Superfine mineral nanobubble flotation device and method with air inflation size mixing coupled with turbulence shearing

Abstract

The invention relates to a superfine mineral nano-bubble flotation device and a superfine mineral nano-bubble flotation method for coupling aerated size mixing with turbulent shearing, belongs to the technical field of mineral processing, and solves the problems that in the prior art, a nano-bubble preparation method is complex in equipment, high in operation cost, not suitable for large-scale application, low in nano-bubble generation efficiency, low in nano-bubble generation concentration and high in production cost. The stability of the generated nano bubbles is poor, and the medicament consumption is large. A superfine mineral nanobubble flotation device with air inflation size mixing coupled with turbulence shearing comprises an air inflation size mixing system, a turbulence shearing system, a flotation system and a control system which are sequentially connected through pipelines. The air inflation size mixing system comprises a pressure tank and an air compressor; an ore pulp outlet of the pressure tank is connected with the turbulence shearing system through a pipeline, and the turbulence shearing system comprises a proportional control valve, a flow velocity and flow monitor and a pressure relief material receiving tank which are sequentially connected through pipelines. And green low-carbon separation of superfine minerals is realized.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to an ultrafine mineral nanobubble flotation device and method using aeration and slurry coupling with turbulent shearing. Background Technology

[0002] Flotation is a method of selectively separating target minerals from gangue particles based on the differences in the physicochemical properties of particle surfaces. Hydrophobic particles adhere to air bubbles and float to the surface to become concentrate, while hydrophilic particles remain in the slurry as tailings. To make minerals easier for beneficiation equipment to identify and separate, and to improve beneficiation efficiency, mineral liberation is necessary. Studies have found that particle size and surface properties have a significant impact on flotation separation performance. For particles of a given size, a minimum critical contact angle is required to initiate flotation, and for smaller particles, a higher contact angle is needed.

[0003] To effectively achieve the liberation of target minerals, minerals are ground increasingly finer, and the smaller particle size makes the interaction between particles and bubbles more difficult. The lower flotation efficiency of ultrafine minerals is mainly due to their small size and mass, resulting in low momentum in the flotation pulp and a low probability of collision with bubbles. This makes it difficult to overcome the energy barrier between the mineral particles and bubbles, preventing them from adhering to the bubble surface, leading to low particle mineralization efficiency and poor flotation recovery. Studies have found that the smaller the bubble size, the larger the gas-liquid interface area available for particle adhesion, and the higher the mineralization efficiency.

[0004] Nanobubbles, as extremely small bubbles with a size of less than 1 μm, can selectively nucleate on the surface of hydrophobic minerals. Through bridging, they promote particle aggregation, increase the apparent size of minerals, and improve the probability of collision between conventional flotation bubbles and particles. This can reduce the amount of flotation reagents used and improve the flotation efficiency of ultrafine minerals. Existing nanobubble preparation methods suffer from problems such as complex equipment, high operating costs, low generation efficiency, poor stability, unsuitability for large-scale applications, and easy clogging during pulp processing. Developing efficient and low-cost generation technologies is of great significance for the flotation of ultrafine minerals. Summary of the Invention

[0005] Based on the above analysis, the present invention aims to provide an ultrafine mineral nanobubble flotation device and method with aeration and turbulent shearing, in order to solve at least one of the following problems in existing nanobubble preparation methods: complex equipment, high operating cost, unsuitability for large-scale application, low nanobubble generation efficiency, low nanobubble generation concentration, poor stability of generated nanobubbles, and large reagent consumption.

[0006] On one hand, embodiments of the present invention provide an ultrafine mineral nanobubble flotation device with aeration and turbulent shearing coupling, comprising an aeration and slurry conditioning system, a turbulent shearing system and a flotation system connected in sequence by pipes, and a control system;

[0007] The aerated slurry conditioning system includes a pressure tank and an air compressor; the feed port of the pressure tank is connected to the feed pipe, the slurry outlet of the pressure tank is connected to the turbulent shearing system through a pipe, and the air inlet of the pressure tank is connected to the air compressor through an air inlet pipe.

[0008] The turbulent shearing system includes a proportional control valve, a flow rate monitor, and a pressure relief receiving tank connected in sequence via pipelines. The inlet of the proportional control valve is connected to the slurry outlet of the pressure tank via a pipeline, and the outlet of the pressure relief receiving tank is connected to the flotation system via a slurry pipeline.

[0009] The pressure tank is equipped with a stirrer, the feed pipe is equipped with a feed valve, the air inlet pipe is equipped with an air inlet valve and a pressure gauge in sequence, and the air inlet pipe is equipped with a bypass system;

[0010] The bypass system includes a main pipe connected to the intake pipe and two branch pipes connected to the main pipe. The main pipe is equipped with a safety braking device, and the two branch pipes are respectively equipped with a first safety exhaust valve and a second safety exhaust valve.

