A method of recovering coarse gold from a floated gold concentrate

Abstract

This invention discloses a method for recovering coarse gold particles from flotation gold concentrate, relating to the field of mineral processing technology. The method includes mixing a surface-activated slurry with magnetic nanofluid bubbles in a predetermined ratio and conveying it to a mineralization pipe with an applied gradient magnetic field. Under the magnetic drive of the gradient magnetic field, mineralization contact occurs, yielding a gas-solid-liquid mineralization mixture. This mixture is then introduced into a flotation separation device with an applied axial magnetic field for magnetically stable flotation separation. The froth product is collected from the top of the flotation separation device as gold concentrate, and the tailings slurry containing magnetic nanoparticles is discharged from the bottom. This invention achieves high-probability, forced contact and strong adhesion between the bubbles and activated particles by conveying the surface-activated slurry and magnetic nanofluid bubbles to a mineralization pipe with an applied gradient magnetic field, thus enhancing the selectivity and efficiency of the mineralization process.

Description

Technical Field

[0001] This invention relates to the field of mineral processing technology, and in particular to a method for recovering coarse gold particles from flotation gold concentrate. Background Technology

[0002] In the field of gold beneficiation, flotation is a key process for processing fine-grained disseminated gold ores and obtaining gold concentrate. However, the recovery of coarse gold particles (referring to +0.074 mm size) that have been liberated or enriched in carrier minerals has always been a technical challenge in conventional flotation processes. To improve the recovery rate of coarse gold particles, existing methods mainly focus on process optimization and equipment improvement, such as adopting a combined process of staged grinding, gravity separation (such as centrifugal concentrators) and flotation, or introducing special flotation equipment designed for coarse particles (such as flash flotation machines) into the flotation loop. The aim is to improve recovery indicators by improving the slurry flow pattern, increasing the collision probability, or capturing liberated coarse gold particles in advance.

[0003] However, coarse gold particles are easily oxidized or contaminated to form a passivation film. Conventional mechanical scrubbing or chemical activation methods have limited efficiency in cleaning and activating coarse gold particles. The functionalized media and agents (such as foaming agents and collector compounds) used in existing processes are usually disposable consumables that are lost with tailings, which can increase production costs and pose a potential environmental burden. Summary of the Invention

[0004] In view of the aforementioned existing problems, the present invention is proposed.

[0005] Therefore, this invention provides a method for recovering coarse gold particles from flotation gold concentrate, which solves the problems of low flotation efficiency due to insufficient surface activation of coarse gold particles, as well as high consumption of functional media and inability to be recycled.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution: This invention provides a method for recovering coarse gold particles from flotation gold concentrate, comprising: concentrating the flotation gold concentrate and adjusting it to a strongly alkaline environment under inert gas protection to obtain a pretreated slurry; simultaneously dispersing superparamagnetic nanoparticles, a thiourethane collector, and an alcohol frother in a liquid phase to prepare a magnetic nanofluid, which is then combined with a gas to generate magnetic nanofluid bubbles; spreading the pretreated slurry into a thin layer and conveying it to a pulsed plasma treatment chamber; bombarding the thin-layer pretreated slurry with pulsed plasma to obtain a surface-activated slurry; and combining the surface-activated slurry with the magnetic nanofluid bubbles. The mixture is mixed according to a set ratio and transported to a mineralization pipeline with an applied gradient magnetic field. Under the magnetic drive of the gradient magnetic field, mineralization contact is carried out to obtain a gas-solid-liquid mineralization mixture. The gas-solid-liquid mineralization mixture is then introduced into a column flotation separation device with an applied axial magnetic field to perform magnetically stable flotation separation. The froth product is collected from the top of the column flotation separation device as gold concentrate, and the tailings slurry containing magnetic nanoparticles is discharged from the bottom. The tailings slurry containing magnetic nanoparticles is then subjected to magnetic separation to separate the magnetic nanoparticle slurry from the final tailings. The magnetic nanoparticle slurry is then fed back to the magnetic nanofluid bubble production process.

[0007] In a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the pretreated slurry is obtained through the following steps: The flotation gold concentrate is fed into a high-efficiency thickener, and a concentrated slurry is obtained by adding flocculants and adjusting the opening of the underflow discharge valve. The concentrated slurry is pumped into a sealed slurry preparation tank, and the inert gas supply pipeline connected to the sealed slurry preparation tank is started to continuously introduce inert gas to replace and maintain the atmosphere inside the sealed slurry preparation tank, thus forming an inert gas environment. In an inert gas environment, sodium hydroxide solution is continuously added to the concentrated slurry in a sealed mixing tank until the pH value of the concentrated slurry reaches the strongly alkaline range, and then the pretreated slurry is output.

[0008] As a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the steps of dispersing superparamagnetic nanoparticles, thiourethane collectors, and alcohol frothers in a liquid phase to prepare a magnetic nanofluid, which is then combined with a gas to generate magnetic nanofluid bubbles, are as follows. In an ultrasonic dispersion device, superparamagnetic iron oxide nanoparticles are added to a carrier liquid, and ultrasonic waves are activated to perform the first stage of dispersion treatment, thereby obtaining a stable nanoparticle suspension. A thiourethane collector and an alcohol foaming agent were added sequentially to a stable nanoparticle suspension in an ultrasonic dispersion device, and ultrasonic waves were started to carry out the second stage of dispersion and mixing to obtain a uniform magnetic nanofluid. Uniform magnetic nanofluid is delivered to the inlet of a Venturi bubble generator, while compressed air is introduced into the air inlet. By adjusting the inlet pressure of the fluid and gas, magnetic nanofluid bubbles are generated using the pressure difference and shearing effect produced by the Venturi tube.

[0009] In a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the steps of spreading the pretreated slurry into a thin layer and conveying it to the pulsed plasma treatment chamber are as follows: The pretreated slurry is spread onto the conveyor belt by a thin-film spreader and then fed into the pulsed plasma processing chamber. A mixture of argon and oxygen is introduced into the pulsed plasma processing chamber as the working gas, and a high-frequency pulse power supply is activated to generate a low-temperature plasma region between the two poles in the chamber.

