A composite treatment agent and method for the settling and transportation of tailings in extra-large copper mines.

Abstract

This invention discloses a composite treatment agent and method for the settling and transportation of tailings in extra-large copper mines, belonging to the field of tailings treatment technology. The composite treatment agent comprises the following molecular structure component A and polyacrylamide component B: where x / y = (6~8):1; n is 52~85, and R1 and R2 are independently selected from hydrogen or methyl. In the process of treating copper tailings slurry, component A is first used to regulate the interface of the copper tailings, and then polyacrylamide is added for flocculation, so that the fine copper tailings particles can be rapidly flocculated and settled to form a dense concentrated underflow, which is then transported to the tailings dam with low energy consumption. This method can improve the slurry settling speed and the concentration of the concentrated underflow, while also improving the slurry fluidity and transportation efficiency, reducing the energy consumption of slurry transportation and pipeline wear, and requiring less reagent, thus saving costs.

Description

Technical Field

[0001] This invention discloses a composite treatment agent, particularly a composite treatment agent and its application method for the settling and transportation of tailings in extra-large copper mines, belonging to the field of tailings treatment technology. Background Technology

[0002] Tailings are a large amount of solid waste generated during the extraction of useful components in the development and utilization of mineral resources. In the mining and beneficiation of copper ore, 200-400 tons of copper tailings are generated for every ton of copper concentrate produced. my country produces nearly 400 million tons of copper tailings annually, accounting for approximately 30% of the country's total tailings production. This demonstrates the enormous quantity of copper tailings, which, if not properly and scientifically managed, will become a serious threat to the ecological environment. In recent years, the increasing mining of low-grade deposits has led to the grinding of copper ore to submicron sizes during mineral sorting to achieve full liberation and efficient recovery of copper concentrate. This has resulted in an increase in fine particles in the tailings slurry. Consequently, the tailings slurry gradually forms a complex system characterized by large quantity, fine particle size, low density, high viscosity, and high mud content, further increasing the difficulty of treatment.

[0003] The processing technology for copper tailings includes slurry settling, thickening, long-distance transportation, and tailings dam storage. The conventional method for copper tailings settling involves adding polymeric flocculants. However, with the increasing fine particle content and mud-like properties of the copper tailings slurry, conventional flocculants struggle to achieve efficient flocculation and settling, exhibiting problems such as slow settling rates, unclarified overflow, and low underflow concentration / high water content. Therefore, coagulant aids such as inorganic salts and quaternary ammonium salt polyelectrolytes have been developed to synergistically improve tailings settling rates and reduce underflow water content. However, most studies only aim to improve settling and thickening efficiency, neglecting the impact on subsequent long-distance tailings slurry transportation, leading to increased slurry viscosity and decreased fluidity. Therefore, in subsequent slurry transportation, either water is added to reduce the concentration of thickened tailings, or reagents are added to disrupt the floc structure in the thickened tailings to improve slurry fluidity. These methods either increase water usage and tailings transportation energy consumption, reduce transportation efficiency, or increase a large amount of chemical consumption, rendering the previous efficient sedimentation and concentration useless and greatly increasing the additional cost of tailings treatment.

[0004] Therefore, it is necessary to develop a multifunctional tailings treatment agent to achieve both efficient sedimentation and concentration of copper tailings and low-energy transportation of high-concentration tailings slurry, thereby improving tailings treatment efficiency and realizing sustainable development of mineral resources. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, the first objective of this invention is to provide a composite treatment agent for the settling and transportation of extra-large copper mine tailings. This composite treatment agent, when used in the treatment of extra-large copper tailings, can increase the settling velocity and concentration of the concentrated underflow of copper tailings, improve the fluidity of the slurry, so as to achieve high-concentration, long-distance, low-energy transportation of copper tailings in subsequent stages and improve the overall efficiency of tailings treatment.