[0011] The flotation system includes a feed pump and flotation equipment. The feed pump inlet is connected to a turbulent shearing system, and the feed pump outlet is connected to the flotation equipment through a flotation feed pipeline.

[0012] Specifically, the control system collects, analyzes, and interlocks data from the agitator, pressure gauge, air inlet valve, proportional control valve, and flow rate monitor.

[0013] On the other hand, embodiments of the present invention provide an ultrafine mineral nanobubble flotation method using aeration and turbulent shearing coupled with the flotation device, comprising the following steps:

[0014] S1. Open the feed valve on the feed pipe and feed a certain concentration of slurry into the pressure tank through the feed port;

[0015] S2. Open the air intake valve on the air compressor and air intake pipe, introduce air into the pressure tank to a certain pressure, start the pressure tank agitator and adjust the speed, and agitate for a certain time under the set pressure.

[0016] S3. Open and adjust the opening of the proportional control valve to control a certain discharge flow rate so that the slurry flows into the pressure relief receiving tank to obtain a slurry rich in nano bubbles.

[0017] S4. The slurry rich in nano bubbles is fed into the flotation equipment through a feed pump for flotation to obtain concentrate and tailings respectively.

[0018] S5. Filter, dry, weigh, and test the concentrate and tailings to analyze the grade and recovery rate of useful substances in the concentrate.

[0019] Furthermore, the mass concentration of the slurry of a certain concentration mentioned in step S1 is 10% to 40%.

[0020] It should be noted that the pressure maintained in the pressure tank after air is introduced in step S2 is 0-5 MPa.

[0021] Specifically, in step S2, the speed of the pressure tank agitator is 100-2000 r / min.

[0022] For example, the stirring time of the pressure tank agitator in step S2 is 0 to 60 minutes under a set pressure.

[0023] Furthermore, in step S3, the opening of the proportional control valve is adjusted by the control system, and the discharge flow rate is controlled to be 1-6 m / s.

[0024] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0025] 1. This invention combines aeration and turbulent shearing. First, the slurry is pressurized and aerated, using pressure to dissolve the gas into the slurry, resulting in a highly saturated gas-dissolved slurry. During pressurization, high-speed stirring and slurry conditioning further promote efficient gas dissolution and full contact with ultrafine mineral particles. A proportional control valve is used for precise and rapid flow control and pressure release, bringing the slurry into a turbulent state. Numerous eddies and localized high-speed flows are generated within the slurry. The turbulent flow contains severe velocity gradients and pressure fluctuations, causing strong shearing forces at the microscopic level. At this point, a large amount of gas dissolved in the slurry rapidly precipitates out. Under the action of high-velocity turbulent shearing, the cut bubbles selectively adsorb onto the surface of hydrophobic minerals, forming nanobubbles with an average size of 0–500 nm, resulting in a slurry rich in nanobubbles. This significantly increases the probability of collision and adhesion between flotation bubbles and mineral particles, enhancing the ultrafine mineral flotation process.

[0026] 2. This invention obtains a slurry rich in nanobubbles by combining aeration and turbulent shearing, wherein the size of the nanobubbles ranges from 0 to 500 nm, and the nanobubble concentration is >1.1 × 10⁻⁶. 9 The nanobubbles generated by the nanobubble flotation process preferentially adsorb onto the surface of hydrophobic minerals, playing a partial collecting role. Mineral particles agglomerate under the bridging capillary force of the nanobubbles, increasing the apparent size of the minerals and reducing the surface area of ​​the adsorbent. This reduces the amount of collector used in the flotation process, improves the flotation efficiency of ultrafine minerals, and achieves green and low-carbon separation of ultrafine minerals.

[0027] 3. By controlling the pressure of the pressure tank to 0-5 MPa and the discharge flow rate to 1-6 m / s, this invention can obtain a high concentration of nanobubbles and a small average size of nanobubbles. Furthermore, the obtained concentration and size of nanobubbles can be maintained for a long time, and the bubbles have strong stability, ensuring that the role and effect of nanobubbles are not diminished throughout the entire flotation process.

[0028] 4. The nanobubble flotation device and method of the present invention meet the actual flotation conditions, have a simple structure, low operating cost, and are easy to apply in industrial applications. There is no need to set up a separate nanobubble preparation device, and there is no need to introduce additional nanobubbles during the flotation process. It has strong versatility and is universally applicable to the flotation of ultrafine minerals.

[0029] In this invention, the above-described technical solutions can be combined with each other to achieve more preferred combinations. Other features and advantages of this invention will be set forth in the following description, and some advantages may become apparent from the description or be learned by practicing the invention. The objects and other advantages of this invention can be realized and obtained from what is particularly pointed out in the description and drawings. Attached Figure Description

[0030] 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.

