Anionic polyacrylamide for accelerating particle sedimentation of copper ore pulp and preparation method of anionic polyacrylamide

Abstract

The invention discloses anionic polyacrylamide for accelerating particle sedimentation of copper ore pulp. The anionic polyacrylamide is prepared from the following components in parts by weight: 110 to 120 parts of acrylamide, 15 to 20 parts of acrylic acid, 5 to 6 parts of urea, 0.001 to 0.005 part of sodium formate, 0.001 to 0.003 part of EDTA-2Na (Ethylene Diamine Tetraacetic Acid), 0.01 to 0.03 part of ammonium persulfate, 0.01 to 0.025 part of sodium hydrogen sulfite and 360 to 370 parts of deionized water. The invention also provides a preparation method of the anionic polyacrylamide. The anionic polyacrylamide disclosed by the invention can accurately adapt to the characteristics of the copper ore pulp, efficiently accelerate particle sedimentation of the copper ore pulp, and can form a stable and compact flocculating agent.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of copper ore dressing, and particularly relates to an anionic polyacrylamide for accelerating the sedimentation of copper ore slurry particles and a preparation method thereof. BACKGROUND

[0002] In the copper ore dressing process, efficient treatment of the slurry is a core link for realizing metal recovery, and the sedimentation separation efficiency directly determines the production capacity and economic benefits of ore dressing. The slurry is a complex suspension system formed by mixing the crushed and finely ground raw ore with water, which contains not only fine mineral particles of valuable metals but also a large amount of gangue minerals. Due to the differences in particle size, density and surface physical and chemical properties, these particles exhibit different behaviors in the sedimentation process. The traditional natural sedimentation method completely relies on the gravity of the particles to realize solid-liquid separation, which not only takes a very long time, usually several hours or even longer, but also is almost ineffective for fine and ultrafine particles, resulting in a large amount of useful minerals lost in the tailings. At the same time, the sedimentation tank occupies a large area and has a low utilization rate of backwater, which seriously restricts the processing capacity of the concentrator. Especially with the continuous decline of global copper ore grade, the amount of ore to be processed increases and the mineral dissemination size becomes finer, further exacerbating the sedimentation bottleneck.

[0003] Therefore, the industry generally introduces flocculants to promote particle aggregation through bridging to accelerate the sedimentation speed. However, the limitations of conventional flocculants in complex slurry are increasingly prominent. The conventional polyacrylamide flocculants are not suitable for copper ore slurry, mainly because of their poor selectivity in interacting with the surfaces of various minerals. Copper particles often have hydrophobicity or specific electrical properties, while the surfaces of gangue such as carbonate minerals or silicate minerals are quite different. Conventional flocculants are difficult to adapt to all particles simultaneously, resulting in low adsorption efficiency. For example, when facing some copper particles with special surface properties, conventional flocculants are difficult to produce strong adsorption with them, resulting in poor flocculation effect. In addition, the flocs formed by these flocculants are mostly loose and fluffy, with low mechanical strength, which are easily broken by shear force in subsequent thickening, filtration or dewatering processes, causing the re-dispersion of the aggregated particles, reducing the sedimentation speed, and leading to uneven concentration of the thickening underflow, prolonged filtration period. More seriously, the floc breakage releases the wrapped fine copper minerals, which are lost with the overflow, directly reducing the grade and recovery rate of copper concentrate. At the same time, the filter cake has a high water content after dewatering, increasing the smelting energy consumption and cost, and the residual flocculants may interfere with the action of subsequent flotation or leaching reagents, forming a vicious cycle.

[0004] Therefore, there is an urgent need for a flocculant that can precisely adapt to the characteristics of copper ore slurry, efficiently accelerate particle sedimentation, and form stable and compact flocs. SUMMARY

[0005] The application aims to provide an anionic polyacrylamide for accelerating the sedimentation of copper ore slurry particles and a preparation method thereof.

[0006] To achieve the above-mentioned object, the present application provides the following technical solutions. The anionic polyacrylamide for accelerating the settlement of copper ore slurry particles comprises the following components in parts by weight: acrylamide 110-120 parts, acrylic acid 15-20 parts, urea 5-6 parts, sodium formate 0.001-0.005 parts, EDTA-2Na 0.001-0.003 parts, ammonium persulfate 0.01-0.03 parts, sodium bisulfite 0.01-0.025 parts, and deionized water 360-370 parts.

[0007] Preferably, the anionic polyacrylamide comprises the following components in parts by weight: acrylamide 110 parts, acrylic acid 20 parts, urea 5.5 parts, sodium formate 0.001 parts, EDTA-2Na 0.001 parts, ammonium persulfate 0.01 parts, sodium bisulfite 0.01 parts, and deionized water 360 parts.

[0008] Preferably, the anionic polyacrylamide comprises the following components in parts by weight: acrylamide 115 parts, acrylic acid 15 parts, urea 5 parts, sodium formate 0.0025 parts, EDTA-2Na 0.002 parts, ammonium persulfate 0.03 parts, sodium bisulfite 0.025 parts, and deionized water 364 parts.