[0006] The second objective of this invention is to provide a method for the settling and transportation of tailings in extra-large copper mines. This method uses a special composite treatment agent to improve the settling velocity of copper tailings and the concentration of the concentrated underflow, while also improving the fluidity of the slurry. This results in improved slurry transportation efficiency, reduced energy consumption and pipeline wear during slurry transportation, and lower reagent dosage, thus saving costs.

[0007] To achieve the above-mentioned technical objectives, the present invention provides a composite treatment agent for the settling and transportation of tailings in extra-large copper mines, comprising component A and component B;

[0008] The molecular structure of component A is as follows:

[0009]

[0010] in,

[0011] x / y = (6~8):1;

[0012] n = 52–85;

[0013] R1 and R2 are independently selected from hydrogen or methyl;

[0014] Component B is a polyacrylamide.

[0015] The component A of this invention has a high acid-ether ratio in its molecular structure. Its carboxyl group serves as an adsorption group to enhance its neutralization effect on the electronegativity of copper tailings particles, thereby reducing electrostatic repulsion between particles and making them easier to aggregate and settle quickly. Simultaneously, component A has a high polyether side chain length, which, after adsorption onto the particle surface, not only provides steric hindrance during floc formation, expelling water molecules from the floc space and thus reducing the water content of the concentrate underflow and increasing its concentration, but also enhances the hydrophobicity of the particle surface, reducing slurry viscosity and improving slurry flowability, thereby improving slurry transport efficiency. Furthermore, component A has a long main chain length, thereby increasing its adsorption on the surface of copper tailings particles, maximizing the effect of the coagulant on slurry settling and transport.

[0016] In the process of treating copper tailings, components A and B of the present invention have a synergistic effect. Component A is adsorbed on the surface of copper tailings particles, and its polyether side chains are oriented toward the solution, which enhances the bridging effect of component B on the particles, enabling it to capture more fine particles in the slurry and thus improve the clarity of the supernatant. Component A can compress the double electric layer of copper tailings particles, so that when component B bridges the copper tailings particles, it forms a dense flocculent structure, thereby improving the settling velocity and the concentration of the concentrated underflow.

[0017] As a preferred embodiment, the weight average molecular weight M of component A is... w =70,000 to 100,000.

[0018] As a preferred embodiment, the number-average molecular mass Mn of component B is 8 million to 12 million.

[0019] As a preferred embodiment, the composite treatment agent comprises the following components in parts by weight: component A 20-150 parts; component B 2-8 parts.

[0020] As a preferred embodiment, the polyacrylamide class includes nonionic polyacrylamide and / or anionic polyacrylamide.

[0021] The present invention also provides a method for the settling and transportation of the composite treatment agent for ultra-large copper mine tailings. The method involves adding component A of the composite treatment agent to the copper mine tailings slurry for stirring and pretreatment, adding component B of the composite treatment agent to the pretreated copper mine tailings slurry, and achieving rapid flocculation and settling through thickening treatment to form a high-concentration concentrated underflow. The concentrated underflow is then transported to the tailings dam through a pipeline.

[0022] As a preferred embodiment, the dosage of component A in the copper mine tailings slurry is 200–1500 g / t.

[0023] As a preferred embodiment, the dosage of component B in the copper mine tailings slurry is 20–80 g / t.

[0024] As a preferred embodiment, component A is added in the form of a solution with a mass concentration of 0.01 to 1.0%.

[0025] As a preferred embodiment, component B is added in the form of a solution with a mass concentration of 0.005 to 0.1%.

[0026] As a preferred embodiment, the stirring pretreatment process involves a stirring speed of 200–400 r / min and a stirring time of 10–20 min. Through stirring, component A can be fully applied to the surface of the copper tailings, achieving surface performance regulation and facilitating subsequent flocculation and sedimentation.

