A bubble generator and a hydrofloatation apparatus

Abstract

The application discloses a kind of bubble generator and hydraulic floatation equipment, belong to mineral processing technical field, solve the problem that separation effect is poor in prior art due to larger bubble scale.The bubble generator, including gas supply unit, flow dividing tee, gas chamber and microwell plate;Flow dividing tee has mutually communicating air inlet branch, emptying branch and gas supply branch;The air outlet of gas supply unit is communicated with air inlet branch, emptying branch is communicated with external environment, and gas supply branch is communicated with gas chamber;Microwell plate is located at the air outlet end of gas chamber.The bubble generator and hydraulic floatation equipment can be used for hydraulic floatation.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology, and particularly relates to a bubble generator and a hydraulic flotation device. Background Technology

[0002] Hydraulic flotation is an emerging coarse particle separation technology with good separation efficiency in the particle size range of 150–1000 μm. It can complement traditional flotation methods in terms of particle size separation.

[0003] The separation effect of hydraulic flotation is mainly affected by the upward flow velocity and the bubble size.

[0004] In existing technologies, the size of the bubbles is relatively large due to the influence of the gas supply pressure, resulting in poor sorting effect. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide a bubble generator and a hydraulic flotation device, which solves the problem of poor separation effect caused by large bubble size in the prior art.

[0006] The objective of this invention is mainly achieved through the following technical solutions:

[0007] This invention provides a bubble generator, including a gas supply unit, a flow divider tee, a gas chamber, and a microporous plate; the flow divider tee has an inlet branch, an outlet branch, and a gas supply branch that are interconnected; the outlet of the gas supply unit is connected to the inlet branch, the outlet branch is connected to the external environment, and the gas supply branch is connected to the gas chamber; the microporous plate is disposed at the outlet end of the gas chamber.

[0008] Furthermore, the flow ratio between the venting branch and the gas supply branch is 1 to 10.

[0009] Furthermore, it also includes a pulse solenoid valve, through which the outlet of the air supply unit is connected to the intake branch.

[0010] Furthermore, a pressure regulator is installed on the connection line between the gas outlet of the gas supply unit and the pulse solenoid valve.

[0011] Furthermore, a gas flow meter is installed on the connection pipeline between the gas outlet of the gas supply unit and the pulse solenoid valve, and / or on the connection pipeline between the tee and the external environment.

[0012] Furthermore, no buffer tanks are installed on the connecting pipelines between the gas supply unit and the branch tee, or between the branch tee and the external environment.

[0013] The present invention also provides a hydraulic flotation device, including the bubble generator described above.

[0014] Furthermore, it also includes a flotation column, a water supply unit, and a water distribution unit; the inlet of the water distribution unit is connected to the water supply unit, and the outlet of the water distribution unit is located at the bottom of the flotation column; a bubble generator is installed on the connecting pipeline between the inlet of the water distribution unit and the water supply unit, and the bubble generator is located outside the flotation column.

[0015] Furthermore, it also includes a pressure sensor located within the fluidized bed of the flotation column.

[0016] Furthermore, it also includes a discharge solenoid valve and a pressure sensor controller. The pressure sensor controller is connected to the pressure sensor and the tail discharge solenoid valve, respectively. The pressure sensor controller receives the pressure in the fluidized bed collected by the pressure sensor and determines whether the pressure in the fluidized bed exceeds the threshold. If it exceeds the threshold, it controls the tail discharge solenoid valve to open and the flotation column discharges tails.

[0017] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0018] A) The bubble generator provided by this invention has a significant effect on the bubble diameter when the gas passes through the microporous plate. Increasing the gas pressure through the orifice is an effective way to reduce the bubble diameter. The gas pressure includes dynamic pressure and static pressure. The bubble generator of this structure forms bubbles through pulse-splitting microporous holes, which has the function of simultaneously increasing the dynamic pressure and static pressure of the airflow.

