Overflow flotation device and flotation method suitable for natural graphite

Abstract

The application provides an overflow flotation device and a flotation method suitable for natural graphite, and relates to the technical field of flotation. The overflow flotation device comprises a machine body, a steady flow ring-shaped plate and a gas charging / stirring assembly. The machine body is used for placing a flotation slurry, and the edge of the machine body is provided with an overflow groove. The overflow groove comprises an overflow main groove and an overflow auxiliary groove. The overflow auxiliary groove is in communication with the overflow main groove, and the overflow auxiliary groove and the overflow main groove are located at different edge sides of the machine body, respectively. The steady flow ring-shaped plate is a hollow and open ring-shaped plate structure, and is connected to the middle part of the machine body. The working end of the stirring assembly and the gas outlet end of the gas charging assembly are both arranged in the center of the machine body. The flotation method is based on the overflow flotation device to perform multi-stage separation on the graphite raw ore. The problem that the graphite concentrate is difficult to separate from the gangue mineral due to high viscosity is solved, the possibility of scraper failure is directly eliminated, the consumption of electric power and materials is reduced, and the maintenance intensity of workers is effectively reduced.

Description

Technical Field

[0001] This application relates to the field of flotation technology, and in particular to an overflow flotation device and flotation method suitable for natural graphite. Background Technology

[0002] Graphite is a good conductor of electricity and is widely used in new energy, electronics and other fields. Graphite is mostly produced using a flotation method where scrapers drive flotation foam. In actual production, the motors used for the foam scrapers often face short circuits and damage. Furthermore, due to the high viscosity of graphite foam, the high concentration and weight of the flotation foam, the scrapers and their auxiliary parts have high scraping strength and bear heavy loads, resulting in frequent electromechanical maintenance and significant consumption of materials and electricity.

[0003] In some regions, the raw graphite ore is mainly composed of small to medium-sized flakes. Flake graphite is a high-quality raw material for producing battery anode materials, and the particle size of flake graphite is strictly limited. Natural graphite has characteristics such as good natural floatability, poor foam fluidity, and high foam viscosity. Therefore, the flotation foam layer is prone to "caking," gangue minerals mixed in the graphite concentrate foam layer are difficult to remove, and the separation effect is poor. At the same time, in the high-aeration flotation process of graphite, the slurry surface is prone to "flocculation," causing large graphite flakes to fall off from the foam layer and form middlings. The middlings are then returned to the ball mill, resulting in over-grinding of the large graphite flakes. To address this, an overflow flotation device and flotation method suitable for natural graphite are provided. Summary of the Invention

[0004] In view of this, the purpose of this application is to provide an overflow flotation device and flotation method suitable for natural graphite, which aims to solve the technical problems in the prior art, such as the difficulty of graphite flotation separation, the serious loss of large flakes, and the high intensity of electromechanical maintenance.

[0005] To achieve the above objectives, the technical solution adopted in this application is as follows: In a first aspect, embodiments of this application provide an overflow flotation apparatus and flotation method suitable for natural graphite, including: The machine body is used to hold flotation slurry, and the side of the machine body is provided with an overflow trough. The overflow trough includes a main overflow trough and an auxiliary overflow trough. The auxiliary overflow trough is connected to the main overflow trough, and the auxiliary overflow trough and the main overflow trough are located on different sides of the machine body, respectively. The stirring assembly and the aeration assembly are both placed inside the flotation slurry. The machine body is equipped with a flow stabilizing plate, which has a flow groove. The stirring component and the air filling component pass through the flow groove, and the flow groove has multiple hollow holes on its periphery.

[0006] In one embodiment of the first aspect, the overflow flotation device further includes a speed limiting element, which includes a limiting platform and a lifting mechanism. The limiting platform and the lifting mechanism are connected. The limiting platform has a first end and a second end. The cross-section of the limiting platform decreases sequentially from the first end to the second end. The second end passes through the flow channel.

