to achieve an accurate and reasonable ratio of medicaments, a first liquid flow meter 24 is also provided between the first peristaltic pump 23 and the mixing barrel 22 .

In this embodiment, by setting a high-precision first liquid flow meter 24 in the pipeline between the dosing tank 21 and the stirring barrel 22, the volume of the collector and the surfactant entering the stirring barrel 22 can be accurately determined, Realize the precise and reasonable proportion of medicines.

A second peristaltic pump 25, a second liquid flow meter 26 and a first flow regulating valve 27 are arranged in the pipeline between the mixing tank 22 and the feed port of the second microchannel 12. Specifically, the second liquid flow meter 26 and the first flow regulating valve 27 are located between the second peristaltic pump 25 and the second microchannel 12.

The uniformly mixed collector and surfactant in the mixing tank 22 are delivered to the feeding port of the second microchannel 12 by the power provided by the second peristaltic pump 25 . The high-precision second liquid flow meter 26 is used to display the flow of the active collector in real time; by adjusting the opening of the first flow control valve 27 in the pipeline, the flow of the active collector entering the oil bubble generator 1 is regulated .

In order to facilitate the control of the on-off of the active collector delivery pipeline, a first solenoid valve 28 is provided on the active collector delivery pipeline, and the first solenoid valve 28 is arranged downstream of the stirring barrel 22 , specifically located in the stirring barrel 22 and the second peristaltic valve Between the pumps 25, it is used to control the opening and closing of the output pipeline of the mixing tank 22.

The clean water delivery pipeline includes a water storage tank 31 and a third peristaltic pump 32. The clean water in the water storage tank 31 is delivered to the oil bubble generator 1 through the third peristaltic pump 32, and enters the oil through the feeding port of the first microchannel 11. Bubble Generator 1.

In order to precisely control the flow of clean water, the clean water delivery pipeline also includes a third liquid flow meter 33 and a second flow regulating valve 34. The third liquid flow meter 33 and the second flow regulating valve 34 are located in the third peristaltic pump 32 and the oil bubble. between generator 1.

In this embodiment, the flow rate of clean water is displayed in real time through the high-precision third liquid flow meter 33 set in the clean water delivery pipeline; the opening degree of the second flow control valve 34 in the clean water delivery pipeline is adjusted to regulate the occurrence of oil bubbles entering the water. The flow rate of clean water in device 1.

In order to control the on-off of the clean water delivery pipeline, the clean water delivery pipeline also includes a second solenoid valve 35. The second solenoid valve 35 is arranged between the water storage tank 31 and the third peristaltic pump 32 for controlling the water storage tank. The opening and closing of the output pipeline of 31.

It should be noted that the dosing box 21, the mixing barrel 22 and the water storage tank 31 are all provided with a liquid level maintaining device, that is, a spherical float self-locking device, so as to keep the liquid level in the container at an appropriate level and provide continuous stability for downstream equipment. incoming materials.

The gas delivery pipeline includes an air compressor 41 and an air storage tank 42 . The air compressor 41 compresses the sucked dry air and stores it in the air storage tank 42 . In order to precisely control the amount and pressure of the air entering the oil bubble generator 1, the gas delivery pipeline also includes a gas flow meter 43, a pressure gauge 44 and a third flow regulating valve 45. The flow regulating valve 45 is arranged between the gas storage tank 42 and the third microchannel 13 .

Understandably, in order to facilitate the control of the on-off of the gas delivery pipeline, the gas delivery pipeline also includes a third solenoid valve (not shown in the figure), and the third solenoid valve is arranged downstream of the gas storage tank 42 , and is specifically located in the gas storage tank 42 . Between the gas tank 42 and the gas flow meter 43 , it is used to control the opening and closing of the output pipeline of the gas storage 42 .

In this embodiment, clean water, uniformly stirred active collector and dry air enter through the feeding port of the first microchannel 11 , the feeding port of the second microchannel 12 and the feeding port of the third microchannel 13 respectively. Oil bubble generator 1. Peristaltic pump, solenoid valve, flow control valve and liquid flow meter are installed on the active collector delivery pipeline, clean water delivery pipeline and air delivery pipeline, which can monitor the flow rate entering the oil bubble generator 1 in real time and adjust the occurrence of oil bubbles. The size, speed and oil film thickness of the active oil bubbles generated in the device 1.

