A flotation method of lead-zinc pyrite based on charge directional heterogeneous agglomeration

Abstract

The present application relates to the technical field of ore flotation, and particularly relates to a flotation method for lead-zinc-iron sulfide ore based on charge directional heterogeneous agglomeration. The flotation method comprises the following steps: adding a pH regulator and a sphalerite inhibitor into lead-zinc-iron sulfide ore slurry to obtain initial ore slurry; suspending a positively charged nano Fe3O4@SiO2-NH2 core-shell particle and the initial ore slurry through a Venturi-cyclone coupling treatment to realize heterogeneous agglomeration of galena and dispersion of sphalerite, and to obtain pretreated ore slurry; performing flotation on the pretreated ore slurry to obtain galena concentrate and lead tailings; and performing flotation on the lead tailings to obtain sphalerite concentrate and flotation tailings. The present application solves the problem of poor separation selectivity between galena and sphalerite in the flotation of lead-zinc-iron sulfide ore.

Description

Technical Field

[0001] The present invention relates to the technical field of ore flotation, and specifically relates to a flotation method for lead-zinc-pyrite based on charge-directed heterogeneous agglomeration. Background Art

[0002] Lead-zinc-pyrite is a composite polymetallic ore that simultaneously contains lead (Pb), zinc (Zn) and pyrite (main components are FeS2 or pyrrhotite Fe 1-x S, 0<x<1). It is an ore type in which three mineral resources of lead, zinc and sulfur (iron) are symbiotically or associated in the same deposit under geological processes. This type of ore often occurs in nature in the form of stratabound layered deposits or hydrothermal vein deposits. Lead-zinc minerals (mainly galena PbS and sphalerite ZnS) and pyrite (pyrite, pyrrhotite, etc.) are closely symbiotic and mutually disseminated, belonging to typical complex and difficult-to-separate polymetallic ores.

[0003] Among them, the flotation separation of galena (PbS) and sphalerite (ZnS) is a classic problem in the field of mineral processing. The traditional process mainly adopts the "depress zinc and float lead" procedure, that is, in an alkaline pulp, depressants such as zinc sulfate (ZnSO4), sodium sulfite (Na2SO3) and cyanide are used to selectively depress sphalerite, and then thio compound collectors such as xanthate and dithiophosphate are added to hydrophobize the surface of galena, so as to realize flotation separation. Although this technical route has been applied for decades, it still faces many challenges as follows: First, the reagent regime is complex and environmentally unfriendly: traditional collectors such as xanthate and dithiophosphate have pungent odors and certain toxicity, while depressants such as cyanide are highly toxic substances, posing a serious threat to the environment and operating personnel.

[0004] Second, the recovery efficiency of fine-grained minerals is low: with the increasing depletion, fineness and complexity of mineral resources, fine-grained minerals have small mass and low momentum during the flotation process, and the collision probability with bubbles decreases significantly, leading to difficulty in improving the recovery rate. Traditional collectors also have poor selective adsorption on fine grains.

[0005] Third, the separation selectivity needs to be improved: galena and sphalerite are often closely symbiotic, and the difference in surface properties after monomer dissociation is reduced. A single depressant system is difficult to achieve high-selectivity separation, which often leads to excessively high zinc content in lead concentrate or excessively high lead content in zinc concentrate, affecting the concentrate grade and recovery rate.

[0006] Therefore, developing a green, efficient and low-cost flotation method for lead-zinc-pyrite is of great significance for promoting the sustainable development of the lead-zinc-pyrite industry. Summary of the Invention

[0007] In view of this, the purpose of the present invention is to provide a flotation method for lead-zinc-pyrite based on charge-directed heterogeneous agglomeration, so as to solve the problem of poor separation selectivity between galena and sphalerite in the existing flotation of lead-zinc-pyrite.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration includes the following steps: S1. Add pH adjuster and sphalerite inhibitor to lead-zinc-pyrite slurry to obtain initial slurry; S2. The positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension and the initial slurry are subjected to Venturi-cyclone coupling treatment to achieve heterogeneous agglomeration of galena and dispersion of sphalerite, thus obtaining a pretreated slurry. S3. Flotation of the pretreated slurry yields galena concentrate slurry and lead tailings slurry; S4. The lead tailings slurry is floated to obtain sphalerite concentrate slurry and flotation tailings slurry.

[0009] Based on the above-mentioned technical means, by utilizing the surface potential difference between galena and sphalerite, positively charged nano-Fe3O4@SiO2-NH2 core-shell particles are introduced as charge bridging media, and combined with the controllable micro-vortex field generated by the Venturi-cyclone coupling reaction, selective agglomeration flotation of galena is achieved while maintaining high dispersion of sphalerite. This effectively solves the problems of low recovery rate of fine-grained minerals, poor separation selectivity, and large dosage of toxic reagents in traditional processes, significantly improves the flotation separation efficiency of fine-grained lead-zinc ores, greatly reduces environmental risks, and achieves the technical effect of green mineral processing.

[0010] Specifically, the advantages of the flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration of the present invention are reflected in the following aspects: First, it significantly improves separation selectivity: In traditional flotation processes, galena and sphalerite have similar surface properties, resulting in poor separation selectivity and low concentrate grade. This method utilizes the surface potential difference between galena and sphalerite by introducing positively charged nano-Fe3O4@SiO2-NH2 core-shell particles as charge bridging mediators. These particles selectively adsorb onto the negatively charged galena surface, achieving heterogeneous agglomeration of galena, while sphalerite remains highly dispersed due to the surface potential difference. This significantly improves the separation selectivity between galena and sphalerite, effectively increasing the concentrate grade. It solves the problem of poor separation selectivity between galena and sphalerite in existing lead-zinc-pyrite flotation processes.

[0011] Secondly, it significantly improves separation efficiency: In existing technologies, fine-grained lead-zinc ore, due to its small mass and large specific surface area, is difficult to effectively collide and adhere with bubbles, resulting in low recovery rates. This method enhances the contact efficiency between nanoparticles and the mineral surface through a controllable micro-vortex field generated by the Venturi-cyclone coupling reaction, promotes the selective agglomeration of galena, and increases the effective particle size and collision probability of the agglomerates. This significantly improves the flotation recovery rate of fine-grained galena, solving the problem of low separation efficiency between galena and sphalerite in existing lead-zinc pyrite flotation processes.

[0012] Third, it effectively reduces environmental risks: In traditional processes, large amounts of toxic inhibitors such as cyanide are typically used to achieve lead-zinc separation, which pose significant risks to the environment and human health. This method replaces some of the toxic chemical agents with positively charged Fe3O4@SiO2-NH2 core-shell particles, achieving selective separation through physicochemical synergy. This significantly reduces the amount of toxic agents used, lowers the content of harmful substances in mineral processing wastewater, effectively mitigates environmental pollution risks, and aligns with the development direction of green mineral processing.

[0013] Fourth, achieving green and efficient mineral processing: This method combines charge-directed heterogeneous agglomeration technology with Venturi-cyclone coupling enhancement technology, which not only improves the flotation separation efficiency and selectivity of fine-grained lead-zinc ore, but also reduces the consumption of chemical reagents, lowers mineral processing costs and environmental impact, and achieves a coordinated unity of efficient resource recovery and environmental protection. It has good industrial application prospects and significant economic and social benefits.

[0014] Preferably, in step S1, lead-zinc-pyrite ore powder is added to water and ball-milled so that the proportion of lead-zinc-pyrite ore powder with a grinding fineness of -74μm is 70-80%, thus obtaining lead-zinc-pyrite ore slurry. The lead-zinc-pyrite slurry contains 66-75% lead-zinc-pyrite powder by mass.

[0015] Preferably, the ball milling time is 6-8 minutes.

[0016] Preferably, in step S1, a pH adjuster and a sphalerite inhibitor are added to the lead-zinc-pyrite slurry, and the mixture is stirred for 5-10 minutes to fully hydrophilize the surface of the sphalerite, thus obtaining the initial slurry.

[0017] Preferably, in step S2, the positively charged nano-Fe3O4@SiO2-NH2 core-shell particle suspension and the initial slurry are treated in a Venturi-cyclone coupling reactor to generate a controllable micro-vortex field of 50~200um. This allows the positively charged nano-Fe3O4@SiO2-NH2 core-shell particle suspension and the initial slurry to undergo intense shearing, mixing, and micro-vortex effects within the Venturi-cyclone coupling reactor, thereby achieving heterogeneous agglomeration of galena and dispersion of sphalerite, resulting in a pretreated slurry. The Venturi-cyclone coupled reactor comprises a Venturi section and a cyclone section. The Venturi section primarily generates initial high shear and achieves rapid, powerful mixing of reagents (nanoparticles, air) with the slurry. The cyclone section utilizes a centrifugal force field to initially separate and screen the fine aggregates formed in the Venturi section from the dispersed particles, maintaining a stable micro-vortex environment. A tangential inlet is used to introduce the fluid from the Venturi diffuser section outlet tangentially into the cyclone cavity at high speed; the inlet interface is designed to be rectangular. The diameter of the larynx in the Venturi section is 7.7 mm, the length of the larynx is 15 mm, the air velocity in the larynx is 40~80 m / s, the contraction angle (α) is 23~30°, and the diffusion angle (β) is 6~8°. The diameter of the swirl coupling cavity in the swirl section is 75~100mm, the ratio of the diameter of the overflow outlet in the swirl section to the diameter of the swirl coupling cavity is 0.2~0.4, and the ratio of the diameter of the underflow outlet in the swirl section to the diameter of the swirl coupling cavity is 0.1~0.2. The eddy shear rate of the Venturi-swirl coupled reactor is 500~800 s. -1 ; The positively charged nano-Fe3O4@SiO2-NH2 core-shell particle suspension contains 1-5 wt% of positively charged nano-Fe3O4@SiO2-NH2 core-shell particles. Add 80 mg of positively charged nano Fe3O4@SiO2-NH2 core-shell particles per liter of initial slurry.

[0018] Preferably, at the injection port of the throat in the Venturi section, the gas flow rate is precisely injected at 0.5 m³ / s using a gas flow meter. 3 Air is supplied at a rate of / min. Flotation reagents are also added through the injection port.