[0031] Figure 1 This is a schematic diagram of the flotation device and flotation process of the present invention;

[0032] Figure 2 This is a nanometer bubble size distribution diagram of Example 3 of the present invention;

[0033] Figure 3 The curves showing the relationship between the flotation recovery rate of ultrafine molybdenite and the amount of flotation reagent in Example 1 and Comparative Example 1 of this invention are shown.

[0034] Figure 4 This is a bar chart comparing the flotation yields of copper-nickel sulfide ore in Example 2 and Comparative Example 2 of the present invention.

[0035] Figure label:

[0036] 1-Feed pipe; 2-Feed valve; 3-Air inlet pipe; 4-Air inlet valve; 5-Pressure gauge; 6-Discharge pipe; 7-Flow rate monitor; 8-Slurry pipe; 9-Flotation feed pipe; 10-Safety brake device; 11-First safety exhaust valve; 12-Second safety exhaust valve; 13-Pressure tank; 14-Air compressor; 15-Pressure relief receiving tank; 16-Feed pump; 17-Flotation equipment; 18-Control system; 19-Proportional control valve. Detailed Implementation

[0037] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0038] Ultrafine minerals generally refer to mineral particles smaller than 10 μm. This includes ultrafine minerals formed through monomer liberation for better separation, gangue minerals in the ore that are prone to mud formation, ultrafine minerals that are easily generated during crushing, grinding, mixing, and transportation, and naturally occurring fine minerals formed by geological processes such as weathering, erosion, and deposition. Due to their small size and mass, ultrafine minerals have low momentum in the flotation pulp, resulting in a low probability of collision with bubbles. They are unable to overcome the energy barrier between the mineral particles and bubbles and thus cannot adhere to the bubble surface, leading to low particle mineralization efficiency and poor flotation recovery. Therefore, obtaining nanobubbles with high concentration and small size is of great significance for improving the flotation efficiency of ultrafine minerals.

[0039] A specific embodiment of the present invention discloses an ultrafine mineral nanobubble flotation device with aeration and turbulent shear coupling, such as... Figure 1 The system includes an aerated slurry conditioning system, a turbulent shearing system, and a flotation system connected in sequence via pipelines, as well as a control system.

[0040] The aerated slurry conditioning system includes a pressure tank 13 and an air compressor 14; the feed port of the pressure tank is connected to the feed pipe 1, the slurry outlet of the pressure tank is connected to the turbulent shearing system through a pipe, and the air inlet of the pressure tank is connected to the air compressor 14 through the air inlet pipe 3.

[0041] The turbulent shearing system includes a proportional control valve 19, a flow rate monitor 7, and a pressure relief receiving tank 15 connected in sequence via pipes. The inlet of the proportional control valve 19 is connected to the slurry outlet of the pressure tank via a pipe, and the outlet of the pressure relief receiving tank is connected to the flotation system via a slurry pipe 8.

[0042] The pressure tank 13 is equipped with a stirrer, the feed pipe 1 is equipped with a feed valve 2, the air inlet pipe 3 is equipped with an air inlet valve and a pressure gauge 5 in sequence, and the air inlet pipe 3 is equipped with a bypass system.

[0043] The bypass system includes a main pipe connected to the intake pipe 3 and two branch pipes connected to the main pipe. The main pipe is equipped with a safety braking device 10, and the two branch pipes are respectively equipped with a first safety exhaust valve 11 and a second safety exhaust valve 12.

[0044] The flotation system includes a feed pump 16 and a flotation device 17. The feed pump inlet is connected to the turbulent shear system, and the feed pump outlet is connected to the flotation device 17 through a flotation feed pipe 9.

[0045] The control system 18 collects, analyzes, and interlocks data from the agitator, pressure gauge, air inlet valve, proportional control valve, and flow rate monitor.

[0046] On the other hand, specific embodiments of the present invention also disclose an ultrafine mineral nanobubble flotation method based on aeration and turbulent shearing, comprising the following steps:

[0047] S1. Open the feed valve on the feed pipe and feed a certain concentration of slurry into the pressure tank through the feed port;

[0048] S2. Open the air intake valve on the air compressor and air intake pipe, introduce air into the pressure tank to a certain pressure, start the pressure tank agitator and adjust the speed, and agitate for a certain time under the set pressure.

[0049] S3. Open and adjust the opening of the proportional control valve to control a certain discharge flow rate so that the slurry flows into the pressure relief receiving tank to obtain a slurry rich in nano bubbles.

[0050] S4. The slurry rich in nanobubbles is fed into the flotation equipment through a feed pump for flotation to obtain concentrate and tailings respectively.

[0051] S5. Filter, dry, weigh, and test the concentrate and tailings to analyze the grade and recovery rate of useful substances in the concentrate.