[0007] In one embodiment of the first aspect, the stirring assembly includes a stirring shaft with a hollow cavity formed therein; The inflation assembly includes an inflation tube that passes through the hollow cavity.

[0008] In one embodiment of the first aspect, the overflow sub-channel has a conical structure, the end of the overflow sub-channel with a larger cross-section is connected to the overflow main channel, and the inclination angle of the inclined surface of the overflow sub-channel is 20°-50°.

[0009] In one embodiment of the first aspect, the overflow main channel has a conical structure, and an output pipe is provided at the end of the overflow main channel with a larger cross-section. The inclination angle of the inclined surface of the overflow main channel is 30°-60°.

[0010] Secondly, embodiments of this application also provide a flotation method, employing the overflow flotation apparatus suitable for natural graphite described in any of the above embodiments, the flotation method comprising: Obtain raw graphite ore, grind and rough beneficiate the raw graphite ore to obtain graphite rough beneficiation concentrate and graphite rough beneficiation tailings; The graphite roughing concentrate is subjected to multi-stage fine cleaning to obtain graphite concentrate; the graphite roughing tailings are subjected to multi-stage scavenging to obtain decarburized tailings.

[0011] In one embodiment of the second aspect, the flotation method further includes: Each stage of fine selection and each stage of scavenging yields intermediate concentrate and intermediate tailings; In multi-stage beneficiation, intermediate tailings are returned to the higher-level beneficiation equipment, while intermediate concentrate flows into the lower-level beneficiation equipment, ultimately yielding graphite concentrate. In multi-stage scavenging, intermediate concentrate is returned to the upper-level scavenging equipment, and intermediate tailings flow into the lower-level scavenging equipment, ultimately yielding decarbonized tailings.

[0012] In one embodiment of the second aspect, the minerals to be selected are ground before each stage of cleaning and each stage of scavenging.

[0013] Compared to existing technologies, the advantages of this application are as follows: This application provides an overflow flotation device and method suitable for natural graphite, which can be used in graphite flotation processes. The overflow flotation device includes a body, a flow-stabilizing ring plate, and an aeration / stirring assembly. The body is used to hold the flotation slurry, and the working end of the stirring assembly and the air outlet end of the aeration assembly are both placed in the flotation slurry. An overflow main tank and an overflow secondary tank connected to the overflow main tank are arranged on the side of the body. In this way, during the flotation process, the stirring assembly stirs the flotation slurry, and the aeration assembly aerates the flotation slurry to generate flotation foam. The flotation foam carries graphite ore and overflows from the top of the body, flowing into the overflow main tank and overflow secondary tank from different sides, completing the collection of graphite foam from multiple sides, and realizing flash flotation of graphite ore. Compared to existing technologies, where flotation foam only flows out from one side, the flotation rate is increased by accelerating the foam flow speed through scrapers. Meanwhile, a flow stabilizer is installed inside the machine body, and a flow channel and perforated holes are opened on the flow stabilizer. During the flotation process, the flotation foam flows to the top of the machine body through the flow channel, which reduces the intensity of the liquid surface "fluttering" and protects the large graphite flakes. Attached Figure Description

[0014] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0015] Figure 1 The following diagram illustrates the structure of the overflow flotation device in some embodiments of this application. Figure 1 ; Figure 2 The following diagram illustrates the structure of the overflow flotation device in some embodiments of this application. Figure 2 ; Figure 3 The following diagram illustrates the structure of the overflow flotation device in some embodiments of this application. Figure 3 ; Figure 4 The flowchart of the flotation method in some embodiments of this application is shown in the figure. Figure 1 ; Figure 5 The flowchart of the flotation method in some embodiments of this application is shown in the figure. Figure 2 .

