Method for improving flotation separation efficiency of micro-fine particle malachite
By using collectors and inorganic acids to treat the surface roughness and hydrophobicity of malachite during the flotation process of fine-grained malachite, and enhancing bubble adhesion, the problem of low flotation efficiency of fine-grained malachite is solved, and efficient copper recovery and separation are achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-02-05
- Publication Date
- 2026-04-03
AI Technical Summary
In existing microbubble flotation technology, the probability of fine-grained malachite colliding and adhering with flotation bubbles is low, resulting in poor flotation effect and copper recovery rate of less than 60%, making it unsuitable for large-scale production applications.
By mixing malachite powder containing fine particles with water in a certain proportion, adding a collector and inorganic acid to treat it, the surface roughness of malachite is changed and micro-nano bubbles are generated to enhance hydrophobicity. Malachite and quartz are then separated using a flotation machine.
It significantly improved the flotation separation efficiency of fine-grained malachite, with copper recovery rate of copper concentrate reaching 85.14%~86.6%, effectively inhibiting the flotation of quartz and improving the separation effect.
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Abstract
Description
Technical Field
[0001] This invention belongs to the field of copper ore beneficiation technology, specifically relating to a method for improving the flotation separation efficiency of fine-grained malachite. Background Technology
[0002] Malachite is a common copper oxide mineral, and flotation is the primary beneficiation method. Malachite is brittle and easily over-grinds during grinding, producing large quantities of fine-grained malachite with a particle size less than 10µm. Currently, the main flotation method for fine-grained malachite is microbubble flotation, which improves flotation efficiency by reducing the diameter of the flotation bubbles. However, in microbubble flotation, the probability of collision and adhesion between fine-grained malachite and flotation bubbles is low, resulting in poor flotation performance and copper recovery rates below 60%, which is unfavorable for large-scale production applications. Summary of the Invention
[0003] To address the aforementioned technical problems, this invention provides a method for improving the flotation separation efficiency of fine-grained malachite.
[0004] The purpose of this invention is to provide a method for improving the flotation separation efficiency of fine-grained malachite and quartz, comprising the following steps: The first slurry is prepared by mixing mineral powder containing fine-grained malachite with water at a mass ratio of 6:15~40. The particle size of the fine-grained malachite is less than 10µm. Mixing quartz powder, malachite powder, and water at a mass ratio of 5:1:15~40 ensures sufficient contact between the mineral powder and the reagent, thereby improving the separation efficiency.
[0005] The collector is added to the first slurry to make the final concentration of the collector 50 mg / L to 240 mg / L, thus obtaining the second slurry.
[0006] Adding inorganic acids to the second slurry induces the formation of carbon dioxide micro / nanobubbles on the malachite surface and increases its surface roughness. Acid treatment with inorganic acids dissolves the malachite surface, forming microscopic etching pits and protrusions, increasing surface roughness, enhancing reagent adsorption, increasing surface hydrophobicity, and improving the collision and adhesion efficiency of millimeter-sized bubbles. Simultaneously, hydrochloric acid treatment causes the malachite surface to react with the acid to produce CO2. This CO2 forms micro / nanobubbles that synergistically enhance the hydrophobicity of the malachite, improving the efficiency of capturing fine malachite particles.
[0007] Flotation involves collecting the flotation froth, filtering, and drying to obtain copper concentrate. During flotation, the malachite surface becomes hydrophobic under the action of the collector, while the quartz surface in the tailings remains hydrophilic. The flotation machine separates malachite and tailings based on the differences in the hydrophobicity of the mineral surfaces and their collision and adhesion with air bubbles. When air is introduced into the second pulp, the hydrophobic malachite particles easily adhere to the air bubbles and rise to the surface of the second pulp, forming the copper concentrate froth product, while the hydrophilic quartz remains in the second pulp, becoming tailings.
[0008] The quartz powder and malachite powder have a particle size of 800 mesh.
[0009] The collector is obtained by mixing fatty acids, fatty alcohol polyoxyethylene ethers and polyethylene glycol in a mass ratio of 70~82:2~10:8~28.
[0010] The inorganic acid is selected from sulfuric acid, hydrochloric acid, and nitric acid.
[0011] The inorganic acid has a mass concentration of 5% to 25% and is used at a dosage of 0.1 mL to 0.7 mL per liter of slurry.
[0012] Preferably, the grinding process is dry grinding.
[0013] Preferably, the mass ratio of the mineral powder containing fine-grained malachite to water is 1:30.
