A method for the asynchronous flotation separation of franklinite from iron sulfide minerals

Abstract

The application discloses a kind of iron wurtzite and sulphide iron ore mineral asynchronous flotation separation method, belong to nonferrous metal sulphide mineral flotation technical field;The application promotes the flotation of iron wurtzite by slurry aeration, realizes the asynchronous flotation of iron wurtzite, pyrite and pyrrhotite by means of high selectivity collector CTB-2 and oxidant calcium hypochlorite, solves the problem of difficult separation of iron wurtzite and pyrrhotite, and uses high concentration copper sulfate as depressor to rapidly improve the grade of zinc concentrate, uses ferrous sulfate to realize the sulfur-free flotation of sulfur concentrate, and finally obtains high-quality zinc concentrate, first sulfur concentrate (pyrite) and second sulfur concentrate (pyrrhotite) products.The application optimizes and simplifies the beneficiation process, cancels the magnetic separation step in the traditional process, and realizes efficient separation of zinc and sulfur through single flotation method.

Description

Technical Field

[0001] This invention belongs to the field of non-ferrous metal sulfide mineral flotation technology, specifically relating to an asynchronous flotation separation method for sphalerite and iron sulfide minerals. Background Technology

[0002] Pyrite and pyrrhotite are two of the most common iron sulfide minerals (pyrites), with good natural floatability and abundant occurrence in polymetallic sulfide ores. Sphalerite has poor natural floatability, and its floatability decreases with increasing iron content in the crystal lattice. Therefore, the flotation of sphalerite / iron sphalerite requires activation with copper sulfate and the use of strong collectors such as xanthate to enhance the flotation. However, copper sulfate has a poor activation effect on iron sphalerite, resulting in unsatisfactory zinc recovery. Furthermore, copper sulfate can activate the flotation of iron sulfide minerals, especially in strong collector systems, leading to a large amount of pyrite floating to the surface. When the coexisting pyrite is predominantly pyrite, the high-alkali lime process makes it relatively easy to separate zinc sulfide minerals from iron sulfide minerals. However, when the pyrite in the ore is predominantly pyrrhotite or has a high pyrrhotite content, the zinc-sulfur separation effect is poor, resulting in low zinc concentrate grade and recovery.

[0003] Because pyrrhotite is magnetic, it can be selectively separated using magnetic separation in production practice. However, sphalerite also possesses some magnetic properties and is easily lost in the magnetic concentrate during magnetic separation. Therefore, the poor natural floatability, difficulty in activation, and magnetic properties of sphalerite, combined with the good natural floatability, ease of activation, and magnetic properties of pyrrhotite, make it difficult to separate sphalerite and pyrrhotite, regardless of whether magnetic separation, flotation, or a combined magnetic-flotation process is used. This remains an unsolved technical challenge in the beneficiation of sulfide minerals.

[0004] Current flotation technologies lack a more scientific and reasonable processing method for this type of ore, resulting in a low overall resource recovery rate. Therefore, it is necessary to propose an asynchronous flotation separation method for sphalerite and iron sulfide minerals to solve the aforementioned technical problems. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide an asynchronous flotation separation method for sphalerite and iron sulfide minerals, which enhances the flotation of sphalerite and promotes the separation of sphalerite from pyrrhotite and pyrite, achieving sulfur beneficiation without sulfuric acid, and obtaining high-quality zinc concentrate and sulfur concentrate.

[0006] Through extensive experiments and repeated research, the inventors discovered that the main reason why sphalerite and pyrrhotite are difficult to separate during the flotation of pyrrhotite-rich lead-zinc sulfide ores and copper-zinc sulfide ores is:

[0007] (1) Copper sulfate has a poor activation effect on iron sphalerite. It is difficult to improve the activation effect on iron sphalerite by increasing the amount of copper sulfate, thus solving the problem of low zinc flotation recovery rate. Moreover, it will cause a large amount of pyrite to float to the surface.

