A method for strengthening the activation flotation of sphalerite and sphalerite copper

Abstract

The present invention discloses a method for enhanced copper activation flotation of sphalerite and sphalerite. The method comprises the following steps: 1) grinding; 2) slurry preparation; 3) activation; and 4) flotation. By introducing air or oxygen into the ore slurry to place it in an oxidizing atmosphere, the slurry potential is regulated, maintaining the slurry potential within a range of 0 to 150 mV throughout the entire copper sulfate activation zinc flotation process. This effectively improves the activation performance of copper sulfate, a conventional zinc activator, and allows zinc flotation to be performed under these conditions. This method addresses the problems of poor activation selectivity and difficult reagent dosage control associated with conventional copper sulfate activators. It also avoids the increased reagent costs and increased difficulty in treating mineral processing wastewater associated with existing combination activators, resulting in energy conservation, environmental protection, and pollution-free operation. The present invention is effectively applicable to the separation and treatment of high-sulfur zinc sulfide ores, particularly those containing pyrrhotite.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing and flotation, and in particular relates to a method for strengthening the activation flotation of sphalerite and sphalerite copper. Background Art

[0002] When sphalerite and ferroalloy are associated with iron-containing sulfide minerals such as pyrite and pyrrhotite, the industry primarily utilizes a zinc-sulfur sequential preferential flotation process to separate ferroalloy from these sulfide minerals. Lime is primarily used as a depressant to suppress the flotation of these sulfide minerals; copper sulfate is then used as an activator to activate the flotation of sphalerite and ferroalloy. Subsequently, froth flotation is performed to separate sphalerite and ferroalloy from pyrite and pyrrhotite using a xanthate collector. However, during the zinc-sulfur separation flotation process, copper sulfate, while activating sphalerite and ferroalloy, also activates the pyrite and pyrrhotite iron-containing sulfide minerals that are suppressed by lime, resulting in excessive iron and sulfur content in the resulting zinc concentrate or concentrate. Consequently, the current use of copper sulfate as an activator often presents challenges such as activation selectivity and difficulty controlling the dosage of the activator.

[0003] Currently, the use of combined activators to replace copper sulfate as activators for sphalerite and marmatite is a new trend in zinc-sulfur separation flotation. This facilitates the synergistic effect of flotation reagents, combines the advantages of various reagents, and better adapts to the complexity of the ore to be floated. Patent CN113477405A discloses a combined activator for sphalerite and marmatite. This activator is an amino acid or a mixture containing amino acids, which solves the problem of poor selectivity of conventional activators for sphalerite and marmatite. Patent CN108940604A discloses a flotation activator for marmatite. This activator is composed of copper sulfate, lead nitrate, sodium sulfide, oxidized paraffin soap, and lauric acid. It has the advantages of good stability and strong selectivity, and solves technical problems such as the low selectivity of marmatite flotation activators, high sulfur content in zinc concentrate or zinc concentrate, and low zinc recovery. However, although the combined activator has greater advantages in activation performance than conventional copper sulfate, the objective problems it brings, such as increased reagent costs and increased difficulty in mineral processing wastewater treatment, cannot be ignored. Summary of the Invention

[0004] The present invention aims to provide a method for enhancing the copper-activated flotation of sphalerite and marmatite, addressing the problems of poor activation selectivity and difficult dosage control of conventional zinc activators using copper sulfate, as well as the high reagent costs and difficulty in treating mineral processing wastewater associated with existing combination activators. The present invention enhances the flotation of sphalerite and marmatite by regulating the pulp potential during the copper sulfate activation process through the introduction of an oxidizing gas such as air or oxygen. The method is effectively applicable to the separation of high-sulfur zinc sulfide ores, particularly those containing pyrrhotite.

[0005] The method for enhancing the copper activation flotation of sphalerite and sphalerite provided by the present invention comprises the following steps:

[0006] 1) Grinding: After the raw ore is crushed, wet ball milling is performed to obtain ore pulp;

[0007] 2) Slurry adjustment: adding a pH adjuster to the slurry obtained in step 1) to adjust the pH of the slurry to an appropriate range;

[0008] 3) Activation: Add oxidizing gas to the slurry obtained in step 2), then add zinc activator, and keep aeration continuously throughout the activation process, and adjust the slurry potential to an appropriate range;

[0009] 4) Flotation: Add zinc collector and frother to the slurry obtained in step 3) and perform aeration flotation to obtain zinc coarse concentrate.