[0014] Preferably, the final concentration of the collector is 60 mg / L. Preferably, the inorganic acid has a mass concentration of 5% to 25% and is used at a dosage of 0.1 mL to 0.7 mL per liter of slurry.
[0015] Preferably, the inorganic acid has a mass concentration of 10% and is used at a dosage of 0.5 mL per liter of slurry.
[0016] Preferably, the mass ratio of the fatty acid, fatty alcohol polyoxyethylene ether, and polyethylene glycol is 76:8:16.
[0017] Preferably, the fatty acid is selected from one or two of oleic acid, linolenic acid, ricinoleic acid, and tall oil fatty acids.
[0018] Preferably, the fatty alcohol polyoxyethylene ether is selected from any two or three of AEO3, AEO6, and AEO9.
[0019] Preferably, the fatty alcohol polyoxyethylene ether is AEO3 or AEO9.
[0020] Preferably, the fatty alcohol polyoxyethylene ether is obtained by mixing AEO3 and AEO9 in a mass ratio of 1:3.
[0021] Preferably, the polyethylene glycol mixture is obtained by mixing polyethylene glycol with a molecular weight of 400 Da and polyethylene glycol with a molecular weight of 50000 Da in a mass ratio of 2:8.
[0022] Compared with the prior art, the present invention has the following beneficial effects: 1. The method for improving the flotation separation efficiency of fine-grained malachite according to the present invention involves mixing malachite-containing mineral powder and water at a mass ratio of 6:15~40 to obtain a first slurry. In the first slurry, the malachite powder and water are in full contact, thereby improving the separation efficiency. Once the water content falls below 60%, the flotation selectivity deteriorates sharply. If the water content exceeds 90%, the unit throughput decreases, significantly increasing equipment investment and operating time to complete the same production task, thus affecting economic benefits. The surface roughness of malachite is altered by an inorganic acid reaction, generating CO2 bubbles and promoting malachite flotation. Carboxylate ions in the collector combine with copper ions on the malachite surface, enhancing the hydrophobicity of the malachite surface and increasing the adhesion strength between malachite and bubbles. Therefore, under the synergistic effect of water, inorganic acid, and collector, the flotation efficiency of malachite is significantly improved, and the copper recovery rate of copper concentrate reaches 85.14%~86.6%.
[0023] The inorganic acid of this invention induces carbon dioxide micro / nanobubbles on the surface of malachite and increases its surface roughness. Acid treatment with the inorganic acid dissolves the malachite surface, forming microscopic etching pits and protrusions, increasing surface roughness, enhancing the adsorption of the agent on the malachite surface, increasing the hydrophobicity of the malachite surface, and improving the collision and adhesion efficiency of millimeter-sized bubbles. Simultaneously, during hydrochloric acid treatment, the malachite surface reacts with the hydrochloric acid to generate CO2. The generated CO2 forms micro / nanobubbles that synergistically enhance the hydrophobicity of malachite, improving the efficiency of capturing fine malachite particles.
[0024] During flotation, the malachite surface becomes hydrophobic under the action of the collector, while the quartz surface in the tailings remains hydrophilic. The flotation machine separates malachite and tailings based on the differences in the hydrophobicity of the mineral surfaces and their collision and adhesion with air bubbles. When air is introduced into the second pulp, the hydrophobic malachite particles easily adhere to the air bubbles and rise to the surface of the second pulp, forming a copper concentrate froth product, while the hydrophilic quartz remains in the second pulp, becoming tailings.
[0025] The collector described in this invention is obtained by mixing fatty acids, fatty alcohol polyoxyethylene ether, and polyethylene glycol in a mass ratio of 70-82:2-10:8-28. The collector uses fatty acids as the main collector, whose carboxylate ions can form stable, insoluble copper carboxylate salts with copper ions on the malachite surface, thereby chemically adsorbing onto the malachite surface and imparting hydrophobicity. Fatty alcohol polyoxyethylene ether, as a nonionic surfactant, disperses the mineral slurry, disperses the fatty acid collector, and cleans the fine clay coating on the mineral surface, thus exposing a fresh malachite reaction interface. Through synergistic adsorption with fatty acids, it forms a denser mixed adsorption layer, enhancing the hydrophobicity of the malachite surface. Polyethylene glycol, as a hydrophobic enhancer and micro / nano bubble trapping agent, has nonpolar molecules that interact with the adsorbed fatty acid hydrophobic chains through van der Waals forces, jointly constructing a thicker, more robust hydrophobic film, strengthening the capture of micro / nano carbon dioxide bubbles, and improving the adhesion strength between bubbles and mineral particles.
