A process for the efficient concentration of lead-zinc oxide ore flotation concentrate tailings

Abstract

This invention relates to the field of mineral processing tailings treatment technology, and discloses a highly efficient thickening process for flotation tailings from lead-zinc oxide ore flotation concentrate. The process includes: preparing a calcium-based coagulant emulsion by mixing calcium-based powder with production return water; dissolving anionic polyacrylamide dry powder into a mother liquor and diluting it online to obtain an extremely dilute working solution; adding the calcium-based coagulant emulsion to the tailings slurry for charge elimination, and introducing it into a first-stage thickening device for preliminary classification and sedimentation; adding the extremely dilute working solution to the first-stage overflow slurry to connect with extremely fine mud, and introducing it into a second-stage thickening device for concentration; before the second-stage overflow slurry enters the final thickening device, sequentially adding polyaluminum chloride standard solution and the extremely dilute working solution to re-crosslink and electrostatically encapsulate the micro-flocs for sedimentation; finally, outputting clarified reclaimed water and merging the underflows from each stage. This invention utilizes the synergistic effect of multiple physicochemical processes to disrupt the colloidal stability of the slurry, thereby increasing the tailings settling velocity and the overall concentration of the underflow.

Description

Technical Field

[0001] This invention relates to the field of mineral processing tailings treatment technology, specifically a high-efficiency concentration process for flotation tailings of oxidized lead-zinc ore flotation concentrate. Background Technology

[0002] During the beneficiation process of lead-zinc oxide ore, a large amount of tailings are generated after crushing and flotation operations. These tailings contain a high proportion of fine mud. Due to the deep liberation of minerals, the fine mud particles are small in size and have a large specific surface area. Their particle surfaces often exhibit strong negative charge. In an aqueous medium, there is electrostatic repulsion between fine mud particles with the same charge, which makes the slurry form a relatively stable colloidal suspension system.

[0003] In conventional tailings thickening treatment, polymeric flocculants are directly added to the slurry to promote particle aggregation and sedimentation. However, due to the strong electrostatic repulsion within the colloidal system, the molecular chains of conventional flocculants are unable to penetrate the hydration layer on the surface of fine particles and adsorb close to the particle surface. This adsorption barrier prevents the flocculant from fully exerting its bridging effect, making it difficult for fine mud to aggregate into large and dense flocs. Therefore, in actual production, problems such as slow tailings settling speed, low underflow concentration in thickening equipment, and turbid overflow water are often encountered. The produced underflow is difficult to meet the material concentration requirements of subsequent tailings dry discharge or paste backfilling processes in the mine.

[0004] In addition, mining concentrators often use on-site production return water as the process water source in the thickening stage. The dissolved ions in the production return water constitute the background ionic strength of the slurry, which has a certain impact on the stability of the colloidal system. During periods of heavy rainfall, such as the rainy season, the production return water will be diluted, and the concentration of background cations such as calcium and magnesium in the water will decrease. The decrease in ionic strength will cause the double electric layer on the surface of the fine mud to expand, further enhancing the repulsive force between particles. This fluctuation in water quality caused by changes in the external environment makes it difficult for the originally fixed dosing system to adapt to the changed properties of the slurry, thus making it difficult to maintain the stable operation of the thickening system. Summary of the Invention

[0005] To address the shortcomings of existing technologies, this invention provides a highly efficient thickening process for flotation concentrate and tailings of oxidized lead-zinc ore. This process solves the problems of slow settling, low underflow concentration, and turbid overflow caused by the colloidal stability of fine tailings mud, as well as the instability of the thickening system due to dilution by rainwater during the rainy season.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: a high-efficiency concentration process for flotation concentrate and flotation tailings of oxidized lead-zinc ore, the process comprising the following steps: adding calcium-based powder to a lime slurry tank equipped with a stirring device, adding on-site production return water to prepare a lime slurry suspension, stirring and allowing it to stand for aging, to obtain a calcium-based coagulant emulsion; Solid anionic polyacrylamide powder is added to a mixing tank, dissolved in recycled water from on-site production to prepare a mother liquor. After stirring and maturing, it is extracted by a metering pump and diluted online with clean water in the main pipeline to obtain an extremely dilute working solution for later use. The tailings from the oxidized ore flotation are transported to the thickening process, where the calcium-based coagulant emulsion is added to the slurry for charge elimination. The slurry is then introduced into the first thickening unit for preliminary classification and settling. The bottom is discharged as coarse particles, and the top overflows as first-stage overflow slurry containing extremely fine mud. The first-stage overflow slurry is introduced into the second-stage thickening equipment. The extremely dilute working fluid is added to the first-stage overflow slurry in the conveying pipeline to make the extremely fine mud network form flocs for thickening. Fine particles are discharged from the bottom and the second-stage overflow slurry overflows from the top. The second-stage overflow slurry is introduced into the end-of-pipe thickening equipment. The pre-prepared polyaluminum chloride standard solution and the ultra-dilute working solution are added sequentially to the main pipeline before entering the end-of-pipe thickening equipment, so that the micro flocs are re-crosslinked in situ and undergo electrostatic encapsulation and sedimentation. The bottom is discharged as ultra-fine mud bottom flow, and the top overflows as clarified reclaimed water. The above coarse particle bottom flow, fine particle bottom flow and ultra-fine mud bottom flow are combined and output to complete the thickening and clarification treatment.

[0007] By adopting the above technical solution, this invention constructs a segmented physicochemical sedimentation mechanism, the specific mechanism of which is as follows: When calcium-based powder is added to water, it undergoes hydration and dissociation, releasing a large number of calcium ions. As high-valence cations, calcium ions enter the tailings slurry and can penetrate the hydration film on the surface of fine mud particles, entering the double electric layer of the particles. According to the colloidal stability theory, the compression effect of a large number of calcium ions reduces the surface potential of the fine mud, weakens the electrostatic repulsion energy between particles, and breaks the colloidal stability of the slurry. At this time, the coarse particles in the slurry lose the suspension and support of the fine mud and preferentially undergo gravity sedimentation in the first stage thickening equipment, thus achieving coarse and fine classification.

[0008] As the grading process proceeds, the first-stage overflow slurry entering the second-stage thickening equipment is enriched with extremely fine mud that has lost its electrostatic repulsion. At this point, anionic polyacrylamide extremely dilute working solution is added. Since the negative charge on the particle surface has been neutralized by the pre-placed calcium ions, the long molecular chains of anionic polyacrylamide can directly approach the surface of the fine mud and generate multi-point adsorption through hydrogen bonds and van der Waals forces. The long molecular chains form a bridging effect between multiple fine particles, aggregating the dispersed extremely fine mud into large flocs and causing them to settle.