[0052] Furthermore, the pulp concentration mentioned in step S1 is 10% to 40% by mass. A lower pulp concentration is beneficial for the contact and adhesion between nanobubbles and mineral particles, but too low a concentration will affect the flotation efficiency. A high pulp concentration will hinder the contact between nanobubbles and mineral particles, reduce the adhesion effect, and even affect the overall performance of flotation. Selecting an appropriate pulp concentration is a key factor in improving the adhesion efficiency between mineral particles and bubbles during the flotation process.

[0053] In one possible design, the slurry comprises tap water and copper-nickel sulfide ore (90% <200 mesh) at a mass concentration of 40%.

[0054] It should be noted that, in step S2, the pressure maintained after air is introduced into the pressure tank is 0–5 MPa, for example, 1 MPa, 1.5 MPa, 2 MPa, 2.5 MPa, 3 MPa, 3.5 MPa, 4 MPa, 4.5 MPa, or 5 MPa; the speed of the pressure tank agitator is 100–2000 r / min, for example, 100, 1000, 1400, 1500, 1600, 1700, 1800, 1900, or 2000 r / min; and the stirring time at the set pressure is 0–60 min, for example, 5 min, 10 min, or 60 min. The gas is dissolved into the slurry at 15 min, 30 min, 40 min, and 60 min times using pressurization and stirring to obtain a slurry with high gas solubility. Under constant temperature conditions, the higher the pressure maintained in the pressure tank, the easier it is for the gas to dissolve into the liquid, increasing the gas saturation in the slurry. However, excessively high pressure significantly increases the quality and safety level of components such as the vessel body, seals, and valves, and increases the complexity and risk of operation. In actual production, the pressure of the pressure tank needs to be determined by comprehensively considering the design and cost of equipment, pipelines, and fittings. Preferably, the pressure is 1.5 MPa or 2 MPa.

[0055] The longer the stirring time, the higher the concentration of nanobubbles generated after discharge and the smaller the average size of the nanobubbles. However, for specific minerals, gases, reagents and equipment conditions, increasing the stirring time to a certain value does not significantly increase the concentration of nanobubbles or decrease the average size of nanobubbles.

[0056] Preferably, the stirring speed is 1400 r / min and the stirring time is 15 min; the stirring speed is 1800 r / min and the stirring time is 8 min.

[0057] Further, in step S3, the opening of the proportional control valve is adjusted by the control system, and the discharge flow rate is controlled to be 1-6 m / s, such as 2.5 m / s or 4 m / s. The slurry flows into the pressure relief receiving tank. At this time, the slurry undergoes turbulent shearing. There are severe velocity gradients and pressure fluctuations in the turbulence, which causes strong shearing forces to be generated at the microscopic level. The instantaneous release of pressure causes a large amount of dissolved gas in the slurry to be rapidly released. Under the high-velocity turbulent shearing action, the bubbles are cut into smaller and smaller sizes, and the gas in the solution is in a supersaturated state. The excess gas is released and preferentially adsorbed on the surface of hydrophobic particles to form nanobubbles, resulting in a slurry rich in nanobubbles. The size range of the nanobubbles is 0-500 nm, preferably 0-185 nm, and the nanobubble concentration is >1.1 × 10⁻⁶. 9 particles / mL; nanobubbles are more fully mixed with particles in the slurry during turbulent shearing, improving flotation efficiency.

[0058] The generated nanobubbles preferentially adsorb onto the surface of hydrophobic minerals, playing a partial collecting role. Mineral particles agglomerate under the bridging capillary force of the nanobubbles, reducing the surface area of ​​the adsorbent and thus reducing the amount of collector used in the flotation process.

[0059] The concentration and average size of nanobubbles obtained after discharge are affected by the combined effects of the pressure tank pressure and discharge flow rate before discharge.

[0060] According to Bernoulli's equation, as the pressure decreases, the fluid velocity increases. Before the proportional control valve is opened, the greater the pressure inside the pressure tank, the more obvious the fluid acceleration effect is after the proportional control valve is opened, and the easier it is to reach a turbulent state.

[0061] When a certain discharge flow rate is controlled, the higher the pressure in the pressure tank within the specified range, the higher the saturation solubility of gas in the slurry, the higher the concentration of nanobubbles, and the smaller the average size of nanobubbles. When the pressure in the pressure tank before discharge is controlled to be constant, the greater the discharge flow rate within the specified range, the stronger the turbulent shearing, and the smaller the size and higher the concentration of nanobubbles.

[0062] Regarding the control of the discharge flow rate, when the discharge flow rate is too high (>6m / s), instantaneous nanobubbles with high concentration and small average size can be obtained after discharge. However, the quality and stability of the nanobubbles are poor. The size of the nanobubbles will increase rapidly in a short time after discharge, and the concentration of nanobubbles will drop rapidly, which is not conducive to subsequent flotation. When the discharge flow rate is too low (<1m / s), the instantaneous nanobubble concentration obtained after discharge is low, the nanobubble size is large, and the quality and stability of the nanobubbles are poor in a short time after discharge.

