A method for recovering copper from ore slime

Abstract

This invention belongs to the field of copper recovery technology in mineral processing, and discloses a method for recovering copper from ore slime. The method includes the following steps: injecting the ore slime to be treated into a high-efficiency mixing tank, stirring at a speed of 150-200 r / min for at least 30 minutes; simultaneously adding a combination of sulfiding agents and polyaspartic acid dispersant to enhance the dispersion effect between heterogeneous mineral particles and eliminate the influence of gangue slime; finally, adding a copper sulfide collector to recover copper sulfide ore from the slime, yielding a copper concentrate product with a copper grade of not less than 14.18% and a copper recovery rate of not less than 70.03%. This invention has strong process adaptability; the fine-grained copper-bearing ore slime generated during underground operations and grinding can be further recovered, improving the comprehensive utilization rate of copper resources and demonstrating significant economic benefits.

Description

Technical Field

[0001] This invention belongs to the field of copper recovery technology in mineral processing, and particularly relates to a method for recovering copper from mineral slime. Background Technology

[0002] With continuous mining, easily exploitable and rich copper ores are gradually decreasing, while lean, surface, and difficult-to-process ores are increasing. During the development and utilization of copper resources, fine-grained gangue minerals restrict the enrichment of useful minerals, resulting in low copper recovery rates. Therefore, it is imperative to fully utilize copper resources and strengthen the recovery of copper-bearing minerals from fine-grained siliceous gangue minerals.

[0003] Because the copper-bearing minerals in the slime are mainly copper oxide minerals with fine particle size, their recovery is quite difficult. If direct flotation is used, the slime, with its small mass and large specific surface area, is easily mixed in with the froth and floats, reducing the quality of the concentrate. At the same time, other slime can easily cover the surface of the copper-bearing minerals, affecting their flotation. In addition, because the slime has a large specific surface area, it adsorbs a large amount of flotation reagents. As the amount of reagents increases, the slime also increases the viscosity of the pulp, leading to poor aeration conditions. In addition, the increased surface dissolution rate of fine particles increases the number of "inevitable ions" in the pulp, ultimately resulting in a low copper recovery rate from the slime.

[0004] To address the aforementioned issues, scholars both domestically and internationally have conducted extensive research on the comprehensive recovery of copper from tailings or slime in recent years, achieving preliminary results. For example, the patent "A Method for Recycling Low-Grade Oxide Copper Ore from Tailings" effectively recovers and utilizes the low-grade oxide copper ore remaining in the tailings, thus utilizing this portion of oxide copper ore resources and solving the problem of the comprehensive recovery rate of mixed copper ore. Another patent, "A Method for Recovering Gold and Copper from Slime," utilizes controlled process parameters and boasts advantages such as low investment, low cost, high gold and copper recovery rate, ease of industrialization, and environmental friendliness, making it suitable for the industry to recover gold and copper from gold-copper-bearing slime.

[0005] The significance of solving the above problems is as follows: In the beneficiation of copper-sulfur polymetallic minerals, underground mining and grinding processes generate a certain amount of slime with a high copper grade. The copper-bearing slime in this slime is mainly composed of copper oxide ore, which has a fine particle size and is difficult to recover. Adding a combination of sulfiding agents and dispersants, along with high-intensity stirring, can sulfide the fine-grained copper oxide ore, enhancing its dispersion effect with the gangue slime. Adding an appropriate amount of copper collector ultimately yields a qualified copper concentrate product, improving the comprehensive utilization rate of copper resources. Summary of the Invention

[0006] To address the problems existing in the prior art, this invention provides a method for recovering copper from ore slime, which is implemented as follows:

[0007] The technical solution of this invention is: a method for recovering copper from ore slime, the specific steps of which are as follows:

[0008] S1) Slurry preparation operation: The sludge to be treated is injected into a high-efficiency mixing tank and stirred continuously for a certain period of time at a certain stirring rate to obtain a slurry in which the sludge is suspended off the bottom and completely dispersed.