[0010] Preferably, in step 1), the grinding fineness is -0.074 mm, accounting for 50% to 65%, and the specific particle size is determined by the specific properties of the ore.

[0011] Preferably, in step 2), the pH adjuster is lime, the amount of lime used is 5000-7000 g / t, and the pH of the slurry is adjusted to 12-13.

[0012] Preferably, in step 3), the oxidizing gas is air or oxygen, and the aeration rate is 6 to 12 L / min, so that the dissolved oxygen content in the slurry is maintained at 3 to 6 mg / L.

[0013] Preferably, the zinc activator in step 3) is copper sulfate, and the dosage is 1000-1500 g / t.

[0014] Preferably, in step 3), the pulp potential is maintained at 0-150 mV, and the pulp potential value is compared with that of a hydrogen standard electrode.

[0015] Preferably, the flotation in step 4) adopts a one-roughing and two-sweeping process, the zinc collector is butyl xanthate, and the foaming agent is terpineol.

[0016] As a preferred embodiment, a crude reagent system is: zinc collector butyrate xanthate 50-80 g / t, foaming agent terpineol 20-30 g / t.

[0017] As a preferred embodiment, the reagent system for the first sweep is: zinc collector butyrrolidone 25-40g / t, foaming agent terpineol 8-15g / t.

[0018] As a preferred embodiment, the reagent system for the second sweep is: zinc collector butanol 10-20g / t, without adding foaming agent terpineol.

[0019] The mechanism of action of the present invention:

[0020] In the process of using copper sulfate to activate zinc flotation, iron sulfides such as pyrite and pyrrhotite associated with sphalerite and sphalerite will also be activated, that is, sphalerite / sphalerite and pyrite / pyrrhotite have "competitive adsorption" for copper ions. On the one hand, this has an adverse effect on the process of copper sulfate activation of zinc flotation. On the other hand, during the zinc flotation process, iron sulfide minerals will also be flotated and recovered along with zinc, resulting in low zinc grade and zinc recovery rate in zinc rough concentrate, and serious zinc-sulfur cross-contamination. In an alkaline system adjusted by lime (pH>12), the activation mechanism of copper sulfate on pyrite and sphalerite and the electrode potential of the reaction are shown in formulas (1-1) and (1-2):

[0021] FeS2+Cu(OH)2+2e→CuFeS2+2OH - E=-49.8mV (1-1)

[0022] ZnS+2Cu(OH)2+2e→Zn(OH)2+Cu2S+2OH - E=180mV (1-2)

[0023] It can be seen from this that when the pulp potential is below -50mV, the copper activation process of sphalerite and pyrite can proceed, and both are activated at this time, and the activation selectivity of copper sulfate is poor; when the pulp potential is higher than -50mV and lower than 180mV, the copper activation process of sphalerite can still proceed effectively, while the copper activation process of pyrite begins to be inhibited; if the potential is further increased to above 180mV, the copper activation process of sphalerite will also be inhibited. In other words, when the pulp potential is higher than -50mV, within a certain range, as the pulp potential increases, the activation selectivity of copper sulfate will be enhanced, and the "competitive adsorption" of copper ions between sphalerite / sphalerite and pyrite / pyrrhotite will be effectively weakened, thereby allowing more copper ions to deactivate sphalerite / sphalerite, and the activation selectivity of copper sulfate and the activation effect on sphalerite / sphalerite are significantly enhanced.

[0024] Based on this technical principle, after lime is added to adjust the pH of the slurry to greater than 12, an oxidizing gas such as air or oxygen is immediately introduced into the slurry to place the slurry in an oxidizing atmosphere. This allows the slurry potential to be regulated so that the slurry potential during the entire copper sulfate activation zinc flotation process is within a potential range of 0 to 150 mV. This allows the copper activation process of sphalerite / sphalerite to proceed effectively, while inhibiting the activation of pyrite / pyrrhotite flotation by copper sulfate, thereby improving the activation selectivity of copper sulfate and enhancing the copper activation flotation effect of zinc.

[0025] Beneficial effects of the present invention:

[0026] 1. The present invention effectively improves the activation performance of copper sulfate, a conventional zinc activator, by regulating the slurry potential, and performs zinc flotation under this condition, thereby solving the problems of poor activation selectivity and poor control of reagent dosage of copper sulfate, a conventional zinc activator, and avoiding the problems of increased reagent costs and increased difficulty in treating mineral processing wastewater caused by existing combined activators. The invention has the characteristics of energy conservation, environmental protection and pollution-free.