[0019] Preferably, before treatment by the Venturi-cyclone coupling reactor, the positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension and the initial slurry are added to the delivery pipeline by a metering pump. The turbulence of the pipeline delivery allows the positively charged nano Fe3O4@SiO2-NH2 core-shell particles to be pre-contacted with the mineral particles for 1-3 minutes.

[0020] Preferably, S3 includes: A frother is added to the pretreated slurry for roughing of galena to obtain roughed galena slurry and roughed lead tailings slurry. A pH adjuster is added to the roughing galena slurry for galena beneficiation, resulting in galena concentrate slurry and beneficiated lead middlings ore slurry. Galena collector and frother are added to the roughing lead tailings slurry to carry out galena scavenging, resulting in scavenged galena slurry and scavenged lead tailings slurry.

[0021] Rapid flotation of galena can be achieved by feeding pretreated slurry into a flotation machine and adding flotation reagents.

[0022] Preferably, S4 includes: pH adjuster, activator, sphalerite collector and frother are added to the scavenged lead tailings slurry to carry out sphalerite roughing to obtain rough sphalerite slurry and rough zinc tailings slurry. A pH adjuster is added to the roughing sphalerite slurry to perform sphalerite beneficiation, resulting in sphalerite concentrate slurry and beneficiated zinc middlings ore slurry. Add sphalerite collector and frother to the roughing zinc tailings slurry, and carry out sphalerite scavenging to obtain scavenged sphalerite slurry and flotation tailings slurry.

[0023] Preferably, the pH adjuster is selected from sodium carbonate (Na2CO3). The zincblende inhibitor is selected from zinc sulfate (ZnSO4). The foaming agent is selected from pine oil (2) # Oil); The galena collector is selected from ethyl thiocyanate; The sphalerite collector is selected from butyl xanthate (sodium butyl xanthate). The activator is selected from copper sulfate (CuSO4).

[0024] Preferably, in step S3, when performing roughing of galena, the amount of frother is 6-8 g / t (i.e., 6-8 g of frother is added to each ton of pretreated slurry), the frothing time is 3-4 min, and the number of roughing operations for galena is 1-2 times. When performing galena beneficiation, the pH should be controlled between 8.8 and 9.0, and the galena beneficiation should be performed 1 to 2 times, with a skimming time of 1 to 3 minutes. When performing galena scavenging, the dosage of galena collector is 10-15 g / t (i.e., 10-15 g of galena collector is added to each ton of roughing lead tailings slurry), the dosage of frother is 3-4 g / t (i.e., 3-4 g of frother is added to each ton of roughing lead tailings slurry), the frothing time is 1-3 minutes, and the number of galena scavenging operations is 1-2 times.

[0025] Preferably, in step S4, during the roughing of sphalerite, the pH is controlled between 11.2 and 11.5, the amount of activator is 20-30 g / t (i.e., 20-30 g of activator is added to each ton of scavenged lead tailings slurry), the amount of sphalerite collector is 100-150 g / t (i.e., 100-150 g of sphalerite collector is added to each ton of scavenged lead tailings slurry), the amount of frother is 10-12 g / t (i.e., 10-12 g of frother is added to each ton of scavenged lead tailings slurry), the number of times sphalerite roughing is performed is 1-2 times, and the frothing time is 3-4 minutes. When performing sphalerite beneficiation, the pH should be controlled between 11.2 and 11.5, and the sphalerite beneficiation should be performed 1 to 2 times, with a skimming time of 1 to 3 minutes. When performing sphalerite scavenging, the dosage of sphalerite collector is 35-50 g / t (i.e., 35-50 g of sphalerite collector is added to each ton of roughing zinc tailings slurry), the dosage of frother is 5-6 g / t (i.e., 5-6 g of frother is added to each ton of roughing zinc tailings slurry), the number of sphalerite scavenging operations is 1-2 times, and the frothing time is 1-3 minutes.

[0026] Preferably, the method further includes: S5, adding flocculant to flotation tailings slurry, concentrating to obtain solution and tailings filter cake, and reusing the solution after treatment.

[0027] The treatment of the solution includes removing suspended solids, heavy metal ions, and residual reagents. The treated water is then returned to the main mineral processing stage to prepare lead-zinc-pyrite slurry. The solution treatment process includes: equalization tank → sedimentation tank → dosing device (coagulation / neutralization) → advanced treatment → reuse. The treated water must meet the direct discharge limits specified in the "Emission Standard of Pollutants for Lead and Zinc Industry" (GB25466-2010) before being used to prepare lead-zinc-pyrite slurry, achieving 100% recycling.

[0028] Preferably, the flocculant is selected from polyacrylamide (PAM), and the dosage of the flocculant is 30~35g / t (i.e., 30~35g of foaming agent is added to each ton of flotation tailings slurry).

[0029] Preferably, step S5 includes: adding flocculant to the flotation tailings slurry, concentrating it for 6-8 hours using a high-efficiency thickener to obtain a thickened overflow solution and tailings filter cake. The thickened overflow solution is treated and reused to reduce fresh water consumption, and the tailings filter cake is stacked and then sent to the tailings dam.

[0030] Preferably, the moisture content of the tailings filter cake is ≤15%.

[0031] Preferably, the zinc grade in the galena concentrate is ≤5%, and the recovery rate of the galena concentrate is ≥90%; the lead grade in the sphalerite concentrate is ≤1%, and the recovery rate of the sphalerite concentrate is ≥90%.

[0032] Preferably, the lead-zinc-pyrite ore powder is fine-grained lead-zinc-pyrite ore powder, which is obtained by crushing, grinding and screening fine-grained lead-zinc-pyrite ore. In the fine-grained lead-zinc-sulfur complex intergrowth ore, the proportion of ore powder with a particle size of -0.074mm in the lead-zinc-sulfur complex intergrowth is 60~65%, that is, the proportion of ore powder with a particle size of less than 0.074mm in the lead-zinc-sulfur complex intergrowth is 60~65%. The composition of the fine-grained lead-zinc-pyrite includes: lead (Pb), zinc (Zn), iron (Fe), sulfur (S), calcium oxide (CaO), aluminum oxide (Al2O3), silicon dioxide (SiO2), silver (Ag*), gold (Au*), and magnesium oxide (MgO), with the balance being other trace components and loss on ignition (LOI). * indicates the content of the corresponding element in g / t.

[0033] The technical principle of the flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration of the present invention is analyzed as follows: 1. Biomimetic Micro-vortex-charge-directed heterogeneous aggregation mechanism: A controllable micro-vortex field of 50~200um is generated through a Venturi-cyclone coupling reactor to simulate the filter-feeding structure of fish gills and enhance the collision of fine particles. When fish breathe, they generate vortices of a specific scale in the water flow through the specific arrangement of gill rakers and the precise opening and closing of their mouths. This efficiently separates and traps food particles in the water flow, while the water itself passes through smoothly. This process does not rely on the chemical capture effect of agents, but on the physical matching between the flow field structure and the particle size.

[0034] According to turbulence theory, the size of the smallest vortex in a vortex is related to the energy dissipation rate and fluid viscosity. By precisely controlling the geometry and inlet velocity of the Venturi-vortex coupled reactor, controllable microvortices with a scale of approximately 50–200 μm can be generated. This scale precisely matches the apparent particle size (45–60 μm) of the target agglomerates (agglomerates formed by galena particles and positively charged nano-Fe3O4@SiO2-NH2 core-shell particles). When the target agglomerates enter a vortex of similar size, they are subjected to strong centrifugal or centripetal forces, thus being captured in the core or edge of the vortex, while the dispersed, smaller sphalerite particles (<20 μm) flow out with the main fluid, achieving a physical sieving similar to fish gills.

[0035] 2. Under pH conditions of 8.8–9.0, positively charged nano-Fe3O4@SiO2-NH2 core-shell particles (approximately 200 nm in diameter, with a Zeta potential of 8–10 mV) are introduced as charge bridging mediators, utilizing the surface potential difference between galena (ζ≈-15 mV) and zincblende (ζ≈-35 mV). The preparation process for this material is mature and can be purchased from companies that produce SiO2 nano-core-shell materials. Fe3O4-NH2 nanoparticles are typically positively charged, while the SiO2 shell provides colloidal stability and a modifiable surface, selectively inducing galena to form 45–60 μm hydrophobic aggregates. At pH 9.0, the surface potential difference between galena (ζ≈-15 mV) and zincblende (ζ≈-35 mV) provides the thermodynamic basis for this selectivity. According to DLVO theory, the total interaction energy between particles is the sum of van der Waals gravitational potential energy and electrostatic repulsive potential energy. The introduction of positively charged nano-Fe3O4@SiO2-NH2 core-shell particles (ζ≈+15mV) alters this energy balance. These positively charged particles exhibit electrostatic attraction with the weakly negatively charged galena surface (ζ≈-15mV). When a single positively charged nano-Fe3O4@SiO2-NH2 core-shell particle adsorbs onto two galena particles simultaneously, a bridge is formed. Due to the low negative potential of the galena surface, the surface charge of the adsorbed positively charged nano-Fe3O4@SiO2-NH2 core-shell particle may be neutralized or even reversed. This leads to a decrease or disappearance of the electrostatic repulsion between the positively charged nano-Fe3O4@SiO2-NH2 core-shell particles, with van der Waals attraction becoming dominant, resulting in aggregation and the formation of target agglomerates. These target agglomerates exhibit a degree of hydrophobicity due to the presence of the SiO2 shell on the surface of the positively charged nano-Fe3O4@SiO2-NH2 core-shell particles. Meanwhile, the surface roughness of the positively charged nano-Fe3O4@SiO2-NH2 core-shell particles can amplify the intrinsic wettability of the material. The target aggregates formed by galena particles and positively charged nano-Fe3O4@SiO2-NH2 core-shell particles have extremely high nanoscale roughness. Even if the individual components are hydrophilic, this micro-nano composite structure may capture micro- and nano-bubbles or form gas films at the solid-liquid interface, thus exhibiting macroscopic hydrophobicity. The positively charged nano-Fe3O4@SiO2-NH2 core-shell particles strongly adsorb onto the more negatively charged surface of zincblende (ζ≈-35mV). Due to the stronger adsorption driving force, the positively charged nano-Fe3O4@SiO2-NH2 core-shell particles may form a dense monolayer covering on the zincblende surface, causing its surface charge to reverse from -35mV to positive potential. At this time, strong electrostatic repulsion will be generated between the zincblende particles wrapped by the positively charged nano-Fe3O4@SiO2-NH2 core-shell particles, thus maintaining a highly dispersed state.