In this embodiment, open the solenoid valve in each conveying pipeline, so that clean water, active collector and air enter the oil bubble generator 1 and fill the first microchannel 11, the second microchannel 12 and the third microchannel 13 respectively Three annular micro-pipes are used to eliminate the influence of residual air in the first micro-channel 11 and the second micro-channel 12 on the preparation of active oil bubbles.

In this embodiment, after the three annular micro-pipes of the oil bubble generator 1 are filled with the corresponding liquid and air, the second solenoid valve 35 in the clean water delivery pipeline is closed, and by adjusting the active collector and the drying air delivery pipeline The opening of the flow regulating valve (the first flow regulating valve 27 and the third flow regulating valve 45), regulate the collector and air flow and flow rate in the second microchannel 12 and the third microchannel 13, until the air is in the second microchannel 12 and the third microchannel 13. The ends of the microchannel 12 and the third microchannel 13 are sheared by the flowing active collector to stably generate air bubbles in the oil.

In this embodiment, after the bubbles in the oil are pushed into the back end thin pipeline (oil bubble output pipeline 14) by the subsequent collector, the second solenoid valve 35 is opened to maintain the flow control valve of the air and active collector pipelines. The opening degree remains unchanged, the opening degree of the second flow control valve 34 in the clean water pipeline is adjusted, and the flow rate and flow rate of the clean water in the first microchannel 11 are regulated, until the collector containing air bubbles can be sheared by the flowing clean water to stably generate activity. Oil bubbles. By regulating the changes in the flow rate and flow rate of clean water in the first microchannel 11, a relatively large range of fluid shear force is generated at the end of the three microchannels, thereby generating stable active oil bubbles with a large size adjustable range and easy control of oil film thickness. In order to meet the needs of different production scales and different coal qualities in different periods.

Example 3

Another specific embodiment of the present invention, as shown in FIG. 4 , discloses a cold-state active oil bubble flotation device for low-rank coal flotation (hereinafter referred to as cold-state active oil bubble flotation device), including embodiments The cold-state active oil bubble preparation device of 3 also includes a bubble generator 5, a flotation column 6 and a circulating pump 7, and the air inlet of the bubble generator 5 is communicated with the oil bubble generator 1. The air inlet is communicated with the oil bubble output pipeline 14, the circulating pump 7 is arranged between the flotation column 6 and the bubble generator 5, and the active oil bubbles generated by the oil bubble generator 1 are sucked into the flotation through the air inlet of the bubble generator 5. Column 6, the bubble generator 5 relies on the negative pressure generated by the circulating pump 7 to circulate the coal slurry at a high speed to inhale the active oil bubbles, and further crush and circulate the slurry for mineralization.

Compared with the prior art, in the cold-state active oil bubble flotation device provided in this embodiment, the oil bubble generator includes three annular microchannels, no heating device, and only relies on the rapid flow and shearing of the liquid in the microchannel to efficiently generate stable oil bubbles. Active oil bubbles; the active collector conveying pipeline, the clean water conveying pipeline and the gas conveying pipeline are respectively connected with the corresponding feeding ports of the three annular microchannels of the oil bubble generator, which can prepare and produce a large adjustable range of size and oil film. The stable active oil bubbles with easy-to-adjust thickness can reduce the amount of flotation collectors and at the same time realize the efficient recovery of low-rank coal clean coal and improve the flotation effect.

Example 4

Another specific embodiment of the present invention, as shown in Figures 1 to 4, discloses a cold-state active oil bubble flotation method for low-rank coal flotation. On the basis of Embodiment 1, the steps include the following examples: Steps 1 to 3 of 1, further comprising:

Step S4: the active oil bubbles generated by the oil bubble generator 1 are sucked into the flotation column 6 through the air inlet of the bubble generator 5; The oil bubbles are further crushed and then mineralized with the circulating pulp.