[0009] Preferably, the anionic polyacrylamide comprises the following components in parts by weight: acrylamide 120 parts, acrylic acid 18 parts, urea 6 parts, sodium formate 0.005 parts, EDTA-2Na 0.003 parts, ammonium persulfate 0.02 parts, sodium bisulfite 0.02 parts, and deionized water 370 parts.

[0010] Preferably, the molecular weight of the anionic polyacrylamide is 19-21 million.

[0011] Preferably, the hydrolysis degree of the anionic polyacrylamide is 23-26%.

[0012] The present application also provides a preparation method of the anionic polyacrylamide, comprising the following steps: S1, dissolving acrylamide, acrylic acid, urea, sodium formate, and EDTA-2Na in deionized water and stirring uniformly; S2, introducing nitrogen into the monomer solution to remove oxygen in the system; then adding ammonium persulfate and sodium bisulfite into the monomer solution to initiate polymerization, and reacting at 25-35℃ for 5-8 hours to form a colloid; S3, granulating, drying, crushing, and screening the colloid to obtain the polyacrylamide.

[0013] Preferably, the time for the nitrogen gas to be introduced in step S2 is 30-60 minutes, more preferably 30 minutes.

[0014] The polyacrylamide of the present application is a high-efficiency high-molecular flocculant, which has a significantly high molecular weight and a unique long molecular chain structure. The molecular weight is usually controlled between 15 million and 24 million, which enables the molecular chain to fully stretch in water to form a linear structure with a wide spatial range. A large number of polar functional groups are densely distributed on the molecular chain, which can be strongly and selectively adsorbed to the surface of copper minerals and gangue particles in the copper ore slurry through electrostatic attraction, hydrogen bonding or van der Waals force and other mechanisms. One molecular chain can simultaneously adsorb multiple particles to form a bridge link between the particles, thereby forming a macro-sized and more compact and stable flocculation. Such large and compact flocculation not only significantly accelerates the settling speed, but also has higher mechanical strength and is less likely to break during subsequent concentration, transportation and dehydration processes, thereby effectively reducing the loss of fine metal particles and laying a solid foundation for improving the recovery rate of copper concentrate and the concentration of bottom stream.

[0015] In addition, the polyacrylamide of the present application also exhibits good adaptability to the copper ore dressing process environment, especially in dealing with the fluctuation of the pH value of the slurry. In the whole process of copper ore dressing, the pH value of the slurry may fluctuate within a certain range due to the requirements of different process links such as flotation and leaching, for example, from weak acidity to weak alkalinity. Satisfactorily, the product can maintain excellent flocculation and sedimentation performance within a wide pH range (5-10). This is mainly due to the stability of the molecular structure in design, which enables the active functional groups to maintain high adsorption activity under different acid-base conditions. Whether in weak acidic conditions (close to pH 5) or in weak alkaline conditions (close to pH 10), it can effectively play the role of electric neutralization and adsorption bridging, avoiding the problem of sharp decline of the effect of conventional flocculants outside a certain pH range. This wide pH adaptability greatly reduces the harsh requirements for accurate control of the slurry environment, enhances the flexibility of process operation, ensures the stability and reliability of the sedimentation effect under different dressing conditions, and provides a strong guarantee for the continuous, stable and efficient production of the dressing plant. DETAILED DESCRIPTION

[0016] In order to facilitate the understanding of the present application, the present application will be described more fully below with reference to specific embodiments. However, the present application can be realized in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0017] In the description of the present application, unless otherwise explicitly defined, the words heating, cleaning, weighing, freezing, etc. should be understood in a broad sense, and those skilled in the art can reasonably determine the specific meaning of the above words in the present application in combination with the specific content of the technical solution.

[0018] In the description of the present application, the description referring to the terms "some embodiments", "examples", etc. means that the specific methods, materials described in combination with the embodiments or examples are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific methods, materials described can be combined in any one or more embodiments or examples in a suitable manner.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0020] In the following examples and comparative examples, the experimental methods used are conventional methods unless otherwise specified, and the materials, reagents, etc. used are commercially available unless otherwise specified.

[0021] Example 1 110 g of acrylamide, 20 g of acrylic acid, 5.5 g of urea, 0.001 g of sodium formate, and 0.001 g of EDTA-2Na were dissolved in 360 g of deionized water and stirred uniformly. Nitrogen was introduced into the monomer solution for 30 minutes to remove oxygen in the system. Then, 0.01 g of ammonium persulfate and 0.01 g of sodium bisulfite were added to the monomer solution to initiate the polymerization reaction, and the reaction was carried out at 25°C for 8 hours to form a colloid.

[0022] The colloid was granulated, dried, crushed, and sieved to obtain a polyacrylamide product.

[0023] The polyacrylamide had a molecular weight of 19 million and a degree of hydrolysis of 23%.