[0036] The beneficial effects of this invention are: This invention relates to a flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration. By utilizing the surface potential difference between galena and sphalerite, positively charged nano-Fe3O4@SiO2-NH2 core-shell particles are introduced as charge bridging media. Combined with a controllable micro-vortex field generated by a Venturi-cyclone coupled reactor, this method effectively achieves selective agglomeration flotation of galena while maintaining high dispersion of sphalerite. This effectively solves the problems of low recovery rate of fine-particle minerals, poor separation selectivity, and large dosage of toxic reagents in traditional processes. It significantly improves the flotation separation efficiency of fine-particle lead-zinc ore, greatly reduces environmental risks, and achieves the technical effect of green mineral processing. It has significant application value in the field of ore flotation technology. Attached Figure Description

[0037] Figure 1 This is a flowchart of the flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to the present invention; Figure 2 A schematic diagram illustrating the interaction mechanism between positively charged nano-Fe3O4@SiO2-NH2 core-shell particles and galena. Figure 3 A schematic diagram illustrating the interaction mechanism between positively charged nano-Fe3O4@SiO2-NH2 core-shell particles and zincblende; Figure 4 This is a schematic diagram of a Venturi-cyclone coupled reactor. Wherein, 1-Venturi section, 11-throat, 12-inlet, 2-swirl section, 21-swirl coupling cavity, 22-overflow outlet, 23-underflow outlet, 24-tangential inlet. Figure 4 The arrows in the diagram indicate the direction of material flow. Detailed Implementation

[0038] The following description, with reference to preferred embodiments, illustrates the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are merely illustrative of the present invention and not intended to limit the scope of protection of the present invention.

[0039] Where specific techniques or conditions are not specified in the detailed embodiments, they shall be performed in accordance with the techniques or conditions described in the literature in this field or in accordance with the product instructions. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0040] In the following examples and comparative examples, the lead-zinc-pyrite ore powder used is fine-grained lead-zinc-pyrite ore; in the raw ore of fine-grained lead-zinc-pyrite ore, the proportion of ore powder with a lead-zinc-sulfur complex intergrowth particle size of -0.074mm is 60~65%.

[0041] The positively charged nano Fe3O4@SiO2-NH2 core-shell particles used are functionalized nanomaterials whose silica shells exhibit a net positive potential through surface modification or specific synthesis conditions. The core is iron(III) oxide (Fe3O4-NH2), and the shell is silica (SiO2). The particle size is about 200nm. The positively charged nano Fe3O4@SiO2-NH2 core-shell particles are finished products and can be purchased from companies that produce SiO2 nano-core-shell materials on the market.

[0042] Example 1

[0043] like Figures 1 to 4 As shown, a flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration includes the following steps: S1. Pulping: 1 kg of fine-grained lead-zinc-pyrite ore powder is added to water and ball-milled for 6 min to achieve a fineness of -74 μm, resulting in a lead-zinc-pyrite ore powder content of 70%, thus obtaining a lead-zinc-pyrite ore slurry. The mass percentage of fine-grained lead-zinc-pyrite ore powder in the slurry is 66%. In this embodiment, the composition and content of fine-grained lead-zinc-pyrite ore include: 0.612% lead (Pb), 1.202% zinc (Zn), 3.55% iron (Fe), 2.15% sulfur (S), 1.24% calcium oxide (CaO), 6.32% aluminum oxide (Al2O3), 77.01% silicon dioxide (SiO2), 68 g / t silver (Ag*), 0.43 g / t gold (Au*), and 7.8% magnesium oxide (MgO), with the balance being other trace components and loss on ignition (LOI). Where * indicates that the content of the corresponding element is in g / t; The lead-zinc-pyrite slurry was transferred into a mixing tank, sodium carbonate was added, the pH value was adjusted to 8.8, and then zinc sulfate was added (60g / t, that is, 60g of zinc sulfate was added to each ton of lead-zinc-pyrite slurry). The mixture was stirred for 8 minutes to fully hydrophilize the surface of the sphalerite and obtain the initial slurry. S2. Nanoparticle pre-contact: Positively charged nano Fe3O4@SiO2-NH2 core-shell particles are dispersed in water to prepare a suspension of positively charged nano Fe3O4@SiO2-NH2 core-shell particles with a mass percentage of 1wt%. Positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension was added to the delivery pipeline at a dosage of 80 mg / L (i.e., 80 mg of positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension was added to each liter of initial slurry) and simultaneously added to the delivery pipeline through a metering pump. The turbulence of the pipeline delivery was used to pre-contact the positively charged nano Fe3O4@SiO2-NH2 core-shell particles with the initial slurry for 1 min to obtain a mixed slurry. Venturi-Swirl Coupled Reactor Treatment: The mixed slurry, after a 1-minute pre-contact period, is pumped into a Venturi-cyclone coupled reactor, and injected at a flow rate of 0.5 m / s through the inlet 12 of the throat 11 in the Venturi section 1 of the reactor. 3 Air flow rate / min, eddy shear rate 500s -1 To achieve heterogeneous agglomeration of galena and dispersion of sphalerite, a pretreated slurry is obtained, which flows out from the underflow outlet 23. The parameters of the Venturi section 1 of the Venturi-swirl coupled reactor are as follows: the diameter of the throat 11 is 7.7 mm, the length of the throat 11 is 15 mm, the contraction angle is 26.5°, the diffusion angle is 7°, and the gas velocity in the throat 11 is 40 m / s; the parameters of the swirl section 2 are as follows: the diameter of the swirl coupling cavity 21 is 87.5 mm, the ratio of the diameter of the overflow outlet 22 to the diameter of the swirl coupling cavity 21 is 0.3, the ratio of the diameter of the underflow outlet 23 to the diameter of the swirl coupling cavity 21 is 0.15, and the tangential inlet 24 in the swirl section 2 is used to control the eddy shear rate to ensure residence time and contact efficiency; S3, Galena flotation: The pretreated slurry obtained after treatment by the Venturi-cyclone coupled reactor was transferred to an XFD type 1.5L flotation cell, and pine oil (2) was added. # Oil (6g / t, i.e., 6g of pine oil is added to each ton of pretreated slurry) is used for one roughing of galena, with a skimming time of 3 minutes, to obtain roughed galena slurry and roughed lead tailings slurry. Sodium carbonate was added to the roughing galena slurry to adjust the pH to 8.8 for the first galena cleaning, resulting in the first galena concentrate slurry and the first cleaned lead middlings slurry. Sodium carbonate was added to the first galena concentrate slurry to adjust the pH to 8.8 for the second galena cleaning, resulting in the second galena concentrate slurry (which, after drying, yields the galena concentrate product) and the second cleaned lead middlings slurry. The first cleaned lead middlings slurry was returned to the pretreatment slurry for repeated galena roughing, and the second cleaned lead middlings slurry was returned to the roughing galena slurry for repeated first galena cleaning. The skimming time for both galena cleaning processes was 2 minutes. Add ethyl thiocyanate (10g / t, i.e., 10g ethyl thiocyanate per ton of roughing lead tailings slurry) and pine oil (2 # Oil (3g / t, i.e., 3g pine oil added per ton of roughing lead tailings slurry) is used for the first galena scavenging, resulting in the first scavenged galena slurry and the first scavenged lead tailings slurry. Ethylene thiocyanate (10g / t, i.e., 10g ethylene thiocyanate added per ton of the first scavenged galena slurry) and pine oil (2g pine oil) are then added to the first scavenged galena slurry. # Oil (3g / t, i.e., 3g of pine oil is added to each ton of first-scavenged galena slurry) is used for the second galena scavenging to obtain the second-scavenged galena slurry and the second-scavenged lead tailings slurry. The first-scavenged lead tailings slurry is returned to the pre-treated slurry for repeated galena roughing, and the second-scavenged galena slurry is returned to the roughing lead tailings slurry for repeated first-scavenging. The skimming time for both galena scavenging processes is 2 minutes. S4, Sphalerite flotation: Sodium carbonate was added to the second scavenging lead tailings slurry to adjust the pH to 11.2, followed by the addition of copper sulfate (20 g / t, i.e., 20 g copper sulfate per ton of second scavenging lead tailings slurry), butyl xanthate (100 g / t, i.e., 100 g butyl xanthate per ton of second scavenging lead tailings slurry), and pine oil (2... # Oil (10g / t, i.e., 10g of pine oil is added to each ton of second-stage lead tailings slurry) is used for one roughing of sphalerite, with a scraping and bubbling time of 3 minutes, to obtain roughing sphalerite slurry and roughing zinc tailings slurry. Sodium carbonate was added to the roughing sphalerite slurry to adjust the pH to 11.2 for the first sphalerite cleaning, resulting in the first sphalerite concentrate slurry and the first cleaned zinc middlings slurry. Sodium carbonate was added to the first sphalerite concentrate slurry to adjust the pH to 11.2 for the second sphalerite cleaning, resulting in the second sphalerite concentrate slurry (which, after drying, yields the sphalerite concentrate product) and the second cleaned zinc middlings slurry. The first cleaned zinc middlings slurry was returned to the second scavenging lead tailings slurry for repeated sphalerite roughing, and the second cleaned zinc middlings slurry was returned to the roughing sphalerite slurry for repeated first sphalerite cleaning. The skimming time for both sphalerite cleaning processes was 2 minutes. Add butyl xanthate (35g / t, i.e., 35g butyl xanthate per ton of roughing zinc tailings slurry) and pine oil (2 #Oil (5g / t, i.e., 5g pine oil added per ton of roughing zinc tailings slurry) is used for the first sphalerite scavenging, resulting in the first scavenged sphalerite slurry and the first scavenged zinc tailings slurry. Butyronitrile (35g / t, i.e., 35g butyronitrile per ton of first scavenged sphalerite slurry) and pine oil (2g pine oil) are then added to the first scavenged sphalerite slurry. # Oil (5g / t, i.e., 5g of pine oil is added to each ton of first-stage scavenged sphalerite slurry) is used for the second-stage scavenging of sphalerite to obtain the second-stage scavenged sphalerite slurry and flotation tailings slurry. The zinc tailings slurry from the first-stage scavenging is returned to the lead tailings slurry from the second-stage scavenging for repeated sphalerite roughing, and the sphalerite slurry from the second-stage scavenging is returned to the roughing zinc tailings slurry for repeated first-stage sphalerite scavenging. The skimming time for both sphalerite scavenging processes is 2 minutes. S5. Tailings treatment: Add polyacrylamide (30g / t, i.e., 30g of polyacrylamide per ton of flotation tailings slurry) to the flotation tailings slurry. After thickening for 6 hours by a high-efficiency thickener, thickened overflow water and tailings filter cake are obtained. The thickened overflow water is recycled and the tailings filter cake (moisture content of 13%) is dry-piled into the tailings dam.