[0016] Explanation of key component symbols: 100-Overflow flotation device; 110-Main body; 111-Main overflow tank; 112-Secondary overflow tank; 120-Agitator assembly; 121-Agitator shaft; 122-Impeller; 130-Aeration assembly; 131-Aeration pipe; 140-Flow stabilizer plate; 141-Through hole; 142-Flow channel; 150-Speed ​​limiter; 151-Limiting platform; 1511-First end; 1512-Second end; 160-Output pipe. Detailed Implementation

[0017] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0018] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0019] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0020] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0021] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0022] This application provides an overflow flotation device 100 and flotation method suitable for natural graphite, which can be used in graphite flotation processes and mineral sorting processes, specifically for the flotation of graphite ore. The overflow flotation device 100 and flotation method for natural graphite provided in this application complete the collection of graphite foam from multiple aspects, achieving flash flotation of graphite ore, avoiding the risk of damage to the scraper motor, and improving the quality of graphite flotation.

[0023] The accompanying drawings in the embodiments of this application will now be described. Figure 1 This is a simplified structural diagram of the overflow flotation device 100 from the front view. Figure 2 This is a simplified top view of the overflow flotation device 100. Figure 3 This is a simplified side view of the overflow flotation device 100. Figure 4 and Figure 5 This is a schematic diagram of the flotation process.

[0024] Combination Figure 1 and Figure 3 As shown, an embodiment of this application provides an overflow flotation device 100 suitable for natural graphite. The overflow flotation device 100 includes a body 110, a stirring assembly 120, and an aeration assembly 130. The body 110 is used to hold the flotation slurry, and an overflow trough is provided on the side of the body 110. The overflow trough includes a main overflow trough 111 and a secondary overflow trough 112, which communicates with the main overflow trough 111. The secondary overflow trough 112 and the main overflow trough 111 are located on different sides of the body 110. The working end of the stirring assembly 120 and the air outlet end of the aeration assembly 130 are both placed in the flotation slurry.

[0025] The body 110 is a pool structure with an open top and side, and its interior is equipped with a cavity for placing flotation slurry and graphite ore. An overflow trough is provided on the top side of the body 110. When flotation foam floats to the top surface of the body 110, it flows into the overflow trough, thereby collecting the graphite carried by the flotation foam.

[0026] The overflow tank can be divided into a main overflow tank 111 and at least one secondary overflow tank 112. The secondary overflow tank 112 and the main overflow tank 111 are located on different sides of the body 110, and the secondary overflow tank 112 is connected to the main overflow tank 111 to collect graphite by flotation from multiple sides of the body 110.

[0027] In this embodiment, the machine body 110 has a cuboid structure, and two overflow sub-channels 112 are provided. The overflow sub-channels 112 and the overflow main channel 111 are located on three sides of the machine body 110, respectively. The two overflow sub-channels 112 are located on two opposite sides of the machine body 110, and the overflow main channel 111 is located on the adjacent side of the overflow sub-channels 112. An outlet is opened at the end of the overflow sub-channel 112 near the overflow main channel 111 so that the graphite flotation foam in the overflow sub-channel 112 flows into the overflow main channel 111. The overflow main channel 111 can simultaneously receive the flotation foam flowing out from the overflow sub-channels 112 and the machine body 110, and then send it into a collection container to realize multi-side overflow flotation of graphite ore, achieve flash flotation of graphite, and reduce energy consumption.

[0028] The overflow sub-channel 112 is located inside the body 110, and the openings of the overflow main channel 111 and the overflow sub-channel 112 are lower than the top surface of the body 110, so that some foam flows into the overflow channel before reaching the top surface of the body 110. At the same time, the peripheral plates of the body 110 can block the foam and restrict the flow direction of the foam.

[0029] The flotation slurry may include diesel oil and alcohol solvents. The working ends of both the agitator 120 and the aeration 130 are located within the machine body 110. After the flotation slurry and graphite ore are placed into the machine body 110, the agitator 120 and the aeration 130 operate simultaneously. The agitator 120 agitates the graphite slurry to ensure uniform mixing. The aeration 130 aerates the slurry, generating a large number of bubbles that carry the graphite to the overflow tank.