[0026] In summary, the method of the present invention for improving the flotation separation efficiency of fine-grained malachite and quartz achieves a significantly higher adsorption intensity and rate on the surface of malachite than on the surface of quartz under the synergistic effect of inorganic acid and collector. This makes it easier for bubbles to collide with fine-grained malachite, thereby effectively suppressing the flotation of quartz while achieving efficient recovery of malachite, ultimately achieving the separation effect of improving the grade of copper concentrate and reducing its quartz content. Detailed Implementation
[0027] To enable those skilled in the art to better understand and implement the technical solutions of the present invention, the following detailed description, in conjunction with preferred embodiments, provides a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.
[0028] It should be noted that all technical terms used in this invention are for the purpose of describing specific embodiments only and are not intended to limit the scope of protection of this invention. Unless otherwise specified, all raw materials, reagents, instruments and equipment used in the following embodiments of this invention can be purchased from the market or prepared by existing methods.
[0029] The main materials used in this invention are fatty acids, AEO9, AEO3, and polyethylene glycol.
[0030] Among them, AEO9, with a purity of 99% and CAS number 9002-92-0, was purchased from Shandong Yousuo Chemical Technology Co., Ltd. AEO3, with a chemical purity and catalog number S12301115, was also purchased from Shandong Yousuo Chemical Technology Co., Ltd. Polyethylene glycol, with a chemical purity and molecular weight of 400 Da, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd. Polyethylene glycol, with a chemical purity and molecular weight of 50,000 Da, was also purchased from Shanghai Maclean Biochemical Technology Co., Ltd.
[0031] The quartz monomineral used in this invention has a quartz content of 98.36% by mass. The malachite monomineral used has a malachite content of 96.71% by mass.
[0032] Fine-grained malachite mineral powder: Because fine-grained malachite mineral powder often contains a large amount of quartz mineral powder during actual production, fine-grained malachite mineral powder and quartz mineral powder are mixed at a mass ratio of 5:1 to simulate the actual conditions of fine-grained malachite mineral powder.
[0033] Example 1 A method for improving the flotation separation efficiency of fine-grained malachite includes the following steps: Quartz and malachite were dry-milled separately and passed through an 800-mesh sieve to obtain quartz powder with a particle size of less than 10µm and fine-grained malachite. The quartz powder, fine-grained malachite, and water were mixed at a mass ratio of 5:1:30 and stirred at 1500 rpm to obtain the first slurry. A collector was added to the first slurry to a final concentration of 60 mg / L, and the mixture was stirred for 2 minutes to obtain the second slurry.
[0034] The collector is a mixture of fatty acids, fatty alcohol polyoxyethylene ether, and polyethylene glycol in a mass ratio of 76:8:16, followed by the addition of water equivalent to eight times the total mass of the fatty acids, fatty alcohol polyoxyethylene ether, and polyethylene glycol. The mixture is stirred at 1000 rpm for 12 minutes at 60°C. The fatty alcohol polyoxyethylene ether is obtained by mixing AEO9 and AEO3 in a mass ratio of 3:1. The fatty acids are obtained by mixing oleic acid and linolenic acid in a mass ratio of 2:1. The polyethylene glycol is obtained by mixing polyethylene glycol with a molecular weight of 400 Da and polyethylene glycol with a molecular weight of 50000 Da in a mass ratio of 2:8.
[0035] Acid treatment was performed by adding 0.5 mL of 10% hydrochloric acid to each liter of the second slurry, followed by aeration flotation. The foam was collected, filtered, and dried to obtain copper concentrate. The slag in the collection tank was collected, filtered, and dried to obtain tailings. The yield, copper grade, and copper recovery rate of the copper concentrate are shown in Table 1. The copper concentrate grade was 48.39%, and the recovery rate was 86.60%.
[0036] Table 1. Copper recovery rate in Example 1 Example 2 A method for improving the flotation separation efficiency of fine-grained malachite includes the following steps: Quartz and malachite were separately dry-milled and passed through an 800-mesh sieve to obtain quartz powder with a particle size of less than 10µm and fine-grained malachite. Quartz powder, fine-grained malachite powder, and water were mixed at a mass ratio of 5:1:15 and stirred at 1500 rpm to obtain the first slurry. A collector was added to the first slurry to a final concentration of 50 mg / L, and the mixture was stirred for 2 minutes to obtain the second slurry.