[0027] The preparation method of component A in the composite treatment agent for the settling and transportation of tailings in extra-large copper mines provided by this invention mainly includes the following steps, obtained by conventional free radical polymerization:

[0028] S1: Raw material preparation; the raw material components acrylic acid and / or methacrylic acid are mixed with methyl allyl alcohol polyoxyethylene ether in a molar ratio of (6-8):1; preferably, the molar ratio of acrylic acid and / or methacrylic acid to methyl allyl alcohol polyoxyethylene ether is (6.5-7):1; preferably, the molecular weight of methyl allyl alcohol polyoxyethylene ether is 2400-3800, more preferably 3000-3600, and its structural formula is shown below:

[0029]

[0030] S2: Reaction system construction; The monomer raw materials are added to the reactor, and a certain amount of initiator and chain transfer agent are added in proportion; Preferably, the initiator is any one of hydrogen peroxide, ammonium persulfate, and sodium persulfate, and the addition amount is 0.5-2.0% of the total mass of the monomer raw materials, more preferably 1.2-1.8%. By using a larger dose of initiator, the polymerization effect of the monomer raw materials can be enhanced, so that the coagulant aid has a higher main chain length, thereby improving the adsorption of component A on the surface of copper tailings particles and maximizing its effect on slurry sedimentation and transportation; Preferably, the chain transfer agent is a mixture of mercaptoacetic acid and mercaptopropionic acid in a mass ratio of 9:(1-3), and the addition amount is 0.3-0.8% of the total mass of the monomer raw materials; More preferably, the mass ratio of mercaptoacetic acid to mercaptopropionic acid in the chain transfer agent is 9:(1-1.5), and the addition amount is 0.3-0.6% of the total mass of the monomer raw materials.

[0031] S3: Polymerization reaction; at a certain temperature, the monomer raw material initiates a polymerization reaction through an initiator to form a high molecular chain polymer; preferably, the reaction temperature is 75-95°C, more preferably 90-95°C; the reaction time is 2-4 hours, more preferably 3-3.5 hours;

[0032] S4: Neutralization treatment; After the polymerization reaction is completed, the polymer chain is neutralized to bring its pH to the ideal value, thus obtaining component A solution; preferably, the pH adjuster is sodium hydroxide, and the pH value is adjusted to 6.5-7.5.

[0033] The weight average molecular weight (M) of component A product finally synthesized in this invention is... wThe molecular weight should be controlled within the range of 70,000 to 100,000, and more preferably within the range of 85,000 to 100,000. A higher molecular weight helps to adsorb two or more copper tailings particles. At the same time, the adsorption of the coagulant on the particle surface also helps the flocculant to bridge and adsorb the particles, so that it can capture more fine particles in the slurry.

[0034] The method of using the composite treatment agent for the settling and transportation of extra-large copper mine tailings provided by this invention is as follows: Copper tailings slurry first enters a pretreatment agitator, and component A with a mass concentration of 0.01–1.0% is continuously added to the pretreatment agitator to regulate the copper tailings interface; the pretreatment slurry is then pumped to a tailings thickener, where a polyacrylamide flocculant with a mass concentration of 0.005–0.1% is continuously added, causing the fine copper tailings particles to rapidly flocculate and settle in the thickener, forming a high-concentration concentrated underflow; the concentrated underflow is then transported to the tailings dam via a long-distance pipeline. Preferably, the dosage of component A is 200–1500 g / t, more preferably 500–1000 g / t. Preferably, the effective volume of the pretreatment agitator is 12–21 m³. 3 The further preferred effective volume is 15-18m³. 3 The stirring speed during the pretreatment process is 200–400 r / min, more preferably 300–350 r / min, and the slurry residence time is 10–20 min, more preferably 14–18 min. In this invention, appropriate stirring speed and sufficient slurry residence time allow the particles in the slurry to fully react and adsorb with the coagulant, reducing reagent consumption and excessive use. Preferably, the polyacrylamide is either nonionic or anionic, more preferably nonionic; the molecular weight of the polyacrylamide is in the range of 8 million–12 million, more preferably 10 million–11 million; the dosage of the polyacrylamide is 20–80 g / t, more preferably 30–65 g / t, more preferably 35–50 g / t. This invention uses nonionic polyacrylamide, which has a better flocculation effect on copper tailings. The molecular weight of 10 million to 11 million can ensure the excellent flocculation ability of polyacrylamide, while avoiding the problem that excessively high molecular weight of the reagent will encapsulate water molecules in the flocs and affect the water content of the concentrated underflow.