[0030] like Figure 2 As shown, in some embodiments, a flow stabilizer plate 140 is provided inside the body 110. The flow stabilizer plate 140 has a flow channel 142. The stirring assembly 120 and the air filling assembly 130 pass through the flow channel 142. A plurality of through holes 141 are provided on the periphery of the flow channel 142.

[0031] The inventors of this application have discovered that graphite beneficiation provides a high degree of protection for large graphite flakes. During the aeration process, the liquid surface and foam are prone to tumbling, which can easily cause large graphite flakes to fall off from the foam, resulting in over-grinding of the large graphite flakes.

[0032] The flow stabilizer plate 140 is a flat plate, its sides fixed inside the body 110. The flow channel 142 penetrates the middle of the flow stabilizer plate 140 to accommodate the insertion of the stirring shaft 121 and impeller 122, while also allowing the flotation froth to rise and flow out. Through holes 141 are formed on the flow stabilizer plate 140, evenly distributed circumferentially along the flow channel 142. The opening ratio of the through holes 141 in the flow stabilizer plate 140 is 80% to 95%, ensuring that the slurry can pass through the center and optimizing the slurry movement trajectory, preventing the surrounding froth from "flipping" and avoiding the shedding of large graphite flakes from the froth.

[0033] The flow stabilizer plate 140 is a hollow, perforated annular square plate structure that is connected to the middle of the body 110. It effectively reduces the intensity of liquid surface "flakes" and is of great significance for protecting the large graphite flakes.

[0034] Combination Figure 1 and Figure 2 As shown, in some embodiments, the overflow flotation device 100 further includes a speed limiting member 150, which includes a limiting platform 151 and a lifting mechanism. The limiting platform 151 and the lifting mechanism are connected. The limiting platform 151 has a first end 1511 and a second end 1512. The cross-section of the limiting platform 151 decreases sequentially from the first end 1511 to the second end 1512. The second end 1512 is provided with a flow channel 142.

[0035] The flow channel 142 is a three-sided annular hollow structure, forming a U-shaped notch on the flow stabilizer plate 140. The limiting platform 151 is located on the side of the notch in the flow stabilizer plate 140. The limiting platform 151 has a conical truncated pyramidal structure, with its cross-sectional area decreasing from top to bottom. The lifting mechanism is connected to the limiting platform 151. By adjusting the lifting space, the limiting platform 151 moves up and down within the flow channel 142, thereby adjusting the coverage space of the limiting platform 151 over the flow channel 142 and restricting the passage space of the foam in the flow channel 142 according to the inflation volume and foam volume.

[0036] The lifting mechanism is located on the outside of the machine body 110. Specifically, it can be a motor gear transmission mechanism. Through gear transmission, it drives the limiting platform 151 to move up and down, thereby optimizing the flow space of the foam and adjusting the amount of foam outflow. If there is too much flotation foam, the limiting platform 151 can be adjusted upward to increase the outflow area of ​​the foam in the flow channel 142 and accelerate the collection of foam overflow.

[0037] Of course, in other embodiments, the lifting mechanism can also be replaced by hydraulic cylinders, pneumatic cylinders, or other lifting mechanisms.

[0038] In some embodiments, the stirring assembly 120 includes a stirring shaft 121 with a hollow cavity inside, and the air-filling assembly 130 includes an air-filling pipe 131 that passes through the hollow cavity.

[0039] The mixing assembly 120 includes a drive motor, a mixing shaft 121, and an impeller 122. One end of the mixing shaft 121 is connected to the motor for transmission, which can be achieved through gear transmission, belt transmission, chain transmission, etc. The impeller 122 is installed at the end of the mixing shaft 121 away from the motor and is located in the middle of the inner side of the machine body 110. Under the drive of the drive motor, the mixing shaft 121 drives the impeller 122 to rotate, thereby mixing the graphite slurry.