[0010] As a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the step of bombarding the pretreated slurry in a thin-layer state with pulsed plasma to obtain a surface-activated slurry is as follows. By adjusting the speed of the transmission baseband drive motor, the transmission time of the slurry thin layer through the low-temperature plasma zone is controlled, and plasma surface bombardment is carried out. The plasma-bombarded slurry thin layer is transported out of the pulsed plasma treatment chamber by a conveyor belt and scraped off from the surface of the conveyor belt by mechanical scraping, outputting activated solid material; The activated solid material is introduced into a buffer slurry tank filled with inert gas, process water is added and the agitator is started to adjust the slurry to obtain surface-activated mineral slurry.

[0011] In a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the step of mixing the surface-activated slurry with magnetic nanofluid bubbles in a predetermined ratio is as follows: The flow rates of the surface-activated mineral slurry and the magnetic nanofluid bubbles are monitored in real time by the first flow meter and the second flow meter, respectively, and the flow signals are transmitted to the PID controller. The PID controller, based on the flow signal and the preset flow ratio, outputs a control signal to adjust the opening of the first regulating valve and the second regulating valve, and outputs a proportionally mixed slurry.

[0012] As a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the steps of performing mineralization contact under the magnetic drive of a gradient magnetic field to obtain a gas-solid-liquid mineralization mixture are as follows. The proportionally mixed slurry is fed into a mineralization pipe with segmented independent electromagnetic coils wound along the axial pipe wall by a feed pump, and a spatial gradient magnetic field is formed by passing a current with a spatial gradient distribution to the electromagnetic coils. The flow rate of the proportionally mixed slurry is monitored in real time, and the speed of the feed pump is controlled accordingly to obtain a gas-solid-liquid mineralized mixture.

[0013] As a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the step of introducing the gas-solid-liquid mineralization mixture into a column flotation separation device with an applied axial magnetic field to perform magnetically stable flotation separation is as follows. The gas-solid-liquid mineralization mixture is introduced into the feed zone at the bottom of the column flotation separator through the feed pipe. The axial magnetic field coil group surrounding the cylindrical separation zone of the column flotation separator is activated and a controllable DC current is applied to establish the axial magnetic field. Under the influence of an axial magnetic field, low-pressure gas is introduced into the separation zone through a microporous gas diffuser located at the bottom of the column flotation separation device, thus creating a flotation environment.

[0014] In a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the steps of collecting froth product as gold concentrate from the upper part of the column flotation separation device and discharging tailings slurry containing magnetic nanoparticles from the bottom are as follows: Based on the flotation environment, an enriched froth layer is formed at the top of the column flotation separation unit, and the enriched froth layer is scraped off from the top to obtain gold concentrate; The unfloated slurry is discharged from the tailings discharge port at the bottom of the column flotation separation unit to obtain tailings slurry containing magnetic nanoparticles.

[0015] In a preferred embodiment of the method for recovering coarse gold particles from flotation gold concentrate according to the present invention, the magnetic separation treatment of the tailings slurry containing magnetic nanoparticles includes the following steps. The tailings slurry containing magnetic nanoparticles is fed into a high gradient magnetic separator for magnetic separation, retaining the magnetic nanoparticles adsorbed on the magnetic medium and discharging non-magnetic minerals as the final tailings. The magnetic field of the high gradient magnetic separator is cut off, and high-pressure flushing water is introduced to peel off the magnetic nanoparticles adsorbed on the magnetic medium to obtain a magnetic nanoparticle enrichment slurry. The magnetic nanoparticle enrichment slurry is concentrated to obtain a high-concentration magnetic nanoparticle slurry, which is then fed back into the magnetic nanofluid bubble fabrication process.

[0016] The beneficial effects of this invention are as follows: By using pulsed plasma to bombard the pretreated slurry in a thin-layer state, the oxide layer and contaminants on the surface of coarse gold particles are efficiently removed, and the surface active sites are significantly increased, providing highly activated interface conditions for subsequent reagent adsorption; by transporting the surface-activated slurry and magnetic nanofluid bubbles to a mineralization pipe with a gradient magnetic field for mineralization contact, a high-probability, forced contact and firm adhesion between the bubbles and the activated particles are achieved, enhancing the selectivity and efficiency of the mineralization process. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of a method for recovering coarse gold particles from flotation gold concentrate.

[0019] Figure 2 A flowchart for pretreatment of mineral slurry and generation of magnetic nanofluid bubbles.

[0020] Figure 3 This is a flowchart for the generation of surface-activated mineral slurry.

[0021] Figure 4 The flowchart shows the generation process of a gas-solid-liquid mineralization mixture.

[0022] Figure 5 This is a comparison chart showing the probability of effective contact between air bubbles and coarse gold particles.

[0023] Figure 6 This is a comparative graph showing the changes in stable mineralization formation rate under different magnetic field strength gradients.

[0024] Figure 7 This is a comparative chart showing the stable mineralization formation rate under different slurry surface conditions. Detailed Implementation

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0027] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that is mutually exclusive with other embodiments.

[0028] Reference Figures 1-7This is one embodiment of the present invention, which provides a method for recovering coarse gold particles from flotation gold concentrate, comprising the following steps: S1. Concentrate the flotation gold concentrate and adjust it to a strongly alkaline environment under inert gas protection to obtain a pretreated slurry. At the same time, disperse superparamagnetic nanoparticles, thiourethane collectors and alcohol frothers in the liquid phase to prepare a magnetic nanofluid, which is then combined with the gas to generate magnetic nanofluid bubbles.

[0029] S1.1: The flotation gold concentrate is fed into a high-efficiency thickener, and a concentrated slurry is obtained by adding flocculant and adjusting the opening of the underflow discharge valve.

[0030] Furthermore, the high-efficiency thickener includes a thickening tank for containing the slurry, a dosing pipeline and dosing point for adding flocculant, a stirring component for promoting uniform mixing of the slurry, and an underflow discharge port and underflow discharge valve located at the bottom of the tank. Simultaneously with the flotation gold concentrate entering the thickening tank of the high-efficiency thickener, flocculant is continuously added to the dosing point through an independent dosing pipeline and mixed with the slurry. The mixed slurry settles and stratifies within the thickening tank, forming a solid enrichment zone at the bottom of the tank. By adjusting the opening of the underflow discharge valve, the discharge rate of the underflow discharge port is controlled, allowing the slurry from the solid enrichment zone to be continuously discharged through the underflow discharge port, thus obtaining concentrated slurry.