[0009] In the final treatment stage, polyaluminum chloride (PAC) is added to address the tiny flocs and residual nanoscale suspended matter in the second-stage overflow slurry caused by fluid shearing. PAC undergoes hydrolysis and polymerization in water, generating polynuclear hydroxy complexes with high positive charges. These highly positively charged polynuclear complexes strongly neutralize and adsorb residual particles. Subsequently, anionic polyacrylamide ultra-dilute working solution is added to perform secondary cross-linking on this basis, reassembling the tiny agglomerates formed by PAC into dense sediments. The synergistic effect of the three stages helps to remove suspended solids in the slurry, increase the overall mass concentration of the underflow, and thus improve the clarity of the overflow water.

[0010] Preferably, based on 100.0 parts by weight of dry ore, the addition amounts of each reagent are as follows: The amount of calcium-based coagulant emulsion added is 1.5 to 1.6 parts by weight; The amount of the extremely dilute working fluid added to the first stage overflow slurry is 15.0 to 25.0 parts by weight; The amount of the polyaluminum chloride standard solution added to the main pipeline is 2.0 to 5.0 parts by weight, and the amount of the extremely dilute working solution added to the main pipeline is 2.0 to 2.5 parts by weight.

[0011] By adopting the above technical solution, the mass balance boundary of the substances in the system is clearly defined. 1.5 to 1.6 parts by weight of calcium-based coagulant can provide the cationic equivalent to cover the surface of mineral particles, avoiding incomplete charge neutralization due to insufficient dosage. At the same time, it reduces the risk of excessive alkalinity of the slurry and subsequent scaling in the pipeline caused by excessive dosage. 15.0 to 25.0 parts by weight of the first stage of ultra-dilute working fluid can provide sufficient polymer bridges to maintain the macroscopic size of the flocs. The final quantitative amount of polyaluminum chloride and 2.0 to 2.5 parts by weight of the second stage of ultra-dilute working fluid form a synergistic ratio, which helps to avoid the steric hindrance effect and colloidal charge reversal caused by excessive local concentration of polymeric agents.

[0012] Preferably, the step of preparing the calcium-based coagulant emulsion includes: The mass concentration of the lime milk suspension is 10% to 15%; the stirring conditions for preparing the calcium-based coagulant emulsion are a rotation speed of 200 r / min to 400 r / min and a settling and maturation time of 30 min to 60 min.

[0013] By adopting the above technical solution, the hydration kinetics of calcium-based coagulants are controlled. A mass concentration of 10% to 15% combined with mechanical shearing of 200 to 400 r / min helps to break up powder agglomeration and avoid incomplete hydration caused by encapsulation. A maturation period of 30 to 60 min provides diffusion time for the dissolution of calcium hydroxide microcrystals, prompting the concentration of dissolved calcium ions in the system to reach the upper limit of saturation, thereby improving coagulation activity.

[0014] Preferably, the step of preparing the extremely dilute working solution includes: The mass concentration of the mother liquor is 0.08% to 0.12%; the stirring and maturation conditions for preparing the mother liquor are a rotation speed of 40 r / min to 60 r / min and a time of 60 min to 90 min; the mass concentration of the diluted ultra-dilute working solution is 0.01% to 0.03%.

[0015] By adopting the above technical solution, a step-concentration dissolution mechanism for polymeric agents is formed. When preparing the mother liquor, a mass concentration of 0.08% to 0.12% avoids inter-chain entanglement of molecular chains due to excessive concentration. Low-speed stirring at 40 to 60 r / min promotes the penetration of water molecules while preventing mechanical degradation and breakage of macromolecular chains. Subsequently, online instantaneous dilution to a working solution of 0.01% to 0.03% allows polyacrylamide molecules to reach a more relaxed free state before being fed into the slurry, increasing the effective bridging radius and helping to reduce the ineffective consumption of the agent.

[0016] Preferably, the step of pre-preparing the polyaluminum chloride standard solution includes: The mass concentration of the polyaluminum chloride standard solution prepared in advance using recycled water from on-site production is 4.0% to 6.0%.

[0017] By adopting the above technical solution, the problem of excessive hydrolysis of inorganic polymer coagulants can be alleviated. A mass concentration of 4.0% to 6.0% maintains the chemical microenvironment stability of polyaluminum chloride in the storage state, preventing the premature formation of inactive aluminum hydroxide precipitate, and enabling a large number of polynuclear complex ions to be released instantaneously in the main injection pipeline.

[0018] Preferably, the step of conveying the oxide ore flotation tailings to the thickening process and introducing them into each thickening device includes: The tailings from the oxidized ore flotation are transported to the thickening process without shearing by a pneumatic diaphragm pump; the first stage thickening equipment is a first-stage inclined plate thickener; the second stage thickening equipment is a second-stage inclined plate thickener; and the final thickening equipment is a final circular pool thickener.

[0019] By adopting the above technical solutions, optimizing the fluid dynamics conditions and settling path, the positive displacement pumping of the pneumatic diaphragm pump reduces the shearing and crushing effect of the centrifugal pump impeller on the slurry particles. The first and second inclined plate thickeners utilize the principle of shallow pool sedimentation to shorten the vertical settling distance of the particles and increase the settling area, separating most of the solid load at the front end of the process. The end circular pool thickener provides a longer hydraulic residence time and a deep compression zone, which is conducive to the long-term drainage and consolidation of the extremely fine mud flocs that have been cross-linked by inorganic and organic agents under the action of gravity.

[0020] Preferably, the feed mass concentration of the oxide ore flotation tailings is controlled to be between 18.0% and 22.0%.

[0021] By adopting the above technical solution, the initial volume concentration of the slurry system is controlled. Within the feed mass concentration range of 18.0% to 22.0%, the mean free path of the particles is in a suitable state conducive to collision flocculation. Too low a concentration will shorten the collision probability between particles and increase the hydraulic load of the equipment; too high a concentration will aggravate the interference sedimentation phenomenon, making it difficult for fine flocs to pass through the high-concentration slurry layer and sink.

[0022] Preferably, the steps of the concentration process include: During the concentration process, an online conductivity meter with a feedforward automatic compensation device is used to detect the background calcium ion equivalent of the water source in real time. When the background calcium and magnesium ion concentration of the water source is diluted and the calcium ion equivalent decreases due to water quality fluctuations, the feedforward automatic compensation device automatically increases the injection volume of the calcium-based coagulant emulsion to compensate for the calcium equivalent difference caused by water quality fluctuations.