[0063] In one possible design, the pulp in step S4 consists of 2g of molybdenite (-10μm) and 60mL of pure water, with kerosene as the flotation reagent. After aeration and turbulent shearing treatment, the pulp enters the flotation equipment for flotation. The highest flotation recovery rate is 7.36% higher than that of the flotation process without aeration and turbulent shearing treatment. When the kerosene dosage is 4mg / L, the flotation recovery rate is 74.27%, which is comparable to the recovery rate when the kerosene dosage is 32mg / L without aeration and turbulent shearing treatment.

[0064] In summary, this invention combines aeration and turbulent shearing to obtain a slurry rich in nanobubbles, significantly increasing the probability of collision and adhesion between flotation bubbles and mineral particles, thus enhancing the ultrafine mineral flotation process. The nanobubbles range in size from 0 to 500 nm, achieving a nanobubble concentration >1.1 × 10⁻⁶. 9The nanobubbles generated at a concentration of particles / mL preferentially adsorb onto the surface of hydrophobic minerals, playing a partial collecting role. Mineral particles aggregate under the capillary force of the nanobubbles, increasing the apparent size of the minerals and reducing the surface area of ​​the adsorbent, thereby reducing the amount of collector used in the flotation process, improving the flotation efficiency of ultrafine minerals, and achieving green and low-carbon separation of ultrafine minerals. By controlling the pressure tank pressure to 0–5 MPa and the discharge flow rate to 1–6 m / s, a high nanobubble concentration and a small average nanobubble size (0–185 nm) can be obtained. Furthermore, the obtained nanobubble concentration and size can be maintained for a long time, exhibiting strong bubble stability, ensuring that the role and effect of nanobubbles are not diminished throughout the entire flotation process. This invention's nanobubble flotation device and method conform to actual flotation conditions, have a simple structure, low operating costs, and are easy to apply industrially. It does not require separate nanobubble preparation equipment, has strong versatility, and is universally applicable to the flotation of ultrafine minerals.

[0065] The following describes the ultrafine mineral nanobubble flotation device and flotation method of the present invention with reference to specific embodiments.

[0066] Example 1

[0067] This embodiment provides a method using the aerated slurry conditioning system, turbulent shearing system, and flotation system of the present invention (such as...). Figure 1 The method for flotation of ultrafine molybdenite (shown in this embodiment) is a pure mineral flotation, without impurities, without calculating pulp concentration, and the yield is equal to the recovery rate.

[0068] The raw materials are 2g of molybdenite (<10μm) and 60mL of pure water. The specific steps are as follows:

[0069] S1. Open the feed valve on the feed pipe and feed the above raw materials into the pressure tank through the feed port;

[0070] S2. Open the air intake valve on the air compressor and air intake pipe, introduce air into the pressure tank to 1.5MPa, start the pressure tank agitator and adjust the speed to 1500r / min, and agitate for 15min under the set pressure.

[0071] S3. Open and adjust the opening of the proportional control valve, and adjust the discharge flow rate to 2.5m / s through the control system so that the slurry flows into the pressure relief receiving tank to obtain a slurry rich in nano bubbles.

[0072] S4. The slurry rich in nano bubbles is fed into a 60mL flotation machine through a feed pump for flotation. The collector is kerosene, which is added directly to the flotation equipment 17 to obtain concentrate and tailings respectively.

[0073] S5. Filter, dry, weigh, and test the concentrate and tailings to analyze the grade and recovery rate of useful substances in the concentrate.

[0074] Concentrate recovery results are as follows Figure 3 As shown.

[0075] Example 2

[0076] This embodiment provides a method using the aerated slurry conditioning system, turbulent shearing system, and flotation system of the present invention (such as...). Figure 1 (As shown) is a method for flotation of copper-nickel sulfide ores.

[0077] The slurry is 1L of actual copper-nickel sulfide ore with a mass concentration of 40% (90% of which is smaller than 200 mesh). The specific steps are as follows:

[0078] S1. Open the feed valve on the feed pipe and feed the above slurry into the pressure tank through the feed port;

[0079] S2. Open the air intake valve on the air compressor and air intake pipe, introduce air into the pressure tank to 2MPa, start the pressure tank agitator and adjust the speed to 1800r / min, and agitate for 8min at the set pressure.

[0080] S3. Open and adjust the opening of the proportional control valve, and adjust the discharge flow rate to 4m / s through the control system so that the slurry flows into the pressure relief receiving tank to obtain a slurry rich in nano bubbles.