[0035] Compared with existing technologies, the beneficial technical effects of the present invention are as follows:

[0036] The key to the composite treatment agent for copper mine tailings settling and transportation provided by this invention lies in the use of component A with a special molecular structure. Its main characteristics are: firstly, the higher proportion of carboxylic acid can neutralize the electronegativity of the particle surface and weaken the electrostatic repulsion between particles, thereby accelerating the settling speed; secondly, the higher polyether side chain length can provide a steric hindrance effect, making the formed flocs more compact and the concentration of the concentrated underflow higher, while also enhancing the hydrophobicity of the particle surface, reducing the viscosity of the slurry, and improving the slurry flowability and transportation efficiency; and thirdly, the higher main chain length can improve the adsorption of the agent on the particles, maximizing its effect on slurry settling and transportation, and reducing agent consumption.

[0037] Currently, the treatment of tailings settling in extra-large copper mines employs flocculants or a combination of flocculants and coagulants. During tailings transportation, to improve fluidity, the slurry concentration needs to be reduced or rheology modifiers need to be added. This approach suffers from drawbacks such as slow settling speed, high water content in the concentrated underflow, high transportation energy consumption, and large reagent consumption. This invention combines component A with a polyacrylamide-based flocculant for copper mine tailings settling and transportation, offering the following significant technical advantages: 1. Settling speed is superior to traditional combinations of coagulants and flocculants, and the supernatant is clearer; 2. It solves the problem of high water content in the concentrated underflow caused by flocculants, significantly increasing the concentration of the concentrated underflow; 3. It greatly improves slurry fluidity, eliminating the need to reduce slurry concentration or add other reagents during tailings transportation, saving transportation energy and reagent costs, and enabling high-concentration, long-distance, low-energy transportation of tailings from extra-large copper mines. Attached Figure Description

[0038] Figure 1 The Fourier transform infrared spectrum is shown for component A in the composite treatment agent prepared in Example 1. Detailed Implementation

[0039] The technical solutions of 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 protection scope of the present invention.

[0040] Example 1

[0041] Settling and transport performance tests were conducted using tailings from a large copper mine in Jiangxi Province. The main minerals in the tailings were quartz, chlorite, and calcite, containing 64.56% SiO2 and 14.60% Al2O3, with a slurry concentration of 20.95%.

[0042] The preparation method of component A in the composite treatment agent is as follows: acrylic acid and methyl allyl alcohol polyoxyethylene ether with a molecular weight of 3200 are selected as monomer raw materials, and are added to the reactor in a molar ratio of 7:1; ammonium persulfate initiator and chain transfer agent with a mass ratio of mercaptoacetic acid to mercaptopropionic acid of 9:1 are added to the reactor, and the addition amounts of the two additives are 1.5% and 0.5% of the total amount of monomer raw materials, respectively; the reactor is heated to 95℃ for polymerization reaction for 3.5h to form a high molecular chain polymer; after the reaction is completed, the high molecular chain polymer is neutralized with sodium hydroxide pH adjuster to adjust the pH value to 7.0 to obtain component A solution.