[0023] By adopting the above technical solution, it is possible to cope with the physical and chemical interference caused by the external environment. The dissolved ions in the on-site production return water constitute the background ionic strength of the slurry. Rainfall will cause the return water to be diluted, and the background ionic strength will decrease, causing the originally compressed micro mud double layer to re-expand and the colloid to return to stability. The online conductivity meter monitors the total activity of conductive ions in the system in real time. When the feedforward logic determines that the ionic strength is lower than the critical threshold, it directly triggers the valve opening adjustment and increases the amount of calcium-based coagulant emulsion injected. This feedback mechanism is conducive to maintaining the compression degree of the slurry double layer.

[0024] Preferably, the step of performing automatic feedforward compensation includes: When performing the aforementioned feedforward automatic compensation, the amount of the calcium-based coagulant emulsion actually added to the slurry is increased to 1.8 to 2.0 parts by weight, based on 100.0 parts by weight of dry ore.

[0025] By adopting the above technical solution, the calcium equivalent loss caused by water dilution can be quantitatively compensated by increasing the amount added to 1.8 to 2.0 parts by weight. This not only fills the gap in the background concentration of calcium ions caused by rainfall and maintains the potential of the system in the destabilization range, but also controls the amount added within the safe upper limit to prevent excessive calcium ions from combining with carbon dioxide in the atmosphere at the end of the process to form calcium carbonate scale and block the return water system.

[0026] Preferably, the calcium-based powder is calcium oxide or calcium hydroxide; the combined output underflow mass concentration is 40.2% to 45.0%.

[0027] By adopting the above technical solution, limiting the source of raw materials and clarifying the final execution effect of the process, calcium oxide or calcium hydroxide provides a more economical calcium ion source, and finally achieves a comprehensive underflow concentration of 40.2% to 45.0%, indicating that this process can overcome the water-holding effect of fine mud, realize solid-liquid separation, and the produced underflow can meet the mechanical index requirements of mine paste filling or tailings dry discharge.

[0028] This invention provides a highly efficient concentration process for flotation concentrate and tailings from oxidized lead-zinc ore flotation. It offers the following advantages: 1. This invention improves the solid-liquid separation effect of fine mud through a segmented dosing mechanism. In the process, calcium-based coagulant emulsion is first added to the slurry to reduce the surface potential of the fine mud and weaken the electrostatic repulsion between particles. Then, anionic polyacrylamide ultra-dilute working solution and polyaluminum chloride standard solution are introduced at different settling stages. By utilizing the long-chain bridging of polymers and the sweeping effect of polynuclear complexes, the dispersed ultra-fine mud is aggregated and cross-linked into large-sized flocs. The multi-stage physicochemical synergistic treatment method destroys the colloidal stability of tailings slurry, improves the settling velocity of solid particles and the overall mass concentration of the underflow.

[0029] 2. This invention improves the utilization rate of the polymer flocculant by optimizing the preparation and injection method. The solid anionic polyacrylamide powder is first dissolved into a mother liquor of 0.08% to 0.12%, and then instantly diluted online through the main pipeline to obtain an extremely dilute working solution of 0.01% to 0.03%. This step-concentration dissolution process avoids the entanglement of polymer molecular chains at high concentrations, allowing the molecular chains to remain in a relatively free and extended state before contacting the slurry, increasing the effective adsorption sites and bridging radius, thereby reducing the ineffective consumption of the agent.

[0030] 3. This invention, by having the ability to adjust to fluctuations in the quality of production return water, helps to maintain the operational stability of the system. The process uses a feedforward automatic compensation device combined with an online conductivity meter to detect the background calcium ion equivalent of the water source in real time. When factors such as rainfall cause the return water to be diluted and the ion strength to decrease, the system can automatically increase the injection volume of calcium-based coagulant emulsion for quantitative compensation. This feedback adjustment mechanism makes up for the calcium equivalent gap caused by changes in water quality, maintains the compressed state of the slurry double electric layer, and reduces the interference of external environmental changes on the concentration and sedimentation process. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the continuous distribution of the Zeta potential in this invention; Figure 2 This is a schematic diagram of the continuous settlement trend curve of the mud-water interface height changing over time according to the present invention. Figure 3 This is a schematic diagram of the continuous interpolation rheological curve of the apparent viscosity of the polymer as a function of shear rate according to the present invention. Figure 4 This is a schematic diagram illustrating the continuous fluctuation trend of the overall undercurrent mass concentration according to the present invention. Figure 5 This is a schematic diagram of the bubble scatter distribution showing the variation of the average chord length of the flocs with fluid residence time according to the present invention. Figure 6 This is a bar chart showing the characteristic absorbance combinations of various batches of supernatant samples according to the present invention. Figure 7 This is a bar chart showing the combined grouping of overflow turbidity of each batch of supernatant samples according to the present invention. Figure 8 A bar graph showing the segmented dehydration rate distribution during different filtration time periods, obtained by differential calculation of the cumulative filtrate volume of the present invention. Figure 9 This is a scatter plot of the two-dimensional spatial characteristic distribution of filter cake moisture content and underflow yield stress for each sampling batch of the present invention. Detailed Implementation

[0032] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] The main raw materials and reagents used in the following examples and comparative examples have the following sources and specifications. Reagents not specifically mentioned are all commercially available analytical grade or higher grade products.

[0034] The tailings from the flotation of oxidized ore were taken from the final tailings bin of the scavenging operation in a lead-zinc concentrator. The feed mass concentration was 18% to 22%, and the particle size distribution was as follows: +37μm particles accounted for 28.85%, -37μm and +19μm particles accounted for 29.54%, -19μm and +10μm particles accounted for 8.74%, -10μm and +5μm particles accounted for 4.16%, and -5μm particles accounted for 28.71%. Anionic polyacrylamide, CAS No. 9003-05-8, with a weight-average molecular weight of 15,000,000 to 20,000,000 and a degree of hydrolysis of 20% to 30%; Polyaluminum chloride, CAS No. 1327-41-9, basicity of 60% to 80%, and alumina mass fraction of not less than 28%; Calcium hydroxide, CAS number 1305-62-0; Calcium oxide, CAS number 1305-78-8; The on-site production wastewater contains a mixed calcium and magnesium ion concentration ranging from 200 mg / L to 900 mg / L.

[0035] In this invention, the units of measurement for all materials and solvents are uniformly referred to as parts by weight.