Compared with the prior art, in the cold-state active oil bubble flotation method provided in this embodiment, the oil bubble generator includes three annular microchannels, without a heating device, and only relies on the rapid flow and shear of the liquid in the microchannel to efficiently generate stable oil bubbles. Active oil bubbles; the active collector conveying pipeline, the clean water conveying pipeline and the gas conveying pipeline are respectively connected with the corresponding feeding ports of the three annular microchannels of the oil bubble generator, which can prepare and produce a large adjustable range of size and oil film. The stable active oil bubbles with easy-to-adjust thickness can reduce the amount of flotation collectors and at the same time realize the efficient recovery of low-rank coal clean coal and improve the flotation effect.

The above description is only a preferred embodiment of the present invention, but the protection scope of the present invention is not limited to this. Substitutions should be covered within the protection scope of the present invention.

Claims (10)

1. a cold-state active oil bubble preparation device for low-rank coal flotation, is characterized in that, comprises active collector conveying pipeline, clear water conveying pipeline, gas conveying pipeline and oil bubble generator (1), The clear water delivery pipeline, the active collector delivery pipeline and the gas delivery pipeline are communicated with the feed inlet of the oil bubble generator (1). 2 . The cold-state active oil bubble preparation device for low-rank coal flotation according to claim 1 , wherein the feeding port comprises a first feeding port, and the clean water conveying pipeline comprises a water storage tank. 3 . (31), the water storage tank (31) is communicated with the first feeding port. 3. The cold-state active oil bubble preparation device for low-rank coal flotation according to claim 1, wherein the active collector conveying pipeline comprises a dosing tank (21) and a stirring barrel (22) , the dosing box (21) transports the evenly stirred surfactant into the stirring barrel (22), and the stirring barrel (22) is used for stirring and mixing the surfactant and the collector added therein. 4 . The cold-state active oil bubble preparation device for low-rank coal flotation according to claim 3 , wherein the feeding port comprises a second feeding port, and the mixing barrel ( 22 ) is connected to the The second feeding port is connected. 5. The cold-state active oil bubble preparation device for low-rank coal flotation according to claim 1, wherein the gas delivery pipeline comprises an air compressor (41) and a gas storage tank (42), so The air compressor (41) compresses the sucked dry air and stores it in the air storage tank (42). 6 . The cold-state active oil bubble preparation device for low-rank coal flotation according to claim 5 , wherein the feeding port comprises a third feeding port, and the gas storage tank (42) is connected to the The third feeding port is communicated. 7. A cold-state active oil bubble flotation method for low-rank coal flotation, wherein the cold-state active oil bubble preparation device according to any one of claims 1-6 is adopted, and the step comprises: Step S1: preparation of active collector, clean water and air; Step S2: Open the solenoid valves in the clean water delivery pipeline, the active collector delivery pipeline and the gas delivery pipeline, so that the clean water, the active collector and the dry air enter the oil bubble generator (1); Step S3: adjusting the openings of the flow control valves in the active collector delivery pipeline, the clean water delivery pipeline and the gas delivery pipeline until stable active oil bubbles are generated in the oil bubble generator (1); Step S4: the active oil bubbles generated by the oil bubble generator (1) are sucked into the flotation column (6) through the air inlet of the bubble generator (5); the bubble generator (5) relies on the circulating pump (7) to circulate the coal slurry to generate The negative pressure sucks the active oil bubbles, and after further crushing, it is mineralized with the circulating pulp. 8. The cold-state active oil bubble flotation method for low-rank coal flotation according to claim 7, characterized in that, the air intake of the oil bubble generator (1) and the bubble generator (5) and the circulating pump (7) is arranged between the flotation column (6) and the bubble generator (5). 9. The cold-state active oil bubble flotation method for low-rank coal flotation according to claim 7, characterized in that, in the step 1, after adding the surfactant into the dosing box (21) and stirring evenly, The first peristaltic pump (23) and the first liquid flow meter (24) are added to the mixing tank (22) to mix with the collector and stir evenly. 10. The cold-state active oil bubble flotation method for low-rank coal flotation according to any one of claims 7-9, wherein in the step 2, the clear water conveying pipeline, the active oil bubble The solenoid valves in the collector delivery line and the gas delivery line are opened simultaneously or sequentially.

Images