[0027] 2. The present invention can effectively enhance the copper activation effect of sphalerite and sphalerite, and contribute to the efficient recovery and utilization of high-sulfur zinc sulfide mineral resources, especially those containing pyrrhotite. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a comparison chart of zinc roughing test results of Example and Comparative Example. DETAILED DESCRIPTION

[0029] In order to more clearly demonstrate the technical effects of the technical solutions provided by the present invention, the present invention is described in detail below using specific embodiments. It is obvious that the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort are also within the scope of protection of the present invention.

[0030] Unless otherwise specified, the experimental methods used in the examples and comparative examples of the present invention are conventional methods, and the materials, reagents, etc. used are all commercially available unless otherwise specified.

[0031] The test ore used in the examples and comparative examples is a high-sulfur cassiterite polymetallic sulfide ore from a foreign country. The ore contains 8.01% zinc, primarily in the form of sphalerite, with a mineral content of approximately 12%. It also contains pyrite and pyrrhotite, with a combined mineral content of approximately 40%. The main gangue minerals are quartz, feldspar, and calcite.

[0032] Example 1

[0033] The flotation test of the raw ore is carried out in the following steps:

[0034] (1) After the raw ore is crushed, it is ground to -0.074mm (55%) using a wet ball mill, and then the ground slurry is poured into the flotation tank;

[0035] (2) Add 6000 g / t lime to the flotation tank and adjust the pulp pH to 12.45;

[0036] (3) air was added to the slurry obtained in step (2) at a rate of 7 L / min, followed by the addition of 1200 g / t of copper sulfate as a zinc activator, and continuous aeration was maintained to control the slurry potential to be 50 mV and the dissolved oxygen content to be 3.5 mg / L during the entire activation process, and the mixture was stirred and activated for 10 min;

[0037] (4) Zinc roughing: 60 g / t zinc collector butyl xanthate was added to the slurry obtained in step (3), stirred for 2 min, and finally 20 g / t frother pine oil was added, stirred for 1 min, and flotation was performed to obtain Zn coarse K and roughing tailings;

[0038] (5) Two-time scanning:

[0039] Scavenging 1: add 30g / t zinc collector butyl xanthate to the roughing tailings obtained in step (4), stir for 2min, then add 10g / t frother pine oil, stir for 1min, and then perform flotation to obtain Zn scavenging Ⅰ K and scavenging tailings 1;

[0040] Scavenging 2: Add 15g / t zinc collector butyl xanthate to the scavenging tailings 1, stir for 1 minute, and then perform aeration flotation and scraping to obtain Zn scavenging II K and floating zinc tailings.

[0041] The flotation results are shown in Table 1.

[0042] Table 1 Zinc flotation test results / %

[0043]

[0044] Comparative Example 1

[0045] The flotation test of the raw ore was carried out using the technical method of zinc-sulfur sequential preferential flotation. The specific steps are as follows:

[0046] (1) After the raw ore is crushed, it is ground to -0.074mm (55%) using a wet ball mill, and then the ground slurry is poured into the flotation tank;

[0047] (2) Add 6000 g / t lime to the flotation tank, adjust the pulp pH to 12.51, and stir for 3 minutes;

[0048] (3) zinc roughing: 1200 g / t zinc activator copper sulfate was added to the slurry obtained in step (2), and the mixture was stirred for 10 min. During the activation process, the slurry potential was about -50 mV and the dissolved oxygen content was about 1 mg / L. Then, 60 g / t zinc collector butyl xanthate was added and the mixture was stirred for 2 min. Finally, 20 g / t frother pine oil was added and the mixture was stirred for 1 min. Zn coarse K and roughing tailings were obtained by flotation.

[0049] (4) Two-time scanning:

[0050] Scavenging 1: Add 30 g / t of zinc collector butyl xanthate to the roughing tailings obtained in step (3) and stir for 2 min; then add 10 g / t of frother pine oil and stir for 1 min, then perform flotation to obtain Zn scavenging Ⅰ K and scavenging tailings 1;

[0051] Scavenging 2: Add 15g / t zinc collector butyl xanthate to the scavenging tailings 1, stir for 1 minute, and then carry out flotation to obtain Zn scavenging II K and floating zinc tailings.

[0052] The flotation results are shown in Table 2.