[0036] Example 1: This embodiment provides a highly efficient concentration process for flotation concentrate and tailings of oxide lead-zinc ore, the process including the following steps: 0.18 parts by weight of calcium hydroxide powder were added to a lime slurry tank equipped with a stirring device, and 1.32 parts by weight of recycled water from on-site production were added to prepare a lime slurry suspension with a mass concentration of 12%. The suspension was stirred at a speed of 400 r / min and allowed to stand for 30 min to mature, thus obtaining a calcium-based coagulant emulsion. 0.0048 parts by weight of solid anionic polyacrylamide powder were added to a mixing tank, and 3.9952 parts by weight of recycled water from the on-site production were added to dissolve it, thus preparing a mother liquor with a mass concentration of 0.12%. The mother liquor was stirred and matured for 90 minutes at a speed of 40 r / min. Then, it was drawn out by a metering pump and 12.0 parts by weight of clean water were added to the main pipeline through a static tubular mixer to instantly dilute it online to obtain an extremely dilute working solution with a mass concentration of 0.03% for later use. The tailings from the flotation of oxidized ore are transported to the thickening process without shearing using a pneumatic diaphragm pump, with the feed mass concentration controlled at 20.0%. Based on 100.0 parts by weight of dry ore, 1.5 parts by weight of the above-mentioned calcium-based coagulant emulsion are added to the slurry to eliminate the negative charge on the surface of the fine mud using calcium ions. The slurry is then directly introduced into the first-stage inclined plate thickener for preliminary classification and sedimentation without flocculants. The bottom is discharged as coarse particles, and the top overflows as the first-stage overflow slurry containing extremely fine mud. The first-stage overflow slurry is introduced into the second-stage inclined plate thickener through a pipeline. 18.0 parts by weight of extremely dilute working fluid is added to the first-stage overflow slurry in the conveying pipeline to make the extremely fine mud network form large flocs, which are then introduced into the second-stage inclined plate thickener for concentration. Fine particles are discharged from the bottom and the second-stage overflow slurry overflows from the top. The second-stage overflow slurry is introduced into the terminal circular thickener. Before entering the circular thickener, 3.0 parts by weight of a 6.0% polyaluminum chloride standard solution prepared with on-site production recycled water and 2.0 parts by weight of an extremely dilute working solution are added sequentially to the main pipeline. This causes the scattered micro-flocs to re-crosslink in situ and undergo electrostatic encapsulation and sedimentation. The bottom of the ultra-fine sludge is discharged, and the top overflows with clarified recycled water. Finally, the coarse particles, fine particles, and ultra-fine sludge are combined and output. The overall sludge mass concentration is ≥41.2%, completing the concentration and clarification treatment.

[0037] Example 2: This embodiment provides a highly efficient concentration process for flotation concentrate and tailings of oxidized lead-zinc ore, including the following steps: Add 0.15 parts by weight of calcium oxide powder to a lime slurry tank equipped with a stirring device, add 1.35 parts by weight of recycled water from on-site production to prepare a lime slurry suspension with a mass concentration of 10%, stir at a speed of 300 r / min and let stand for 45 min to obtain a calcium-based coagulant emulsion. Add 0.0028 parts by weight of solid anionic polyacrylamide dry powder to the mixing tank, add 3.4972 parts by weight of on-site production recycled water to dissolve it, prepare a mother liquor with a mass concentration of 0.08%, stir and mature for 75 minutes at a speed of 50 r / min, then extract it by metering pump and add 24.5 parts by weight of clean water in the main pipeline through a static tubular mixer, and instantly dilute it online to obtain an extremely dilute working solution with a mass concentration of 0.01% for later use; The tailings from the oxidized ore flotation are transported to the thickening process without shearing using a pneumatic diaphragm pump, with the feed mass concentration controlled at 18.0%. Based on 100.0 parts by weight of dry ore, 1.5 parts by weight of the above-mentioned calcium-based coagulant emulsion are added to the slurry to eliminate the negative charge on the surface of the fine mud using calcium ions. The slurry is then directly introduced into the first-stage inclined plate thickener for preliminary classification and sedimentation without flocculants. The bottom is discharged as coarse particles, and the top overflows as the first-stage overflow slurry containing extremely fine mud. The first-stage overflow slurry is introduced into the second-stage inclined plate thickener through a pipeline. 15.0 parts by weight of extremely dilute working fluid is added to the first-stage overflow slurry in the conveying pipeline to make the extremely fine mud network form large flocs, which are then introduced into the second-stage inclined plate thickener for concentration. Fine particles are discharged from the bottom and the second-stage overflow slurry overflows from the top. The second-stage overflow slurry is introduced into the terminal circular thickener. 2.0 parts by weight of a pre-prepared 4.0% polyaluminum chloride standard solution (using on-site production recycled water) and 2.5 parts by weight of an extremely dilute working solution are added sequentially to the main pipe before entering the circular thickener. This causes the fragmented micro-flocs to re-crosslink in situ and undergo electrostatic encapsulation and sedimentation. Extremely fine sludge is discharged from the bottom, while clarified reclaimed water overflows from the top. Finally, the coarse, fine, and extremely fine sludge slurries are combined and output, achieving a combined slurry concentration ≥40.2%, thus completing the concentration and clarification process.

[0038] Example 3: This embodiment provides a highly efficient concentration process for flotation concentrate and tailings of oxide lead-zinc ore, the process including the following steps: 0.24 parts by weight of calcium oxide powder were added to a lime slurry tank equipped with a stirring device, and 1.36 parts by weight of recycled water from on-site production were added to prepare a lime slurry suspension with a mass concentration of 15%. The suspension was stirred at a speed of 200 r / min and allowed to stand for 60 min to mature, thus obtaining a calcium-based coagulant emulsion. 0.0055 parts by weight of solid anionic polyacrylamide powder were added to a mixing tank, and 5.4945 parts by weight of recycled water from the on-site production were added to dissolve it, thus preparing a mother liquor with a mass concentration of 0.1%. The mother liquor was stirred and matured for 60 minutes at a speed of 60 r / min. Then, it was drawn out by a metering pump and 22.0 parts by weight of clean water were added to the main pipeline through a static tubular mixer to instantly dilute it online to obtain an extremely dilute working solution with a mass concentration of 0.02% for later use. The tailings from the oxidized ore flotation are transported to the thickening process without shearing using a pneumatic diaphragm pump, with the feed mass concentration controlled at 22.0%. Based on 100.0 parts by weight of dry ore, 1.6 parts by weight of the above-mentioned calcium-based coagulant emulsion are added to the slurry to eliminate the negative charge on the surface of the fine mud using calcium ions. The slurry is then directly introduced into the first-stage inclined plate thickener for preliminary classification and sedimentation without flocculants. The bottom is discharged as coarse particles, and the top overflows as the first-stage overflow slurry containing extremely fine mud. The first-stage overflow slurry is introduced into the second-stage inclined plate thickener through a pipeline. 25.0 parts by weight of extremely dilute working fluid is added to the first-stage overflow slurry in the conveying pipeline to make the extremely fine mud network form large flocs, which are then introduced into the second-stage inclined plate thickener for concentration. Fine particles are discharged from the bottom and the second-stage overflow slurry overflows from the top. The second-stage overflow slurry is introduced into the terminal circular thickener. Before entering the circular thickener, 5.0 parts by weight of a pre-prepared 5.0% polyaluminum chloride standard solution and 2.5 parts by weight of an extremely dilute working solution are added sequentially to the main pipeline. This causes the scattered micro-flocs to re-crosslink in situ and undergo electrostatic encapsulation and sedimentation. The bottom of the ultra-fine sludge is discharged, and the top overflows with clarified reclaimed water. Finally, the coarse particles, fine particles, and ultra-fine sludge are combined and output. The overall sludge mass concentration is ≥45.0%, completing the concentration and clarification treatment.