[0040] The aeration assembly 130 includes an air pump and an aeration pipe 131. The stirring shaft 121 has a hollow structure. The end of the aeration pipe 131 away from the air pump passes through the hollow cavity of the stirring shaft 121. The bottom end of the stirring shaft 121 is also provided with an air outlet to allow the gas in the aeration pipe 131 to enter the machine body 110 and generate flotation foam in the graphite slurry inside the machine body 110. By integrating the aeration pipe 131 with the stirring shaft 121, the installation space occupied by each component is reduced, and the overall structure is simplified.

[0041] Combination Figure 1 and Figure 3 As shown, in some embodiments, the overflow sub-channel 112 has a conical structure, and the end of the overflow sub-channel 112 with a larger cross-section is connected to the overflow main channel 111. The inclined angle of the slope of the overflow sub-channel 112 is 20°-50°.

[0042] The overflow sub-channel 112 is a conical inclined channel with a horizontal top and an inclined bottom, with an inclination angle of 20°-50° relative to the horizontal plane. Specifically, the inclination angle can be 20°, 30°, 40°, 50°, etc.

[0043] In this embodiment, the bottom side of the overflow sub-channel 112 is inclined at an angle of 30° relative to the horizontal plane.

[0044] The end of the overflow sub-channel 112 near the limiting platform 151 is higher than the end near the overflow main channel 111. At the same time, the end of the overflow sub-channel 112 near the overflow main channel 111 is provided with an outlet so that the flotation foam flows into the overflow main channel 111 along the inclined surface after entering the overflow sub-channel 112.

[0045] Combination Figure 1 and Figure 3 As shown, in some embodiments, the overflow main channel 111 has a conical structure, and the end of the overflow main channel 111 with a larger cross-section is provided with an output pipe 160. The slope angle of the overflow main channel 111 is 30°-60°.

[0046] The overflow main channel 111 is also a conical inclined channel, with its top side horizontal and its bottom side inclined, and the inclination angle relative to the horizontal plane is 30°-60°. Specifically, the inclination angle can be 30°, 40°, 50°, 60°, etc.

[0047] In this embodiment, the bottom side of the overflow sub-channel 112 is tilted at an angle of 40° relative to the horizontal plane.

[0048] The two ends of the overflow main tank 111 are set at different heights and are respectively connected to two overflow auxiliary tanks 112. At the same time, an output pipe 160 is set at the lower end of the overflow main tank 111 so that the flotation foam flows out along the slope to the collection container after entering the overflow main tank 111.

[0049] In a set of comparative examples, graphite ore with a fixed carbon content of 10.21% and a grinding fineness of +100 mesh (50% content) was divided into two portions, each weighing 1 kg, designated as Comparative Example 1 and Comparative Example 2. The comparative examples used a reagent condition of 100-300 g / t diesel oil and 50-150 g / t fusel oil, with stirring for 3 min at a stirring rate of 1992 r / min, and obtained graphite concentrate using an aerated flotation machine. The aeration rates for Comparative Example 1 and Comparative Example 2 were 0.3 L / min and 0.1 L / min, respectively.

[0050] In Comparative Example 1, the overflow flotation device 100 provided in the above-described examples was used, while in Comparative Example 2, a single-sided scraper flotation device was used. Comparative Example 1 yielded a graphite rough concentrate with a fixed carbon content of 25.54%, a recovery rate of 94.51%, and a +100 mesh content of 30.21%; Comparative Example 2 also yielded a graphite rough concentrate with a fixed carbon content of 25.89%, a recovery rate of 92.45%, and a +100 mesh content of 26.21%.

[0051] Comparing Comparative Example 1 and Comparative Example 2, it was found that the overflow flotation device 100 showed less change in graphite fixed carbon and a higher recovery rate compared to the traditional flotation machine, and had a good protective effect on large graphite flakes.