[0008] (2) Unlike pyrite, pyrrhotite, which has been activated and adsorbed with strong collectors (such as xanthate), is particularly difficult to suppress, resulting in poor zinc enrichment during zinc beneficiation and a significant increase in lime consumption. However, researchers have not realized this problem and continue to treat pyrrhotite as the same as pyrite. Therefore, in systems where pyrite and pyrrhotite coexist, they must be treated as two separate minerals.

[0009] (3) The zinc flotation process uses a large amount of lime and the pulp pH is high. When the middlings are returned sequentially, the pulp alkalinity of the sulfur flotation process will increase, which will increase the amount of sulfuric acid used.

[0010] To address the aforementioned technical problems, this invention proposes an asynchronous flotation separation method for iron sphalerite and iron sulfide minerals, comprising:

[0011] S1. The raw ore is ball-milled and classified to obtain a slurry of a predetermined fineness;

[0012] S2. Add the first pyrite inhibitor to the slurry, and at the same time aerate the slurry. Then add sphalerite activator, sphalerite collector and foaming agent to obtain the treated slurry.

[0013] S3. The treated slurry enters the flotation machine for semi-mixed flotation to obtain flotation froth and tailings.

[0014] S4. The foam obtained from the semi-flotation operation is mixed with a second pyrite inhibitor, a sphalerite activator and a sphalerite collector to carry out the first zinc-sulfur separation, and obtain zinc rough concentrate and first sulfur concentrate. The first sulfur concentrate is pyrite.

[0015] S5. Add inhibitors to zinc crude concentrate and perform a second zinc-sulfur separation to obtain zinc concentrate and zinc middlings.

[0016] S6. Add pyrite activator and pyrite collector to the tailings obtained from the semi-mixed flotation operation, and carry out sulfur flotation operation to obtain the second sulfur concentrate and the final tailings. The second sulfur concentrate is pyrrhotite.

[0017] In the preferred embodiment, in step S1, the raw ore is ball-milled and classified until -0.075mm accounts for more than 80%.

[0018] In the preferred embodiment, in step S2, the slurry aeration time is 0~30 min, and the aeration rate is 0~2.0 m³ / min. 3 / min, the specific parameters depend on the specifications of the aeration, flotation, and mixing equipment, the ore processing capacity, and the properties of the ore.

[0019] In the preferred embodiment, in step S2, the first pyrite inhibitor mainly inhibits pyrrhotite and is composed of one or more of lime, calcium hypochlorite, and sodium sulfite.

[0020] More preferably, the first pyrite inhibitor is calcium hypochlorite.

[0021] In a preferred embodiment, in step S2, the zincblende activator is copper sulfate.

[0022] In the preferred embodiment, in step S2, the sphalerite collector mainly collects sphalerite and pyrite, and the sphalerite collector is CTB-2 collector;

[0023] The collector CTB-2 is a composition of a metal corrosion inhibitor and a black powder, with a mass ratio of (20~50):(50~80); the black powder is a non-foaming black powder.

[0024] More preferably, the metal corrosion inhibitor is one or a combination of benzotriazole, methylbenzotriazole, and sodium mercaptobenzothiazole.

[0025] More preferably, the black powder is one or a combination of alcohol black powders such as sodium diisopropyl dithiophosphate, sodium disec-butyl dithiophosphate, and sodium diisopentyl dithiophosphate.

[0026] More preferably, the sphalerite collector is used in combination with the Z-200 collector.

[0027] The working principle of collector CTB-2 is as follows: the metal corrosion inhibitor in CTB-2 prevents the oxidation and dissolution of sphalerite during slurry aeration and conditioning; the black dye in CTB-2 has a strong complexing ability for copper but a very poor complexing ability for iron. Therefore, after activation with copper sulfate and oxidation with calcium hypochlorite, CTB-2 has a strong collecting ability for sphalerite, but almost no collecting effect on pyrrhotite.

[0028] In a preferred embodiment, in step S2, the foaming agent is MIBC.

[0029] In the preferred embodiment, in step S3, during the semi-flotation operation, the first pyrite inhibitor is calcium hypochlorite, with a dosage of 200~600g / t; the sphalerite activator is copper sulfate, with a dosage of 100~300g / t; the sphalerite collector is CTB-2, with a dosage of 10~30g / t; and the frother MIBC is used at a dosage of 0~30g / t.

