Method for separating and floating sphalerite and pyrite from lead flotation tailings

Abstract

The invention discloses a method for separating and floating sphalerite and pyrite from lead flotation tailings, and belongs to the technical field of mineral separation. According to the method, ferrous sulfate is firstly added into ore pulp to ionize Fe < 2 + > to promote adsorption of baicalin on the surface of the pyrite, so that inhibition on minerals is enhanced, floatability difference between the pyrite and sphalerite is further increased, then Fe < 2 + > adsorbed on the surface of the pyrite can be oxidized into Fe < 3 + > by adding hydrogen peroxide, Fe < 3 + > has relatively weak affinity to baicalin, and the flotation effect of the pyrite on the surface of the pyrite is improved. Therefore, the baicalin is desorbed from the surface of the mineral, the hydrophilic film is destroyed, and the pyrite is exposed out of the fresh surface again, so that the inhibition and activation are realized. The system has the advantages of strong action effect, no toxicity, environmental protection and high applicability, and compared with the traditional inhibitor lime, the alkalinity in the whole system can be reduced, the recovery of rare and noble metals is ensured, and the comprehensive recovery benefit is integrally improved.

Description

Technical Field

[0001] The invention relates to a method for separating and flotating sphalerite and pyrite from lead beneficiation tailings, belonging to the technical field of ore dressing. Background Art

[0002] In the flotation of lead-zinc sulfide minerals, pyrite is often associated with galena, sphalerite, and precious metals such as gold and silver. Reducing sulfur in the selected lead-zinc concentrate has always been a key and challenging issue in the field of mineral processing. Pyrite is also a raw material for the industrial production of sulfuric acid. Therefore, it is necessary to recover sulfur from tailings with high sulfur content to ensure its economic value.

[0003] Traditional inhibitor lime has varying degrees of inhibitory effect on precious metals such as gold and silver in the ore, which is not conducive to the recovery and utilization of precious metals such as gold and silver in the ore. Lime can easily clog pipelines and cause a large amount of reagent waste, increasing the cost of mineral processing. Sulfur selection is difficult. After pyrite is inhibited by lime, it usually needs to be activated by adding a large amount of acid before it can be recovered. Sulfuric acid is mainly used in production, but sulfuric acid is a hazardous chemical and is not easy to store. Therefore, new inhibitors and activators need to be developed. Summary of the Invention

[0004] In order to solve the problem of difficulty in separating pyrite and sphalerite in lead tailings, the present invention provides a method for separating sphalerite and pyrite from lead tailings by flotation. In the method, a mixed system of ferrous sulfate and baicalin is used as a pyrite inhibitor, and hydrogen peroxide is used as a pyrite depressant. The specific steps are as follows:

[0005] (1) Zinc roughing: ferrous sulfate, baicalin, copper sulfate, potassium butyl xanthate and No. 2 oil are sequentially added to the lead tailings for roughing to obtain zinc roughing concentrate and zinc roughing tailings.

[0006] (2) Zinc scavenging: copper sulfate, potassium butyl xanthate and No. 2 oil are added to the zinc roughing tailings obtained in step (1) to carry out scavenging for three times, and the scavenged concentrate from the first scavenging operation is returned to the zinc roughing operation, and the other scavenged concentrates are returned to the previous level in turn to finally obtain zinc tailings.

[0007] (3) Zinc concentration: ferrous sulfate and baicalin are added to the zinc rougher concentrate obtained in step (1) to inhibit pyrite, and three concentrations are performed. The tailings of the first concentration operation are returned to the zinc rougher operation, and the tailings of other concentration operations are returned to the previous level in turn. After three concentrations, the final zinc concentrate is obtained.

[0008] (4) Sulfur roughing: adding hydrogen peroxide, potassium butyl xanthate and No. 2 oil to the zinc tailings obtained in step (2) to perform a roughing operation to obtain a sulfur roughing concentrate and sulfur roughing tailings.