[0044] Example 2

[0045] like Figures 1 to 4 As shown, a flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration includes the following steps: S1. Pulping: Add 1 kg of fine-grained lead-zinc-pyrite ore powder to water and ball mill for 7 min, so that the proportion of lead-zinc-pyrite ore powder with a grinding fineness of -74 μm is 75%, to obtain lead-zinc-pyrite ore slurry. The mass percentage of fine-grained lead-zinc-pyrite ore powder in the lead-zinc-pyrite ore slurry is 70%. In this embodiment, the composition and content of fine-grained lead-zinc-pyrite ore include: 0.611% lead (Pb), 1.204% zinc (Zn), 3.42% iron (Fe), 2.18% sulfur (S), 1.24% calcium oxide (CaO), 6.45% aluminum oxide (Al2O3), 77.01% silicon dioxide (SiO2), 68 g / t silver (Ag*), 0.43 g / t gold (Au*), and 7.76% magnesium oxide (MgO), with the balance being other trace components and loss on ignition (LOI). Where * indicates that the content of the corresponding element is in g / t; The lead-zinc-pyrite slurry was transferred into a mixing tank, sodium carbonate was added, the pH value was adjusted to 9.0, and then zinc sulfate was added (75g / t, that is, 75g of zinc sulfate was added to each ton of lead-zinc-pyrite slurry). The mixture was stirred for 8 minutes to fully hydrophilize the surface of sphalerite and obtain the initial slurry. S2. Nanoparticle pre-contact: Positively charged nano Fe3O4@SiO2-NH2 core-shell particles are dispersed in water to prepare a suspension of positively charged nano Fe3O4@SiO2-NH2 core-shell particles with a mass percentage of 3wt%. Positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension was added to the delivery pipeline at a dosage of 80 mg / L (i.e., 80 mg of positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension was added to each liter of initial slurry) and simultaneously added to the delivery pipeline through a metering pump. The turbulence of the pipeline delivery was used to pre-contact the positively charged nano Fe3O4@SiO2-NH2 core-shell particles with the initial slurry for 2 minutes to obtain a mixed slurry. Venturi-Swirl Coupled Reactor Treatment: The mixed slurry, after a 2-minute pre-contact period, is pumped into a Venturi-cyclone coupled reactor, and injected at a flow rate of 0.5 m / s through the inlet 12 of the throat 11 in the Venturi section 1 of the reactor. 3 Air flow rate / min, eddy shear rate 650s -1 This process aims to achieve heterogeneous agglomeration of galena and dispersion of sphalerite, resulting in a pretreated slurry. The parameters of the Venturi section 1 of the Venturi-swirl coupled reactor are as follows: the diameter of the throat 11 is 7.7 mm, the length of the throat 11 is 15 mm, the contraction angle is 26.5°, the diffusion angle is 7°, and the gas velocity in the throat 11 is 60 m / s; the parameters of the swirl section 2 are as follows: the diameter of the swirl coupling cavity 21 is 87.5 mm, the ratio of the diameter of the overflow outlet 22 to the diameter of the swirl coupling cavity 21 is 0.3, the ratio of the diameter of the underflow outlet 23 to the diameter of the swirl coupling cavity 21 is 0.15, and the tangential inlet 24 in the swirl section 2 is used to control the eddy shear rate to ensure residence time and contact efficiency; S3, Galena flotation: The pretreated slurry obtained after treatment by the Venturi-cyclone coupled reactor was transferred to an XFD type 1.5L flotation cell, and pine oil (2) was added. # Oil (7g / t, i.e., 7g of pine oil is added to each ton of pretreated slurry) is used for one roughing of galena, with a skimming time of 3.5min, to obtain roughed galena slurry and roughed lead tailings slurry; Sodium carbonate was added to the roughing galena slurry to adjust the pH to 9.0 for the first galena cleaning, resulting in the first galena concentrate slurry and the first cleaned lead middlings slurry. Sodium carbonate was added to the first galena concentrate slurry to adjust the pH to 9.0 for the second galena cleaning, resulting in the second galena concentrate slurry (which, after drying, yields the galena concentrate product) and the second cleaned lead middlings slurry. The first cleaned lead middlings slurry was returned to the pretreatment slurry for repeated galena roughing, and the second cleaned lead middlings slurry was returned to the roughing galena slurry for repeated first galena cleaning. The skimming time for both galena cleaning processes was 2 minutes. Add ethyl thiocyanate (12.5 g / t, i.e., 12.5 g ethyl thiocyanate per ton of roughing lead tailings slurry) and pine oil (2 # Oil (3.5g / t, i.e., 3.5g pine oil added per ton of roughing lead tailings slurry) was used for the first galena scavenging, resulting in the first scavenged galena slurry and the first scavenged lead tailings slurry. Ethylene thiocyanate (12.5g / t, i.e., 12.5g ethylene thiocyanate added per ton of the first scavenged galena slurry) and pine oil (2... # Oil (3.5g / t, i.e., 3.5g pine oil added to each ton of first-stage scavenged galena slurry) is used for the second scavenging of galena to obtain the second-stage scavenged galena slurry and the second-stage scavenged lead tailings slurry. The first-stage scavenged lead tailings slurry is returned to the pre-treatment slurry for repeated galena roughing, and the second-stage scavenged galena slurry is returned to the roughing lead tailings slurry for repeated first-stage galena scavenging. The skimming time for both galena scavenging processes is 2 minutes. S4, Sphalerite flotation: Sodium carbonate was added to the second scavenging lead tailings slurry to adjust the pH to 11.3. Then, copper sulfate (25 g / t, i.e., 25 g copper sulfate per ton of the second scavenging lead tailings slurry), butyl xanthate (120 g / t, i.e., 120 g butyl xanthate per ton of the second scavenging lead tailings slurry), and pine oil (2...) were added. # Oil (11g / t, i.e., 11g of pine oil is added to each ton of second-stage scavenged lead tailings slurry) is used for one roughing of sphalerite, with a skimming time of 3.5min, to obtain roughing sphalerite slurry and roughing zinc tailings slurry; Sodium carbonate was added to the roughing sphalerite slurry to adjust the pH to 11.3 for the first sphalerite cleaning, resulting in the first sphalerite concentrate slurry and the first cleaned zinc middlings slurry. Sodium carbonate was added to the first sphalerite concentrate slurry to adjust the pH to 11.3 for the second sphalerite cleaning, resulting in the second sphalerite concentrate slurry (which, after drying, yields the sphalerite concentrate product) and the second cleaned zinc middlings slurry. The first cleaned zinc middlings slurry was returned to the second scavenging lead tailings slurry for repeating the sphalerite roughing, and the second cleaned zinc middlings slurry was returned to the roughing sphalerite to repeat the first sphalerite cleaning. The skimming time for both sphalerite cleaning processes was 2 minutes. Add butyl xanthate (at a dosage of 40 g / t, i.e., 40 g butyl xanthate per ton of roughing zinc tailings slurry) and pine oil (2 # Oil (5.5g / t, i.e., 5.5g pine oil added per ton of roughing zinc tailings slurry) was used for the first sphalerite scavenging, resulting in the first scavenged sphalerite slurry and the first scavenged zinc tailings slurry. Butyroxanone (40g / t, i.e., 40g butyroxanone added per ton of the first scavenged sphalerite slurry) and pine oil (2... # Oil (5.5g / t, i.e., 5.5g of pine oil added to each ton of first-stage scavenged sphalerite slurry) is used for the second-stage scavenging of sphalerite to obtain the second-stage scavenged sphalerite slurry and flotation tailings slurry. The zinc tailings slurry from the first-stage scavenging is returned to the lead tailings slurry from the second-stage scavenging for repeated sphalerite roughing, and the sphalerite slurry from the second-stage scavenging is returned to the roughing zinc tailings slurry for repeated first-stage sphalerite scavenging. The skimming time for both sphalerite scavenging processes is 2 minutes. S5. Tailings treatment: Add polyacrylamide (32.5g / t, i.e., 32.5g of polyacrylamide per ton of flotation tailings slurry) to the flotation tailings slurry. After concentration for 7 hours by a high-efficiency thickener, thickened overflow water and tailings filter cake are obtained. The thickened overflow water is recycled and the tailings filter cake (moisture content of 12%) is dry-piled into the tailings dam.