[0019] B) The bubble generator provided by the present invention is equipped with a pulse solenoid valve. By controlling the frequency of the pulse solenoid valve and the switching time within one cycle, the steady-state airflow provided by the gas supply unit can be converted into pulse airflow. In this way, converting the steady-state continuous airflow into pulse airflow can effectively increase the dynamic pressure of the airflow, drive the bubbles to desorb in advance and reduce the longitudinal coalescence after desorption. On the basis of unchanged gas supply, the instantaneous dynamic pressure of the gas is effectively increased, thereby generating finer bubbles.

[0020] C) The bubble generator provided by this invention is equipped with a flow splitter. By adjusting the flow splitting ratio, without increasing the flow velocity of the airflow entering the supply branch, the total airflow of the supply unit is increased and some gas is discharged, thereby increasing the static pressure of the gas entering the microporous plate and further driving the bubbles to desorb in advance, reducing the bubble size. It should be noted that, according to the Bernoulli equation principle, the total mechanical energy of any two points on the streamline in fluid flow is conserved. The mechanical energy of the airflow in the supply branch increases due to the increase in airflow velocity, while the energy of the gas entering the supply branch increases due to the constant momentum and static pressure.

[0021] D) The hydraulic flotation equipment provided by the present invention has a bubble generator and a water distribution unit as two relatively independent components. The bubble generator is set on the connection pipe between the water inlet of the water distribution unit and the water supply unit, and is located outside the flotation column. The bubble size can be independently adjusted by the bubble generator, and the rising water flow speed can be independently controlled by the water supply unit and the water distribution unit, thereby greatly improving the adaptability of mineral separation.

[0022] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description and the accompanying drawings. Attached Figure Description

[0023] The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts.

[0024] Figure 1 A schematic diagram of the structure of the bubble generator provided by the present invention;

[0025] Figure 2 This is a schematic diagram of the structure of the hydraulic flotation equipment provided by the present invention;

[0026] Figure 3 This is a flowchart of the process for recovering coarse molybdenum ore particles from molybdenum flotation tailings used in Embodiments 1 and 2 of the present invention.

[0027] Figure label:

[0028] 1-Feed pump; 2-Slurry flow meter; 3-Overflow tank; 4-Pressure sensor; 5-Water distribution unit; 6-Flotation column; 7-Pulse solenoid valve; 8-Water supply unit; 9-Micro-orifice plate; 10-Gas chamber; 11-Pressure sensor controller; 12-Drain solenoid valve; 13-Gas supply unit; 14-Pressure regulator; 15-Gas flow meter; 16-Diverter tee. Detailed Implementation

[0029] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0030] This invention provides a bubble generator, see [link to relevant documentation]. Figure 1The system includes an air supply unit 13 (e.g., an air compressor), a pulse solenoid valve 7 (e.g., a high-frequency solenoid valve), a diverter tee 16, an air chamber 10, and a microporous plate 9. The diverter tee 16 has an inlet branch, an outlet branch, and an air supply branch that are interconnected. The outlet of the air supply unit 13 is connected to the inlet branch through the pulse solenoid valve 7. The outlet branch is connected to the external environment. The air supply branch is connected to the air chamber 10. The microporous plate 9 is located at the outlet of the air chamber 10. For example, the microporous plate 9 can be located on the connecting pipe between the water distribution unit 5 of the hydraulic flotation equipment and the water supply unit 8 of the hydraulic flotation equipment. The gas (e.g., air) provided by the air supply unit 13 enters the connecting pipe in sequence through the inlet branch, the air supply branch, the air chamber 10, and the microporous plate 9 to form microbubbles.

[0031] It should be noted that the pressure of the gas passing through the microporous plate 9 will significantly affect the bubble diameter. Increasing the gas pressure through the orifice is an effective way to reduce the bubble diameter. The gas pressure includes dynamic pressure and static pressure. The bubble generator of this structure forms bubbles through pulse-splitting microporous holes, which has the function of simultaneously increasing the dynamic pressure and static pressure of the airflow.

[0032] Compared with the prior art, the bubble generator provided by the present invention is equipped with a pulse solenoid valve 7. By controlling the frequency of the pulse solenoid valve 7 and the switching time within one cycle, the steady-state airflow provided by the gas supply unit 13 can be converted into pulse airflow. In this way, converting the steady-state continuous airflow into pulse airflow can effectively increase the dynamic pressure of the airflow, drive the bubbles to desorb in advance and reduce the longitudinal coalescence after desorption. On the basis of unchanged gas supply, the instantaneous dynamic pressure of the gas is effectively increased, thereby generating finer bubbles.