[0009] (5) Sulfur concentration: The sulfur roughing concentrate obtained in step (4) is concentrated twice again, and the tailings from the first concentration are returned to the sulfur roughing operation, and the tailings from the second concentration are returned to the first concentration operation.

[0010] (6) Sulfur scavenging: hydrogen peroxide, potassium butyl xanthate and No. 2 oil are added to the sulfur roughing tailings obtained in step (4) to carry out two scavenging operations, the scavenged concentrate from the first scavenging operation is returned to the sulfur roughing operation, and the scavenged concentrate from the second scavenging operation is returned to the first scavenging operation. After the two scavenging operations are completed, sulfur tailings are obtained.

[0011] Preferably, in step (1), the amount of ferrous sulfate used is 400-600 g / t, the amount of baicalin used is 300-400 g / t, the amount of copper sulfate used is 300-500 g / t, the amount of potassium butyl xanthate used is 100-140 g / t, and the amount of No. 2 oil used is 20-25 g / t.

[0012] Preferably, in step (2), during the first sweep, the amount of copper sulfate is 150-200 g / t, the amount of potassium butyl xanthate is 50-70 g / t, and the amount of No. 2 oil is 10-15 g / t; during the second sweep, the amount of copper sulfate is 70-100 g / t, the amount of potassium butyl xanthate is 20-40 g / t, and the amount of No. 2 oil is 5-10 g / t; during the third sweep, the amount of copper sulfate is 30-50 g / t, the amount of potassium butyl xanthate is 10-20 g / t, and the amount of No. 2 oil is 1-5 g / t.

[0013] Preferably, in step (3), during the first selection, the amount of ferrous sulfate is 200-300 g / t, and the amount of baicalin is 150-200 g / t; during the second selection, the amount of ferrous sulfate is 100-150 g / t, and the amount of baicalin is 80-100 g / t; during the third selection, the amount of ferrous sulfate is 50-75 g / t, and the amount of baicalin is 40-50 g / t.

[0014] Preferably, in step (4), the amount of hydrogen peroxide used is 600-800 g / t, the amount of potassium butyl xanthate used is 80-120 g / t, and the amount of No. 2 oil used is 15-20 g / t.

[0015] Preferably, in step (6), during the first sweep, the amount of hydrogen peroxide used is 300-400 g / t, the amount of potassium butyl xanthate used is 40-60 g / t, and the amount of No. 2 oil used is 7-10 g / t; during the second sweep, the amount of hydrogen peroxide used is 150-200 g / t, the amount of potassium butyl xanthate used is 20-30 g / t, and the amount of No. 2 oil used is 3-5 g / t.

[0016] Preferably, in each step, each agent is added and allowed to react for at least 3 minutes before adding the next agent.

[0017] The inhibitor of the present invention, baicalin, has the following structural formula:

[0018]

[0019] Principle of invention: In the slurry, due to the exposure of Zn on the surface of sphalerite and pyrite, 2+ or Fe 2+ Baicalin is easily adsorbed on the surface of these minerals, forming a hydrophilic film with these ions, reducing the floatability of the minerals, Fe 2+ Baicalin has a strong affinity for baicalin, so baicalin is more easily adsorbed on the surface of pyrite, thereby forming a selective inhibition of pyrite. Ferrous sulfate is added to the system to ionize Fe 2+ It promotes the adsorption of baicalin on the surface of pyrite, thereby strengthening the inhibition of minerals and further increasing the floatability difference between pyrite and sphalerite. After adding copper sulfate, Cu 2+ The reaction on the surface of sphalerite forms polysulfide (CuS), which enhances the floatability of sphalerite. 2+ The formed hydrophilic film hinders the Cu 2 + The adsorption on the surface of pyrite, so after adding xanthate, xanthate can be adsorbed on the surface of sphalerite, but not on the surface of pyrite, thereby achieving effective separation of sphalerite and pyrite. By adding hydrogen peroxide, the Fe adsorbed on the surface of pyrite can be removed. 2+ Oxidized to Fe 3+ , Fe 3+ The affinity for baicalin is weak, so baicalin is desorbed from the mineral surface, the hydrophilic film is destroyed, and the fresh surface of pyrite is exposed again to achieve deinhibition and activation.