[0043] The application method of the composite treatment agent in tailings settling and transportation is as follows: the tailings slurry first enters an effective volume of 18m³. 3 A pretreatment agitator was used, and component A (0.5% by mass, 1000 g / t) was continuously added to the pretreatment agitator for interface control of copper tailings. The stirring speed of the tailings slurry in the pretreatment agitator was 350 r / min and the residence time was 18 min. Then, the pretreated slurry was pumped to a tailings thickener, and nonionic polyacrylamide flocculant (0.025% by mass, 45 g / t, molecular weight approximately 10 million) was continuously added to rapidly flocculate and settle the fine copper tailings particles in the thickener, forming a high-concentration concentrated underflow. The concentrated underflow was then pumped to the tailings dam through a 16 km long pipeline.

[0044] The analysis revealed that component A had a weight-average molecular weight of 96,700, a copper tailings underflow concentration of 65.22%, and a concentrated underflow apparent viscosity of 109.29 mPa·s at 300 rpm.

[0045] Comparative Example 1

[0046] Other conditions were the same as in Example 1, except that the tailings slurry did not enter the pretreatment mixer, and no component A was added for pretreatment. The tailings slurry was directly pumped to the tailings thickener, and a nonionic polyacrylamide flocculant with a mass concentration of 0.025% and a dosage of 45 g / t was continuously added. Its molecular weight was approximately 10 million.

[0047] The copper tailings underflow concentration was found to be 54.04%; the apparent viscosity of the concentrated underflow at 300 rpm was 133.76 mPa·s; compared to Example 1, the tailings transport energy consumption was approximately 22.39% higher.

[0048] Comparative Example 2

[0049] Other conditions are the same as in Example 1, except that: the tailings slurry enters the pretreatment mixer and is continuously fed with a traditional coagulant, cetyltrimethylammonium bromide (CTAB), at a mass concentration of 0.5% and a dosage of 1500 g / t, to regulate the copper tailings interface; then the pretreated slurry is pumped to the tailings thickener and a nonionic polyacrylamide flocculant, at a mass concentration of 0.025% and a dosage of 60 g / t, with a molecular weight of approximately 10 million, is continuously fed.

[0050] The copper tailings underflow concentration was found to be 53.23%; the apparent viscosity of the concentrated underflow at 300 rpm was 135.14 mPa·s; compared to Example 1, the tailings transport energy consumption was approximately 23.65% higher.

[0051] Comparative Example 3

[0052] Other conditions are the same as in Example 1, except that: the tailings slurry enters the pretreatment agitator, and a traditional coagulant, cetyltrimethylammonium bromide (CTAB), with a mass concentration of 1.0% and a dosage of 1800 g / t, is continuously added to regulate the copper tailings interface; then the pretreated slurry is pumped to the tailings thickener, and a nonionic polyacrylamide flocculant with a mass concentration of 0.025% and a dosage of 60 g / t, with a molecular weight of approximately 17 million, is continuously added to cause the copper tailings to flocculate and settle in the thickener, forming a concentrated underflow; then the concentrated underflow is pumped to the slurry mixing tank, and an industrial-grade naphthalene-based water-reducing agent with a mass concentration of 1.0% and a dosage of 2000 g / t is continuously added as a rheology modifier; then the concentrated underflow is pumped to the tailings dam through a 16 km long pipeline.

[0053] The copper tailings underflow concentration was found to be 52.35%; the apparent viscosity of the concentrated underflow at 300 rpm was 126.02 mPa·s; compared to Example 1, the tailings transport energy consumption was approximately 15.31% higher.

[0054] Example 2

[0055] The difference from Example 1 is that in the preparation method of component A in the composite treatment agent, the monomer raw materials are methacrylic acid and methyl allyl alcohol polyoxyethylene ether with a molecular weight of 2400. The other preparation methods are the same, and the application method of the composite treatment agent is the same.

[0056] The analysis revealed that component A had a weight-average molecular weight of 83,600, a copper tailings underflow concentration of 64.39%, and a concentrated underflow apparent viscosity of 111.45 mPa·s at 300 rpm.