[0081] S4. The slurry rich in nano bubbles is fed into a 1L flotation machine for flotation via a feed pump. The collector is xanthate, which is directly added to the flotation equipment 17 to obtain concentrate and tailings respectively.

[0082] S5. Filter, dry, weigh, and test the concentrate and tailings to analyze the grade and recovery rate of useful substances in the concentrate.

[0083] Flotation yield results as follows Figure 4 As shown.

[0084] Comparative Example 1

[0085] This embodiment provides a method for flotation of ultrafine molybdenite.

[0086] The raw materials are 2g of molybdenite (<10μm) and 60mL of pure water. The specific steps are as follows:

[0087] Step 1: Feed the slurry into the 60mL flotation device 17 through the feed pump, turn on the agitator, add the kerosene collector, and then perform aeration flotation.

[0088] Step 2: Filter, dry, weigh, and test the concentrate and tailings to analyze the grade and recovery rate of useful substances in the concentrate.

[0089] Concentrate recovery results are as follows Figure 3 As shown.

[0090] Comparative Example 2

[0091] This embodiment provides a method for flotation of copper-nickel sulfide ore.

[0092] The slurry is 1L of actual copper-nickel sulfide ore with a mass concentration of 40% (90% of which is smaller than 200 mesh). The specific steps are as follows:

[0093] Step 1: Feed the slurry into the 1L flotation equipment 17 through the feed pump for flotation. Turn on the agitator, add xanthate collector and carry out flotation to obtain concentrate and tailings respectively.

[0094] Step 2: Filter, dry, weigh, and test the concentrate and tailings to analyze the grade and recovery rate of useful substances in the concentrate.

[0095] Flotation yield results as follows Figure 4 As shown.

[0096] Depend on Figure 3 It can be seen that the highest flotation recovery rate of molybdenite in Comparative Example 1 without aeration, slurry conditioning, and turbulent shearing treatment was 84.64%. In Example 1, after aeration, slurry conditioning, and turbulent shearing treatment, the highest flotation recovery rate was 92%, which was 7.36% higher than that of Comparative Example 1. In Example 1, the flotation recovery rate of molybdenite after aeration, slurry conditioning, and turbulent shearing treatment was 32.7% higher than that of Comparative Example 1 when the kerosene dosage was 4 mg / L. Its recovery rate was comparable to that when the kerosene dosage was 32 mg / L without aeration, slurry conditioning, and turbulent shearing treatment. This indicates that after treatment by this device, the flotation recovery rate of ultrafine particles can be effectively improved and the reagent dosage can be reduced.

[0097] Depend on Figure 4 As can be seen, after aeration and turbulent shearing in Example 2, the flotation yield of copper-nickel sulfide ore was 9.86%, which is 3.42% higher than that of Comparative Example 2 (6.44%). This indicates that the device can effectively improve the actual flotation yield of ore.

[0098] Example 3

[0099] In this embodiment, a nanoparticle tracker is used to evaluate and characterize the quality of nanobubbles generated in the system after the fluid has been processed by the aeration and turbulence shearing system of this invention.

[0100] Given that slurries containing mineral particles can interfere with the tracking of nanobubbles by the nanoparticle tracker during the evaluation process, based on the similarity theory of fluid mechanics, pure water was used instead of ultrafine mineral slurries with a mass concentration of 10-40% for evaluation, which met the requirements.

[0101] The specific steps are as follows:

[0102] S1. Open the feed valve on the feed pipe and feed 500ml of pure water into the pressure tank through the feed port;

[0103] S2. Open the air intake valve on the air compressor and air intake pipe, introduce air into the pressure tank to 3MPa, start the pressure tank agitator and adjust the speed to 1400r / min, and agitate for 5min at the set pressure.

[0104] S3. Open and adjust the opening of the proportional control valve, and adjust the discharge flow rate to 3m / s through the control system so that the pressurized and stirred pure water flows into the pressure relief receiving tank to obtain water rich in nano bubbles.

[0105] S5. Take a sample from the pressure relief receiving tank and use a nanoparticle tracker to measure the concentration and size of the nanobubbles. The results are as follows: Figure 2 As shown in Table 1.

[0106] The fluid is processed by the aeration and slurry conditioning system and the turbulent shearing system of this invention, resulting in a nanobubble concentration of 1.28 × 10⁻⁶. 9 The particles / mL and the average size of 162.7 nm indicate that the fluid treated by the device and method of this invention has a high concentration of nanobubbles, small size, and strong stability.

[0107] Examples 4-6

[0108] In this embodiment, a nanoparticle tracker is used to evaluate and characterize the quality of nanobubbles generated in the system after the fluid has been processed by the aeration and turbulence shearing system of this invention.

[0109] The specific steps are the same as in Example 1, except that the pressure of the pressure tank, stirring time, and discharge flow rate are different. The specific parameters and the concentration and size of the nanobubbles are shown in Table 2.