[0053] Table 2 Zinc flotation test results / %

[0054]

[0055] Comparing the data in Tables 1 and 2, it can be seen that, compared to Comparative Example 1, the zinc grade in the crude Zn K in Example 1 was increased from 23.86% to 34.53%, and the zinc recovery rate was increased from 86.85% to 91.67%, while the sulfur grade and sulfur recovery rate were reduced to 34.01% and 22.97%, respectively. Thus, when the method of the present invention is used to flotate zinc from this raw ore, the problems of poor activation selectivity with conventional copper sulfate activators, and low zinc grade and zinc recovery in the crude zinc concentrate, are effectively resolved, the sulfur content in the crude zinc concentrate is reduced, and better flotation indicators are achieved.

[0056] Example 2

[0057] The flotation test of the raw ore is carried out in the following steps:

[0058] (1) After the raw ore is crushed, it is ground to -0.074mm (55%) using a wet ball mill, and then the ground slurry is poured into the flotation tank;

[0059] (2) Add 6000 g / t lime to the flotation tank and adjust the pulp pH to 12.48;

[0060] (3) adding air to the slurry obtained in step (2) at a rate of 8 L / min, then adding 1200 g / t of copper sulfate as a zinc activator, and maintaining continuous aeration to control the slurry potential to be 80 mV and the dissolved oxygen content to be 4.5 mg / L during the entire activation process, and stirring and activating for 10 min;

[0061] (4) Zinc roughing: 60 g / t zinc collector butyl xanthate was added to the slurry obtained in step (3) and stirred for 2 min; finally, 20 g / t frother pine oil was added and stirred for 1 min, and Zn coarse K and roughing tailings were obtained by flotation.

[0062] (5) Two-time scanning:

[0063] Scavenging 1: add 30g / t zinc collector butyl xanthate to the roughing tailings of step (4) and stir for 2min; then add 10g / t frother pine oil and stir for 1min, then perform aeration flotation to obtain Zn scavenging ⅠK and scavenging tailings 1;

[0064] Scavenging 2: Add 15g / t zinc collector butyl xanthate to the scavenging tailings 1, stir for 1 minute, and then perform aeration flotation and scraping to obtain Zn scavenging II K and floating zinc tailings.

[0065] The flotation results are shown in Table 3.

[0066] Table 3 Zinc flotation test results / %

[0067]

[0068] Comparing the data in Tables 2 and 3, it can be seen that compared to Comparative Example 1, the zinc grade in the crude Zn K in this embodiment was increased from 23.86% to 37.01%, and the zinc recovery rate was increased from 86.85% to 94.58%, while the sulfur grade and sulfur recovery rate were reduced to 33.21% and 18.48%, respectively. This shows that the present invention effectively enhances the activation effect of copper sulfate on zinc flotation, significantly improves the activation selectivity of copper sulfate, and achieves better flotation indicators.

[0069] Example 3

[0070] The experimental steps of this example are the same as those of Example 1, except that the aeration rate is 9 L / min, the pulp potential is 120 mV, and the dissolved oxygen content is 5.5 mg / L. The flotation results are shown in Table 4.

[0071] Table 4 Zinc flotation test results / %

[0072]

[0073] Comparing the data in Table 2 and Table 4, it can be seen that compared with Comparative Example 1, the zinc grade in the crude Zn K in this embodiment is increased from 23.86% to 37.40%, the zinc recovery rate is increased from 86.85% to 94.40%, while the sulfur grade and sulfur recovery rate are reduced to 33.12% and 20.98%, respectively.

[0074] Example 4

[0075] The experimental steps of this example are the same as those of Example 1, except that the aeration rate is 6 L / min, the pulp potential is 0 mV, and the dissolved oxygen content is 3 mg / L. The flotation results are shown in Table 5.

[0076] Table 5 Zinc flotation test results / %

[0077]

[0078] Comparing the data in Table 2 and Table 5, it can be seen that compared with Comparative Example 1, the zinc grade in the crude Zn K in this embodiment is increased from 23.86% to 29.08%, the zinc recovery rate is increased from 86.85% to 89.55%, while the sulfur grade and sulfur recovery rate are reduced to 33.16% and 25.34%, respectively.

[0079] Example 5

[0080] The experimental steps of this example are the same as those of Example 1, except that the aeration rate is 12 L / min, the pulp potential is 150 mV, and the dissolved oxygen content is 6 mg / L. The flotation results are shown in Table 6.

[0081] Table 6 Zinc flotation test results / %

[0082]

[0083] Comparing the data in Table 2 and Table 6, it can be seen that compared with Comparative Example 1, the zinc grade in the crude Zn K in this embodiment is increased from 23.86% to 37.52%, the zinc recovery rate is increased from 86.85% to 94.21%, while the sulfur grade and sulfur recovery rate are reduced to 32.76% and 20.55%, respectively.