[0031] S1.2: Pump the concentrated slurry into the sealed mixing tank and start the inert gas supply pipeline connected to the sealed mixing tank to continuously introduce inert gas to replace and maintain the atmosphere inside the sealed mixing tank, thus forming an inert gas environment.

[0032] Furthermore, the concentrated slurry is pumped from the high-efficiency thickener to the top inlet of the sealed slurry tank via a conveying pipeline. The main valve of the inert gas supply pipeline connected to the inert gas cylinder is opened, and the gas pressure is regulated by the pressure reducing valve on the inert gas supply pipeline, allowing the inert gas to enter the gas distributor at the bottom of the sealed slurry tank through the pipeline. At the same time as the inert gas is introduced, the exhaust valve at the top of the sealed slurry tank is opened to expel the original air in the sealed slurry tank. When the oxygen content in the gas discharged from the exhaust valve is lower than the safe oxygen content threshold, the exhaust valve is closed, and the flow control valve on the inert gas supply pipeline is adjusted to allow the inert gas to be continuously introduced into the sealed slurry tank at a constant flow rate, maintaining a slight positive pressure inside the sealed slurry tank and forming an inert gas environment.

[0033] It should be noted that during the alkaline slurry preparation process in gold beneficiation, in order to prevent oxidation of the mineral (such as gold) surface, it is necessary to ensure that the oxygen concentration in the reaction environment is reduced to a level that cannot support a significant oxidation reaction. The safe threshold for oxygen content is set according to the inert protection standard (controlling the oxygen volume concentration in the protected space to below 1%). When the actual gas oxygen volume concentration reaches the safe threshold for oxygen content, it is determined that the air in the sealed slurry preparation tank has been fully replaced, and the exhaust valve can be closed.

[0034] S1.3: In an inert gas environment, sodium hydroxide solution is continuously added to the concentrated slurry in a closed mixing tank until the pH value of the concentrated slurry reaches the strongly alkaline range, and the pretreated slurry is output.

[0035] Furthermore, while maintaining the continuous supply of inert gas to the sealed mixing tank via the inert gas supply pipeline, the agitator inside the sealed mixing tank is activated to stir the concentrated slurry. The valve of the dosing pipeline connecting the sodium hydroxide solution storage tank and the sealed mixing tank is opened, and the dosing metering pump is activated. The sodium hydroxide solution is pumped into the sealed mixing tank through the dosing pipeline and mixed with the concentrated slurry. The pH value of the slurry is continuously monitored in real time using a pH meter installed in the sealed mixing tank. When the pH meter shows that the pH value of the slurry reaches the strongly alkaline range (e.g., 10.5 to 12.0), the dosing metering pump and the dosing pipeline valve are closed, and the addition of sodium hydroxide solution is stopped, resulting in a pretreated slurry.

[0036] S1.4: In an ultrasonic dispersion device, superparamagnetic iron oxide nanoparticles are added to a carrier liquid, and ultrasonic waves are started to perform the first stage of dispersion treatment to obtain a stable nanoparticle suspension.

[0037] Furthermore, a carrier liquid is added to the dispersion container of the ultrasonic dispersion device. After the carrier liquid fills the effective volume of the dispersion container (e.g., 1 liter), a fixed mass of superparamagnetic iron oxide nanoparticles (e.g., 2 grams per 1 liter of carrier liquid) is slowly added to the dispersion chamber of the ultrasonic dispersion device containing the carrier liquid under mechanical stirring. The ultrasonic generator of the ultrasonic dispersion device is then activated. The ultrasonic generator drives the ultrasonic amplitude transformer immersed in the liquid surface of the dispersion chamber to generate high-frequency mechanical vibration, forming a cavitation effect in the carrier liquid, which breaks down and disperses the aggregates of superparamagnetic iron oxide nanoparticles. During the first stage of dispersion treatment (e.g., 10–30 minutes), the ultrasonic dispersion process continues until the superparamagnetic iron oxide nanoparticles are uniformly dispersed in the carrier liquid, forming a stable nanoparticle suspension.

[0038] It should be noted that cavitation effect refers to an acoustic phenomenon in which, when ultrasound propagates in a liquid medium, the local pressure of the liquid rapidly decreases to below the liquid's saturated vapor pressure, resulting in the generation of a large number of tiny bubbles (cavitation bubbles) inside the liquid. These bubbles grow rapidly and then violently collapse during a positive pressure cycle, generating extremely strong local high temperature, high pressure, and high-speed microjets at the moment of collapse.

[0039] S1.5: Add thiouric acid ester collectors and alcohol foaming agents sequentially to the stable nanoparticle suspension in the ultrasonic dispersion device, and start the ultrasonic wave to carry out the second stage of dispersion and mixing to obtain a uniform magnetic nanofluid.

[0040] Furthermore, while keeping the ultrasonic dispersion device in operation, a fixed mass (e.g., 10 grams per liter of stable nanoparticle suspension) of thiourethane collector solution is pumped into the dispersion chamber of the ultrasonic dispersion device using the first dosing pump, mixing with the stable nanoparticle suspension in the dispersion chamber. A fixed mass (e.g., 5 grams per liter of stable nanoparticle suspension) of alcohol foaming agent solution is pumped into the same dispersion chamber using the second dosing pump. After both agents have been added, the ultrasonic generator of the ultrasonic dispersion device is activated to perform a second stage of dispersion and mixing treatment on the stable nanoparticle suspension, thiourethane collector, and alcohol foaming agent. During the second stage of dispersion treatment (e.g., 5–15 minutes), the ultrasonic waves, through cavitation effect and mechanical action, promote the full interaction and uniform dispersion of the thiourethane collector and alcohol foaming agent with the superparamagnetic iron oxide nanoparticles in the carrier liquid, thus obtaining a uniform magnetic nanofluid.