[0052] Embodiments of this application also provide a flotation method employing the overflow flotation apparatus 100 suitable for natural graphite in any of the above embodiments.

[0053] Combination Figure 4 and Figure 5 As shown, the flotation methods include: S10, roughing the raw ore to obtain graphite roughing concentrate and graphite roughing tailings.

[0054] Obtain crushed graphite ore with a fixed carbon content of 9.91% and a particle size of less than 2 mm. Grind the graphite ore to a fineness of 60% until the content of -100 mesh is 50%.

[0055] The graphite ore is separated using an overflow flotation device 100. The graphite ore is placed into the body 110 of the overflow flotation device 100, and diesel oil is added at 100~300g / t, fusel oil at 50~150g / t, the foam layer thickness is 60~100mm, and the aeration rate is 800~1200Nm. 3 The slurry concentration is 20-35% per hour, yielding graphite roughing concentrate and graphite roughing tailings.

[0056] In this embodiment, 200 g / t of diesel oil and 100 g / t of fusel oil are added, and the inflation volume of the inflation assembly 130 is controlled to be 1200 Nm. 3 / h, the thickness of the foam layer is 80mm, and the slurry concentration is 30%.

[0057] S20 is used to refine graphite roughing concentrate and scavenging graphite roughing tailings to obtain graphite concentrate and decarburized tailings.

[0058] The finer treatment of graphite roughing concentrate adopts a multi-stage flotation method of five grinding and six selections to improve the separation purity of graphite. Specifically, it can be divided into regrinding 1, fine selection 1, regrinding 2, fine selection 2, regrinding 3, fine selection 3, regrinding 4, fine selection 4, regrinding 5, fine selection 5, and fine selection 6. Intermediate products that do not meet the flotation standards are returned step by step to finally obtain graphite concentrate.

[0059] The selected operation parameters for each level are shown in Table 1.

[0060]

[0061] Table 1 It should be noted that the overflow flotation device 100 provided in this application is used for selection processes one, two, three, and four. However, after multiple flotations, the graphite content increases, and due to the agglomeration of graphite, caking is likely to occur. Continuing to use the overflow flotation device 100 may cause the flotation foam to caking and fail to overflow into the overflow tank. Therefore, for selection processes five and six, a natural graphite flotation device provided by patent number CN217615329U can be used. The natural graphite flotation device uses a scraper to propel the flotation foam, thereby accelerating the flow of flotation foam when the graphite content is too high.

[0062] A stirred mill can be used for grinding. The specific equipment operating parameters are shown in Table 2.

[0063] Table 2 In this embodiment, firstly, the grinding conditions are defined as the grinding parameters for regrinding in Table 2. After grinding the graphite roughing concentrate using a stirred mill, it enters the overflow flotation device 100 in the cleaning process for primary flotation. In the cleaning process, the foam layer thickness is 25 mm and the aeration rate is 1200 Nm.3 The slurry concentration was 25% at a rate of 1 / h, yielding primary intermediate concentrate and primary intermediate tailings. The fixed carbon content of the primary intermediate concentrate was 62.95%.

[0064] Secondly, the grinding conditions were limited to the grinding parameters of regrinding step 2 in Table 2. After grinding the primary intermediate concentrate using a stirred mill, it entered the overflow flotation unit 100 in the secondary cleaning step 2 for secondary flotation. In the secondary cleaning step 2, the froth layer thickness was 25 mm and the aeration rate was 1100 Nm. 3 The pulp concentration is 20% at a rate of 1 h, yielding secondary intermediate concentrate and secondary intermediate tailings. The fixed carbon content of the secondary intermediate concentrate is 78.54%. Simultaneously, the primary intermediate tailings undergo further grinding and roughing processes.