[0046] Example 3

[0047] like Figures 1 to 4 As shown, a flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration includes the following steps: S1. Pulping: Add 1 kg of fine-grained lead-zinc-pyrite ore powder to water and ball mill for 8 min, so that the proportion of lead-zinc-pyrite ore powder with a grinding fineness of -74 μm is 80%, to obtain lead-zinc-pyrite ore slurry. The mass percentage of fine-grained lead-zinc-pyrite ore powder in the lead-zinc-pyrite ore slurry is 75%. In this embodiment, the composition and content of fine-grained lead-zinc-pyrite ore include: 0.61% lead (Pb), 1.203% zinc (Zn), 3.43% iron (Fe), 2.15% sulfur (S), 1.34% calcium oxide (CaO), 6.56% aluminum oxide (Al2O3), 75.05% silicon dioxide (SiO2), 68 g / t silver (Ag*), 0.43 g / t gold (Au*), and 9.3% magnesium oxide (MgO), with the balance being other trace components and loss on ignition (LOI). Where * indicates that the content of the corresponding element is in g / t; The lead-zinc-pyrite slurry was transferred into a mixing tank, sodium carbonate was added, the pH value was adjusted to 9.0, and then zinc sulfate (90g / t, i.e., 90g of zinc sulfate was added to each ton of lead-zinc-pyrite slurry) was added. The mixture was stirred for 8 minutes to fully hydrophilize the surface of the sphalerite and obtain the initial slurry. S2. Pre-contact of nanoparticles: Positively charged nano Fe3O4@SiO2-NH2 core-shell particles are dispersed in water to prepare a suspension of positively charged nano Fe3O4@SiO2-NH2 core-shell particles with a mass percentage of 5wt%. Positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension was added to the delivery pipeline at a dosage of 80 mg / L (i.e., 80 mg of positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension was added to each liter of initial slurry) and simultaneously added to the delivery pipeline through a metering pump. The turbulence of the pipeline delivery was used to pre-contact the positively charged nano Fe3O4@SiO2-NH2 core-shell particles with the initial slurry for 3 minutes to obtain a mixed slurry. Venturi-Swirl Coupled Reactor Treatment: The mixed slurry, after pre-contact for 3 minutes, is pumped into a Venturi-cyclone coupled reactor, and injected at a flow rate of 0.5 m / s through the inlet 12 of the throat 11 in the Venturi section 1 of the reactor. 3 Air flow rate / min, eddy shear rate 800s -1 This process aims to achieve heterogeneous agglomeration of galena and dispersion of sphalerite, resulting in a pretreated slurry. The parameters of the Venturi section 1 of the Venturi-swirl coupled reactor are as follows: the diameter of the throat 11 is 7.7 mm, the length of the throat 11 is 15 mm, the contraction angle is 26.5°, the diffusion angle is 7°, and the gas velocity in the throat 11 is 80 m / s; the parameters of the swirl section 2 are as follows: the diameter of the swirl coupling cavity 21 is 87.5 mm, the ratio of the diameter of the overflow outlet 22 to the diameter of the swirl coupling cavity 21 is 0.3, the ratio of the diameter of the underflow outlet 23 to the diameter of the swirl coupling cavity 21 is 0.15, and the tangential inlet 24 in the swirl section 2 is used to control the eddy shear rate to ensure residence time and contact efficiency; S3, Galena flotation: The pretreated slurry obtained after treatment by the Venturi-cyclone coupled reactor was transferred to an XFD type 1.5L flotation cell, and pine oil (2) was added. # Oil (8g / t, i.e., 8g of pine oil is added to each ton of pretreated slurry) is used for roughing of galena, with a skimming time of 4min, to obtain roughed galena slurry and roughed lead tailings slurry. Sodium carbonate was added to the roughing galena slurry to adjust the pH to 9.0 for the first galena cleaning, resulting in the first galena concentrate slurry and the first cleaned lead middlings slurry. Sodium carbonate was added to the first galena concentrate slurry to adjust the pH to 9.0 for the second galena cleaning, resulting in the second galena concentrate slurry (which, after drying, yields the galena concentrate product) and the second cleaned lead middlings slurry. The first cleaned lead middlings slurry was returned to the pretreatment slurry for repeated galena roughing, and the second cleaned lead middlings slurry was returned to the roughing galena slurry for repeated first galena cleaning. The skimming time for both galena cleaning processes was 3 minutes. Add ethyl thiocyanate (15g / t, i.e., 15g ethyl thiocyanate per ton of roughing lead tailings slurry) and pine oil (2 # Oil (4g / t, i.e., 4g pine oil added per ton of roughing lead tailings slurry) is used for the first galena scavenging, resulting in the first scavenged galena slurry and the first scavenged lead tailings slurry. Ethylene thiocyanate (15g / t, i.e., 15g ethylene thiocyanate added per ton of the first scavenged galena slurry) and pine oil (2g pine oil) are then added to the first scavenged galena slurry. # Oil (4g / t, i.e., 4g of pine oil is added to each ton of first-stage scavenged galena slurry) is used for the second scavenging of galena slurry to obtain the second-stage scavenged galena slurry and the second-stage scavenged lead tailings slurry. The first-stage scavenged lead tailings slurry is returned to the pre-treated slurry for repeated galena roughing, and the second-stage scavenged galena slurry is returned to the roughing lead tailings for repeated first-stage galena scavenging. The skimming time for both galena scavenging processes is 3 minutes. S4, Sphalerite flotation: Sodium carbonate was added to the second scavenging lead tailings slurry to adjust the pH to 11.5, followed by the addition of copper sulfate (30 g / t, i.e., 30 g copper sulfate per ton of second scavenging lead tailings slurry), butyl xanthate (150 g / t, i.e., 150 g butyl xanthate per ton of second scavenging lead tailings slurry), and pine oil (2... # Oil (12g / t, i.e., 12g of pine oil is added to each ton of second-stage lead tailings slurry) is used for one roughing of sphalerite, with a scraping and bubbling time of 4min, to obtain roughing sphalerite slurry and roughing zinc tailings slurry. Sodium carbonate was added to the roughing sphalerite slurry to adjust the pH to 11.5 for the first sphalerite cleaning, resulting in the first sphalerite concentrate slurry and the first cleaned zinc middlings slurry. Sodium carbonate was added to the first sphalerite concentrate slurry to adjust the pH to 11.5 for the second sphalerite cleaning, resulting in the second sphalerite concentrate slurry (which, after drying, yields the sphalerite concentrate product) and the second cleaned zinc middlings slurry. The first cleaned zinc middlings slurry was returned to the second scavenging lead tailings slurry for repeated sphalerite roughing, and the second cleaned zinc middlings slurry was returned to the roughing sphalerite slurry for repeated first sphalerite cleaning. The skimming time for both sphalerite cleaning processes was 3 minutes. Add butyl xanthate (50g / t, i.e., 50g butyl xanthate per ton of roughing zinc tailings slurry) and pine oil (2 # Oil (6g / t, i.e., 6g pine oil added per ton of roughing zinc tailings slurry) was used for the first sphalerite scavenging, resulting in the first scavenged sphalerite slurry and the first scavenged zinc tailings slurry. Butyronitrile (50g / t, i.e., 50g butyronitrile per ton of first scavenged sphalerite slurry) and pine oil (2g pine oil) were added to the first scavenged sphalerite slurry. # Oil (6g / t, i.e., 6g of pine oil is added to each ton of first-stage scavenged sphalerite slurry) is used for the second-stage scavenging of sphalerite to obtain the second-stage scavenged sphalerite slurry and flotation tailings slurry. The zinc tailings slurry from the first-stage scavenging is returned to the lead tailings from the second-stage scavenging to repeat the roughing of sphalerite. The sphalerite slurry from the second-stage scavenging is returned to the roughing zinc tailings to repeat the first-stage scavenging of sphalerite. The skimming time for both sphalerite scavenging processes is 3 minutes. S5. Tailings treatment: Add polyacrylamide (35g / t, i.e., 35g of polyacrylamide per ton of flotation tailings slurry) to the flotation tailings slurry. After thickening for 8 hours by a high-efficiency thickener, thickened overflow water and tailings filter cake are obtained. The thickened overflow water is recycled and the tailings filter cake (moisture content of 12%) is dry-piled into the tailings dam.