[0030] In the preferred embodiment, during the first zinc-sulfur separation process in step S4, the second pyrite inhibitor is lime or calcium hypochlorite, the sphalerite activator is copper sulfate, and the sphalerite collector is CTB-2.

[0031] More preferably, in step S4, during the first zinc-sulfur separation operation, the second pyrite inhibitor is lime, with a dosage of 1000~3000 g / t; the zinc sphalerite activator copper sulfate is used at a dosage of 100~200 g / t; and the zinc sphalerite collector CTB-2 is used at a dosage of 5~10 g / t.

[0032] More preferably, in step S4, the first zinc-sulfur separation is an open-circuit operation, in which the water is circulated separately within this operation.

[0033] In the preferred embodiment, during the second zinc-sulfur separation process in step S5, the inhibitor is one or a combination of copper sulfate and lead nitrate.

[0034] More preferably, in the second zinc-sulfur separation operation, the inhibitor is copper sulfate, with a dosage of 400~800 g / t.

[0035] In the preferred embodiment, in step S6, during the sulfur concentrate flotation operation, the pyrite activator is one or more combinations of sulfuric acid, oxalic acid, and ferrous sulfate; the pyrite collector is one or more combinations of butyl xanthate, ethyl thiocyanate, and Z-200.

[0036] More preferably, in step S6, during the sulfur concentrate flotation operation, the pyrite activator is ferrous sulfate, with a dosage of 100~200g / t; the pyrite collector is xanthate, with a dosage of 30~50g / t.

[0037] This invention discloses an asynchronous flotation separation method for sphalerite and iron sulfide minerals, aiming to promote the activation and collection of sphalerite and overcome the difficulty in flotation separation of sphalerite and pyrrhotite, thereby improving the grade and recovery rate of zinc concentrate, reducing zinc-sulfur intermingling, and achieving efficient and comprehensive resource recovery and utilization. This method fully utilizes the natural floatability differences of sphalerite, pyrite, and pyrrhotite, innovatively employing slurry aeration to promote the activation and flotation of sphalerite. Based on the highly selective collector CTB-2 and the pyrrhotite oxidation inhibitor calcium hypochlorite, asynchronous flotation of sphalerite, pyrite, and pyrrhotite is achieved, facilitating subsequent zinc-sulfur separation. In the second zinc-sulfur separation process, a high concentration of copper sulfate is used to suppress pyrite, rapidly increasing the grade of zinc concentrate.

[0038] Compared with the prior art, the beneficial effects of the technical solution of the present invention are as follows:

[0039] (1) By aerating the slurry, the activation effect of iron sphalerite is fundamentally improved, and the problem of low zinc flotation recovery rate is solved.

[0040] (2) The mineral processing flow has been optimized and simplified, eliminating the magnetic separation step in the traditional process, and zinc and sulfur can be separated efficiently by a single flotation method.

[0041] (3) Based on a highly selective collector and an oxidation inhibitor for pyrrhotite, asynchronous flotation of pyrite and pyrrhotite was achieved through a semi-mixed flotation process, solving the problem of subsequent zinc-sulfur separation. The zinc-sulfur separation operation is simple, the separation efficiency is high, and the zinc concentrate has good indicators.

[0042] (4) Safety hazards during production are greatly reduced, and environmental pollution is also reduced. Because the amount of calcium hypochlorite used in the front-end semi-flotation operation is small and the slurry alkalinity is low, the amount of sulfuric acid used in the subsequent sulfur beneficiation process is greatly reduced, and safe and environmentally friendly reagents such as ferrous sulfate and oxalic acid can be used to eliminate the need for sulfuric acid.

[0043] (5) Product quality upgrade and resource utilization efficiency improved. This method was used to achieve asynchronous flotation of sphalerite, pyrite and pyrrhotite, which greatly improved the grade of zinc concentrate and obtained high-quality first sulfur concentrate (pyrite) and second sulfur concentrate (pyrrhotite). The two sulfur concentrates have different values, which achieved the refined development and utilization of resources. Attached Figure Description

[0044] Figure 1 This is a process flow diagram from Example 1.