[0039] Example 4: This embodiment provides a highly efficient concentration process for flotation concentrate and tailings of oxide lead-zinc ore, the process including the following steps: 0.216 parts by weight of calcium hydroxide powder were added to a lime slurry tank equipped with a stirring device, and 1.584 parts by weight of recycled water from on-site production were added to prepare a lime slurry suspension with a mass concentration of 12%. The suspension was stirred at a speed of 400 r / min and allowed to stand for 30 min to mature, thus obtaining a calcium-based coagulant emulsion. Add 0.004 parts by weight of solid anionic polyacrylamide dry powder to the mixing tank, add 3.996 parts by weight of on-site production recycled water to dissolve it, prepare a mother liquor with a mass concentration of 0.1%, stir and mature for 90 minutes at a speed of 40 r / min, then extract it by a metering pump and add 16.0 parts by weight of clean water in the main pipeline through a static tubular mixer, and instantly dilute it online to obtain an extremely dilute working solution with a mass concentration of 0.02% for later use; Oxidized ore flotation tailings are transported to the thickening process without shearing using a pneumatic diaphragm pump, with the feed mass concentration controlled at 20.0%. Based on 100.0 parts by weight of dry ore, during the thickening process, the background calcium and magnesium ion concentration in the on-site production return water is diluted due to the rainy season. The online conductivity meter of the feedforward automatic compensation device detects the decrease in the background calcium ion equivalent of the water source in real time. The feedforward automatic compensation device automatically increases the injection volume of calcium-based coagulant emulsion, raising the actual amount of calcium-based coagulant emulsion added to the slurry to 2.0 parts by weight to compensate for the calcium equivalent difference caused by water quality fluctuations. Calcium ions are used to eliminate the negative charge on the surface of fine mud. The slurry is then directly introduced into the first-stage inclined plate thickener for preliminary classification and sedimentation without flocculants. Coarse particles are discharged from the bottom, and the first-stage overflow slurry containing extremely fine mud overflows from the top. The first-stage overflow slurry is introduced into the second-stage inclined plate thickener through a pipeline. 18.0 parts by weight of extremely dilute working fluid is added to the first-stage overflow slurry in the conveying pipeline to make the extremely fine mud network form large flocs, which are then introduced into the second-stage inclined plate thickener for concentration. Fine particles are discharged from the bottom and the second-stage overflow slurry overflows from the top. The second-stage overflow slurry is introduced into the terminal circular thickener. Before entering the circular thickener, 3.0 parts by weight of a 5.0% polyaluminum chloride standard solution prepared on-site using recycled water and 2.0 parts by weight of an extremely dilute working solution are added sequentially to the main pipeline. This causes the fragmented micro-flocs to re-crosslink in situ and undergo electrostatic encapsulation and sedimentation, overcoming the interference of the rainy season. The bottom of the slurry is discharged as extremely fine mud, while the top overflows as clarified reclaimed water. Finally, the coarse, fine, and extremely fine mud slurries are combined and output, with a combined bottom slurry mass concentration ≥41.2%, completing the concentration and clarification treatment.

[0040] Comparative Example 1: Compared with Example 1, the difference is that no calcium-based coagulant emulsion was added to the slurry, that is, no treatment was performed to eliminate the negative charge on the surface of the fine mud with calcium ions; otherwise, they are the same.

[0041] Comparative Example 2: Compared with Example 1, the difference is that: instead of online instantaneous dilution through a static tubular mixer, the 0.1% mass concentration anionic polyacrylamide mother liquor was directly added to the first stage overflow slurry, while the rest were the same.

[0042] Comparative Example 3: Compared with Example 1, the difference is that the mixing method of the first overflow slurry and the extremely dilute anionic polyacrylamide working fluid is changed from natural fluid dynamic mixing by pipeline transportation to mechanical mixing by introducing a high-strength mechanical stirring tank. All other aspects are the same.

[0043] Comparative Example 4: Compared to Example 1, the difference is that no polyaluminum chloride standard solution was added to the main pipeline before entering the terminal circular tank; all other aspects are the same. Comparative Example 5: Compared with Example 4, the difference is that no feedforward automatic compensation device was set up for closed-loop accounting. When the water quality fluctuates during the rainy season and the background calcium and magnesium ion concentration of the water source is diluted, the calcium-based coagulant emulsion is still added at a fixed dosage of 1.5 parts by weight. All other aspects are the same.

[0044] Test Example 1: The slurry from the main pipeline before feeding into the first inclined plate thickener in Example 1, after being treated with calcium-based coagulant emulsion, was taken as the first test sample. The corresponding node slurry from Comparative Example 1, which was not treated with calcium-based coagulant emulsion, was taken as the second test sample. 50 mL of each of the first and second test samples were measured and diluted with deionized water at a volume ratio of 1:100. The samples were then dispersed in an ultrasonic cleaner for 3 minutes. The dispersed suspension was injected into the sample cell of the Zeta potential analyzer using a syringe. Five independent measurements were performed at 25°C. The Zeta potential data were recorded and the average value was calculated.

[0045] Take 1000 mL of the mixed slurry after the first overflow slurry in Example 1 is transported through the pipeline and a very dilute anionic polyacrylamide working solution is added, and inject it into the first 1000 mL stoppered graduated cylinder; take 1000 mL of the mixed slurry at the corresponding node of Comparative Example 1, that is, the mixed slurry with an equal amount of very dilute anionic polyacrylamide working solution added but without calcium treatment in the early stage, and inject it into the second 1000 mL stoppered graduated cylinder.