[0057] Comparative Example 4

[0058] Other conditions are the same as in Example 1, except that in the preparation method of component A in the composite treatment agent, the monomer raw materials are methacrylic acid and isopentenyl polyethylene glycol ether with a molecular weight of 1800. Other preparation methods are the same, and the method of using the composite treatment agent is the same.

[0059] The analysis showed that component A had a weight-average molecular weight of 65,200; a copper tailings underflow concentration of 61.15%; and a concentrated underflow apparent viscosity of 115.37 mPa·s at 300 rpm. Compared to Example 2, the tailings transport energy consumption was approximately 3.52% higher.

[0060] Example 3

[0061] The difference from Example 1 is that in the preparation method of component A in the composite treatment agent, the monomer raw materials are acrylic acid and methyl allyl alcohol polyoxyethylene ether with a molecular weight of 3200, which are mixed in a molar ratio of 6:1 and added to the reactor. The other preparation methods are the same, and the method of using the composite treatment agent is the same.

[0062] The analysis revealed that component A had a weight-average molecular weight of 92,300, a copper tailings underflow concentration of 64.56%, and a concentrated underflow apparent viscosity of 110.46 mPa·s at 300 rpm.

[0063] Comparative Example 5

[0064] Other conditions are the same as in Example 1, except that in the preparation method of component A in the composite treatment agent, the monomer raw materials are acrylic acid and methyl allyl alcohol polyoxyethylene ether with a molecular weight of 3200, which are mixed in a molar ratio of 4:1 and added to the reactor. Other preparation methods are the same, and the method of using the composite treatment agent is the same.

[0065] The analysis showed that component A had a weight-average molecular weight of 80,700; a copper tailings underflow concentration of 61.58%; and a concentrated underflow apparent viscosity of 115.93 mPa·s at 300 rpm. Compared to Example 3, the tailings transport energy consumption was approximately 4.95% higher.

[0066] Example 4

[0067] The difference from Example 1 is that in the preparation method of component A in the composite treatment agent, ammonium persulfate initiator and chain transfer agent with a mass ratio of mercaptoacetic acid to mercaptopropionic acid of 9:1 are added to the reactor respectively. The addition amounts of the two additives are 1.0% and 0.5% of the total amount of monomer raw materials, respectively. The reactor is heated to 85°C for polymerization reaction for 3 hours to form a high molecular chain polymer. Other preparation methods are the same, and the method of using the composite treatment agent is the same.

[0068] The analysis revealed that component A had a weight-average molecular weight of 73,500, a copper tailings underflow concentration of 63.17%, and a concentrated underflow apparent viscosity of 111.81 mPa·s at 300 rpm.

[0069] Comparative Example 6

[0070] Other conditions are the same as in Example 1, except that: in the preparation method of component A in the composite treatment agent, ammonium persulfate initiator and mercaptoacetic acid chain transfer agent are added to the reactor, and the addition amounts of the two additives are 0.3% and 0.5% of the total amount of monomer raw materials, respectively; the reactor is heated to 85°C for polymerization reaction for 3 hours to form a high molecular chain polymer. Other preparation methods are the same, and the method of using the composite treatment agent is the same.

[0071] The analysis showed that component A had a weight-average molecular weight of 44,600; the copper tailings underflow concentration was 58.19%; and the apparent viscosity of the concentrated underflow at 300 rpm was 119.64 mPa·s. Compared with Example 4, the tailings transport energy consumption was approximately 7.01% higher.

[0072] Example 5

[0073] Settling and transport performance tests were conducted using tailings from a large copper mine in Yunnan Province. The main minerals in the tailings were quartz, feldspar, chlorite, and mica, containing 56.88% SiO2, 13.20% Al2O3, and a slurry concentration of 22.46%.