[0041] S1.6: The uniform magnetic nanofluid is delivered to the inlet of the Venturi bubble generator, while compressed air is introduced into the air inlet. By adjusting the inlet pressure of the fluid and gas, magnetic nanofluid bubbles are generated by the pressure difference and shearing action generated by the Venturi tube.

[0042] Furthermore, a uniform magnetic nanofluid is pumped into the fluid inlet pipe of the Venturi bubble generator, while simultaneously opening the valve of the compressed air source, allowing compressed air to enter the gas inlet of the Venturi bubble generator through the gas pipe. The fluid pressure regulating valve on the uniform magnetic nanofluid pipe is adjusted to allow the uniform magnetic nanofluid to enter the Venturi tube constriction section of the Venturi bubble generator at a set pressure. Simultaneously, the gas pressure reducing valve on the compressed air pipe is adjusted to allow the gas to enter at a set pressure. When the uniform magnetic nanofluid passes through the throat of the Venturi tube at high speed, a pressure drop is generated at the throat, which draws the compressed air into the stream. The high-speed fluid exerts a strong shearing effect on the drawn-in gas, breaking the gas into tiny bubbles. At the same time, the functional substances in the uniform magnetic nanofluid coat the surface of the bubbles, thereby generating magnetic nanofluid bubbles at the outlet of the diffuser section of the Venturi bubble generator.

[0043] S2. Spread the pretreated slurry into a thin layer and transport it to the pulsed plasma treatment chamber. Use pulsed plasma to bombard the thin-layer pretreated slurry to obtain a surface-activated slurry.

[0044] S2.1: The pretreated slurry is spread on the conveyor belt by a thin film spreader and sent into the pulsed plasma processing chamber.

[0045] Furthermore, the pretreated slurry is pumped into the feed hopper of the membrane distributor through the feed pipe. The slit opening at the bottom of the feed hopper evenly distributes the pretreated slurry onto the surface of the conveyor belt moving at a constant speed below. An adjustable scraper installed behind the feed hopper maintains a set gap (e.g., 1 to 3 mm) with the surface of the conveyor belt, smoothing the flowing pretreated slurry into a continuous and uniformly thick thin layer of slurry. The conveyor belt drive device is activated to pull the conveyor belt with the thin layer of slurry forward. After passing through a sealed transition section, the conveyor belt carrying the thin layer of slurry is continuously fed into the internal processing area of ​​the pulsed plasma processing chamber.

[0046] S2.2: A mixture of argon and oxygen is introduced into the pulsed plasma processing chamber as the working gas, and a high-frequency pulse power supply is started to generate a low-temperature plasma region between the two poles in the chamber.

[0047] Furthermore, the valves of the argon and oxygen pipelines connected to the pulsed plasma processing chamber are opened. After being regulated by their respective flow controllers, the argon and oxygen enter the gas mixer at a fixed flow ratio (e.g., 9:1) to form a mixed gas composed of argon and oxygen. The mixed gas is introduced into the pulsed plasma processing chamber through the inlet, the main circuit of the high-frequency pulse power supply of the pulsed plasma processing chamber is closed, and the high-frequency pulse power supply is started. The high-frequency pulse power supply applies a high-frequency pulse high voltage between the anode and cathode inside the pulsed plasma processing chamber. Under the action of the high voltage, the mixed gas in the pulsed plasma processing chamber is broken down and ionized, and a diffuse, luminous low-temperature plasma region is excited in the space between the anode and cathode.

[0048] S2.3: By adjusting the speed of the transmission baseband drive motor, the transmission time of the thin layer of slurry through the low-temperature plasma zone is controlled to perform plasma surface bombardment.

[0049] Furthermore, based on the processing requirements that the thin slurry layer needs to achieve in the low-temperature plasma zone, the required transmission time is calculated, and based on the transmission time and the known length of the low-temperature plasma zone in the pulsed plasma processing chamber, the target operating linear speed required for the transmission baseband is determined; by adjusting the frequency output of the inverter connected to the transmission baseband drive motor, the speed of the drive motor is adjusted to the set value of the target operating linear speed; the transmission baseband runs at a constant speed after adjustment, carrying the thin slurry layer through the low-temperature plasma zone in the pulsed plasma processing chamber at a constant speed, and continuously receiving surface bombardment of low-temperature plasma during the transmission process.

[0050] It should be noted that the treatment requirements for the slurry thin layer in the low-temperature plasma zone are as follows: to achieve effective modification of the surface of mineral particles, especially coarse gold particles, in the slurry thin layer through plasma bombardment; this modification needs to remove or weaken the natural oxide layer and organic pollutants on the surface of coarse gold particles, generate nanoscale roughness on the surface of coarse gold particles to increase the specific surface area and reactive sites of the surface of coarse gold particles, and may introduce specific hydrophilic or hydrophobic groups on the surface of coarse gold particles. The treatment process must ensure that the slurry thin layer is heated uniformly as a whole, and avoid local overheating that could lead to adverse changes in mineral properties.

[0051] S2.4: The thin layer of slurry treated by plasma bombardment is transported out of the pulsed plasma treatment chamber by the conveyor belt, and scraped off from the surface of the conveyor belt by mechanical scraping, and the activated solid material is output.

[0052] Furthermore, the conveyor belt carrying the plasma-bombarded slurry thin layer moves continuously under the traction of the conveyor belt drive device, passing through the outlet sealing section of the pulsed plasma treatment chamber. Outside the pulsed plasma treatment chamber, below the running path of the conveyor belt, a scraper with a mechanical scraping device is installed. When the conveyor belt passes the scraper, the scraper peels off the plasma-bombarded slurry thin layer adhering to the surface of the conveyor belt. The peeled blocky or flaky material falls into the activated solid material collection hopper located directly below the scraper under the action of gravity, and the activated solid material is output.

[0053] S2.5: The activated solid material is introduced into a buffer slurry tank filled with inert gas, process water is added and the agitator is started to adjust the slurry to obtain surface-activated mineral slurry.