[0046] After mixing the first and second stopper cylinders by flipping them upside down three times, place them on a horizontal test platform, turn on the timer, observe the position change of the mud-water interface during the settling process, record the scale value of the interface between the clear liquid layer and the turbid slurry at the preset time nodes, and obtain the data on the change of interface height over time. The settling test environment temperature is maintained in the range of 20℃ to 25℃.

[0047] Table 1: Data on Zeta potential and sedimentation dynamics

[0048] According to Table 1 and Figure 1 and Figure 2It can be seen that the average Zeta potential of the high mud flotation tailings in Comparative Example 1 without calcium-based coagulant emulsion treatment is around -42.1mV. The mineral particles are attached with negative charges, and the system exhibits electrostatic stability. Under the test conditions, the electrostatic repulsion between the fine mud particles restricts the particles from approaching each other. Although anionic polyacrylamide working solution was added to the system of Comparative Example 1, the electrostatic repulsion was not eliminated. When the polymer chain segments approached the particle surface, an electrostatic barrier was generated, which limited the bridging effect. In terms of macroscopic sedimentation data feedback, the mud-water interface of Comparative Example 1 decreased from 1000mL to 785mL within 300 seconds. The main body of the slurry remained in a suspended state, and the overall sedimentation rate was low.

[0049] In Example 1, after the addition of calcium-based coagulant emulsion, the average Zeta potential of the test system shifted from around -42.1 mV to around -12.6 mV. Divalent calcium ions entered the adsorption and diffusion layers of mineral particles, neutralizing the negative charge on the surface of fine mud and generating a double-layer compression effect. The reduction of the electrostatic repulsion barrier improved the coagulation conditions between fine particles. Combined with the subsequent addition of extremely dilute anionic polyacrylamide working solution, the extended polymer chains could contact the surface of mineral particles through the reduced electrostatic barrier and form preliminary flocs.

[0050] Sedimentation data showed that the mud-water interface in Example 1 decreased to 457 mL within the first 90 seconds and reached a compressed volume of 149 mL at 300 seconds. The neutralization of static charge and the flocculation process of polymer segments showed a synergistic mechanism, which is beneficial to improving the solid-liquid separation efficiency of the high mud-based slurry system.

[0051] The Zeta potentials corresponding to the time nodes from 150 seconds to 300 seconds in Table 1 are not recorded in this section because the Zeta potential analysis is a series of five independent, repeated offline sampling measurements of the dispersed suspension, rather than a dynamic parameter continuously acquired online during the sedimentation process of the graduated cylinder. Furthermore, the data from the first five independent measurements already meet the requirements for statistical calculation and error analysis.

[0052] Test Example 2: A 0.02% (w / w) anionic polyacrylamide working solution obtained by online dilution using a static tubular mixer in Example 2 was used as the first rheological test sample. An undiluted 0.1% (w / w) anionic polyacrylamide mother liquor from Comparative Example 2 was used as the second rheological test sample. The first and second rheological test samples were injected into the test area of ​​a coaxial cylindrical rotational rheometer, respectively. The test environment temperature was set to 25°C, and the shear rate of the rotational rheometer was controlled from 1.1 s⁻¹. -1 Gradually increasing to 100.5s -1 The apparent viscosity data of the first and second rheological test samples under different shear rates were recorded.

[0053] During the stable operation of the end-circular thickener in Example 2, three equal-time-interval underflow samples were continuously taken at the discharge outlet to obtain three sets of comprehensive underflow samples from Example 2; during the stable operation of the thickener in Comparative Example 2, three underflow samples were taken at the same time interval to obtain three sets of comprehensive underflow samples from Comparative Example 2.

[0054] Weigh 200g of each of the above-collected integrated underflow samples and place them in a pre-weighed evaporating dish. Transfer the evaporating dish containing the underflow sample into an electric heating drying oven and dry it at 105℃ until constant weight. Remove the evaporating dish and place it in a desiccator to cool to room temperature before weighing. Calculate the integrated underflow mass concentration of each group of integrated underflow samples based on the mass difference before and after drying.

[0055] Table 2: Rheological parameters and combined undercurrent concentration test data

[0056] According to Table 2 and Figure 3 and Figure 4 It can be seen that the 0.1% concentration of anionic polyacrylamide mother liquor in Comparative Example 2, at a shear rate of 1.1 s⁻¹, showed a significant improvement. -1 Increased to 100.5s -1 At that time, the apparent viscosity decreased from 45.83 mPa·s to 7.14 mPa·s. The decrease in viscosity reflects that at this concentration, the polymer chain segments are coiled and entangled, and disintegrated and aligned under shearing. In Example 2, the apparent viscosity of the 0.02% anionic polyacrylamide working solution was generally low and the decrease was small. This difference indicates that at a lower concentration, water molecules provide sufficient solubilization space for long carbon chains, and the molecular chains are more likely to be in a stretched state, reducing entanglement resistance.

[0057] The underflow mass concentration data further verified the correlation between polymer chain segment conformation and flocculation effect. The underflow mass concentration of Comparative Example 2 was 31.85% to 33.04% in three samplings. Due to the coiling and entanglement of molecular chains at higher concentrations, the effective polar groups binding mineral particles decreased, limiting the collision range and netting efficiency. After online dilution, the underflow mass concentration of Example 2 increased to 40.35% to 41.22% in three samplings.

[0058] While maintaining the same amount of dry powder, reducing the concentration causes the polymer molecular chains to tend to extend, providing more effective adsorption sites, increasing the probability of binding with highly muddy particles and improving bridging and settling behavior. Data comparison supports the technical logic of reducing the working fluid concentration to promote molecular chain extension and thus increase the underflow concentration.

[0059] The shear rate in Table 2 is 25.4 s⁻¹. -1 up to 100.5s-1 The corresponding sampling batches and concentration blanks are not recorded because the acquisition of rheological parameters belongs to the micro-fluid characteristic analysis within a laboratory-specific instrument. This is a parallel and independent testing process with the sequential isochronous sampling of underflow from a thickener in the industrial field. Furthermore, the underflow sampling only sets three consecutive observation batches. Therefore, real-time monitoring data was not recorded in this part.

[0060] Test Example 3: The probe of the focused beam reflectance measuring instrument was placed inside the feed pipe of the second inclined plate thickener in Example 3 and inside the mechanical stirring tank in Comparative Example 3. The data acquisition frequency of the focused beam reflectance measuring instrument was set, and the chord length distribution of the floc particles inside the slurry was continuously monitored online when the slurry passed through the test node area. The average chord length data of different time nodes in the time period from the 15th second to the 135th second were recorded.