[0084] Comparison of the zinc roughing test results of Examples 1 to 3 and the comparative example is shown in Figure 1 .

[0085] from Figure 1It can be seen that when conventional copper sulfate is used as a zinc activator and the ore is flotated using the conventional zinc-sulfur sequential priority flotation technology under the same reagent, the zinc grade and zinc recovery rate of the obtained zinc concentrate are low, the sulfur grade and sulfur recovery rate are high, and the zinc flotation index is poor. However, the method of the present invention is adopted, that is, lime is used to adjust the slurry pH to >12, and then the slurry potential is regulated by aeration so that the slurry potential of the entire copper sulfate activated zinc flotation process is in the potential range of 0-150mV and the dissolved oxygen content is in the range of 3-6mg / L. After sufficient stirring and activation, a zinc collector and a frother are added in sequence to carry out zinc flotation. This can significantly enhance the copper activation flotation effect of sphalerite and marmatite, greatly improve the zinc flotation index, and effectively solve the problems of poor activation selectivity of copper sulfate as a conventional zinc activator and high sulfur content in the zinc concentrate. It has obvious advantages in technical indicators, thereby effectively making up for the shortcomings of the existing technology.

[0086] In fact, in the present invention, lime is added to adjust the pH to above 12, and then an oxidizing gas such as air or oxygen is added to the slurry. Then, copper sulfate is added as a zinc activator, and continuous aeration is maintained to control the slurry potential in the entire copper activation process within the potential range of 0 to 150 mV and the dissolved oxygen content within the range of 3 to 6 mg / L. After stirring and activation for 8 to 12 minutes, a zinc collector and a frother are added in sequence to carry out zinc flotation. The amount of the zinc collector is within the range of 50 to 80 g / t, and the amount of the frother is within the range of 20 to 30 g / t. Any value is acceptable and has good feasibility and practical effect. Therefore, the present invention is not limited to the above-mentioned embodiment. Various changes can be made within the knowledge of ordinary technicians in this field without departing from the scope of the present invention.

Claims

1. A method for enhancing the activation flotation of sphalerite and sphalerite copper, comprising the following steps: 1) Grinding: After the raw ore is crushed, wet ball milling is performed to obtain ore pulp; 2) Slurry adjustment: adding a pH adjuster to the slurry obtained in step 1) to adjust the pH of the slurry to an appropriate range; 3) Activation: Add oxidizing gas to the slurry obtained in step 2), then add zinc activator, and keep aeration continuously throughout the activation process, and adjust the slurry potential to an appropriate range; 4) Flotation: Add zinc collector and frother to the slurry obtained in step 3) and perform aeration flotation to obtain zinc coarse concentrate; In step 2), the pH adjuster is lime, the amount of lime is 5000-7000 g / t, and the pH of the slurry is adjusted to 12-13; In step 3), the oxidizing gas is air or oxygen, and the aeration rate is 6-12 L / min, so that the dissolved oxygen content in the slurry is maintained at 3-6 mg / L, and continuous aeration is maintained throughout the entire activation process; In step 3), the slurry potential is maintained at 0-150 mV, and the slurry potential value is compared with the hydrogen standard electrode; In step 3), the zinc activator is copper sulfate, and the dosage is 1000-1500 g / t.

2. The method for strengthening the copper activation flotation of sphalerite and sphalerite according to claim 1, characterized in that: In the step 1), the grinding fineness is -0.074 mm, accounting for 50% to 65%.

3. The method for strengthening the copper activation flotation of sphalerite and sphalerite according to claim 1, characterized in that: Step 4) The flotation adopts a one-roughing and two-sweeping process, the zinc collector is butyl xanthate, and the frother is terpineol.

4. The method for strengthening the copper activation flotation of sphalerite and sphalerite according to claim 3, characterized in that: The first-class reagent system is: zinc collector xanthate 50~80g / t, foaming agent terpineol 20~30g / t.

5. The method for strengthening the copper activation flotation of sphalerite and sphalerite according to claim 3, characterized in that: The dosage system for Yisao is: zinc collector xanthate 25~40g / t, foaming agent terpineol 8~15g / t.

6. The method for strengthening the copper activation flotation of sphalerite and sphalerite according to claim 3, characterized in that: The reagent system for the second sweep is: zinc collector butanol 10~20g / t, without adding foaming agent terpineol.

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