[0065] Secondly, the grinding conditions are limited to the grinding parameters of regrinding stage 3 in Table 2. After grinding the secondary intermediate concentrate using a stirred mill, it enters the overflow flotation unit 100 in the cleaning stage 3 for tertiary flotation. In the cleaning stage 3, the froth layer thickness is 23 mm and the aeration rate is 900 Nm³. 3 The pulp concentration is 18% per hour, yielding third-grade intermediate concentrate and third-grade intermediate tailings. The fixed carbon content of the third-grade intermediate concentrate is 88.86%. Simultaneously, the second-grade intermediate tailings undergo further regrinding and beneficiation processes.

[0066] Secondly, the grinding conditions are limited to the grinding parameters of regrinding four in Table 2. After grinding the third-stage intermediate concentrate with a stirred mill, it enters the overflow flotation unit 100 in the fourth-stage cleaning process for fourth-stage flotation. In the fourth-stage cleaning process, the froth layer thickness is 15 mm and the aeration rate is 800 Nm. 3 The pulp concentration is 15% at a rate of 1 / h, yielding fourth-grade intermediate concentrate and fourth-grade intermediate tailings. The fixed carbon content of the fourth-grade intermediate concentrate is 92.56%. Simultaneously, the third-grade intermediate tailings undergo regrinding and further cleaning processes.

[0067] Secondly, the grinding conditions are limited to the grinding parameters of regrinding stage 5 in Table 2. After grinding the fourth-stage intermediate concentrate using a stirred mill, it enters the overflow flotation unit 100 in the fifth-stage cleaning stage for fifth-stage flotation. In the fifth-stage cleaning stage, the froth layer thickness is 50 mm and the aeration rate is 500 Nm. 3 The pulp concentration was 12% at a rate of 1 / h, yielding fifth-grade intermediate concentrate and fifth-grade intermediate tailings. The fixed carbon content of the fifth-grade intermediate concentrate was 94.34%. Simultaneously, the fourth-grade intermediate tailings were subjected to regrinding and further refining processes.

[0068] Finally, the fifth-stage intermediate tailings are subjected to regrinding and cleaning processes (stage 4 and stage 4), and the fifth-stage intermediate concentrate is subjected to six-stage flotation in the overflow flotation unit 100 of the cleaning process (stage 6). In the cleaning process (stage 6), the froth layer thickness is 45 mm and the aeration rate is 450 Nm³.3 The process involves grinding the slurry at a concentration of 8% per hour to obtain graphite concentrate and sixth-stage intermediate tailings. The sixth-stage intermediate tailings are then subjected to regrinding and refining processes. The final graphite concentrate has a fixed carbon content of 95.43%, a recovery rate of 94.12%, and a +100 mesh content of 20.31%.

[0069] The graphite roughing tailings are successively processed through two grinding stages and two continuous scavenging stages to obtain graphite tailings. The intermediate concentrate obtained from the scavenging is returned to the previous process stage by stage.

[0070] The operating parameters for each level of sweeping and selection are shown in Table 3.

[0071]

[0072] Table 3 The grinding equipment used is a ball mill, and the specific equipment operating parameters are shown in Table 4.

[0073]

[0074] Table 4 In this embodiment, firstly, the grinding conditions are defined as the grinding parameters in Table 4. The graphite roughing tailings are ground using a ball mill and then enter the overflow flotation unit 100 in scavenging stage one for primary scavenging. In scavenging stage one, the froth layer thickness is 25 mm and the aeration rate is 1200 Nm³. 3 The slurry concentration was 25% at a rate of 1 / h, yielding primary scavenging concentrate and primary scavenging tailings. The fixed carbon content of the primary scavenging tailings was 1.72%.

[0075] Then, the tailings from the primary scavenging process undergo further grinding and roughing. The tailings are then fed into the overflow flotation unit 100 in the secondary scavenging stage for secondary flotation. In the secondary scavenging stage, the froth layer thickness is 25 mm, and the aeration rate is 1200 Nm³. 3 The pulp concentration is 25% at a rate of 1000 m³ / h, yielding secondary scavenging concentrate and decarbonized tailings. The secondary scavenging concentrate is then subjected to further grinding and scavenging processes. The final decarbonized tailings have a fixed carbon content of 0.65%.