[0110] Comparative Example 3

[0111] In this embodiment, a nanoparticle tracker is used to evaluate and characterize the quality of nanobubbles generated in the system after the fluid has been processed by the aeration and turbulence shearing system of this invention.

[0112] The specific steps are as follows:

[0113] Step 1: Open the feed valve on the feed pipe and feed 500ml of pure water into the pressure tank through the feed port;

[0114] Step 2: Opening and adjusting the opening of the proportional control valve resulted in the inability to generate turbulence and nanobubbles.

[0115] Comparative Example 4

[0116] In this embodiment, a nanoparticle tracker is used to evaluate and characterize the quality of nanobubbles generated in the system after the fluid has been processed by the aeration and turbulence shearing system of this invention.

[0117] The specific steps are as follows:

[0118] S1. Open the feed valve on the feed pipe and feed 500ml of pure water into the pressure tank through the feed port;

[0119] S2. Open the air intake valve on the air compressor and air intake pipe, introduce air into the pressure tank to 3MPa, start the pressure tank agitator and adjust the speed to 1400r / min, and agitate for 5min at the set pressure.

[0120] S3. Open and adjust the opening of the proportional control valve, and adjust the discharge flow rate to 7m / s through the control system so that the pressurized and stirred pure water flows into the pressure relief receiving tank to obtain water containing nano bubbles.

[0121] S5. Take a sample from the pressure relief receiving tank and use a nanoparticle tracker to measure the concentration and size of the nanobubbles. The results are shown in Table 1.

[0122] Comparative Example 5

[0123] In this embodiment, a nanoparticle tracker is used to evaluate and characterize the quality of nanobubbles generated in the system after the fluid has been processed by the aeration and turbulence shearing system of this invention.

[0124] The specific steps are as follows:

[0125] S1. Open the feed valve on the feed pipe and feed 500ml of pure water into the pressure tank through the feed port;

[0126] S2. Open the air intake valve on the air compressor and air intake pipe, introduce air into the pressure tank to 3MPa, start the pressure tank agitator and adjust the speed to 1400r / min, and agitate for 5min at the set pressure.

[0127] S3. Open and adjust the opening of the proportional control valve, and adjust the discharge flow rate to 0.8m / s through the control system so that the pressurized and stirred pure water flows into the pressure relief receiving tank to obtain water containing nano bubbles.

[0128] S5. Take a sample from the pressure relief receiving tank and use a nanoparticle tracker to measure the concentration and size of the nanobubbles. The results are shown in Table 1.

[0129] Table 1. Nanobubble size and stability

[0130]

[0131] Table 1 shows that the concentration, average size, and stability of nanobubbles generated in the fluid after discharge are influenced by the combined effects of the pressure in the pressure tank before discharge and the discharge flow rate. Within the parameter range set in this invention, the concentration, average size, and stability of nanobubbles generated in the fluid are significantly better than those not conforming to the parameters set in this invention. Examples 3 and 6 show that when the discharge flow rate is constant, the higher the pressure in the pressure tank, the higher the saturated solubility of the gas in the fluid, the higher the concentration of nanobubbles, and the smaller the average size of the nanobubbles. Examples 3 and 4 show that when the pressure in the pressure tank before discharge is constant, the higher the discharge flow rate, the stronger the turbulent shearing, and the smaller the size and higher the concentration of nanobubbles in the fluid. Examples 3 and Comparative Example 4 show that when the discharge flow rate is too high, a certain concentration can be obtained in the fluid after discharge. High concentration and small average size of instantaneous nanobubbles are obtained, but the quality and stability of nanobubbles are poor. After discharge, the size of nanobubbles increases rapidly in a short time, and the concentration of nanobubbles drops rapidly, which is not conducive to subsequent flotation. As can be seen from Example 3 and Comparative Example 5, when the discharge flow rate is too low, the instantaneous nanobubble concentration obtained in the fluid after discharge is low and the nanobubble size is large. Moreover, the quality and stability of nanobubbles are poor in a short time after discharge. As can be seen from Example 3 and Example 5, when the pressure tank pressure and discharge flow rate are the same, increasing the stirring time is beneficial to increasing the concentration of nanobubbles and reducing the average size of nanobubbles, but the effect is not significant. Therefore, the stirring time in actual production needs to be determined by comprehensively considering the quality of nanobubbles and the total flotation time. As can be seen from Example 1 and Comparative Example 3, without aeration and slurry conditioning, nanobubbles cannot be generated.

[0132] Based on the similarity theory of fluid mechanics and the results of flow field simulation, the above-mentioned rules obtained by using pure water for evaluation can be applied to ultrafine mineral slurries with a mass concentration of 10-40%. In actual production, the determination of pressure tank pressure and discharge flow rate also needs to take into account the total amount of slurry to be flotated and the equipment manufacturing and operating costs.