[0024] Example 2 115 g of acrylamide, 15 g of acrylic acid, 5 g of urea, 0.0025 g of sodium formate, and 0.002 g of EDTA-2Na were dissolved in 364 g of deionized water and stirred uniformly.

[0025] Nitrogen was introduced into the monomer solution for 30 minutes to remove oxygen in the system. Then, 0.03 g of ammonium persulfate and 0.025 g of sodium bisulfite were added to the monomer solution to initiate the polymerization reaction, and the reaction was carried out at 30°C for 6 hours to form a colloid.

[0026] The colloid is granulated, dried, crushed, and sieved to obtain a polyacrylamide product.

[0027] The polyacrylamide has a molecular weight of 21 million and a degree of hydrolysis of 25%.

[0028] Example 3 120 g of acrylamide, 18 g of acrylic acid, 6 g of urea, 0.005 g of sodium formate, and 0.003 g of EDTA-2Na were dissolved in 370 g of deionized water and stirred uniformly.

[0029] Nitrogen was introduced into the monomer solution for 60 minutes to remove oxygen in the system. Then, 0.02 g of ammonium persulfate and 0.02 g of sodium bisulfite were added to the monomer solution to initiate the polymerization reaction, and the reaction was carried out at 35°C for 5 hours to form a colloid.

[0030] The colloid was granulated, dried, crushed, and sieved to obtain a polyacrylamide product.

[0031] The polyacrylamide has a molecular weight of 21 million and a degree of hydrolysis of 25%.

[0032] Performance test Standard sedimentation column experiment: 500 mL of uniform copper ore slurry was taken in a 1000 mL graduated cylinder, 0.1% (mass concentration) PAM solution was added, the mixing conditions of the feedwell of an industrial thickener were simulated, high-intensity mixing was performed using a stirrer for 20 seconds, then the slurry was allowed to settle, and the height of the clear liquid layer (graduated cylinder scale) was recorded.

[0033] The experimental results are shown in Table 1 below.

[0034] Table 1. Height of clear liquid layer after sedimentation

[0035] As can be seen from the results in Table 1, compared with commercially available ordinary PAM, the polyacrylamide of Examples 1-3 of the present application can effectively accelerate the sedimentation of copper ore slurry particles.

[0036] The above only describes the preferred embodiments of the present application and does not limit the present application in any form. Any simple modification, equivalent change, and modification made to the above embodiments in accordance with the technical essence of the present application, without departing from the technical solutions of the present application, are still within the scope of the technical solutions of the present application.

Claims

1. An anionic polyacrylamide for accelerating the settling of copper ore slurry particles, characterized in that, The product comprises the following components by weight: 110-120 parts acrylamide, 15-20 parts acrylic acid, 5-6 parts urea, 0.001-0.005 parts sodium formate, 0.001-0.003 parts EDTA-2Na, 0.01-0.03 parts ammonium persulfate, 0.01-0.025 parts sodium bisulfite, and 360-370 parts deionized water.

2. The anionic polyacrylamide according to claim 1, characterized in that, The anionic polyacrylamide comprises the following components by weight: 110 parts acrylamide, 20 parts acrylic acid, 5.5 parts urea, 0.001 parts sodium formate, 0.001 parts EDTA-2Na, 0.01 parts ammonium persulfate, 0.01 parts sodium bisulfite, and 360 parts deionized water.

3. The anionic polyacrylamide according to claim 1, characterized in that, The anionic polyacrylamide comprises the following components by weight: 115 parts acrylamide, 15 parts acrylic acid, 5 parts urea, 0.0025 parts sodium formate, 0.002 parts EDTA-2Na, 0.03 parts ammonium persulfate, 0.025 parts sodium bisulfite, and 364 parts deionized water.

4. The anionic polyacrylamide according to claim 1, characterized in that, The anionic polyacrylamide comprises the following components by weight: 120 parts acrylamide, 18 parts acrylic acid, 6 parts urea, 0.005 parts sodium formate, 0.003 parts EDTA-2Na, 0.02 parts ammonium persulfate, 0.02 parts sodium bisulfite, and 370 parts deionized water.

5. The anionic polyacrylamide according to any one of claims 1 to 4, characterized in that, The anionic polyacrylamide has a molecular weight of 19-21 million.

6. The anionic polyacrylamide according to any one of claims 1 to 4, characterized in that, The degree of hydrolysis of the anionic polyacrylamide is 23-26%.

7. A method for preparing anionic polyacrylamide as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Dissolve acrylamide, acrylic acid, urea, sodium formate, and EDTA-2Na in deionized water and stir until homogeneous; S2. Nitrogen gas is introduced into the monomer solution to remove oxygen from the system; then ammonium persulfate and sodium bisulfite are added to the monomer solution to initiate the polymerization reaction. The reaction is carried out at 25-35℃ for 5-8 hours to form a colloid. S3. Granulate, dry, pulverize and sieve the colloid to obtain the polyacrylamide.

8. The method according to claim 7, characterized in that, In step S2, nitrogen gas is introduced for 30-60 minutes.

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