[0054] Furthermore, the activated solid material falls directly into a buffer slurry preparation tank filled with inert gas through the outlet of the activated solid material collection hopper. The buffer slurry preparation tank is continuously supplied with inert gas through an independent inert gas supply pipeline to maintain the inert gas environment inside the tank. The valve connecting the process water pipeline is opened, and process water is added to the buffer slurry preparation tank through the valve and pipeline. The amount of process water added is controlled according to the required slurry concentration. After the process water is added, the agitator installed in the buffer slurry preparation tank is started to stir and mix the activated solid material and process water in the buffer slurry preparation tank. Stirring continues until the activated solid material is completely dispersed in the process water to obtain surface-activated slurry.

[0055] It should be noted that process water refers to the process water from the plant's recycled water pool. Its function is to adjust the slurry concentration of activated solid materials so that the activated solid materials reach a slurry concentration range suitable for subsequent flotation operations (such as 30% to 40% solid mass concentration). At the same time, it serves as a dispersion medium to ensure that the activated mineral particles can be uniformly suspended, avoiding re-agglomeration, and providing suitable fluid conditions for subsequent mixing with magnetic nanofluid bubbles.

[0056] S3. The surface-activated mineral slurry and magnetic nanofluid bubbles are mixed in a set ratio and transported to a mineralization pipe with an applied gradient magnetic field. Under the magnetic drive of the gradient magnetic field, mineralization contact is carried out to obtain a gas-solid-liquid mineralization mixture.

[0057] S3.1: The flow rates of the surface-activated slurry and the magnetic nanofluid bubbles are monitored in real time by the first flow meter and the second flow meter respectively, and the flow signals are transmitted to the PID controller.

[0058] Furthermore, the surface-activated slurry flows through a first flow meter installed in the pipeline. The sensor (such as an electromagnetic coil) inside the first flow meter converts the flow state of the surface-activated slurry into a proportional raw electrical signal. At the same time, the magnetic nanofluid bubbles flow through a second flow meter installed in the pipeline. The sensor inside the second flow meter converts the flow state of the magnetic nanofluid bubbles into a proportional raw electrical signal. The first and second flow meters respectively convert the raw electrical signals characterizing their respective volumetric flow rates into standardized analog current signals, which are then transmitted to the signal input port of the PID controller via a signal cable.

[0059] S3.2: The PID controller outputs a control signal based on the flow signal and the preset flow ratio to adjust the opening of the first regulating valve and the second regulating valve, and outputs a proportionally mixed slurry.

[0060] Furthermore, the PID controller receives flow signals from the first and second flow meters and calculates the real-time ratio of the surface-activated slurry flow rate to the magnetic nanofluid bubble flow rate. The PID controller compares this real-time ratio with the flow ratio (e.g., 4:1) and calculates the control signal value used to correct the deviation using the PID control algorithm. The expression is as follows: ; in, Indicates in At any given time, the value of the control signal output by the PID controller; Indicates in At any given moment, the difference between the real-time measured ratio of the surface-activated slurry flow rate to the magnetic nanofluid bubble flow rate and the flow rate ratio; This is the proportional gain coefficient of the PID controller, with an exemplary value range of 0.5-2.0; This refers to the integral gain coefficient of the PID controller, with an exemplary value range of 0.05-0.2min. -1 ; This is the derivative gain coefficient of the PID controller, with an exemplary value range of 0.1-0.5min; Indicates from 0 to any intermediate moment within the time period The corresponding instantaneous deviation value of the flow rate ratio; The derivative of the integral variable represents an infinitesimal time interval; express At the present moment The instantaneous rate of change.

[0061] The control signal value is sent to the actuators of the first and second regulating valves, driving the valve cores of the first and second regulating valves to move to change the opening degree. After the opening degree is adjusted, the surface-activated slurry and the magnetic nanofluid bubbles enter the static pipeline mixer for mixing, and output the proportionally mixed slurry.

[0062] It should be noted that the flow rate ratio is set directly based on three key process parameters: the solid mass concentration of the surface-activated slurry, the gold carrying capacity of the magnetic nanofluid bubbles, and the optimal flow rate of the target slurry through the mineralization pipe. It is determined by a calculation that balances the total mass flow rate of gold minerals in the slurry with the total adsorption capacity available on the bubble surface, ensuring that the bubble surface area generated per unit time is sufficient to effectively capture the target coarse gold particles in the slurry.

[0063] S3.3: The proportionally mixed slurry is fed into the mineralization pipe, which is segmented with independent electromagnetic coils wound along the axial pipe wall, by a feed pump. A spatial gradient magnetic field is formed by passing a current with a spatial gradient distribution to the electromagnetic coil.

[0064] Furthermore, the proportioned mixed slurry enters the suction port of the feed pump through the connecting pipe. After being pressurized by the feed pump, it is transported to the inlet of the mineralization pipeline through the outlet pipe. The outer wall of the mineralization pipeline is divided into multiple continuous sections along the axial direction, and each section is independently wound with a set of electromagnetic coils. The positive and negative terminals of the DC power supply are connected to the terminals of each set of electromagnetic coils in sequence through cables, and the power control panel is operated to pass DC current with progressively increasing intensity to each set of electromagnetic coils from the inlet to the outlet. Since the current intensity carried by the electromagnetic coils at different positions along the pipeline axis is different, according to the principle of electromagnetic induction, a spatial gradient magnetic field with gradually increasing intensity is formed in the cylindrical cavity inside the mineralization pipeline from the inlet to the outlet.

[0065] It should be noted that the principle of electromagnetic induction is the core physical law guiding the generation of gradient magnetic fields in mineralization pipelines. Specifically, when a direct current passes through an electromagnetic coil wound around the wall of the mineralization pipeline, according to Ampere's law, the direct current will generate a steady magnetic field around the electromagnetic coil in the direction of the current. By independently controlling the magnitude of the current passing through multiple sets of electromagnetic coils wound in segments along the pipeline axis, the current intensity at different spatial locations is made different, thereby generating magnetic fields of different intensities in the local areas corresponding to each coil.

[0066] S3.4: Real-time monitoring of the flow rate of the proportionally mixed slurry, and feedback control of the feed pump speed to obtain a gas-solid-liquid mineralized mixture.