[0045] Figure 2 The results are from the XRD qualitative analysis of the first sulfur concentrate.

[0046] Figure 3 The results are from the XRD qualitative analysis of the second sulfur concentrate.

[0047] Figure 4 The results are the quantitative analysis results of the first sulfur concentrate.

[0048] Figure 5 This is the quantitative analysis result of the second sulfur concentrate. Detailed Implementation

[0049] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. 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.

[0050] In conventional flotation schemes, copper sulfate and xanthate, a strong collector, are added to enhance the flotation of sphalerite. However, due to the unique mineral characteristics and pulp environment of sphalerite, copper sulfate has a poor activation effect on it, and increasing the amount of copper sulfate is insufficient to fundamentally improve the activation effect and solve the problem of low zinc flotation recovery. Furthermore, this reagent system of activator + strong collector is particularly prone to causing large amounts of pyrite to float. The traditional solution in high-alkali lime processes is to add a large amount of lime to suppress pyrite floating and ensure selective enrichment of sphalerite. However, pyrrhotite activated with copper sulfate and adsorbed with xanthate exhibits significantly different flotation behavior from pyrite; it has excellent floatability and is quite stable. In the zinc flotation process, the amount of lime used is particularly large, but the zinc concentrate quality remains poor. Therefore, pyrrhotite and pyrrhotite should not be treated the same as pyrite.

[0051] This invention recognizes this problem and proposes a solution: promote the activation and flotation of sphalerite through slurry aeration to address the low zinc recovery rate; achieve selective collection of sphalerite using a highly selective collector and inhibit pyrrhotite flotation under low-alkali conditions using an oxidant to achieve asynchronous flotation of pyrite and pyrrhotite, preventing pyrrhotite from entering the zinc-sulfur separation stage and thus solving the problem of difficult zinc-sulfur separation; improve lime utilization efficiency and reduce sulfuric acid usage in the sulfur flotation stage and lime usage in the zinc-sulfur separation stage through water treatment and graded reuse; and reduce the amount of sulfuric acid used in the sulfur flotation stage and lime usage in the zinc-sulfur separation stage.

[0052] Therefore, slurry aeration is carried out during the semi-flotation slurry conditioning stage to improve the activation effect of copper sulfate on sphalerite. The highly selective collector CTB-2 is selected to replace xanthate as the collector for sphalerite, and calcium hypochlorite is used as an oxidant to inhibit pyrrhotite, thus strengthening the selective inhibition of pyrrhotite. The pyrite in the semi-flotation froth is mainly pyrite, with a very low pyrrhotite content, thereby achieving asynchronous flotation of pyrite. In the subsequent zinc-sulfur separation stage, the pyrrhotite content is very low, and the problem of difficult separation between sphalerite and pyrrhotite no longer exists. CTB-2 has a weak collecting capacity for pyrite; in the open-circuit process of the first zinc-sulfur separation, lime can be used to inhibit the flotation of pyrite and obtain the first sulfur concentrate. The highly alkaline water in this operation is recycled here, which not only improves the utilization efficiency of lime but also has little impact on the water quality of the subsequent sulfur beneficiation process. In the second zinc-sulfur separation process, a large amount of copper sulfate is added to inhibit the flotation of pyrite, thereby rapidly improving the grade of the zinc concentrate. Because the zinc flotation process uses less lime and there is no alkaline water recycled to the sulfur flotation process, pyrrhotite is only slightly inhibited and still maintains good natural floatability. Only a small amount of activator needs to be added in the sulfur flotation stage to activate the flotation of pyrrhotite and achieve efficient recovery and utilization of pyrrhotite.

[0053] This invention proposes an asynchronous flotation separation method for sphalerite and iron sulfide minerals, comprising:

[0054] S1. The raw ore is ball-milled and classified to obtain a slurry of a predetermined fineness;

[0055] S2. The slurry is aerated, and then the first pyrite inhibitor, sphalerite activator, sphalerite collector and foaming agent are added to obtain the treated slurry.