[0133] In summary, this invention combines aeration and turbulent shearing to obtain a pulp rich in nanobubbles, significantly increasing the probability of collision and adhesion between flotation bubbles and mineral particles, thus enhancing the flotation process of ultrafine minerals. The generated nanobubbles preferentially adsorb onto the surface of hydrophobic minerals, playing a partial collecting role. Mineral particles agglomerate under the bridging capillary force of nanobubbles, increasing the apparent size of the minerals and reducing the surface area of ​​the adsorbent reagents, thereby reducing the amount of collector used in the flotation process, improving the flotation efficiency of ultrafine minerals, and achieving green and low-carbon separation of ultrafine minerals. By controlling the pressure tank pressure to 0-5 MPa and the discharge flow rate to 1-6 m / s, a high nanobubble concentration and a small average nanobubble size can be obtained. Furthermore, the obtained nanobubble concentration and size can be maintained for a long time, and the bubbles have strong stability, ensuring that the role and effect of nanobubbles are not diminished throughout the entire flotation process. The nanobubble flotation device and method of this invention meet the actual flotation conditions, have a simple structure, low operating costs, are easy to industrialize, do not require separate nanobubble preparation equipment, have strong versatility, and are universally applicable to the flotation of ultrafine minerals.

[0134] 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 flotation device for ultrafine mineral nanobubbles coupled with aeration and turbulent shearing, characterized in that, It includes an aerated slurry conditioning system, a turbulent shearing system, and a flotation system connected in sequence via pipelines, as well as a control system; The aerated slurry conditioning system includes a pressure tank and an air compressor. The feed port of the pressure tank is connected to the feed pipe, the slurry outlet of the pressure tank is connected to the turbulent shearing system through a pipe, and the air inlet of the pressure tank is connected to the air compressor through an air inlet pipe. The turbulent shearing system includes a proportional control valve, a flow rate monitor, and a pressure relief receiving tank connected in sequence via pipelines. The inlet of the proportional control valve is connected to the slurry outlet of the pressure tank via a pipeline, and the outlet of the pressure relief receiving tank is connected to the flotation system via a slurry pipeline.

2. The flotation apparatus according to claim 1, characterized in that, The pressure tank is equipped with a stirrer, the feed pipe is equipped with a feed valve, the air inlet pipe is equipped with an air inlet valve and a pressure gauge in sequence, and the air inlet pipe is equipped with a bypass system; The bypass system includes a main pipe connected to the intake pipe and two branch pipes connected to the main pipe. The main pipe is equipped with a safety braking device, and the two branch pipes are respectively equipped with a first safety exhaust valve and a second safety exhaust valve.

3. The flotation apparatus according to claim 1, characterized in that, The flotation system includes a feed pump and flotation equipment. The feed pump inlet is connected to a turbulent shearing system, and the feed pump outlet is connected to the flotation equipment through a flotation feed pipeline.

4. The flotation apparatus according to claim 1, characterized in that, The control system collects, analyzes, and interlocks data from the agitator, pressure gauge, air inlet valve, proportional control valve, and flow rate monitor.

5. A method for ultrafine mineral nanobubble flotation using aeration-regulated slurry coupled with turbulent shearing, comprising flotation using the flotation apparatus described in any one of claims 1 to 4, characterized in that, Includes the following steps: S1. Open the feed valve on the feed pipe and feed a certain concentration of slurry into the pressure tank through the feed port; S2. Open the air intake valve on the air compressor and air intake pipe, introduce air into the pressure tank to a certain pressure, start the pressure tank agitator and adjust the speed, and agitate for a certain time under the set pressure. S3. Open and adjust the opening of the proportional control valve to control a certain discharge flow rate so that the slurry flows into the pressure relief receiving tank to obtain a slurry rich in nano bubbles. S4. The slurry rich in nano bubbles is fed into the flotation equipment through a feed pump for flotation to obtain concentrate and tailings respectively. S5. Filter, dry, weigh, and test the concentrate and tailings to analyze the grade and recovery rate of useful substances in the concentrate.

6. The flotation method according to claim 5, characterized in that, The mass concentration of the slurry mentioned in step S1 is 10% to 40%.

7. The flotation method according to claim 5, characterized in that, In step S2, the pressure maintained after air is introduced into the pressure tank is 0-5 MPa.

8. The flotation method according to claim 7, characterized in that, In step S2, the speed of the agitator in the pressure tank is 100-2000 r / min.

9. The flotation method according to claim 8, characterized in that, The stirring time of the pressure tank agitator in step S2 is 0 to 60 minutes under the set pressure.

10. The flotation method according to claim 5, characterized in that, In step S3, the opening of the proportional control valve is adjusted by the control system, and the discharge flow rate is controlled to be 1-6 m / s.

Images