[0076] The mineral processing method that combines overflow flotation and conventional flotation using the above-mentioned flotation machine directly eliminates the wear and tear on the motor and scraper, which plays a positive role in reducing the intensity of electromechanical maintenance and improving the quality of graphite flotation.

[0077] In summary, the overflow flotation device 100 and flotation method for natural graphite provided in this application adopt an overflow type flotation method with a design that eliminates the need for scraper and motor power, thus reducing the consumption of electricity and labor intensity, in line with the concept of green and low-carbon production. The process design concept of high volume, low concentration, and low foam layer utilizes the inherent good floatability of graphite to improve the fluidity of concentrate foam and promote efficient separation of graphite from gangue. The use of the limiting stage 151 and the flow stabilizing plate 140 accelerates the flow efficiency of foam, ensuring that the graphite flotation liquid surface does not exhibit "flooding" under high aeration conditions, thus guaranteeing a high flake ratio for graphite.

[0078] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0079] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An overflow flotation device suitable for natural graphite, characterized in that, include: The machine body is used to hold flotation slurry, and the side of the machine body is provided with an overflow trough. The overflow trough includes a main overflow trough and an auxiliary overflow trough. The auxiliary overflow trough is connected to the main overflow trough, and the auxiliary overflow trough and the main overflow trough are located on different sides of the machine body, respectively. The stirring assembly and the aeration assembly are both placed inside the flotation slurry. The machine body is provided with a flow stabilizing plate, the flow stabilizing plate has a flow groove, the stirring component and the air filling component pass through the flow groove, and the flow groove has multiple hollow holes on its periphery. The overflow flotation device further includes a speed limiting component, which includes a limiting platform and a lifting mechanism. The limiting platform and the lifting mechanism are connected. The limiting platform has a first end and a second end. The cross-section of the limiting platform decreases sequentially from the first end to the second end. The second end passes through the flow groove. The overflow sub-channel has a conical structure, and the end with the larger cross-section of the overflow sub-channel is connected to the overflow main channel. The inclination angle of the inclined surface of the overflow sub-channel is 20°-50°. The overflow main channel has a conical structure, and the end with the larger cross-section of the overflow main channel is provided with an output pipe. The inclination angle of the inclined surface of the overflow main channel is 30°-60°.

2. The overflow flotation device for natural graphite according to claim 1, characterized in that, The stirring assembly includes a stirring shaft, and a hollow cavity is formed inside the stirring shaft; The inflation assembly includes an inflation tube that passes through the hollow cavity.

3. A flotation method, characterized in that, The overflow flotation apparatus suitable for natural graphite according to any one of claims 1 to 2, the flotation method comprising: Obtain raw graphite ore, grind and rough beneficiate the raw graphite ore to obtain graphite rough beneficiation concentrate and graphite rough beneficiation tailings; The graphite roughing concentrate is subjected to multi-stage beneficiation to obtain graphite concentrate; the graphite roughing tailings are subjected to multi-stage scavenging to obtain decarburized tailings.

4. The flotation method according to claim 3, characterized in that, The flotation method further includes: Each stage of fine selection and each stage of scavenging yields intermediate concentrate and intermediate tailings; In multi-stage beneficiation, intermediate tailings are returned to the higher-level beneficiation equipment, and intermediate concentrate flows into the lower-level beneficiation equipment, ultimately yielding graphite concentrate. In multi-stage scavenging, intermediate concentrate is returned to the upper-level scavenging equipment, and intermediate tailings flow into the lower-level scavenging equipment, ultimately yielding decarbonized tailings.

5. The flotation method according to claim 3 or 4, characterized in that, The minerals to be selected are ground before each stage of selection and each stage of scavenging.

Images