[0056] S3. The treated slurry enters the flotation machine for semi-mixed flotation to obtain flotation froth and tailings.

[0057] S4. The foam obtained from the semi-flotation operation is mixed with a second pyrite inhibitor, a sphalerite activator and a sphalerite collector to carry out the first zinc-sulfur separation, and obtain zinc rough concentrate and first sulfur concentrate. The first sulfur concentrate is pyrite.

[0058] S5. Add pyrite inhibitor to zinc rough concentrate to carry out a second zinc-sulfur separation to obtain zinc concentrate and zinc middlings;

[0059] S6. Add pyrite activator and pyrite collector to the tailings obtained from the semi-mixed flotation operation, and carry out sulfur flotation operation to obtain the second sulfur concentrate and the final tailings. The second sulfur concentrate is pyrrhotite.

[0060] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0061] Comparative Example 1

[0062] The comparative example used the same test samples as the example, and its grinding fineness and copper beneficiation process were also consistent with the example. In the zinc beneficiation process, 2000 g / t lime was added to the copper flotation tailings as a pyrite depressant, 200 g / t copper sulfate as a sphalerite activator, 20 g / t butyl xanthate as a sphalerite collector, and 20 g / t No. 2 oil as a frother for zinc preferential flotation. The experiment found that even with a large amount of lime, the yield of coarse zinc flotation was still relatively high. Analysis showed that, in addition to pyrite, a large amount of pyrrhotite floated in the coarse zinc flotation. During the refining process, the already floated pyrrhotite was very difficult to suppress, resulting in a relatively large amount of lime used in the refining operation. After two refining operations (total lime usage was 2000 g / t), the final zinc concentrate was obtained, but the flotation indicators of the zinc concentrate were still unsatisfactory. Due to the large amount of lime used in zinc beneficiation, the pulp pH was high, and the sulfuric acid usage was increased to 3000 g / t during the sulfur flotation process. In the comparative example, the main technical parameters of the product are listed in Table 1.

[0063] In traditional methods, although a large amount of lime is used to suppress the flotation of pyrite, the strong collecting ability of xanthate still results in a significant amount of pyrite, especially pyrrhotite, floating to the surface. In the zinc refining stage, the adsorption of xanthate on the surface of pyrrhotite is relatively stable, making it difficult to suppress the flotation of this mineral by increasing the amount of lime, resulting in very low zinc-sulfur separation efficiency. Furthermore, related experimental results show that using No. 2 oil as a frother in the zinc flotation stage also causes pyrrhotite to float and subsequent zinc refining to become difficult. Using MIBC as a frother almost eliminates the entrainment of pyrrhotite. The traditional process is lengthy, uses a large amount of reagents, and achieves a zinc concentrate grade of only 15.5% and a recovery rate of only 55%, far lower than that of asynchronous flotation processes.

[0064] Example 1

[0065] The test ore was a copper-zinc-sulfur ore from a region in Inner Mongolia. This ore contained 0.36% copper, 0.45% zinc, and 16.75% sulfur, with pyrrhotite accounting for 75% of the total sulfur. First, the raw ore was ball-milled and classified to a particle size of -0.075mm (75%). Sodium sulfite and zinc sulfate were used as a combined depressant for sphalerite, CTB-2 as a copper collector, and No. 2 oil as a frother for copper flotation. After one roughing, two cleaning, and two scavenging processes, copper concentrate and copper flotation tailings were obtained.

[0066] To the copper flotation tailings, 400 g / t calcium hypochlorite is added as a first pyrite depressant, 200 g / t copper sulfate as a sphalerite activator, 20 g / t CTB-2 as a sphalerite collector, and 20 g / t MIBC as a frother for semi-mixed flotation. To the resulting zinc flotation froth, 1000 g / t lime is added as a second pyrite depressant, and 100 g / t copper sulfate as an iron sphalerite activator for zinc-sulfur separation. After a primary separation, zinc rough concentrate and first pyrite concentrate are obtained. To the zinc rough concentrate, 400 g / t copper sulfate is added as a depressant for a secondary zinc-sulfur separation to obtain a high-grade zinc concentrate product. To the zinc flotation tailings, 150 g / t ferrous sulfate is added as an activator, and 40 g / t butyl xanthate as a collector. After a primary roughing process, second pyrite concentrate and final tailings are obtained. (Flotation process referenced). Figure 1 .