[0074] The preparation method of component A in the composite treatment agent is as follows: acrylic acid and methyl allyl alcohol polyoxyethylene ether with a molecular weight of 3200 are selected as monomer raw materials, and are added to the reactor in a molar ratio of 7:1; ammonium persulfate initiator and chain transfer agent with a mass ratio of mercaptoacetic acid to mercaptopropionic acid of 9:1 are added to the reactor, and the addition amounts of the two additives are 1.5% and 0.5% of the total amount of monomer raw materials, respectively; the reactor is heated to 90℃ for polymerization reaction for 3.5h to form a high molecular chain polymer; after the reaction is completed, the high molecular chain polymer is neutralized with sodium hydroxide pH adjuster to adjust the pH value to 7.0 to obtain component A solution.

[0075] The application method of the composite treatment agent in tailings settling and transportation is as follows: the tailings slurry first enters an effective volume of 21m³. 3A pretreatment agitator was used, and component A (0.5% by mass, 750 g / t) was continuously added to the pretreatment agitator for interface control of copper tailings. The stirring speed of the tailings slurry in the pretreatment agitator was 300 r / min and the residence time was 20 min. Then, the pretreated slurry was pumped to a tailings thickener, and anionic polyacrylamide flocculant (0.025% by mass, 35 g / t) with a molecular weight of 10 million to 11 million was continuously added to rapidly flocculate and settle the fine copper tailings particles in the thickener, forming a high-concentration concentrated underflow. The concentrated underflow was then pumped to the tailings dam through a 30 km long pipeline.

[0076] The analysis revealed that component A had a weight-average molecular weight of 93,800, a copper tailings underflow concentration of 64.93%, and a concentrated underflow apparent viscosity of 110.48 mPa·s at 300 rpm.

[0077] Comparative Example 7

[0078] Other conditions are the same as in Example 5, except that: the pretreated slurry is pumped to the tailings thickener, and then a cationic polyacrylamide flocculant with a mass concentration of 0.025% and a dosage of 35g / t is continuously added. Its molecular weight is 11 million to 12 million. The other composite treatment agents are used in the same way, and the preparation method of component A is the same.

[0079] The analysis showed that component A had a weight-average molecular weight of 93,800; a copper tailings underflow concentration of 60.61%; and a concentrated underflow apparent viscosity of 112.31 mPa·s at 300 rpm. Compared to Example 5, the tailings transport energy consumption was approximately 1.66% higher.

[0080] Example 6

[0081] Settling and transport performance tests were conducted using tailings from a large copper mine in Tibet. The main minerals in the tailings were quartz, mica, chlorite, and minerals, containing 61.73% SiO2 and 13.87% Al2O3, with a slurry concentration of 21.62%.

[0082] The preparation method of component A in the composite treatment agent is as follows: acrylic acid and methyl allyl alcohol polyoxyethylene ether with a molecular weight of 3200 are selected as monomer raw materials, and are added to the reactor in a molar ratio of 6.5:1; ammonium persulfate initiator and chain transfer agent with a mass ratio of mercaptoacetic acid to mercaptopropionic acid of 9:1 are added to the reactor, and the addition amounts of the two additives are 1.5% and 0.5% of the total amount of monomer raw materials, respectively; the reactor is heated to 90℃ for polymerization reaction for 3 hours to form a high molecular chain polymer; after the reaction is completed, the high molecular chain polymer is neutralized with sodium hydroxide pH adjuster to adjust the pH value to 7.0 to obtain component A solution.

[0083] The application method of the composite treatment agent in tailings settling and transportation is as follows: the tailings slurry first enters an effective volume of 13.5 m³. 3 A pretreatment agitator was used, and component A (0.5% by mass, 800 g / t) was continuously added to the pretreatment agitator for interface control of copper tailings. The stirring speed of the tailings slurry in the pretreatment agitator was 240 r / min and the residence time was 14 min. Then, the pretreated slurry was pumped to a tailings thickener, and an anionic polyacrylamide flocculant (0.025% by mass, 40 g / t) with a molecular weight of 10 million to 11 million was continuously added to rapidly flocculate and settle the fine copper tailings particles in the thickener, forming a high-concentration concentrated underflow. The concentrated underflow was then pumped to the tailings dam through a 7 km long pipeline.