[0048] Comparative Example 1 A flotation method for fine-grained lead-zinc pyrite includes the following steps: S1. Pulping: Add 1 kg of fine-grained lead-zinc-pyrite ore powder to water and ball mill for 8 min, so that the proportion of lead-zinc-pyrite ore powder with a grinding fineness of -74 μm is 80%, to obtain lead-zinc-pyrite ore slurry. The mass percentage of fine-grained lead-zinc-pyrite ore powder in the lead-zinc-pyrite ore slurry is 75%. In this embodiment, the composition and content of fine-grained lead-zinc-pyrite ore include: 0.609% lead (Pb), 1.205% zinc (Zn), 3.61% iron (Fe), 2.12% sulfur (S), 1.21% calcium oxide (CaO), 6.54% aluminum oxide (Al2O3), 77.12% silicon dioxide (SiO2), 68 g / t silver (Ag*), 0.43 g / t gold (Au*), and 7.2% magnesium oxide (MgO), with the balance being other trace components and loss on ignition (LOI). Where * indicates that the content of the corresponding element is in g / t; The lead-zinc-pyrite slurry was transferred into a mixing tank, sodium carbonate was added, the pH value was adjusted to 9.0, and then zinc sulfate (90g / t, i.e., 90g of zinc sulfate was added to each ton of lead-zinc-pyrite slurry) was added. The mixture was stirred for 8 minutes to fully hydrophilize the surface of the sphalerite and obtain the initial slurry. S2, Venturi-Swirl Coupled Reactor Treatment: like Figure 4 As shown, the initial slurry is pumped into the Venturi-cyclone coupled reactor, and a flow rate of 0.5 m / s is injected through the inlet 12 of the throat 11 in the Venturi section 1 of the Venturi-cyclone coupled reactor. 3 Air flow rate / min, eddy shear rate 800s -1 This process aims to achieve heterogeneous agglomeration of galena and dispersion of sphalerite, resulting in a pretreated slurry. The parameters of the Venturi section 1 of the Venturi-swirl coupled reactor are as follows: the diameter of the throat 11 is 7.7 mm, the length of the throat 11 is 15 mm, the contraction angle is 26.5°, the diffusion angle is 7°, and the gas velocity in the throat 11 is 80 m / s; the parameters of the swirl section 2 are as follows: the diameter of the swirl coupling cavity 21 is 87.5 mm, the ratio of the diameter of the overflow outlet 22 to the diameter of the swirl coupling cavity 21 is 0.3, the ratio of the diameter of the underflow outlet 23 to the diameter of the swirl coupling cavity 21 is 0.15, and the tangential inlet 24 in the swirl section 2 is used to control the eddy shear rate to ensure residence time and contact efficiency; S3, Galena flotation: The pretreated slurry obtained after treatment by the Venturi-cyclone coupled reactor was transferred to an XFD-type 1.5L flotation cell, and ethyl thiocyanate (45g / t, i.e., 45g of ethyl thiocyanate per ton of pretreated slurry) and pine oil (2) were added. #Oil (8g / t, i.e., 8g of pine oil is added to each ton of pretreated slurry) is used for roughing of galena, with a skimming time of 4min, to obtain roughed galena slurry and roughed lead tailings slurry. Sodium carbonate was added to the roughing galena slurry to adjust the pH to 9.0 for the first galena cleaning, resulting in the first galena concentrate slurry and the first cleaned lead middlings slurry. Sodium carbonate was added to the first galena concentrate slurry to adjust the pH to 9.0 for the second galena cleaning, resulting in the second galena concentrate slurry (which, after drying, yields the galena concentrate product) and the second cleaned lead middlings slurry. The first cleaned lead middlings slurry was returned to the pretreatment slurry for repeated galena roughing, and the second cleaned lead middlings slurry was returned to the roughing galena slurry for repeated first galena cleaning. The skimming time for both galena cleaning processes was 3 minutes. Add ethyl thiocyanate (15g / t, i.e., 15g ethyl thiocyanate per ton of roughing lead tailings slurry) and pine oil (2 # Oil (4g / t, i.e., 4g pine oil added per ton of roughing lead tailings slurry) is used for the first galena scavenging, resulting in the first scavenged galena slurry and the first scavenged lead tailings slurry. Ethylene thiocyanate (15g / t, i.e., 15g ethylene thiocyanate added per ton of the first scavenged galena slurry) and pine oil (2g pine oil) are then added to the first scavenged galena slurry. # Oil (4g / t, i.e., 4g of pine oil is added to each ton of first-stage scavenged galena slurry) is used for the second scavenging of galena slurry to obtain the second-stage scavenged galena slurry and the second-stage scavenged lead tailings slurry. The first-stage scavenged lead tailings slurry is returned to the pre-treated slurry for repeated galena roughing, and the second-stage scavenged galena slurry is returned to the roughing lead tailings for repeated first-stage galena scavenging. The skimming time for both galena scavenging processes is 3 minutes. S4, Sphalerite flotation: Sodium carbonate was added to the second scavenging lead tailings slurry to adjust the pH to 11.5, followed by the addition of copper sulfate (30 g / t, i.e., 30 g copper sulfate per ton of second scavenging lead tailings slurry), butyl xanthate (150 g / t, i.e., 150 g butyl xanthate per ton of second scavenging lead tailings slurry), and pine oil (2... # Oil (12g / t, i.e., 12g of pine oil is added to each ton of second-stage lead tailings slurry) is used for one roughing of sphalerite, with a scraping and bubbling time of 4min, to obtain roughing sphalerite slurry and roughing zinc tailings slurry. Sodium carbonate was added to the roughing sphalerite slurry to adjust the pH to 11.5 for the first sphalerite cleaning, resulting in the first sphalerite concentrate slurry and the first cleaned zinc middlings slurry. Sodium carbonate was added to the first sphalerite concentrate slurry to adjust the pH to 11.5 for the second sphalerite cleaning, resulting in the second sphalerite concentrate slurry (which, after drying, yields the sphalerite concentrate product) and the second cleaned zinc middlings slurry. The first cleaned zinc middlings slurry was returned to the second scavenging lead tailings for repeating the sphalerite roughing, and the second cleaned zinc middlings slurry was returned to the roughing sphalerite to repeat the first sphalerite cleaning. The skimming time for both sphalerite cleaning processes was 3 minutes. Add butyl xanthate (50g / t, i.e., 50g butyl xanthate per ton of roughing zinc tailings slurry) and pine oil (2 # Oil (6g / t, i.e., 6g pine oil added per ton of roughing zinc tailings slurry) was used for the first sphalerite scavenging, resulting in the first scavenged sphalerite slurry and the first scavenged zinc tailings slurry. Butyronitrile (50g / t, i.e., 50g butyronitrile per ton of first scavenged sphalerite slurry) and pine oil (2g pine oil) were added to the first scavenged sphalerite slurry. # Oil (6g / t, i.e., 6g of pine oil is added to each ton of first-stage scavenged sphalerite slurry) is used for the second-stage scavenging of sphalerite to obtain the second-stage scavenged sphalerite slurry and flotation tailings slurry. The zinc tailings slurry from the first-stage scavenging is returned to the lead tailings from the second-stage scavenging to repeat the roughing of sphalerite. The sphalerite slurry from the second-stage scavenging is returned to the roughing zinc tailings to repeat the first-stage scavenging of sphalerite. The skimming time for both sphalerite scavenging processes is 3 minutes. S5. Tailings treatment: Add polyacrylamide (35g / t, i.e., 35g of polyacrylamide per ton of flotation tailings slurry) to the flotation tailings slurry. After thickening for 8 hours by a high-efficiency thickener, thickened overflow water and tailings filter cake are obtained. The thickened overflow water is recycled and the tailings filter cake (moisture content of 12%) is dry-piled into the tailings dam.

[0049] Comparative Example 2 A flotation method for fine-grained lead-zinc pyrite includes the following steps: S1. Pulping: Add 1 kg of fine-grained lead-zinc-pyrite ore powder to water and ball mill for 8 min, so that the proportion of lead-zinc-pyrite ore powder with a grinding fineness of -74 μm is 80%, to obtain lead-zinc-pyrite ore slurry. The mass percentage of fine-grained lead-zinc-pyrite ore powder in the lead-zinc-pyrite ore slurry is 75%. In this embodiment, the composition and content of fine-grained lead-zinc-pyrite ore include: 0.614% lead (Pb), 1.206% zinc (Zn), 3.48% iron (Fe), 2.17% sulfur (S), 1.29% calcium oxide (CaO), 6.53% aluminum oxide (Al2O3), 76.5% silicon dioxide (SiO2), 68 g / t silver (Ag*), 0.43 g / t gold (Au*), and 8.1% magnesium oxide (MgO), with the balance being other trace components and loss on ignition (LOI). Where * indicates that the content of the corresponding element is in g / t; The lead-zinc-pyrite slurry was transferred into a mixing tank, sodium carbonate was added, the pH value was adjusted to 9.0, and then zinc sulfate (90g / t, i.e., 90g of zinc sulfate was added to each ton of lead-zinc-pyrite slurry) was added. The mixture was stirred for 8 minutes to fully hydrophilize the surface of the sphalerite and obtain the initial slurry. S2. Pre-contact of nanoparticles: Positively charged nano Fe3O4@SiO2-NH2 core-shell particles are dispersed in water to prepare a suspension of positively charged nano Fe3O4@SiO2-NH2 core-shell particles with a mass percentage of 5wt%. Positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension was added to the delivery pipeline at a dosage of 80 mg / L (i.e., 80 mg of positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension was added to each liter of initial slurry) and simultaneously added to the delivery pipeline through a metering pump. The turbulence of the pipeline delivery was used to pre-contact the positively charged nano Fe3O4@SiO2-NH2 core-shell particles with the lead-zinc-pyrite slurry for 3 minutes to obtain a mixed slurry. S3, Galena flotation: After 3 minutes of pre-contact, the mixed slurry was transferred to an XFD-type 1.5L flotation cell, and pine oil (2) was added. # Oil (8g / t, i.e., 8g of pine oil is added to each ton of mixed ore slurry) is used for one roughing of galena, with a skimming time of 4min, to obtain roughing galena slurry and roughing lead tailings slurry; Sodium carbonate was added to the roughing galena slurry to adjust the pH to 9.0 for the first galena cleaning, resulting in the first galena concentrate slurry and the first cleaned lead middlings slurry. Sodium carbonate was added to the first galena concentrate slurry to adjust the pH to 9.0 for the second galena cleaning, resulting in the second galena concentrate slurry (which, after drying, yields the galena concentrate product) and the second cleaned lead middlings slurry. The first cleaned lead middlings slurry was returned to the mixed slurry for repeated galena roughing, and the second cleaned lead middlings slurry was returned to the roughing galena slurry for repeated first galena cleaning. The skimming time for both galena cleaning processes was 3 minutes. Add ethyl thiocyanate (15g / t, i.e., 15g ethyl thiocyanate per ton of roughing lead tailings slurry) and pine oil (2 # Oil (4g / t, i.e., 4g pine oil added per ton of roughing lead tailings slurry) is used for the first galena scavenging, resulting in the first scavenged galena slurry and the first scavenged lead tailings slurry. Ethylene thiocyanate (15g / t, i.e., 15g ethylene thiocyanate added per ton of the first scavenged galena slurry) and pine oil (2g pine oil) are then added to the first scavenged galena slurry. # Oil (4g / t, i.e., 4g of pine oil is added to each ton of first-stage scavenged galena slurry) is used for the second scavenging of galena slurry to obtain the second-stage scavenged galena slurry and the second-stage scavenged lead tailings slurry. The first-stage scavenged lead tailings slurry is returned to the pre-treated slurry for repeated galena roughing, and the second-stage scavenged galena slurry is returned to the roughing lead tailings slurry for repeated first-stage galena scavenging. The skimming time for both galena scavenging processes is 3 minutes. S4, Sphalerite flotation: Sodium carbonate was added to the second scavenging lead tailings slurry to adjust the pH to 11.5, followed by the addition of copper sulfate (30 g / t, i.e., 30 g copper sulfate per ton of second scavenging lead tailings slurry), butyl xanthate (150 g / t, i.e., 150 g butyl xanthate per ton of second scavenging lead tailings slurry), and pine oil (2... # Oil (12g / t, i.e., 12g of pine oil is added to each ton of second-stage lead tailings slurry) is used for one roughing of sphalerite, with a scraping and bubbling time of 4min, to obtain roughing sphalerite slurry and roughing zinc tailings slurry. Sodium carbonate was added to the roughing sphalerite slurry to adjust the pH to 11.5 for the first sphalerite cleaning, resulting in the first sphalerite concentrate slurry and the first cleaned zinc middlings slurry. Sodium carbonate was added to the first sphalerite concentrate slurry to adjust the pH to 11.5 for the second sphalerite cleaning, resulting in the second sphalerite concentrate slurry (which, after drying, yields the sphalerite concentrate product) and the second cleaned zinc middlings slurry. The first cleaned zinc middlings slurry was returned to the second scavenging lead tailings slurry for repeated sphalerite roughing, and the second cleaned zinc middlings slurry was returned to the roughing sphalerite slurry for repeated first sphalerite cleaning. The skimming time for both sphalerite cleaning processes was 3 minutes. Add butyl xanthate (50g / t, i.e., 50g butyl xanthate per ton of roughing zinc tailings slurry) and pine oil (2 # Oil (6g / t, i.e., 6g pine oil added per ton of roughing zinc tailings slurry) was used for the first sphalerite scavenging, resulting in the first scavenged sphalerite slurry and the first scavenged zinc tailings slurry. Butyronitrile (50g / t, i.e., 50g butyronitrile per ton of first scavenged sphalerite slurry) and pine oil (2g pine oil) were added to the first scavenged sphalerite slurry. # Oil (6g / t, i.e., 6g of pine oil is added to each ton of first-stage scavenged sphalerite slurry) is used for the second-stage scavenging of sphalerite to obtain the second-stage scavenged sphalerite slurry and flotation tailings slurry. The zinc tailings slurry from the first-stage scavenging is returned to the lead tailings slurry from the second-stage scavenging for repeated sphalerite roughing, and the sphalerite slurry from the second-stage scavenging is returned to the roughing zinc tailings slurry for repeated first-stage sphalerite scavenging. The skimming time for both sphalerite scavenging processes is 3 minutes. S5. Tailings treatment: Add polyacrylamide (35g / t, i.e., 35g of polyacrylamide per ton of flotation tailings slurry) to the flotation tailings slurry. After thickening for 8 hours by a high-efficiency thickener, thickened overflow water and tailings filter cake are obtained. The thickened overflow water is recycled and the tailings filter cake (moisture content of 12%) is dry-piled into the tailings dam.