[0020] Beneficial effects of the present invention:

[0021] (1) The present invention provides a method for first inhibiting and then de-inhibiting pyrite, wherein the inhibitor is Fe 2+ (Ferrous sulfate) and baicalin work together in combination. The inhibitor is used in the zinc-sulfur separation stage, has a good inhibitory effect on pyrite and does not affect subsequent activation; the activator is hydrogen peroxide, which is used to de-inhibit and activate pyrite, has a strong activation effect, and has a simple structure, low cost, is environmentally friendly, and has strong practicality.

[0022] (2) The inhibitor baicalin used in the present invention is a flavonoid compound that is biodegradable, non-toxic, and environmentally friendly. It is mainly derived from the more common plant Scutellaria baicalensis. The organic inhibitor and its combined inhibitor described in the present invention have stable properties, good inhibitory effects, small dosages, safe use, strong adaptability, and broad application prospects. The activator cost is low, the dosage of the agent is low, the applicability is strong, and it is non-toxic and green.

[0023] (3) The inhibitory effect of the inhibitor and activator of the present invention is better than that of lime and sulfuric acid, and the concentrate grade and recovery rate are significantly improved when the dosage is less. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Flowchart of the flotation separation process of the present invention. DETAILED DESCRIPTION

[0025] The present invention is further described in detail below with reference to the accompanying drawings and specific embodiments, but the protection scope of the present invention is not limited to the contents described above.

[0026] Example 1

[0027] The Zn grade in the lead tailings from a lead-zinc sulfide ore is 1.28%, and the S grade is 6.95%. Among them, Zn mainly exists in the form of sphalerite, and S mainly exists in the form of pyrite. The lead tailings are used as feed ore. The separation process flow chart is as follows: Figure 1 , ore pulp to be flotated: float lead in the ore first to obtain lead tailings, which is the ore pulp to be flotated, and then perform the following operations:

[0028] (1) Zinc roughing: Add 400 g / t of ferrous sulfate to the pulp to be floated and react with the pulp for 3 minutes, 300 g / t of baicalin and 300 g / t of copper sulfate and 100 g / t of potassium butyl xanthate and 20 g / t of No. 2 oil and react with them for 3 minutes to obtain zinc roughing concentrate and zinc roughing tailings.

[0029] (2) Zinc scavenging: The zinc rougher tailings obtained in step (1) are scavenged three times. In the first scavenging, 150 g / t of copper sulfate is added to the pulp to react with the pulp for 3 minutes, 50 g / t of potassium butyl xanthate, and 10 g / t of No. 2 oil are added to the pulp to react with the pulp for 3 minutes. Before the second scavenging, 70 g / t of copper sulfate is added to the pulp to react with the pulp for 3 minutes, 20 g / t of potassium butyl xanthate, and 5 g / t of No. 2 oil are added to the pulp to react with the pulp for 3 minutes; before the third scavenging, 30 g / t of copper sulfate is added to the pulp to react with the pulp for 3 minutes, 10 g / t of potassium butyl xanthate, and 1 g / t of No. 2 oil are added to the pulp to react with the pulp for 3 minutes, and scavenging is performed. The concentrate of the first scavenging is returned to the zinc rougher, and the concentrates of the second and third scavenging are returned to the previous scavenging respectively. After the three scavengings are completed, zinc tailings are obtained.