[0033] Meanwhile, the bubble generator provided by this invention is equipped with a flow divider tee 16. By adjusting the flow divider ratio, without increasing the flow velocity of the airflow entering the air supply branch, the total airflow of the air supply unit 13 is increased and some gas is discharged, thereby increasing the static pressure of the gas entering the microporous plate 9, further driving the bubbles to desorb in advance and reducing the bubble size. It should be noted that, according to the Bernoulli equation principle, the total mechanical energy of any two points on the streamline in fluid flow is conserved. The mechanical energy of the airflow in the air supply branch increases due to the increase in airflow velocity, while the static pressure of the gas entering the air supply branch increases due to the constant momentum.

[0034] In order to further adjust the static pressure of the gas, for example, the flow ratio (i.e., the split ratio) between the vent branch and the gas supply branch is 1 to 10, such as 1, 3, 4, 6, 8 or 10.

[0035] In order to adjust the air supply pressure of the air supply unit 13, a pressure regulator 14 is provided on the connection pipeline between the air outlet of the air supply unit 13 and the pulse solenoid valve 7. The air supply pressure of the air supply unit 13 can be adjusted by the pressure regulator 14.

[0036] In order to enable operators to understand the flow ratio and the gas flow rate in the intake branch and / or exhaust branch in real time, a gas flow meter 15 is provided on the connection pipe between the outlet of the gas supply unit 13 and the pulse solenoid valve 7 and / or the connection pipe between the flow tee 16 and the external environment. The gas flow meter 15 can obtain the gas flow rate in the supply branch and / or exhaust branch in real time.

[0037] Experiments have shown that in the bubble generator of the present invention, no buffer tank is installed on the connecting pipe between the gas supply unit 13 and the diversion tee 16, or on the connecting pipe between the diversion tee 16 and the external environment. This is because the test data shows that installing buffer tanks on the connecting pipes at these two locations would cause unstable gas supply.

[0038] The present invention also provides a hydraulic flotation device, including the bubble generator described above.

[0039] Compared with the prior art, the beneficial effects of the hydraulic flotation equipment provided by the present invention are basically the same as those of the bubble generator provided above, and will not be described in detail here.

[0040] Understandably, for the specific structure of hydraulic flotation equipment, please refer to [link / reference needed]. Figure 2 The system includes a flotation column 6, a water supply unit 8 (e.g., a water pump), and a water distribution unit 5. The inlet of the water distribution unit 5 is connected to the water supply unit 8, and the outlet of the water distribution unit 5 is located at the bottom of the flotation column 6 to form an upward water flow within the flotation column 6. A bubble generator is installed on the connecting pipe between the inlet of the water distribution unit 5 and the water supply unit 8. The air outlet of the microporous plate of the bubble generator is connected to the connecting pipe between the inlet of the water distribution unit 5 and the water supply unit 8, and the bubble generator is located outside the flotation column 6.

[0041] Common hydraulic flotation equipment mainly achieves foam formation through hydraulic cavitation. The foam size depends on the cavitation intensity, i.e. the rising water velocity. Therefore, it is impossible to independently control the rising water velocity and the foam size, resulting in poor adaptability to mineral separation.

[0042] In this invention, the bubble generator and the water distribution unit 5 are two relatively independent components. The bubble generator is located on the connecting pipe between the water inlet of the water distribution unit 5 and the water supply unit 8, and is located outside the flotation column 6. The bubble generator can independently adjust the bubble size, and the water supply unit 8 and the water distribution unit 5 can independently control the rising water flow speed, thereby greatly improving the adaptability of mineral separation.

[0043] In practical applications, in order to ensure that the height of the fluidized bed within the flotation column 6 is crucial for safe production, the aforementioned hydraulic flotation equipment also includes a pressure sensor 4 installed within the fluidized bed of the flotation column 6. By testing the pressure, the height of the fluidized bed within the flotation column 6 can be effectively reflected.