[0061] After the end-stage circular thickener of Example 3 entered the stable overflow discharge stage, three batches of overflow reclaimed water were continuously collected at the overflow weir outlet as supernatant samples of Example 3; after the end-stage circular thickener of Comparative Example 4 entered the stable overflow discharge stage, three batches of overflow reclaimed water were collected according to the same rules as supernatant samples of Comparative Example 4.

[0062] The supernatant samples of Example 3 and Comparative Example 4 collected from each batch were measured and injected into the sample bottle of the laser turbidimeter to measure the overflow turbidity. Subsequently, a portion of the supernatant samples of Example 3 and Comparative Example 4 were extracted and placed in a quartz cuvette and placed in a UV-Vis spectrophotometer. The absorbance of the characteristic groups of anionic polyacrylamide was measured at a wavelength of 210 nm, and the test environment temperature was maintained at 25°C.

[0063] Table 3: Online chord length and overflow water quality test data

[0064] According to Table 3 and Figures 5 to 7 It can be seen that after mechanical stirring in Comparative Example 3, the average chord length of the internal fluid increased to 102.5 μm in the first 45 seconds, and then decreased, dropping to 22.4 μm at 135 seconds. The sharp decrease in chord length data indicates that the floc structure in the high muddy environment is relatively fragile. The continuous shear force generated by mechanical stirring exceeds the floc crosslinking strength, causing irreversible damage to the initial large flocs, resulting in the solid particles disintegrating and dispersing again.

[0065] Example 3 uses a micro-disturbance flow field formed by the drop in the feed pipe for mixing. The average chord length drops to 82.6 μm around 75 seconds, then increases again and reaches 128.7 μm at 135 seconds. The initial drop in chord length reflects the local rupture of flocs when passing through the drop section of the pipe flow, while the secondary increase in chord length in the later stage indicates that the turbulent conditions of the pipe flow, combined with the anionic polyacrylamide segments, promote the re-crosslinking and stitching of the residual segments, verifying the technical feasibility of the micro-disturbance flow field to avoid high-intensity shear damage.

[0066] Comparative Example 4, which did not contain polyaluminum chloride, had absorbance values ​​above 0.389 au for all three batches of supernatant, demonstrating that a large number of residual anionic polyacrylamide segments were free in the overflow recycled water. These residual segments increased the electrostatic stability of the fine mud colloids, which kept the overflow turbidity of Comparative Example 4 within the range of 65.4 NTU to 72.1 NTU for a long time.

[0067] In Example 3, after the introduction of polyaluminum chloride treatment, the absorbance of each batch of supernatant was maintained in the range of 0.038au to 0.045au, and the overflow turbidity was controlled in the range of 10.8 NTU to 12.6 NTU. The polynuclear inorganic aluminate ions generated by the ionization of polyaluminum chloride and the free polyacrylamide segments undergo electrostatic neutralization and adsorption to form a composite coprecipitate. The charge neutralization and physical encapsulation remove the high molecular residues and nano-sized mud colloids in the suspended system, reduce the overflow turbidity, and ensure that the water quality of the reclaimed water system meets the standards.

[0068] The blank spaces for average chord length corresponding to batches 1 to 3 in Table 3, and the blank spaces for absorbance and overflow turbidity corresponding to 15 seconds to 135 seconds, are not recorded because the average chord length measurement is a fixed-point dynamic characterization parameter acquisition inside the pipeline fluid, while the absorbance and overflow turbidity measurement are offline sampling tests during the overflow liquid drainage stage at the end of the system. The aforementioned measurement links are in completely different spatial process nodes and time dimensions, and cannot generate overlapping mapping data. Therefore, the corresponding parts do not record cross-test data.

[0069] Test Example 4: The discharge slurry from the bottom of the thickener in Example 4 was taken as the first rheological test object; the discharge slurry from the bottom of the thickener in Comparative Example 5 was taken as the second rheological test object. The first and second rheological test objects were respectively placed into the test cups of a coaxial cylindrical rotary rheometer. The test environment temperature of the rotary rheometer was set to 25°C. The shear stress control mode was adopted, and the shear stress applied by the rotary rheometer was gradually increased from 10 Pa to 150 Pa. The critical shear stress values ​​corresponding to the flow deformation of the first and second rheological test objects, i.e., the sudden change in shear rate, were recorded. The critical shear stress values ​​were taken as the bottom flow yield stress of the first and second rheological test objects.

[0070] Measure 200 mL of the discharged pulp at the bottom of the thickener at the end of Example 4 as the first filtration test object; measure 200 mL of the discharged pulp at the bottom of the thickener at the end of Comparative Example 5 as the second filtration test object. Place the first filtration test object and the second filtration test object separately in a Buchner funnel lined with a standard filter paper. Start the suction filtration operation under a constant vacuum of 0.08 MPa, and place a graduated cylinder under the suction flask to collect the filtrate. Start the timer and record the cumulative volume of the filtrate collected in the graduated cylinder at the 30-second, 60-second, 90-second, 120-second, and 150-second time points for Example 4 and the cumulative volume of the filtrate for Comparative Example 5.

[0071] When the plate-and-frame filter press supporting Example 4 is in the discharging stage, randomly collect three filter cakes as the filter cake samples of Example 4; when the plate-and-frame filter press supporting Comparative Example 5 is in the discharging stage, randomly collect three filter cakes as the filter cake samples of Comparative Example 5. Weigh the initial masses of the filter cake samples of Example 4 and the filter cake samples of Comparative Example 5 respectively. Transfer the filter cake samples of Example 4 and the filter cake samples of Comparative Example 5 into a constant-temperature blast drying oven at 105 °C and dry them to a constant weight. Weigh the dried masses of the filter cake samples of Example 4 and the filter cake samples of Comparative Example 5, and calculate the moisture content of the filter cakes of Example 4 and the moisture content of the filter cakes of Comparative Example 5 based on the difference between the initial mass and the dried mass.

[0072] Table 4: Data table for filtration kinetics and underflow physical property tests

[0073] According to Table 4 and Figure 8 and Figure 9 It can be obtained that the cumulative volume of the filtrate of the discharged pulp in Comparative Example 5 at 150 seconds of suction filtration is 65.4 mL, and the dehydration rate is relatively low. This indicates that there is more interstitial water retained inside the particle aggregates in Comparative Example 5, and the particle structure will undergo compressive deformation under the external pressure difference, resulting in the reduction of the pore channels and an increase in the physical resistance to water permeability. The cumulative volume of the filtrate of Example 4 reaches 109.3 mL at 150 seconds, and the amount of filtrate析出 in each time period is higher than that of Comparative Example 5. This shows that the flocs formed by the synergistic action of the reagent system in Example 4 have good pore retention ability, and the pore channels tend to remain connected under negative pressure suction, reducing the resistance of the solid-liquid separation medium.