[0030] (3) Zinc concentration: The zinc roughing concentrate obtained in step (1) is subjected to three rounds of concentration, and ferrous sulfate and baicalin are added before each round of concentration. The tailings of the first round of concentration are combined with the concentrate of the first round of scavenging and returned to the roughing, and the tailings of the second and third rounds of concentration are returned to the previous round of concentration, respectively. After the three rounds of concentration, the final zinc concentrate is obtained; wherein the amount of ferrous sulfate added in the three rounds of concentration is 200 g / t, 100 g / t, and 50 g / t, respectively, and the amount of baicalin added in the three rounds of concentration is 150 g / t, 80 g / t, and 40 g / t, respectively. Each agent is allowed to act for 3 minutes after addition.

[0031] (4) Sulfur roughing: 600 g / t of hydrogen peroxide was added to the zinc tailings obtained in step (2) and reacted with the pulp for 3 min, and 80 g / t of potassium butyl xanthate and 1.5 g / t of No. 2 oil were added to the pulp for 3 min, and sulfur roughing concentrate and sulfur roughing tailings were obtained by roughing.

[0032] (5) Sulfur concentration: The sulfur roughing concentrate obtained in step (4) is concentrated twice again, the tailings from the first concentration are returned to the sulfur roughing, and the tailings from the second concentration are returned to the first concentration operation. After the two concentrations are completed, the final sulfur concentrate is obtained.

[0033] (6) Sulfur scavenging: The sulfur roughing tailings obtained in step (4) are scavenged twice. During the first scavenging, 300 g / t of hydrogen peroxide is added to the sulfur roughing tailings to react with the slurry for 3 minutes, and 40 g / t of potassium butyl xanthate and 7 g / t of No. 2 oil are added to the slurry for 3 minutes; during the second scavenging, 150 g / t of hydrogen peroxide is added to react with the slurry for 3 minutes, and 20 g / t of potassium butyl xanthate and 3 g / t of No. 2 oil are added to react with the slurry for 3 minutes. The concentrate from the first scavenging is returned to the sulfur roughing, and the concentrate from the second scavenging is returned to the previous scavenging. After the two scavengings are completed, sulfur tailings are obtained.

[0034] Table 1 shows the amount of collector used in each flotation operation, Table 2 shows the amount of activator used in each flotation operation, and Table 3 shows the final flotation test results.

[0035] Table 1 Inhibitor dosage for each operation (g / t)

[0036] inhibitors Zinc roughing Zinc Select I Zinc Select II Zinc Select III total Baicalin 300 150 80 40 670 Ferrous sulfate 400 200 100 50 750

[0037] Table 2 Activator dosage for each operation (g / t)

[0038] Activator Sulfur roughing Sulfur Scavenging I Sulfur Sweep II total hydrogen peroxide 600 300 150 1050

[0039] Table 3 Flotation separation test results

[0040]

[0041] The zinc concentrate obtained had a Zn grade of 52.72%, a S grade of 27.67%, a Zn recovery rate of 91.02%, and a S recovery rate of 8.80%. The sulfur concentrate obtained had a Zn grade of 0.49%, a S grade of 46.49%, a Zn recovery rate of 5.13%, and a S recovery rate of 89.57%.

[0042] Comparative Example 1

[0043] For comparison, this comparative example differs from Example 1 in that lime is used as the depressant and sulfuric acid is used as the activator. The flotation steps and the amounts of other chemicals used are the same as those in Example 2. Table 4 shows the amount of depressant used in each flotation operation, Table 5 shows the amount of activator used in each flotation operation, and Table 6 shows the final flotation test results.

[0044] Table 4 Inhibitor dosage for each operation (g / t)

[0045] inhibitors Zinc roughing Zinc Select I Zinc Select II Zinc Select III total lime 3000 1500 750 380 5630

[0046] Table 5 Activation dosage for each operation (g / t)

[0047] Activator Sulfur roughing Sulfur Scavenging I Sulfur Sweep II total sulfuric acid 600 300 150 1050

[0048] Table 6 Flotation separation test results

[0049]

[0050] The zinc concentrate obtained had a Zn grade of 47.19%, a S grade of 33.82%, a Zn recovery rate of 87.74%, and a S recovery rate of 11.58%. The sulfur concentrate obtained had a Zn grade of 0.64%, a S grade of 42.03%, a Zn recovery rate of 7.13%, and a S recovery rate of 86.18%.