[0067] Example 2

[0068] The test ore and processing method were the same as in Example 1.

[0069] 400 g / t of calcium hypochlorite was added to the copper flotation tailings as a first pyrite depressant. Simultaneously, the slurry was aerated, with the gas flow rate controlled at 3 dm³. 3The aeration rate is 10 min, followed by the addition of 200 g / t copper sulfate as a sphalerite activator, 20 g / t CTB-2 as a sphalerite collector, and 20 g / t MIBC as a frother for zinc flotation. 1000 g / t lime is added to the resulting zinc flotation froth as a second pyrite depressant, and 100 g / t copper sulfate is added as an iron sphalerite activator for zinc-sulfur separation. After one separation, zinc rough concentrate and first sulfur concentrate are obtained. 400 g / t copper sulfate is added to the zinc rough concentrate as a depressant for a second zinc-sulfur separation, yielding a high-grade zinc concentrate product. 150 g / t ferrous sulfate is added to the zinc flotation tailings as an activator, and 40 g / t butyl xanthate as a collector. After one roughing stage, second sulfur concentrate and final tailings are obtained. (Flotation process referenced). Figure 1 The main technical parameters of the product are listed in Table 1.

[0070] Experimental results show that when using the highly selective collector CTB-2, its collecting ability for pyrrhotite is very poor. With a small amount of calcium hypochlorite (400 g / t) as a depressant, pyrrhotite hardly floats, while sphalerite and some pyrite enter the zinc flotation froth. During the first zinc-sulfur separation, 1000 g / t of lime is sufficient to fully suppress this portion of pyrite, thus achieving efficient separation. Adding 400 g / t of copper sulfate to the zinc concentrate significantly improves the zinc concentrate grade, yielding a zinc concentrate with a zinc grade of 38.20% and a recovery rate of 70.28%, exhibiting particularly good flotation performance.

[0071] Specifically, in the asynchronous flotation scheme (Example 1), the first sulfur concentrate obtained had an Fe grade of 43.3%, a sulfur grade of 51.2%, and an Fe+S content of 94.5%, which, combined with XRD qualitative analysis, indicates it to be high-purity pyrite. The second sulfur concentrate obtained had an Fe grade of 56.3%, a S grade of 33.3%, and an Fe+S content of 89.6%, which, combined with XRD qualitative analysis, indicates it to be high-purity pyrrhotite.

[0072] A comparison of the results of Example 2 and Example 1 revealed that slurry aeration can further promote the activation and flotation of sphalerite. In Example 1, the zinc recovery rate increased from 55.00% to 70.28% in the system without slurry aeration, while in the slurry aeration system, the zinc recovery rate further increased from 70.28% to 79.32%, indicating that slurry aeration is a feasible way to enhance the activation and flotation of sphalerite.

[0073] Table 1. Results of the Examples and Comparative Examples (%)

[0074]

[0075] Furthermore, in this asynchronous flotation separation method for sphalerite and iron sulfide minerals based on slurry aeration, the asynchronous flotation of pyrite is achieved by using the highly selective collector CTB-2. In the semi-mixed flotation operation, 2000 g / t of lime is replaced by 400 g / t of calcium hypochlorite, and the pH of the semi-mixed flotation tailings slurry also decreases from 11.5 to 8.3. The pyrite activator is significantly reduced in the sulfur flotation stage. In the comparative example, 3000 g / t of sulfuric acid is required for activation, while in this example, 150 g / t of ferrous sulfate is sufficient to fully activate the pyrite.

[0076] The above content is only a specific implementation example of the present invention, and not all application examples of the present invention. All schemes that follow the technical concept of the present invention or make modifications based on the technical concept of the present invention are within the protection scope of the claims of the present invention.