[0044] Considering that once the height of the fluidized bed exceeds the threshold, timely discharge of ore is required, the above-mentioned hydraulic flotation equipment also includes a tailings solenoid valve 12 and a pressure sensor controller 11. The pressure sensor controller 11 is connected to the pressure sensor 4 and the tailings solenoid valve 12 respectively. The pressure sensor controller 11 receives the pressure in the fluidized bed collected by the pressure sensor 4 and determines whether the pressure in the fluidized bed exceeds the threshold. If it exceeds the threshold, it controls the tailings solenoid valve 12 to open, and the flotation column 6 discharges tailings.

[0045] Understandably, in order to enable the feeding of the flotation column 6, the above-mentioned hydraulic flotation equipment also includes an overflow trough 3 located at the top of the flotation column 6 and a feed pump 1 connected to the feed inlet of the flotation column 6.

[0046] In order to monitor the flow rate of the feed slurry in real time, the above-mentioned hydraulic flotation equipment also includes a slurry flow meter 2 installed on the connecting pipeline between the feed pump 1 and the flotation column 6, which monitors the flow rate of the feed slurry in real time.

[0047] For example, the above-mentioned hydraulic flotation equipment can be used in the recovery process of coarse molybdenum ore particles from molybdenum flotation tailings, see [link to relevant documentation]. Figure 3 It includes the following steps:

[0048] Step 1: After the molybdenite flotation process has been completed and the mass percentage of particles with a particle size of less than 200 mesh reaches more than 65%, the raw ore is floated to obtain raw ore flotation concentrate and raw ore flotation tailings; the raw ore flotation tailings are hydraulically classified to obtain coarse molybdenite tailings with a classification particle size greater than the classification particle size and fine molybdenite tailings with a classification particle size less than the classification particle size.

[0049] Step 2: Perform hydraulic flotation on the coarse molybdenum tailings to obtain hydraulic flotation tailings and hydraulic flotation concentrate;

[0050] Step 3: Mix the hydraulic flotation concentrate with the raw molybdenite ore as the molybdenite to be flotated in Step 1, and repeat Steps 1 to 2 to complete the recovery of coarse molybdenum ore particles.

[0051] The hydraulic flotation process utilizes the hydraulic flotation equipment provided by this invention.

[0052] In this way, by reprocessing the raw ore flotation tailings through hydraulic classification and hydraulic flotation, valuable molybdenum-containing coarse particles (i.e., hydraulic flotation concentrate) in the raw ore flotation tailings can be effectively recovered. These valuable molybdenum-containing coarse particles can then be returned to the grinding process. This effectively recovers the coarse molybdenum ore lost in the raw ore flotation tailings stream, increases the total molybdenum recovery rate, and features high molybdenum recovery rate, low environmental pollution, high economic benefits, and simple process.

[0053] For example, in step 2 above, the classification particle size is 150 μm. This is because, on the one hand, hydraulic flotation typically has good separation efficiency in the particle size range of 150–1000 μm. By classifying the initial flotation tailings in step 2, the initial flotation tailings are divided into coarse molybdenum tailings with a particle size of more than 150 μm and fine molybdenum tailings with a particle size of less than 150 μm, which facilitates subsequent hydraulic flotation of the coarse molybdenum tailings. On the other hand, tests show that the coarse molybdenum tailings with a particle size of more than 150 μm contain a relatively high molybdenum content. By performing hydraulic flotation again on this portion of the tailings, the total molybdenum recovery rate can be effectively improved.

[0054] Example 1

[0055] This embodiment mainly focuses on the flotation tailings obtained after flotation of raw ore from a molybdenum mine in western Henan Province. The hydraulic flotation equipment provided by this invention is used, and the recovery method includes the following steps:

[0056] Step a: Grind the molybdenite to be floated to approximately 65% ​​using a ball mill to a mesh size of -200. Then, perform roughing, scavenging, and cleaning processes sequentially to obtain the flotation concentrate and tailings of the original ore.

[0057] Step b: Hydraulically classify the raw ore flotation tailings to obtain coarse molybdenum tailings with a particle size of more than 150 μm and fine molybdenum tailings with a particle size of less than 150 μm.