[0051] The comparison shows that the system using baicalin and hydrogen peroxide in Example 1 can achieve better flotation index than lime and sulfuric acid, indicating that baicalin has a stronger inhibitory effect on sulfur than lime and a better flotation effect on zinc. The activation effect of hydrogen peroxide is also stronger than that of sulfuric acid.

[0052] Example 2

[0053] The Zn grade in the copper-lead mixed tailings of a copper-lead-zinc sulfide ore is 1.36%, and the S grade is 7.68%. Among them, Zn mainly exists in the form of sphalerite, and S mainly exists in the form of pyrite. The lead tailings are used as feed ore. The separation process flow chart is as follows: Figure 1 . Pulp to be floated: The original ore is first subjected to copper-lead mixed flotation to obtain copper-lead mixed tailings. This copper-lead mixed tailings is the slurry to be floated, and then the following operations are performed:

[0054] (1) Zinc roughing: Add 500 g / t of ferrous sulfate to the pulp to be floated and react with the pulp for 3 minutes, 350 g / t of baicalin and 400 g / t of copper sulfate and react with the pulp for 3 minutes, 120 g / t of potassium butyl xanthate and 23 g / t of No. 2 oil and react with them for 3 minutes. After roughing, zinc roughing concentrate and zinc roughing tailings are obtained.

[0055] (2) Zinc scavenging: The zinc rougher tailings obtained in step (1) are scavenged three times. In the first scavenging, 175 g / t of copper sulfate is added to the pulp to react with the pulp for 3 minutes, 60 g / t of potassium butyl xanthate, and 13 g / t of No. 2 oil are added to the pulp to react with the pulp for 3 minutes; before the second scavenging, 80 g / t of copper sulfate is added to the pulp to react with the pulp for 3 minutes, 30 g / t of potassium butyl xanthate, and 8 g / t of No. 2 oil are added to the pulp to react with the pulp for 3 minutes; before the third scavenging, 40 g / t of copper sulfate is added to the pulp to react with the pulp for 3 minutes, 15 g / t of potassium butyl xanthate, and 4 g / t of No. 2 oil are added to the pulp to react with the pulp for 3 minutes to carry out scavenging; the concentrate of the first scavenging is returned to the zinc rougher, and the concentrates of the second and third scavenging are returned to the previous scavenging respectively. After the three scavengings are completed, zinc tailings are obtained.

[0056] (3) Zinc concentration: The zinc rougher concentrate obtained in step (1) was subjected to three rounds of concentration. Ferrous sulfate and baicalin were added before each round of concentration. The tailings from the first round of concentration were combined with the concentrate from the first round of scavenging and returned to the zinc rougher. The tailings from the second and third rounds of concentration were returned to the previous round of concentration. After the three rounds of concentration, the final zinc concentrate was obtained. The amount of ferrous sulfate added in the three rounds of concentration was 250 g / t, 130 g / t, and 65 g / t, respectively. The amount of baicalin added in the three rounds of concentration was 180 g / t, 90 g / t, and 45 g / t, respectively. Each agent was allowed to react for 3 minutes after addition.

[0057] (4) Sulfur roughing: 700 g / t of hydrogen peroxide was added to the zinc tailings obtained in step (2) and reacted with the slurry for 3 minutes, and 100 g / t of potassium butyl xanthate and 18 g / t of No. 2 oil were added to the slurry for 3 minutes to obtain sulfur roughing concentrate and sulfur roughing tailings.

[0058] (5) Sulfur concentration: The sulfur roughing concentrate obtained in step (4) is concentrated twice again, the tailings from the first concentration are returned to the sulfur roughing, and the tailings from the second concentration are returned to the first concentration operation. After the two concentrations are completed, the final sulfur concentrate is obtained.