[0050] Comparative Example 3 A traditional flotation method for fine-grained lead-zinc pyrite includes the following steps: S1. Pulping: Add 1 kg of fine-grained lead-zinc-pyrite ore powder to water and ball mill for 8 min, so that the proportion of lead-zinc-pyrite ore powder with a grinding fineness of -74 μm is 80%, to obtain lead-zinc-pyrite ore slurry. The mass percentage of fine-grained lead-zinc-pyrite ore powder in the lead-zinc-pyrite ore slurry is 75%. In this embodiment, the composition and content of fine-grained lead-zinc-pyrite ore include: 0.608% lead (Pb), 1.208% zinc (Zn), 3.52% iron (Fe), 2.16% sulfur (S), 1.26% calcium oxide (CaO), 6.12% aluminum oxide (Al2O3), 77.21% silicon dioxide (SiO2), 68 g / t silver (Ag*), 0.43 g / t gold (Au*), and 7.8% magnesium oxide (MgO), with the balance being other trace components and loss on ignition (LOI). Where * indicates that the content of the corresponding element is in g / t; S2, Galena flotation: The lead-zinc-pyrite ore slurry was transferred to an XFD-type 1.5L flotation cell. Calcium oxide was added to adjust the pH to 9.0. Then, ethyl thiocyanate (45 g / t, i.e., 45 g of ethyl thiocyanate per ton of lead-zinc-pyrite ore slurry), zinc sulfate (1200 g / t, i.e., 1200 g of zinc sulfate per ton of lead-zinc-pyrite ore slurry), sodium sulfite (800 g / t, i.e., 800 g of sodium sulfite per ton of lead-zinc-pyrite ore slurry) and pine oil (2... # Oil (16g / t, i.e., 16g of pine oil is added to each ton of lead-zinc-pyrite ore slurry) is used for one roughing of galena, with a frothing time of 4min, to obtain roughing galena slurry and roughing lead tailings slurry. Calcium oxide is added to the roughing galena slurry to adjust the pH to 9.0. Then, zinc sulfate (120 g / t, i.e., 1200 g zinc sulfate per ton of roughing galena slurry) and sodium sulfite (80 g / t, i.e., 800 g sodium sulfite per ton of roughing galena slurry) are added for the first galena cleaning, yielding the first galena concentrate slurry and the first cleaned lead middlings slurry. Calcium oxide is added to the first galena concentrate slurry to adjust the pH to 9.0. Then, zinc sulfate (120 g / t, i.e., 1200 g zinc sulfate per ton of the first galena concentrate slurry) and sodium sulfite (80 g / t, i.e., 800 g sodium sulfite per ton of the first galena concentrate slurry) are added for the second galena cleaning, yielding the second galena concentrate slurry and the second cleaned lead middlings slurry. In the lead middlings ore slurry, calcium oxide is added to the second galena concentrate slurry to adjust the pH to 9.0. Then, zinc sulfate (120g / t, i.e., 1200g zinc sulfate per ton of second galena concentrate slurry) and sodium sulfite (80g / t, i.e., 800g sodium sulfite per ton of second galena concentrate slurry) are added for the third galena beneficiation, resulting in the third galena concentrate slurry (dried to obtain galena concentrate product) and the third beneficiation lead middlings ore slurry. The first beneficiation lead middlings ore slurry is returned to the pretreatment slurry for repeated galena roughing, the second beneficiation lead middlings ore slurry is returned to the roughing galena ore slurry for repeated first galena beneficiation, and the third beneficiation lead middlings ore slurry is returned to the first galena concentrate slurry for repeated second galena beneficiation. The skimming time for each of the three galena beneficiation processes is 3 minutes. Add ethyl thiocyanate (15g / t, i.e., 15g ethyl thiocyanate per ton of roughing lead tailings) and pine oil (2) to the roughing lead tailings slurry. # Oil (8g / t, i.e., 8g pine oil added per ton of roughing lead tailings) is used for the first galena scavenging, resulting in the first scavenged galena slurry and the first scavenged lead tailings slurry. Ethylene sulfide (15g / t, i.e., 15g ethylene sulfide per ton of first scavenged galena slurry) and pine oil (2g pine oil) are added to the first scavenged galena slurry. # Oil, at a dosage of 8g / t (i.e., 8g of pine oil is added to each ton of the first scavenged galena slurry), is used for the second scavenging of galena slurry to obtain the second scavenged galena slurry and the second scavenged lead tailings slurry. Ethylene thiocyanate (at a dosage of 15g / t, i.e., 15g of ethylene thiocyanate is added to each ton of the second scavenged galena slurry) and pine oil (2... #Oil (8g / t, i.e., 8g of pine oil is added to each ton of second-scavenged galena slurry) is used for third-scavenged galena slurry to obtain third-scavenged galena slurry and third-scavenged lead tailings slurry. The first-scavenged lead tailings slurry is returned to the pre-treated slurry for repeated galena roughing. The second-scavenged galena slurry is returned to the roughing lead tailings slurry for repeated first-scavenged galena slurry. The third-scavenged galena slurry is returned to the first-scavenged galena slurry for repeated second-scavenged galena slurry. The skimming time for each of the three galena scavenging processes is 3 minutes. S3, Sphalerite flotation: Add copper sulfate (1200g / t, i.e., 1200g copper sulfate per ton of third-stage scavenged lead tailings slurry) as an activator to the slurry. Then add calcium oxide to adjust the pH to 11.5. Subsequently, add butyl xanthate (320g / t, i.e., 320g butyl xanthate per ton of third-stage scavenged lead tailings slurry) and pine oil (2... # Oil (16g / t, i.e., 16g of pine oil is added to each ton of lead tailings slurry from the third scavenging process) is used to perform one roughing of sphalerite, with a frothing time of 4min, to obtain roughing sphalerite slurry and roughing zinc tailings slurry. Calcium oxide was added to the roughing sphalerite slurry to adjust the pH to 11.5 for the first sphalerite cleaning, resulting in a first sphalerite concentrate slurry and a first-cleaned zinc middlings slurry. Sodium carbonate was added to the first sphalerite concentrate slurry to adjust the pH to 11.5 for the second sphalerite cleaning, resulting in a second sphalerite concentrate slurry and a second-cleaned zinc middlings slurry. Sodium carbonate was added to the second sphalerite concentrate slurry to adjust the pH to 11.5 for the third sphalerite cleaning, resulting in a third sphalerite concentrate slurry (dried to obtain sphalerite concentrate product) and a third-cleaned zinc middlings slurry. The first-cleaned zinc middlings slurry was returned to the second scavenging lead tailings slurry for repeated sphalerite roughing. The second-cleaned zinc middlings slurry was returned to the roughing sphalerite slurry for repeated first sphalerite cleaning. The third-cleaned zinc middlings slurry was returned to the first sphalerite concentrate slurry for repeated second sphalerite cleaning. The skimming time for each of the three sphalerite cleaning processes was 3 minutes. Add butyl xanthate (105g / t, i.e., 105g butyl xanthate per ton of roughing zinc tailings slurry) and pine oil (2 # Oil (8g / t, i.e., 8g pine oil added per ton of roughing zinc tailings slurry) was used for the first sphalerite scavenging, resulting in the first scavenged sphalerite slurry and the first scavenged zinc tailings slurry. Butyronitrile (105g / t, i.e., 105g butyronitrile per ton of the first scavenged sphalerite slurry) and pine oil (2g pine oil) were added to the first scavenged sphalerite slurry. #Oil, at a dosage of 8g / t (i.e., 8g of pine oil is added to each ton of the first scavenged sphalerite slurry), is used for the second sphalerite scavenging to obtain the second scavenged sphalerite slurry and the second scavenged zinc tailings slurry. Butyronitrile xanthate (at a dosage of 105g / t, i.e., 105g of butyronitrile xanthate is added to each ton of the second scavenged sphalerite slurry) and pine oil (2... # Oil (8g / t, i.e., 8g of pine oil added to each ton of second-stage scavenged sphalerite slurry) is used for the third-stage scavenging of sphalerite to obtain the third-stage scavenged sphalerite slurry and flotation tailings slurry. The zinc tailings slurry from the first-stage scavenging is returned to the lead tailings slurry from the second-stage scavenging to repeat the sphalerite roughing. The sphalerite slurry from the second-stage scavenging is returned to the roughing zinc tailings slurry to repeat the first-stage sphalerite scavenging. The sphalerite slurry from the third-stage scavenging is returned to the first-stage sphalerite slurry to repeat the second-stage sphalerite scavenging. The skimming time for each of the three sphalerite scavenging stages is 3 minutes. S4. Tailings treatment: Add polyacrylamide (35g / t, i.e., 35g of polyacrylamide per ton of flotation tailings slurry) to the flotation tailings slurry. After thickening for 8 hours by a high-efficiency thickener, thickened overflow water and tailings filter cake are obtained. The thickened overflow water is recycled and the tailings filter cake (moisture content of 12%) is dry-piled into the tailings dam. Detection and Analysis The grades of Pb and Zn in the fine-grained lead-zinc-pyrite powder used in Examples 1 to 3, and in the flotation tailings obtained from the dried flotation tailings slurry of Comparative Examples 1 and 2, as well as in the flotation tailings obtained from the galena concentrate, sphalerite concentrate, and dried flotation tailings slurry of Comparative Example 3, were determined. The yields of the galena concentrate and sphalerite concentrate, as well as the recovery rates of Pb and Zn, were calculated. The results are shown in Tables 1 to 6.