[0058] Step c: Put the coarse molybdenum tailings into a mixing tank for slurry preparation to form a slurry with a mass concentration of 30%, and add 80g / t of kerosene as a collector.

[0059] Step d: Add foaming agent No. 2 oil to the water supply unit and adjust the concentration to 20 ppm;

[0060] Step e: After the hydraulic flotation equipment stabilizes, hydraulic separation is started to recover coarse molybdenite, and hydraulic flotation tailings and hydraulic flotation concentrate are obtained. The water supply unit has a water flow rate of 8L / min, the total air supply unit has a total air flow rate of 10L / min, the split ratio is 4, and the slurry flow rate is 2L / min.

[0061] Step f: Mix the hydraulic flotation concentrate with the raw molybdenite ore as the molybdenite to be floated in step a. Repeat steps a to e to complete the recovery of coarse molybdenum ore particles.

[0062] Table 1. Separation Indicators of Hydraulic Flotation in this Embodiment

[0063]

[0064]

[0065] As shown in Table 1, the grade of coarse molybdenum tailings with a particle size of 150 μm or more was reduced to 0.0043% after hydraulic flotation, and the recovery rate of hydraulic flotation was 84.49%, proving that the recovery process in this embodiment can effectively recover molybdenum from the flotation tailings of the original ore.

[0066] Example 2

[0067] This embodiment mainly focuses on the flotation tailings obtained after flotation of raw ore from a molybdenum mine in western Henan Province. The hydraulic flotation equipment provided by this invention is used, and the recovery method includes the following steps:

[0068] Step a: Grind the molybdenite to be floated to approximately 65% ​​using a ball mill to a mesh size of -200. Then, perform roughing, scavenging, and cleaning processes sequentially to obtain the flotation concentrate and tailings of the original ore.

[0069] Step b: Hydraulically classify the raw ore flotation tailings to obtain coarse molybdenum tailings with a particle size of more than 150 μm and fine molybdenum tailings with a particle size of less than 150 μm.

[0070] Step c: Put the coarse molybdenum tailings into a mixing tank for slurry preparation to form a slurry with a mass concentration of 38%, and add 100g / t of kerosene as a collector.

[0071] Step d: Add foaming agent No. 2 oil to the water supply unit and adjust the concentration to 25 ppm;

[0072] Step e: After the hydraulic flotation equipment stabilizes, hydraulic separation is started to recover coarse molybdenite, and hydraulic flotation tailings and hydraulic flotation concentrate are obtained. The water supply unit has a water flow rate of 10 L / min, the total air supply unit has a total air flow rate of 15 L / min, the split ratio is 6, and the slurry flow rate is 3.5 L / min.

[0073] Step f: Mix the hydraulic flotation concentrate with the raw molybdenite ore as the molybdenite to be floated in step a. Repeat steps a to e to complete the recovery of coarse molybdenum ore particles.

[0074] Table 2. Hydraulic flotation separation indexes of this embodiment.

[0075]

[0076]

[0077] As shown in Table 2, the grade of coarse molybdenum tailings with a particle size of 150 μm or more was reduced to 0.0035% after hydraulic flotation, and the recovery rate of hydraulic flotation was 87.90%, which proves that the recovery process in this embodiment can effectively recover molybdenum from the flotation tailings of the original ore.

[0078] Comparative Example 1

[0079] This comparative example mainly focuses on the flotation tailings obtained from the flotation of raw ore in a molybdenum mine in western Henan. The recovery method is basically the same as that in Example 2, the only difference being that the hydraulic flotation equipment does not include a diversion tee. The recovery method in this comparative example includes the following steps:

[0080] Step a: Grind the molybdenite to be floated to approximately 65% ​​using a ball mill to a mesh size of -200. Then, perform roughing, scavenging, and cleaning processes sequentially to obtain the flotation concentrate and tailings of the original ore.

[0081] Step b: Hydraulically classify the raw ore flotation tailings to obtain coarse molybdenum tailings with a particle size of more than 150 μm and fine molybdenum tailings with a particle size of less than 150 μm.