[0067] Furthermore, a flow meter is installed on the inlet pipe of the mineralization pipeline to continuously measure the real-time flow rate of the proportioned mixed slurry. The real-time flow rate is converted into an electrical signal and transmitted to the speed controller of the feed pump. The real-time flow rate is compared with the flow rate setpoint (e.g., 0.5 to 5 cubic meters per minute). If the real-time flow rate deviates from the flow rate setpoint, an adjustment command is calculated through a PID control algorithm and output to the drive motor of the feed pump to adjust the speed of the feed pump, so that the flow rate of the proportioned mixed slurry is stabilized near the flow rate setpoint. After the proportioned mixed slurry with a stable flow rate completes the mineralization process in the mineralization pipeline, it is discharged from the outlet of the mineralization pipeline to obtain a gas-solid-liquid mineralized mixture.

[0068] Figure 5 This study compares the probability of effective contact between bubbles and coarse gold particles per unit time under different process conditions. The variation in the frequency of effective contact between bubbles and coarse gold particles, presented as a broken line, reflects the changes in the frequency of effective contact under varying magnetic field strength gradients. Figure 5It can be seen that, without the application of a gradient magnetic field or with a low magnetic field gradient, the contact between bubbles and coarse gold particles mainly depends on the flow of slurry and random collisions, and the probability of effective contact is relatively low. However, with the introduction of the gradient magnetic field and its gradual increase in intensity, the bubbles undergo directional migration and aggregation under the action of the magnetic force, making them more likely to converge towards the area where coarse gold particles are located, thereby significantly increasing the probability of effective contact per unit time. This indicates that guiding the movement behavior of magnetic nanofluid bubbles through a gradient magnetic field can provide a more sufficient and stable contact prerequisite for the subsequent mineralization attachment process.

[0069] Figure 6 The study demonstrates a comparison of stable mineralization formation rates under different magnetic field intensity gradients. Specifically, by comparing the stable mineralization formation rates under no-gradient magnetic field conditions and under applied gradient magnetic field conditions, it reflects the influence of the magnetic field gradient on the adhesion stability of bubbles and coarse-grained gold mineralization. Figure 6 It can be seen that under the condition of no gradient magnetic field, even if the bubbles have come into contact with the coarse gold particles, their adhesion state is still easily affected by the disturbance of the slurry flow, and the increase in the stable mineralization formation rate is limited. However, after applying a gradient magnetic field, the magnetic nanofluid bubbles can maintain their contact time on the surface of the coarse gold particles under the constraint of the magnetic field force, making the formed adhesion less likely to fall off. As a result, the stable mineralization formation rate continues to increase with the increase of the magnetic field strength gradient. This indicates that the gradient magnetic field can not only promote the contact between the bubbles and the coarse gold particles, but also enhance the mechanical stability of the adhesion during the mineralization process, which plays an important role in improving the effectiveness of the mineralization process.

[0070] Figure 7 This study presents a comparison of stable mineralization formation rates under different slurry surface conditions, including a comparative analysis of the stable mineralization formation rates of slurries without surface activation treatment and those with surface activation after plasma treatment under the same mineralization conditions. Figure 7 It can be seen that in the slurry without surface activation treatment, the number of active sites on the surface of coarse gold particles is limited, and the bonding ability of the adhesion interface formed by bubbles after contact is weak, resulting in a low overall stable mineralization formation rate. In contrast, in the surface-activated slurry after plasma treatment, the oxide layer and contaminants on the surface of coarse gold particles are effectively removed, and the number of active sites increases significantly, making it easier for bubbles to form a stable adhesion structure after contact. This results in a higher stable mineralization formation rate throughout the mineralization process. This indicates that surface activation treatment plays a key role in enhancing interfacial bonding during the mineralization process. Combined with the effect of gradient magnetic field, it helps to further improve the selectivity and stability of the mineralization process.

[0071] S4. The gas-solid-liquid mineralization mixture is introduced into a column flotation separation device with an applied axial magnetic field to perform magnetically stable flotation separation. The froth product is collected from the top of the column flotation separation device as gold concentrate, and the tailings slurry containing magnetic nanoparticles is discharged from the bottom.

[0072] S4.1: The gas-solid-liquid mineralization mixture is introduced into the feed zone at the bottom of the column flotation separator through the feed pipe. The axial magnetic field coil group surrounding the cylindrical separation zone of the column flotation separator is started and a controllable DC current is applied to establish the axial magnetic field.

[0073] Furthermore, the gas-solid-liquid mineral mixture is pumped through a pipeline to the feed port at the bottom of the column flotation separator, and enters the feed zone of the column flotation separator through the feed pipe. The power switch of the axial magnetic field coil group is closed. The axial magnetic field coil group consists of multiple coils evenly spaced around the outer wall of the cylindrical separation zone of the column flotation separator. The controllable DC power supply in the power cabinet is started, and the output current of the controllable DC power supply is adjusted to a predetermined value (such as 200 amperes). The current is transmitted to the axial magnetic field coil group through the cable. When the current passes through the axial magnetic field coil group, an axial magnetic field with a direction parallel to the axis of the separation zone and a uniform intensity is generated inside the cylindrical separation zone of the column flotation separator.

[0074] S4.2: Under the action of an axial magnetic field, low-pressure gas is introduced into the separation zone through a microporous gas diffuser located at the bottom of the column flotation separation device to form a flotation environment.

[0075] Furthermore, under the condition of the presence of an axial magnetic field, the valve of the gas pipeline connected to the low-pressure gas source is opened, and the low-pressure gas flows through the gas pipeline to the microporous gas diffuser installed at the bottom of the column flotation separation device. The low-pressure gas is dispersed into a large number of fine bubbles through the micro-channels distributed on the microporous gas diffuser. The fine bubbles enter the cylindrical separation zone of the column flotation separation device from the bottom of the column flotation separation device, and rise and diffuse in the separation zone, making full contact with the gas-solid-liquid mineralized mixture rising from the feed area, thereby forming a flotation environment in the cylindrical separation zone of the column flotation separation device.

[0076] S4.3: Based on the flotation environment, an enriched froth layer is formed at the top of the column flotation separation unit, and the enriched froth layer is scraped off from the top to obtain gold concentrate.