Claims

1. A method for the asynchronous flotation separation of franklinite from iron sulfide minerals, characterized in that The method comprises the following steps: S1, the raw ore is subjected to ball milling and grading treatment to obtain ore slurry with a predetermined fineness; S2, a first pyrite inhibitor is added to the ore slurry, while the ore slurry is subjected to aeration treatment, and then a sphalerite activator, a sphalerite collector and a foaming agent are added to obtain treated ore slurry; S3, the treated ore slurry is fed into a flotation machine to perform semi-mixed flotation to obtain flotation froth and tailings; S4, the froth obtained in the semi-mixed flotation is added with a second pyrite inhibitor, a sphalerite activator and a sphalerite collector to perform first zinc-sulfur separation to obtain zinc rough concentrate and first sulfur concentrate, and the first sulfur concentrate is pyrite; S5, the zinc rough concentrate is added with an inhibitor to perform second zinc-sulfur separation to obtain zinc concentrate and zinc middlings; S6, the tailings obtained in the semi-mixed flotation are added with a pyrite activator and a pyrite collector to perform sulfur flotation to obtain second sulfur concentrate and final tailings, and the second sulfur concentrate is pyrrhotite; In step S2, the first pyrite inhibitor mainly inhibits pyrrhotite, and the first pyrite inhibitor is calcium hypochlorite, and the amount is 200-600 g / t; In step S2, the sphalerite activator is copper sulfate, and the amount is 100-300 g / t; In step S2, the foaming agent is MIBC, and the amount is 20-30 g / t; In step S2, the sphalerite collector mainly collects sphalerite and pyrite, and the sphalerite collector is CTB-2 collector, and the amount is 10-30 g / t; The sphalerite collector CTB-2 is a combination of metal corrosion inhibitor and black drug, and the mass ratio of the metal corrosion inhibitor to the black drug is (20-50):(50-80); The metal corrosion inhibitor is one or a combination of benzotriazole, methyl benzotriazole and sodium mercaptobenzothiazole; The black drug is one or a combination of diisopropyl sodium dithiophosphate, di-sec-butyl sodium dithiophosphate and diisopentyl sodium dithiophosphate; In step S4, in the first zinc-sulfur separation, the second pyrite inhibitor is lime, the amount is 1000-3000 g / t, the sphalerite activator is copper sulfate, the amount is 100-200 g / t, and the sphalerite collector is CTB-2, the amount is 5-10 g / t.

2. The method for the asynchronous flotation separation of franklinite from iron sulfide minerals according to claim 1, characterized in that, In step S1, the raw ore is subjected to ball milling and grading treatment to a fineness of more than 80% of-0.075 mm.

3. The method for the asynchronous flotation separation of franklinite from iron sulfide minerals according to claim 1, characterized in that, In step S1, in step S2, the pulp aeration time is 0-30 min, and the aeration amount is 0-2.0 m 3 / min.

4. The method for the separation of iron-sphalerite from iron-sulfide minerals by differential flotation according to claim 1, characterized in that, The sphalerite collector is used in combination with Z-200 collector.

5. The method for the separation of iron-sphalerite from iron-sulfide minerals by differential flotation according to claim 1, characterized in that, In step S5, in the second zinc-sulfur separation, the inhibitor is one or a combination of copper sulfate and lead nitrate; In the second zinc-sulfur separation, the inhibitor is copper sulfate, and the amount is 400-800 g / t.

6. A method for the differential flotation separation of smithsonite from iron sulphide minerals according to claim 1, characterized in that, In step S6, in the sulfur concentrate flotation, the pyrite activator is one or a combination of sulfuric acid, oxalic acid and ferrous sulfate, and the pyrite collector is one or a combination of butyl xanthate, ethyl thiourea and Z-200; In step S6, in the sulfur concentrate flotation, the pyrite activator is ferrous sulfate, the amount is 100-200 g / t, and the pyrite collector is butyl xanthate, the amount is 30-50 g / t.

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