[0082] Step c: Put the coarse molybdenum tailings into a mixing tank for slurry preparation to form a slurry with a mass concentration of 38%, and add 100g / t of kerosene as a collector.

[0083] Step d: Add foaming agent No. 2 oil to the water supply unit and adjust the concentration to 25 ppm;

[0084] Step e: After the hydraulic flotation equipment stabilizes, hydraulic separation is started to recover coarse molybdenite, and hydraulic flotation tailings and hydraulic flotation concentrate are obtained. The water supply unit has a water flow rate of 10 L / min, the total air supply unit has a total air flow rate of 15 L / min, the split ratio is 6, and the slurry flow rate is 3.5 L / min.

[0085] Step f: Mix the hydraulic flotation concentrate with the raw molybdenite ore as the molybdenite to be floated in step a. Repeat steps a to e to complete the recovery of coarse molybdenum ore particles.

[0086] Table 3. Hydraulic flotation separation indexes of this embodiment

[0087] Sample number Sample Name Molybdenum grade (%) 1 Coarse molybdenum tailings with a particle size of 150 μm or more 0.0187 2 Hydraulic flotation concentrate 0.0357 3 hydraulic flotation tailings 0.0085

[0088] As shown in Table 3, the grade of coarse molybdenum tailings with a particle size of 150 μm or more was reduced to 0.0085% after hydraulic flotation, and the recovery rate of hydraulic flotation was 73.70%.

[0089] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention.

Claims

1. A hydraulic flotation device, characterized in that, Includes a bubble generator, flotation column, water supply unit, and water distribution unit; The water inlet of the water distribution unit is connected to the water supply unit, and the water outlet of the water distribution unit is located at the bottom of the flotation column. The bubble generator is located on the connecting pipe between the water inlet of the water distribution unit and the water supply unit, and the bubble generator is located outside the flotation column; the bubble generator and the water distribution unit are two relatively independent components, the bubble size is independently adjusted by the bubble generator, and the rising water flow speed is independently controlled by the water supply unit and the water distribution unit. The bubble generator includes a gas supply unit, a flow divider tee, a gas chamber, and a microporous plate; the flow divider tee has an inlet branch, an outlet branch, and a gas supply branch that are interconnected; the outlet of the gas supply unit is connected to the inlet branch, the outlet branch is connected to the external environment, and the gas supply branch is connected to the gas chamber; the microporous plate is located at the outlet end of the gas chamber. The bubble generator also includes a pulse solenoid valve. The outlet of the gas supply unit is connected to the inlet branch through the pulse solenoid valve. No buffer tank is installed on the connecting pipeline between the gas supply unit and the branch tee, or between the branch tee and the external environment. By adjusting the flow ratio of the splitter tee, without increasing the flow velocity of the airflow entering the air supply branch, the total air flow rate of the air supply unit is increased and some gas is discharged, thereby increasing the static pressure of the gas entering the microporous plate, driving the bubbles to desorb in advance, and reducing the bubble size.

2. The hydraulic flotation equipment according to claim 1, characterized in that, The flow ratio between the venting branch and the gas supply branch is 1 to 10.

3. The hydraulic flotation equipment according to claim 1, characterized in that, A pressure regulator is installed on the connection pipeline between the air outlet of the air supply unit and the pulse solenoid valve.

4. The hydraulic flotation equipment according to claim 1, characterized in that, A gas flow meter is installed on the gas outlet of the gas supply unit, on the connecting pipe between the gas outlet and the pulse solenoid valve, and / or on the connecting pipe between the tee and the external environment.

5. The hydraulic flotation equipment according to claim 1, characterized in that, It also includes a pressure sensor located within the fluidized bed of the flotation column.

6. The hydraulic flotation equipment according to claim 1, characterized in that, It also includes a discharge solenoid valve and a pressure sensor controller. The pressure sensor controller is connected to the pressure sensor and the tail discharge solenoid valve, respectively. The pressure sensor controller receives the pressure in the fluidized bed collected by the pressure sensor and determines whether the pressure in the fluidized bed exceeds a threshold. If it exceeds the threshold, it controls the tail discharge solenoid valve to open, and the flotation column discharges tails.

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