[0077] Furthermore, in the flotation environment, the mineralized bubbles with coarse gold particles attached continue to rise due to their reduced density, and gather and merge at the gas-liquid interface at the top of the column flotation separator to form a stable enriched foam layer. A rotating scraper installed at the top of the column flotation separator and partially immersed in the enriched foam layer rotates at a constant speed around the central axis. The scraper blades of the rotating scraper scrape the enriched foam layer into the annular foam trough surrounding the top of the column flotation separator. The gold-rich foam gathers in the annular foam trough and is discharged through the discharge pipe connected to the annular foam trough, thereby obtaining gold concentrate.

[0078] S4.4: Discharge the unfloated slurry from the tailings discharge port at the bottom of the column flotation separator to obtain tailings slurry containing magnetic nanoparticles.

[0079] Furthermore, within the cylindrical separation zone of the column flotation separator, mineral particles that are not attached to the bubbles and float to the surface settle and collect at the bottom of the column flotation separator under the action of gravity. The collected slurry is continuously discharged through the tailings discharge port located at the conical bottom of the column flotation separator, thus obtaining tailings slurry containing magnetic nanoparticles.

[0080] S5. Perform magnetic separation on the tailings slurry containing magnetic nanoparticles to separate the magnetic nanoparticle slurry from the final tailings, and feed the magnetic nanoparticle slurry back to the magnetic nanofluid bubble production process.

[0081] S5.1: The tailings slurry containing magnetic nanoparticles is fed into a high-gradient magnetic separator for magnetic separation, retaining the magnetic nanoparticles adsorbed on the magnetic medium and discharging non-magnetic minerals as the final tailings.

[0082] Furthermore, the tailings slurry containing magnetic nanoparticles is pumped into the feed box of a high-gradient magnetic separator. The tailings slurry flows evenly from the feed box into the separation chamber of the high-gradient magnetic separator, which is filled with a magnetically concentrated medium. At the same time, the excitation coil of the high-gradient magnetic separator is activated to generate a high-gradient magnetic field in the separation chamber. When the tailings slurry containing magnetic nanoparticles flows through the separation chamber filled with the magnetically concentrated medium, the magnetic nanoparticles in the slurry are adsorbed and retained on the magnetically concentrated medium under the action of the high-gradient magnetic field, while the non-magnetic mineral particles are carried by the slurry through the magnetically concentrated medium and discharged from the non-magnetic mineral outlet of the high-gradient magnetic separator, thus obtaining the final tailings.

[0083] S5.2: Cut off the magnetic field of the high gradient magnetic separator and introduce high-pressure flushing water to peel off the magnetic nanoparticles adsorbed on the magnetic medium to obtain a magnetic nanoparticle enrichment slurry.

[0084] Furthermore, after the high-gradient magnetic separator completes the separation of non-magnetic minerals, the power supply to the excitation coil of the high-gradient magnetic separator is cut off, causing the high-gradient magnetic field in the separation chamber to disappear. The valve connected to the high-pressure water source is opened, and high-pressure flushing water is pumped into the flushing water inlet of the high-gradient magnetic separator through the pipeline and sprayed onto the magnetically concentrated medium in the separation chamber in the form of a high-speed jet. The high-pressure water flow generates a strong fluid scouring effect on the magnetically concentrated medium, completely peeling off the magnetic nanoparticles adsorbed on the surface of the magnetically concentrated medium. The peeled magnetic nanoparticles are mixed with the high-pressure flushing water to form a slurry, which flows out from the magnetic material outlet of the high-gradient magnetic separator, obtaining a magnetic nanoparticle enriched slurry.

[0085] S5.3: Concentrate the magnetic nanoparticle enrichment slurry to obtain a high-concentration magnetic nanoparticle slurry, and feed it back into the magnetic nanofluid bubble production process.

[0086] Furthermore, the magnetic nanoparticle-enriched slurry is pumped into the central feed cylinder of a high-efficiency thickener. Within the settling zone of the high-efficiency thickener, the magnetic nanoparticles settle and concentrate under gravity. The rake frame at the bottom of the high-efficiency thickener collects the settled magnetic nanoparticles to the bottom discharge port. By controlling the opening of the underflow discharge valve, a slurry with a high solid concentration is discharged, resulting in a high-concentration magnetic nanoparticle slurry. The high-concentration magnetic nanoparticle slurry is then pumped through a conveying pipeline to an ultrasonic dispersion device used to prepare magnetic nanofluid bubbles, where it is reused as a raw material in the magnetic nanofluid production process.

[0087] In summary, this invention achieves efficient removal of oxide layers and contaminants from coarse gold particles by bombarding a thin-layer pretreated slurry with pulsed plasma, significantly increasing surface active sites and providing highly activated interfacial conditions for subsequent reagent adsorption. Furthermore, by transporting the surface-activated slurry and magnetic nanofluid bubbles to a mineralization pipe with an applied gradient magnetic field for mineralization contact, a high-probability, forced contact and firm adhesion between the bubbles and activated particles are achieved, enhancing the selectivity and efficiency of the mineralization process.