[0009] S2) Addition of reagents: A certain amount of combined sulfiding reagents is added to the slurry obtained in S1) for sulfidation. After stirring for a period of time, a certain amount of dispersant is added. The slurry is then injected into the flotation machine for flotation.

[0010] S3) Flotation operation: The slurry treated in S2) is fed into the flotation cell for copper roughing and copper scavenging flotation operations to obtain a copper roughing mixed concentrate and tailings. The copper roughing mixed concentrate is added with a small amount of inhibitor and copper collector for copper cleaning operation 1, to obtain copper cleaning concentrate 1 and copper cleaning tailings 1. The copper cleaning concentrate 1 is then subjected to copper cleaning operation 2 without the addition of reagents to obtain copper concentrate 2 and copper cleaning tailings 2. The copper cleaning tailings 1 are sequentially returned to the high-efficiency stirred tank, and the copper cleaning tailings 2 are sequentially returned to the copper cleaning operation 1.

[0011] S4) Copper tailings processing operation: Copper scavenging tailings are fed into the subsequent sulfur flotation system to recover sulfur.

[0012] Furthermore, the impeller structure in the stirring tank in S1) is a three-bladed variable cross-section impeller with a stirring speed of 150-200 r / min and a stirring time of more than 30 min.

[0013] Furthermore, in S1), the slurry concentration is 33.33%, with a fluctuation of no more than 5%, and the content of 90-92% of the slurry particles with a fineness of -0.045mm is obtained.

[0014] Furthermore, the combined sulfiding agent in S2) is a mixture of ammonium sulfate and sodium sulfide, with the amount of ammonium sulfate being 400-500 g / t and the amount of sodium sulfide being 600-750 g / t; the dispersant is polyaspartic acid, with the amount being 800-1000 g / t.

[0015] Furthermore, in S3), the copper roughing time is no less than 6 minutes. During copper roughing, a small amount of CaO is added to adjust the pulp pH to 9.5-10.0, and a mixed collector of esters and xanthates (50 g / t + 30 g / t) is added, along with 16 g / t of 2... #Oil; the copper scavenging time is not less than 4 minutes, and 20 g / t + 10 g / t of mixed ester and xanthate collectors are added during copper scavenging; lime is added to adjust the pulp pH to 9.8-10.5 during the first copper cleaning operation, and 10 g / t of ester collector is added; the second copper cleaning operation is a blank cleaning; the flotation time for both the first and second copper cleaning operations is not less than 4 minutes.

[0016] Furthermore, the copper grade recovered in the method is not less than 14.18%, and the copper recovery rate is not less than 70.03%.

[0017] A copper concentrate prepared by the method described above.

[0018] Combining all the above technical solutions, the advantages and positive effects of this invention are as follows:

[0019] Compared to traditional impellers, the three-bladed variable cross-section impeller in the mixing tank features a helical structure and a larger working area, effectively suspending the slurry deposited at the bottom of the tank. This makes it more suitable for solid-liquid suspension applications and provides better dispersion. The three-bladed variable cross-section impeller employs streamlined mixing technology, making it suitable for a wide range of liquid viscosities. At the same impeller-to-tank diameter ratio and flow rate, it saves nearly 50-70% more energy than traditional inclined-blade impellers. Therefore, it is named a high-efficiency mixing tank.

[0020] This invention targets fine-grained copper oxide minerals in mineral slime. It develops a combined sulfiding agent and dispersant, employing a high-efficiency stirring tank for slurry preparation. This process sulfidates the fine-grained copper oxide minerals, enhancing their dispersion with gangue slime. Prolonged stirring combined with the dispersant effectively disperses the aggregated copper oxide slime and removes the fine-grained slime coating the surface of copper-bearing minerals. This enhances the adsorption capacity of the flotation sulfiding agent on the copper oxide mineral surface, achieving a synergistic effect between stirring, slurry preparation, and the combined sulfiding agent. Ultimately, this invention eliminates the adverse effects of fine-grained slime on copper-bearing minerals, improving the overall recovery rate of copper oxide ore. Furthermore, the process is simple, requires minimal investment, and the dispersant, polyaspartic acid, decomposes automatically, causing no impact on the environment or water quality. Attached Figure Description

[0021] Figure 1 This is a process flow diagram of a method for recovering copper from ore slime according to the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0023] To address the problems existing in the prior art, this invention provides a method for recovering copper from ore slime, employing a high-efficiency stirring tank and an innovative combination of sulfiding agents and dispersants. The following is a detailed description... Figure 1 The present invention will be described in detail.