[0074] In Comparative Example 5, the filter cake moisture content of the three sampling batches ranged from 30.95% to 32.18%, and the yield stress ranged from 84.7 Pa to 88.6 Pa. Overall, the filter cake was in the range of high moisture content and high yield stress. The high yield stress indicates that there is significant electrostatic repulsion and hydration film resistance among the suspended particles in Comparative Example 5, which increases the shear stress required for initial flow and the resistance of underflow transport in the field. At the same time, it limits the effect of mechanical pressing on the discharge of water from the pulp, resulting in a high filter cake moisture content. In Example 4, the filter cake moisture content of the three sampling batches decreased to 21.85% to 22.42%, and the yield stress decreased to 46.2 Pa to 49.1 Pa. The simultaneous decrease of the two indicators indicates that the electrostatic double layer compression effect causes the bound water on the particle surface to be partially converted into free water. The increase of free water reduces the frictional resistance between particles, improves the rheological transport characteristics, and enhances the water removal performance and solid-liquid separation efficiency of the pulp in Example 4 during the mechanical pressing process.

[0075] The blank spaces in Table 4 corresponding to the filter cake moisture content and underflow yield stress data for the time nodes, as well as the blank spaces corresponding to the cumulative volume of filtrate for the sampling batches, are due to the fact that the filtration kinetics test is a continuous time node observation process under constant vacuum conditions, while the filter cake moisture content test and underflow yield stress test are offline material physical property extraction processes for independent batches. The above test objects are independent of each other in terms of process stage and test logic, and cannot generate corresponding mapping data. Therefore, cross-test data were not recorded at the corresponding positions.

[0076] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A highly efficient concentration process for flotation concentrate and tailings of oxidized lead-zinc ore, characterized in that, The process includes the following steps: Calcium-based powder is added to a lime slurry tank equipped with a stirring device, and recycled water from on-site production is added to prepare a lime milk suspension. The suspension is stirred and allowed to stand for aging to obtain a calcium-based coagulant emulsion. Solid anionic polyacrylamide powder is added to a mixing tank, dissolved in recycled water from on-site production to prepare a mother liquor. After stirring and maturing, it is extracted by a metering pump and diluted online with clean water in the main pipeline to obtain an extremely dilute working solution for later use. The tailings from the oxidized ore flotation are transported to the thickening process, where the calcium-based coagulant emulsion is added to the slurry for charge elimination. The slurry is then introduced into the first thickening unit for preliminary classification and settling. The bottom is discharged as coarse particles, and the top overflows as first-stage overflow slurry containing extremely fine mud. The first-stage overflow slurry is introduced into the second-stage thickening equipment. The extremely dilute working fluid is added to the first-stage overflow slurry in the conveying pipeline to make the extremely fine mud network form flocs for thickening. Fine particles are discharged from the bottom and the second-stage overflow slurry overflows from the top. The second-stage overflow slurry is introduced into the end-of-pipe thickening equipment. The pre-prepared polyaluminum chloride standard solution and the ultra-dilute working solution are added sequentially to the main pipeline before entering the end-of-pipe thickening equipment, so that the micro flocs are re-crosslinked in situ and undergo electrostatic encapsulation and sedimentation. The bottom is discharged as ultra-fine mud bottom flow, and the top overflows as clarified reclaimed water. The above coarse particle bottom flow, fine particle bottom flow and ultra-fine mud bottom flow are combined and output to complete the thickening and clarification treatment.

2. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 1, characterized in that, Based on 100.0 parts by weight of dry ore, the dosage of each reagent is as follows: The amount of the calcium-based coagulant emulsion added is 1.5 to 1.6 parts by weight; The amount of the extremely dilute working fluid added to the first stage overflow slurry is 15.0 to 25.0 parts by weight; The amount of the polyaluminum chloride standard solution added to the main pipeline is 2.0 to 5.0 parts by weight, and the amount of the extremely dilute working solution added to the main pipeline is 2.0 to 2.5 parts by weight.

3. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 1, characterized in that, The step of preparing the calcium-based coagulant emulsion includes: The mass concentration of the lime milk suspension is 10% to 15%; the stirring conditions for preparing the calcium-based coagulant emulsion are a rotation speed of 200 r / min to 400 r / min and a settling and maturation time of 30 min to 60 min.

4. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 1, characterized in that, The steps for preparing the extremely dilute working solution include: The mass concentration of the mother liquor is 0.08% to 0.12%; the stirring and maturation conditions for preparing the mother liquor are a rotation speed of 40 r / min to 60 r / min and a time of 60 min to 90 min; the mass concentration of the diluted ultra-dilute working solution is 0.01% to 0.03%.

5. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 1, characterized in that, The step of pre-preparing the polyaluminum chloride standard solution includes: The mass concentration of the polyaluminum chloride standard solution prepared in advance using recycled water from on-site production is 4.0% to 6.0%.

6. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 1, characterized in that, The steps of conveying the oxide ore flotation tailings to the thickening process and introducing them into various thickening equipment include: The oxide ore flotation tailings are transported to the concentration process without shearing by a pneumatic diaphragm pump. The first stage thickening equipment is a first-stage inclined plate thickener; the second stage thickening equipment is a second-stage inclined plate thickener; and the final thickening equipment is a final circular pool thickener.

7. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 1, characterized in that, The feed mass concentration of the oxide ore flotation tailings is controlled at 18.0% to 22.0%.

8. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 1, characterized in that, The steps involved in the concentration process include: During the concentration process, an online conductivity meter with a feedforward automatic compensation device is used to detect the background calcium ion equivalent of the water source in real time. When the background calcium and magnesium ion concentration of the water source is diluted and the calcium ion equivalent decreases due to water quality fluctuations, the feedforward automatic compensation device automatically increases the injection volume of the calcium-based coagulant emulsion to compensate for the calcium equivalent difference caused by water quality fluctuations.

9. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 8, characterized in that, The steps for performing automatic feedforward compensation include: When performing the aforementioned feedforward automatic compensation, the amount of the calcium-based coagulant emulsion actually added to the slurry is increased to 1.8 to 2.0 parts by weight, based on 100.0 parts by weight of dry ore.

10. The high-efficiency concentration process for lead-zinc oxide ore flotation concentrate and flotation tailings according to claim 1, characterized in that, The calcium-based powder is calcium oxide or calcium hydroxide; the combined output underflow mass concentration is 40.2% to 45.0%.

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