[0088] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A method for recovering coarse gold particles from flotation gold concentrate, characterized in that: include, The flotation gold concentrate was concentrated and adjusted to a strongly alkaline environment under inert gas protection to obtain a pretreated slurry. Simultaneously, superparamagnetic nanoparticles, thiourethane collectors, and alcohol frothers were dispersed in the liquid phase to prepare a magnetic nanofluid. This nanofluid was then combined with gas to generate magnetic nanofluid bubbles. The steps are as follows: The flotation gold concentrate is fed into a high-efficiency thickener, and a concentrated slurry is obtained by adding flocculants and adjusting the opening of the underflow discharge valve. The concentrated slurry is pumped into a sealed slurry preparation tank, and the inert gas supply pipeline connected to the sealed slurry preparation tank is started to continuously introduce inert gas to replace and maintain the atmosphere inside the sealed slurry preparation tank, thus forming an inert gas environment. In an inert gas environment, sodium hydroxide solution is continuously added to the concentrated slurry in a closed mixing tank until the pH value of the concentrated slurry reaches the strongly alkaline range, and the pretreated slurry is output. In an ultrasonic dispersion device, superparamagnetic iron oxide nanoparticles are added to a carrier liquid, and ultrasonic waves are activated to perform the first stage of dispersion treatment, thereby obtaining a stable nanoparticle suspension. A thiourethane collector and an alcohol foaming agent were added sequentially to a stable nanoparticle suspension in an ultrasonic dispersion device, and ultrasonic waves were started to carry out the second stage of dispersion and mixing to obtain a uniform magnetic nanofluid. Uniform magnetic nanofluid is delivered to the inlet of a Venturi bubble generator, while compressed air is introduced into the air inlet. By adjusting the inlet pressure of the fluid and gas, magnetic nanofluid bubbles are generated using the pressure difference and shearing effect generated by the Venturi tube. The pretreated slurry is spread into a thin layer and transported to a pulsed plasma treatment chamber. The thin layer of pretreated slurry is bombarded with pulsed plasma to obtain a surface-activated slurry. The surface-activated mineral slurry is mixed with magnetic nanofluid bubbles in a set ratio and transported to a mineralization pipe with an applied gradient magnetic field. Under the magnetic drive of the gradient magnetic field, mineralization contact is carried out to obtain a gas-solid-liquid mineralization mixture. The gas-solid-liquid mineralization mixture is introduced into a column flotation separation unit with an applied axial magnetic field to perform magnetically stable flotation separation. The froth product is collected from the top of the column flotation separation unit as gold concentrate, and the tailings slurry containing magnetic nanoparticles is discharged from the bottom. Magnetic separation is performed on tailings slurry containing magnetic nanoparticles to separate the magnetic nanoparticle slurry from the final tailings, and the magnetic nanoparticle slurry is fed back into the magnetic nanofluid bubble production process.

2. The method for recovering coarse gold particles from flotation gold concentrate as described in claim 1, characterized in that: The steps for spreading the pretreated slurry into a thin layer and conveying it to the pulsed plasma processing chamber are as follows: The pretreated slurry is spread onto the conveyor belt by a thin-film spreader and then fed into the pulsed plasma processing chamber. A mixture of argon and oxygen is introduced into the pulsed plasma processing chamber as the working gas, and a high-frequency pulse power supply is activated to generate a low-temperature plasma region between the two poles in the chamber.

3. The method for recovering coarse gold particles from flotation gold concentrate as described in claim 2, characterized in that: The process involves bombarding a thin-layer pre-treated slurry with pulsed plasma to obtain a surface-activated slurry. The steps are as follows: By adjusting the speed of the transmission baseband drive motor, the transmission time of the slurry thin layer through the low-temperature plasma zone is controlled, and plasma surface bombardment is carried out. The plasma-bombarded slurry thin layer is transported out of the pulsed plasma treatment chamber by a conveyor belt and scraped off from the surface of the conveyor belt by mechanical scraping, outputting activated solid material; The activated solid material is introduced into a buffer slurry tank filled with inert gas, process water is added and the agitator is started to adjust the slurry to obtain surface-activated mineral slurry.

4. The method for recovering coarse gold particles from flotation gold concentrate as described in claim 1, characterized in that: The steps for mixing the surface-activated mineral slurry with magnetic nanofluid bubbles in a predetermined ratio are as follows: The flow rates of the surface-activated mineral slurry and the magnetic nanofluid bubbles are monitored in real time by the first flow meter and the second flow meter, respectively, and the flow signals are transmitted to the PID controller. The PID controller, based on the flow signal and the preset flow ratio, outputs a control signal to adjust the opening of the first regulating valve and the second regulating valve, and outputs a proportionally mixed slurry.

5. The method for recovering coarse gold particles from flotation gold concentrate as described in claim 4, characterized in that: The mineralization contact process, driven by a gradient magnetic field, to obtain a gas-solid-liquid mineralized mixture, comprises the following steps. The proportionally mixed slurry is fed into a mineralization pipe with independent electromagnetic coils wound in sections along the axial pipe wall via a feed pump. A spatial gradient magnetic field is formed by passing a current with a spatial gradient distribution to the electromagnetic coils. The flow rate of the proportionally mixed slurry is monitored in real time, and the speed of the feed pump is controlled accordingly to obtain a gas-solid-liquid mineralized mixture.

6. The method for recovering coarse gold particles from flotation gold concentrate as described in claim 1, characterized in that: The steps for introducing the gas-solid-liquid mineralization mixture into a column flotation separation device with an applied axial magnetic field to perform magnetically stable flotation separation are as follows. The gas-solid-liquid mineralization mixture is introduced into the feed zone at the bottom of the column flotation separator through the feed pipe. The axial magnetic field coil group surrounding the cylindrical separation zone of the column flotation separator is activated and a controllable DC current is applied to establish the axial magnetic field. Under the influence of an axial magnetic field, low-pressure gas is introduced into the separation zone through a microporous gas diffuser located at the bottom of the column flotation separation device, thus creating a flotation environment.

7. The method for recovering coarse gold particles from flotation gold concentrate as described in claim 6, characterized in that: The steps for collecting the froth product from the top of the column flotation separation unit as gold concentrate and discharging the tailings slurry containing magnetic nanoparticles from the bottom are as follows: Based on the flotation environment, an enriched froth layer is formed at the top of the column flotation separation unit, and the enriched froth layer is scraped off from the top to obtain gold concentrate; The unfloated slurry is discharged from the tailings discharge port at the bottom of the column flotation separation unit to obtain tailings slurry containing magnetic nanoparticles.

8. The method for recovering coarse gold particles from flotation gold concentrate as described in claim 1, characterized in that: The magnetic separation treatment of tailings slurry containing magnetic nanoparticles involves the following steps. The tailings slurry containing magnetic nanoparticles is fed into a high gradient magnetic separator for magnetic separation, retaining the magnetic nanoparticles adsorbed on the magnetic medium and discharging non-magnetic minerals as the final tailings. The magnetic field of the high gradient magnetic separator is cut off, and high-pressure flushing water is introduced to peel off the magnetic nanoparticles adsorbed on the magnetic medium to obtain a magnetic nanoparticle enrichment slurry. The magnetic nanoparticle enrichment slurry is concentrated to obtain a high-concentration magnetic nanoparticle slurry, which is then fed back into the magnetic nanofluid bubble fabrication process.

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