[0024] like Figure 1 As shown, this invention provides a method for recovering copper from ore slime, achieving flotation separation of copper-bearing minerals from fine-grained, easily mud-forming gangue minerals in the ore slime. The flotation separation method includes:

[0025] Step 1, mixing and slurry preparation: The slurry is injected into a high-efficiency mixing tank. The impeller structure inside the tank is a three-bladed variable cross-section impeller. The mixing speed is set to 150-200 r / min, and the mixing time is greater than 30 min. When the slurry is in a suspended and completely dispersed state, the reagent is added to the tank.

[0026] Step 2, reagent addition: After adding ammonium sulfate and sodium sulfide, stir to allow the dispersed fine-grained copper oxide ore to be sulfided. After stirring for a period of time, add polyaspartic acid dispersant to the slurry to disperse the copper sulfide ore and magnesium silicate fine mud with heterogeneous surface charges. After stirring thoroughly, the slurry is injected into the flotation machine for flotation.

[0027] Step 3: Flotation of copper sulfide ore. After being stirred with reagents, the slurry enters the flotation cell for copper roughing and copper scavenging flotation, yielding a mixed copper roughing concentrate and tailings. The mixed copper roughing concentrate is then subjected to a copper cleaning operation with the addition of a small amount of depressant and copper collector, yielding a copper cleaning concentrate and copper cleaning tailings. The copper cleaning concentrate is then subjected to a copper cleaning operation a second time without the addition of reagents, yielding a copper concentrate and copper cleaning tailings. The copper cleaning tailings from the first copper cleaning operation are sequentially returned to the high-efficiency stirred tank, and the copper cleaning tailings from the second copper cleaning operation are sequentially returned to the copper cleaning operation.

[0028] Step four: Copper tailings processing. The copper scavenged tailings are then fed into the subsequent sulfur flotation system to recover sulfur.

[0029] Preferably, in step one, the concentration of sludge in the high-efficiency mixing tank is about 33.33%, with a fluctuation of no more than 5%, the content of sludge particles with a fineness of -0.045mm is 90-92%, the impeller structure in the tank is a three-bladed variable cross-section impeller, the mixing speed is set to 150-200r / min, and the mixing time is greater than 30min.

[0030] Preferably, in step two, the amounts of ammonium sulfate and sodium sulfide are 400-500 g / t and 600-750 g / t, respectively, and the amount of polyaspartic acid is 800-1000 g / t.

[0031] Preferably, in step three, the copper roughing time is 6 minutes. During copper roughing, a small amount of CaO is added to adjust the pulp pH to 9.5-10.0, and a mixed collector of esters and xanthates is added at 50 g / t + 30 g / t, along with 16 g / t of 2... # Oil; the copper scavenging time is 4 min, and 20 g / t + 10 g / t of mixed ester and xanthate collectors are added during copper scavenging; lime is added to adjust the pulp pH to 9.8-10.5 during the first copper cleaning operation, and 10 g / t of ester collector is added; the second copper cleaning operation is a blank cleaning; the flotation times for the first and second copper cleaning operations are 4 min and 4 min, respectively.

[0032] To verify the technical effects of the present invention, the following description, in conjunction with the accompanying drawings, illustrates the technical or experimental effects of the present invention under comparative testing. The specific implementation process of the present invention is shown below. Figure 1 This embodiment conducts an experimental study on the sludge produced in a copper mine in Jiangxi Province. The specific experimental indicators and data are shown in Table 1.