[0051] The grades of Pb and Zn were determined by atomic absorption spectrophotometry (AAS).

[0052] The grade of Pb was determined with reference to the atomic absorption spectrophotometry (AAS) method for lead (GB / T 8151.5-2012), and the grade of Zn was determined with reference to the atomic absorption spectrophotometry (AAS) method for zinc (GB / T 8152.4-2006). The yield of galena concentrate is calculated as follows: galena concentrate yield = (mass of galena concentrate / mass of fine-grained lead-zinc-pyrite powder) × 100%; The yield of sphalerite concentrate is calculated as follows: yield of sphalerite concentrate = (mass of sphalerite concentrate / mass of fine-grained lead-zinc-pyrite powder) × 100%; The method for calculating the Pb recovery rate is as follows: Pb recovery rate = [(yield of galena concentrate product × Pb grade in galena concentrate product) / Pb grade in fine-grained lead-zinc-pyrite powder] × 100%; The Zn recovery rate is calculated as follows: Zn recovery rate = [(yield of sphalerite concentrate × Zn grade in sphalerite concentrate) / Zn grade in fine-grained lead-zinc-pyrite powder] × 100%.

[0053] Table 1 shows the grade, yield, and recovery results in Example 1.

[0054] Table 2 shows the grade, yield, and recovery results in Example 2.

[0055] Table 3 shows the grade, yield, and recovery rate results in Example 3.

[0056] Table 4 shows the grade, yield, and recovery results for Comparative Example 1.

[0057] Table 5 shows the grade, yield, and recovery results for Comparative Example 2.

[0058] Table 6 shows the grade, yield, and recovery results for Comparative Example 3.

[0059] Comparative analysis of Tables 1 to 6 shows that Examples 1 to 3 all employed a fine-particle lead-zinc-pyrite beneficiation method based on charge-directed heterogeneous agglomeration, including nanoparticle pre-contact and Venturi-cyclone coupled reactor treatment, with progressive optimization of indicators. Example 3 showed the best indicators: the Pb grade in the galena concentrate was 66.78%, the Pb recovery rate was 92.24%, and the Zn grade in the galena concentrate was 4.3%. In all three examples, the Zn grade in the galena concentrate was below 5%, and the Pb grade in the sphalerite concentrate was extremely low (only 0.4% in Example 3), thus proving that the charge-directed heterogeneous agglomeration-based lead-zinc-pyrite flotation method of the present invention can effectively suppress sphalerite flotation and avoid intermingling.

[0060] Compared to Example 3, Comparative Example 1 (without nanoparticles) showed a 16.62 percentage point decrease in lead grade and a 10 percentage point decrease in recovery rate in the galena concentrate product; and a 6.72 percentage point decrease in zinc grade and a 10.88% decrease in recovery rate in the sphalerite concentrate product. This indicates that the lack of nanoparticle pre-contact resulted in insufficient galena agglomeration and increased lead-zinc intermingling. Comparative Example 2 (without a Venturi-cyclone coupled reactor) showed a Pb grade of 58.34% and a Pb recovery rate of 85.93% in the galena concentrate product, both lower than in Example 3. This suggests that the lack of high-intensity fluid shearing is detrimental to galena agglomeration and sphalerite dispersion. Comparative Example 3 (conventional process) showed the least ideal results, with a Zn grade as high as 13.88% in the galena concentrate product. This indicates that the conventional process is significantly inefficient in fine particle separation and exhibits severe lead-zinc intermingling.

[0061] In summary, the fine-particle lead-zinc-pyrite beneficiation method based on charge-directed heterogeneous agglomeration used in Example 3 yields concentrates with superior performance across all comparative examples. The core of this invention lies in the synergistic effect of positively charged nano-Fe3O4@SiO2-NH2 core-shell particles with a Venturi-cyclone coupled reactor to achieve selective agglomeration of galena and dispersion of sphalerite, significantly improving separation efficiency and reducing intermingling.

[0062] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention.

Claims

1. A flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration, characterized in that, Includes the following steps: S1. Add pH adjuster and sphalerite inhibitor to lead-zinc-pyrite slurry to obtain initial slurry; S2. The positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension and the initial slurry are subjected to Venturi-cyclone coupling treatment to achieve heterogeneous agglomeration of galena and dispersion of sphalerite, thus obtaining a pretreated slurry. S3. Flotation of the pretreated slurry yields galena concentrate slurry and lead tailings slurry; S4. The lead tailings slurry is floated to obtain sphalerite concentrate slurry and flotation tailings slurry.

2. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 1, characterized in that, In step S1, lead-zinc-pyrite ore powder is added to water and ball-milled to achieve a grinding fineness of -74μm, with the proportion of lead-zinc-pyrite ore powder reaching 70-80%, thus obtaining lead-zinc-pyrite ore slurry. The lead-zinc-pyrite slurry contains 66-75% lead-zinc-pyrite powder by mass.

3. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 1, characterized in that, In step S2, the positively charged nano Fe3O4@SiO2-NH2 core-shell particle suspension and the initial slurry are treated by a Venturi-cyclone coupling reactor to achieve heterogeneous agglomeration of galena and dispersion of sphalerite, thus obtaining a pretreated slurry. The Venturi-swirl coupled reactor includes a Venturi section and a swirl section; The diameter of the larynx in the Venturi section is 7.7 mm, the length of the larynx is 15 mm, the air velocity in the larynx is 40~80 m / s, the contraction angle is 23~30°, and the diffusion angle is 6~8°. The diameter of the swirl coupling cavity in the swirl section is 75~100mm, the ratio of the diameter of the overflow outlet in the swirl section to the diameter of the swirl coupling cavity is 0.2~0.4, and the ratio of the diameter of the underflow outlet in the swirl section to the diameter of the swirl coupling cavity is 0.1~0.

2. The eddy shear rate of the Venturi-swirl coupled reactor is 500~800 s. -1 ; The positively charged nano-Fe3O4@SiO2-NH2 core-shell particle suspension contains 1-5 wt% of positively charged nano-Fe3O4@SiO2-NH2 core-shell particles. Add 80 mg of positively charged nano Fe3O4@SiO2-NH2 core-shell particles per liter of initial slurry.

4. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 1, characterized in that, S3 includes: A frother is added to the pretreated slurry for roughing of galena to obtain roughed galena slurry and roughed lead tailings slurry. A pH adjuster is added to the roughing galena slurry for galena beneficiation, resulting in galena concentrate slurry and beneficiated lead middlings ore slurry. Galena collector and frother are added to the roughing lead tailings slurry to carry out galena scavenging, resulting in scavenged galena slurry and scavenged lead tailings slurry.

5. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 4, characterized in that, S4 includes: pH adjuster, activator, sphalerite collector and frother are added to the scavenged lead tailings slurry to carry out sphalerite roughing to obtain rough sphalerite slurry and rough zinc tailings slurry. A pH adjuster is added to the roughing sphalerite slurry to perform sphalerite beneficiation, resulting in sphalerite concentrate slurry and beneficiated zinc middlings ore slurry. Add sphalerite collector and frother to the roughing zinc tailings slurry, and carry out sphalerite scavenging to obtain scavenged sphalerite slurry and flotation tailings slurry.

6. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 5, characterized in that, The pH adjuster is selected from sodium carbonate; The sphalerite inhibitor is selected from zinc sulfate; The foaming agent is selected from pine oil; The galena collector is selected from ethyl thiocyanate; The sphalerite collector is selected from butyl xanthate; The activator is selected from copper sulfate.

7. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 5, characterized in that, In S3, when performing roughing of galena, the amount of frother is 6~8g / t, the frothing time is 3~4min, and the roughing of galena is performed 1~2 times. When performing galena beneficiation, the pH should be controlled between 8.8 and 9.0, and the galena beneficiation should be performed 1 to 2 times, with a skimming time of 1 to 3 minutes. When performing galena scavenging, the amount of galena collector used is 10-15 g / t, the amount of frother used is 3-4 g / t, the frothing time is 1-3 min, and the number of galena scavenging operations is 1-2 times.

8. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 5, characterized in that, In step S4, during the roughing of sphalerite, the pH is controlled between 11.2 and 11.5, the amount of activator is 20-30 g / t, the amount of sphalerite collector is 100-150 g / t, the amount of frother is 10-12 g / t, the number of times the roughing of sphalerite is performed is 1-2 times, and the frothing time is 3-4 min. When performing sphalerite beneficiation, the pH should be controlled between 11.2 and 11.5, and the sphalerite beneficiation should be performed 1 to 2 times, with a skimming time of 1 to 3 minutes. When performing sphalerite scavenging, the amount of sphalerite collector used is 35~50g / t, the amount of frother used is 5~6g / t, the number of sphalerite scavenging operations is 1~2 times, and the frothering time is 1~3min.

9. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 5, characterized in that, Also includes: S5. Add flocculant to the flotation tailings slurry, concentrate to obtain solution and tailings filter cake, and reuse the solution after treatment.

10. The flotation method for lead-zinc pyrite based on charge-directed heterogeneous agglomeration according to claim 2, characterized in that, The lead-zinc-pyrite ore powder is a fine-grained lead-zinc-pyrite ore powder. In the fine-grained lead-zinc-sulfur complex intergrowth ore, the proportion of ore powder with a particle size of -0.074 mm is 60-65%. The composition of the fine-grained lead-zinc pyrite includes: lead, zinc, iron, sulfur, calcium oxide, aluminum oxide, silicon dioxide, silver, gold and magnesium oxide, with the balance being other trace components and loss on ignition (LOI).

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