[0037] The collector is a mixture of fatty acids, fatty alcohol polyoxyethylene ether, and polyethylene glycol in a ratio of 82:10:8, followed by the addition of water equivalent to eight times the total mass of the fatty acids, fatty alcohol polyoxyethylene ether, and polyethylene glycol. The mixture is stirred at 500 rpm for 5 minutes at 40°C. The fatty alcohol polyoxyethylene ether is obtained by mixing AEO9 and AEO6 in a mass ratio of 5:5. The fatty acids are obtained by mixing oleic acid and linolenic acid in a mass ratio of 2:1. The polyethylene glycol is obtained by mixing polyethylene glycol with a molecular weight of 400 and polyethylene glycol with a molecular weight of 50,000 in a mass ratio of 2:8.
[0038] 0.1 mL of 5% hydrochloric acid was added to each liter of the second slurry for acid treatment, followed by aeration flotation. The foam was collected, filtered, and dried to obtain copper concentrate. The slag in the collection tank was collected, filtered, and dried to obtain tailings. The yield, copper grade, and copper recovery rate of the copper concentrate are shown in Table 2.
[0039] Table 2. Test results of Example 2 Example 3 A method for improving the flotation separation efficiency of fine-grained malachite includes the following steps: Quartz and malachite were dry-milled separately and passed through an 800-mesh sieve to obtain quartz powder with a particle size of less than 10µm and fine-grained malachite. Quartz powder, fine-grained malachite powder, and water were mixed at a mass ratio of 5:1:40 and stirred at 1500 rpm to obtain the first slurry. A collector was added to the first slurry to a final concentration of 240 mg / L, and the mixture was stirred for 2 minutes to obtain the second slurry.
[0040] The collector is a mixture of fatty acids, fatty alcohol polyoxyethylene ether, and polyethylene glycol in a ratio of 70:2:28, followed by the addition of water equivalent to eight times the total mass of the fatty acids, fatty alcohol polyoxyethylene ether, and polyethylene glycol. The mixture is stirred at 1500 rpm for 20 minutes at 80°C. The fatty alcohol polyoxyethylene ether is obtained by mixing AEO9 and AEO3 in a mass ratio of 3:1. The fatty acids are obtained by mixing oleic acid and linolenic acid in a mass ratio of 2:1. The polyethylene glycol is obtained by mixing polyethylene glycol with a molecular weight of 400 and polyethylene glycol with a molecular weight of 50,000 in a mass ratio of 2:8.
[0041] 0.7 mL of 25% hydrochloric acid was added to each liter of the second slurry for acid treatment, followed by aeration flotation. The foam was collected, filtered, and dried to obtain copper concentrate. The slag in the collection tank was collected, filtered, and dried to obtain tailings. The yield, copper grade, and copper recovery rate of the copper concentrate are shown in Table 3.
[0042] Table 3 shows the experimental results of Example 3. Comparative Example 1 A method for improving the flotation separation efficiency of fine-grained malachite includes the following steps: The inorganic acid in Example 1 was omitted, while other conditions remained the same as in Example 1, resulting in refined copper ore and tailings. The yield, copper grade, and copper recovery rate of the refined copper ore are shown in Table 5.
[0043] Compared to Example 1, Comparative Example 1 showed a 5.82% lower copper grade and a 31.98% lower copper recovery rate. This is because no inorganic acid treatment was used during the slurry preparation process. Consequently, the malachite surface lacked micro / nano bubbles, resulting in lower hydrophobicity and a reduced copper recovery rate. The decreased hydrophilicity / hydrophobicity difference between the malachite and quartz surfaces also reduced selectivity, leading to a lower concentrate copper grade. Furthermore, the absence of micro / nano bubbles on the malachite surface after inorganic acid treatment lowered the probability of adhesion after collisions with bubbles, further reducing the malachite particle flotation rate.
[0044] Table 4 shows the experimental results of Comparative Example 1. Comparative Example 2 A method for improving the flotation separation efficiency of fine-grained malachite includes the following steps: The polyethylene glycol in Example 1 was omitted, while other conditions remained the same as in Example 1, resulting in refined copper ore and tailings. The yield, copper grade, and copper recovery rate of the refined copper ore are shown in Table 5.
[0045] Compared to Example 1, Comparative Example 2 showed a 4.50% lower copper grade and a 15.09% lower copper recovery rate. Polyethylene glycol (PEG) in the collector enabled the malachite surface to capture more micro / nano bubbles during acid treatment, promoting the hydrophobic flotation of malachite. Simultaneously, PEG had a certain agglomeration effect on fine malachite particles, promoting collision and adhesion between malachite and bubbles. Therefore, without PEG in the collector component, both the concentrate copper recovery rate and copper grade decreased.