[0033] The experimental results in Table 1 show that when ammonium sulfate and sodium sulfide are used at dosages of 400-500 g / t and 600-750 g / t respectively, and polyaspartic acid is used at dosage of 800-1000 g / t to adjust the slurry, and a combination of lime and copper sulfide ore collector is added, with pine oil as a foaming agent, the slurry preparation is successful. Figure 1 During the process flow test, a copper concentrate with a copper grade of 14.18% and a copper recovery rate of 70.03% can be obtained.

[0034] Table 1. Results of copper recovery tests in ore slime / %

[0035]

[0036] Comprehensive analysis shows that by injecting ore slime into a high-efficiency mixing tank with a three-bladed variable cross-section impeller and stirring for a long time, using ammonium sulfate and sodium sulfide as a combined sulfidation agent for copper-bearing ore slime, and polyaspartic acid as a dispersant for copper minerals and other ore slime, adjusting the pH value of the slurry, and adding a copper collector to recover the sulfidated copper-bearing fine slime, the goal of efficiently recovering copper-bearing minerals from the ore slime can be achieved.

[0037] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for recovering copper from ore slime, characterized in that, The specific steps of the method are as follows: S1) Slurry preparation operation: The sludge to be treated is injected into a high-efficiency mixing tank and stirred continuously for a certain period of time at a certain stirring rate to obtain a slurry in which the sludge is suspended off the bottom and completely dispersed. S2) Addition of reagents: A certain amount of combined sulfiding reagents is added to the slurry obtained in S1) for sulfidation. After stirring for a period of time, a certain amount of dispersant is added. The slurry is then injected into the flotation machine for flotation. The combined sulfiding agent is a mixture of ammonium sulfate and sodium sulfide, with the amount of ammonium sulfate being 400-500 g / t and the amount of sodium sulfide being 600-750 g / t. The dispersant is polyaspartic acid, and the dosage is 800-1000 g / t; S3) Flotation operation: The slurry treated in S2) is fed into the flotation cell for copper roughing and copper scavenging flotation operations to obtain copper roughing mixed concentrate and tailings. The copper roughing mixed concentrate is added with a small amount of inhibitor and copper collector for copper cleaning operation 1 to obtain copper cleaning concentrate 1 and copper cleaning tailings 1. The copper cleaning concentrate 1 is then subjected to copper cleaning operation 2 without the addition of reagents to obtain copper concentrate 2 and copper cleaning tailings 2. The copper cleaning tailings 1 are sequentially returned to the high-efficiency stirred tank, and the copper cleaning tailings 2 are sequentially returned to the copper cleaning operation 1. The copper roughing time shall not be less than 6 minutes. During copper roughing, a small amount of CaO shall be added to adjust the pH of the pulp to 9.5-10.

0. A mixed collector of esters and xanthates shall be added at 50 g / t + 30 g / t, and 16 g / t of 2... # Oil; the copper scavenging time is not less than 4 minutes, and a mixed collector of esters and xanthates of 20 g / t + 10 g / t is added during copper scavenging; during the first copper refining operation, lime is added to adjust the pH of the pulp to 9.8-10.5, and 10 g / t of ester collector is added; the second copper refining operation is a blank refining operation; the flotation time for both the first and second copper refining operations is not less than 4 minutes; S4) Copper tailings processing operation: Copper scavenging tailings are fed into the subsequent sulfur flotation system to recover sulfur.

2. The method according to claim 1, characterized in that, The impeller structure in the mixing tank in S1) is a three-bladed variable cross-section impeller with a mixing speed of 150-200 r / min and a mixing time of more than 30 min.

3. The method according to claim 1, characterized in that, The slurry obtained in S1) has a concentration of 33.33%, with a fluctuation of no more than 5%, and a particle content of 90-92% with a mud fineness of -0.045mm.

4. The method according to claim 1, characterized in that, The copper grade recovered in the method is 14.18%, and the copper recovery rate is 70.03%.

5. A copper concentrate, characterized in that, The copper concentrate is prepared by the method described in any one of claims 1-4.

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