[0084] The analysis revealed that component A had a weight-average molecular weight of 93,100, a copper tailings underflow concentration of 64.62%, and a concentrated underflow apparent viscosity of 109.75 mPa·s at 300 rpm.

[0085] Comparative Example 8

[0086] Other conditions are the same as in Example 6, except that the stirring speed of the tailings slurry in the pretreatment mixer is 180 r / min and the residence time is 8 min. The methods of using other composite treatment agents are the same, and the preparation method of component A is the same.

[0087] The analysis showed that component A had a weight-average molecular weight of 93,100; a copper tailings underflow concentration of 62.33%; and a concentrated underflow apparent viscosity of 111.39 mPa·s at 300 rpm. Compared to Example 6, the tailings transport energy consumption was approximately 1.49% higher.

[0088] In this invention, copper ore tailings slurry is pretreated with component A to increase the tailings settling velocity and the concentration of the concentrated underflow, while simultaneously improving the fluidity of the concentrated underflow to reduce transportation energy consumption. Specifically, improved fluidity is manifested in a reduction of the slurry's apparent viscosity. The transportation energy consumption of the slurry in this invention is evaluated using the following formula.

[0089] The formula for calculating the energy consumption of slurry transportation is as follows:

[0090] E = P × t

[0091] Where: E—energy consumption for transporting the slurry, kWh

[0092] P—Power of the transfer pump, kW

[0093] t — time, h

[0094] The calculation formula for the delivery pump is as follows:

[0095]

[0096] Where: P—power of the delivery pump, kW

[0097] ΔP — Pressure drop provided by the delivery pump, Pa

[0098] Q—Slurry volumetric flow rate, m³ / s

[0099] η P —Transfer pump efficiency

[0100] The pressure drop generated when slurry flows in a pipe is calculated using the following formula (Hagen-Poiseuille equation):

[0101]

[0102] Where: ΔP—pressure drop provided by the delivery pump, Pa

[0103] η—Slurry viscosity, Pa·s

[0104] L—Pipe length, in meters

[0105] v—average flow velocity of the slurry, m / s

[0106] ρ—Slurry density, kg / m³

[0107] d—pipe diameter, m

[0108] The above descriptions are merely preferred embodiments of the present invention and some examples from the technical exploration process of the present invention. However, the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for settling and transporting tailings in a super-large copper mine using a composite treatment agent, characterized in that: Component A of the composite treatment agent is added to the copper mine tailings slurry for stirring and pretreatment. Component B of the composite treatment agent is added to the pretreated copper mine tailings slurry and thickened to achieve rapid flocculation and sedimentation, forming a high-concentration concentrated underflow. The concentrated underflow is transported to the tailings dam through a pipeline. The composite treatment agent comprises component A and component B; The molecular structure of component A is as follows: ； in, x / y = (6.5~7) : 1; n is 52~85; R1 and R2 are independently selected from hydrogen or methyl; Component B is a polyacrylamide; The weight average molecular weight M of component A w =70,000 to 100,000; The dosage of component A in the copper mine tailings slurry is 200~1500 g / t; The dosage of component B in the copper mine tailings slurry is 20~80 g / t; During the stirring pretreatment process, the stirring speed is 200~400 r / min and the time is 10~20 min; The polyacrylamide class includes nonionic polyacrylamide and / or anionic polyacrylamide.

2. The method for settling and transporting tailings in extra-large copper mines using the composite treatment agent according to claim 1, characterized in that: Component A is added in the form of a solution with a mass concentration of 0.01~1.0%; Component B is added in the form of a solution with a mass concentration of 0.005~0.1%.

3. The method for settling and transporting tailings in extra-large copper mines using the composite treatment agent according to claim 1, characterized in that: The number-average molecular weight Mn of component B is 8 million to 12 million.

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