[0046] Table 5 shows the experimental results of Comparative Example 2. Comparative Example 3 A method for improving the flotation separation efficiency of fine-grained malachite includes the following steps: The fatty alcohol polyoxyethylene ether in Example 1 was omitted, while other conditions remained the same as in Example 1, resulting in refined copper ore and tailings. The yield, copper grade, and copper recovery rate of the refined copper ore are shown in Table 6.
[0047] Compared to Example 1, Comparative Example 3 showed a 3.47% lower copper grade and a 15.81% lower copper recovery rate. The fatty alcohol polyoxyethylene ether in the collector generates more microbubbles during flotation. These microbubbles, compared to ordinary millimeter-sized bubbles, are more likely to collide and adhere to fine malachite particles, resulting in a higher malachite float rate. Simultaneously, the fatty alcohol polyoxyethylene ether promotes the adsorption of fatty acids on the malachite surface, making the malachite surface more hydrophobic and widening the hydrophilicity-hydrophobicity difference between malachite and quartz surfaces, thus enhancing flotation selectivity. Therefore, without polyethylene glycol in the collector composition, both the concentrate copper recovery rate and copper grade are reduced.
[0048] Table 6 shows the separation results of Comparative Example 3. In summary, the polyethylene glycol and fatty alcohol polyoxyethylene ether in the inorganic acid and collector of this invention significantly affect copper grade and recovery rate.
[0049] It should be noted that when numerical ranges are involved in this invention, it should be understood that both endpoints of each numerical range and any value between the two endpoints can be selected. Since the steps and methods used are the same as in the embodiments, preferred embodiments are described in this invention to avoid redundancy. Although preferred embodiments of this invention have been described, those skilled in the art, once they understand the inventive concept of this invention, can make other changes and modifications to these embodiments, and all such changes and modifications fall within the scope of this invention.
[0050] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. If such modifications and variations fall within the scope of equivalents of this invention, then this invention also intends to include these modifications and variations.
Claims
1. A method for improving the flotation separation efficiency of fine-grained malachite, characterized in that, Includes the following steps: The first slurry was prepared by mixing mineral powder containing fine-grained malachite with water at a mass ratio of 6:15~40; the particle size of the fine-grained malachite was less than 10µm. The collector is added to the first slurry to make the final concentration of the collector 50 mg / L~240 mg / L, thus obtaining the second slurry; Inorganic acid is added to the second slurry to generate carbon dioxide micro-nano bubbles on the surface of malachite and increase the surface roughness of malachite. Flotation involves collecting flotation foam, filtering, and drying to obtain copper concentrate, thus completing the flotation separation of fine-grained malachite. The collector is obtained by mixing fatty acids, fatty alcohol polyoxyethylene ethers and polyethylene glycol in a mass ratio of 70~82:2~10:8~28. The inorganic acid is selected from any one of sulfuric acid, hydrochloric acid, and nitric acid; The inorganic acid has a mass concentration of 5% to 25% and is used at a dosage of 0.1 mL to 0.7 mL per liter of slurry.
2. The method for improving the flotation separation efficiency of fine-grained malachite and quartz according to claim 1, characterized in that, The mass ratio of the mineral powder containing fine-grained malachite to water is 1:
30.
3. The method for improving the flotation separation efficiency of fine-grained malachite according to claim 1, characterized in that, The final concentration of the collector is 60 mg / L.
4. The method for improving the flotation separation efficiency of fine-grained malachite according to claim 1, characterized in that, The inorganic acid has a mass concentration of 10% and is used at a dosage of 0.5 mL per liter of slurry.
5. The method for improving the flotation separation efficiency of fine-grained malachite according to claim 1, characterized in that, The mass ratio of the fatty acid, fatty alcohol polyoxyethylene ether, and polyethylene glycol is 76:8:
16.
6. The method for improving the flotation separation efficiency of fine-grained malachite according to claim 1, characterized in that, The fatty acid is selected from one or two of oleic acid, linolenic acid, ricinoleic acid, and tall oil fatty acids.
7. The method for improving the flotation separation efficiency of fine-grained malachite according to claim 1, characterized in that, The fatty alcohol polyoxyethylene ether is selected from any two or three of AEO3, AEO6, and AEO9.
8. The method for improving the flotation separation efficiency of fine-grained malachite according to claim 7, characterized in that, The fatty alcohol polyoxyethylene ether is obtained by mixing AEO3 and AEO9 in a mass ratio of 1:3.