[0059] (6) Sulfur scavenging: The sulfur roughing tailings obtained in step (4) are scavenged twice. During the first scavenging, 350 g / t of hydrogen peroxide is added to the sulfur roughing tailings to react with the slurry for 3 minutes, and 50 g / t of potassium butyl xanthate and 8 g / t of No. 2 oil are added to the slurry to react with the slurry for 3 minutes; during the second scavenging, 180 g / t of hydrogen peroxide is added to react with the slurry for 3 minutes, and 25 g / t of potassium butyl xanthate and 4 g / t of No. 2 oil are added to react with the slurry for 3 minutes; the concentrate from the first scavenging is returned to the sulfur roughing, and the concentrate from the second scavenging is returned to the previous scavenging. After the two scavengings are completed, sulfur tailings are obtained.

[0060] Table 7 shows the amount of collector used in each flotation operation, Table 8 shows the amount of activator used in each flotation operation, and Table 9 shows the final flotation test results.

[0061] Table 7 Inhibitor dosage for each operation (g / t)

[0062] inhibitors Zinc roughing Zinc Select I Zinc Select II Zinc Select III total Baicalin 350 180 90 45 665 Ferrous sulfate 500 250 130 65 945

[0063] Table 8 Activator dosage for each operation (g / t)

[0064] Activator Sulfur roughing Sulfur Scavenging I Sulfur Sweep II total hydrogen peroxide 700 350 180 1230

[0065] Table 9 Flotation separation test results

[0066]

[0067] The zinc concentrate obtained had a Zn grade of 52.97%, a S grade of 28.37%, a Zn recovery rate of 90.75%, and an S recovery rate of 8.61%. The sulfur concentrate obtained had a Zn grade of 0.48%, a S grade of 47.91%, a Zn recovery rate of 5.11%, and a S recovery rate of 90.27%.

[0068] Comparative Example 2

[0069] For comparison, the difference between this comparative example and Example 2 is that the inhibitor used in this comparative example is lime, the activator is sulfuric acid, and the flotation steps and the dosages of other chemicals are the same as those in Example 2. Table 10 shows the dosage of the inhibitor in each flotation operation, Table 11 shows the dosage of the activator in each flotation operation, and Table 12 shows the final flotation test results.

[0070] Table 10 Inhibitor dosage for each operation (g / t)

[0071] inhibitors Zinc roughing Zinc Select I Zinc Select II Zinc Select III total lime 4000 2000 1000 500 7500

[0072] Table 11 Activation dosage for each operation (g / t)

[0073] Activator Sulfur roughing Sulfur Scavenging I Sulfur Sweep II total sulfuric acid 800 400 200 1400

[0074] Table 12 Flotation separation test results

[0075]

[0076] The zinc concentrate obtained had a Zn grade of 45.72%, a S grade of 35.78%, a Zn recovery rate of 88.75%, and a S recovery rate of 12.30%. The sulfur concentrate obtained had a Zn grade of 0.58%, a S grade of 43.27%, a Zn recovery rate of 6.50%, and a S recovery rate of 85.81%.

[0077] Example 3

[0078] The Zn grade in the lead tailings from a lead-zinc sulfide ore is 1.08%, and the S grade is 8.56%. Among them, Zn mainly exists in the form of sphalerite, and S mainly exists in the form of pyrite. The lead tailings are used as feed ore. The separation process flow chart is as follows: Figure 1 . Pulp to be floated: The raw ore is floated with lead first to obtain lead tailings. This lead tailings is the slurry to be floated, and then the following operations are carried out:

[0079] (1) Zinc roughing: Add 600 g / t of ferrous sulfate to the pulp to be floated and react with the pulp for 3 minutes, 400 g / t of baicalin and 500 g / t of copper sulfate and react with the pulp for 3 minutes, 140 g / t of potassium butyl xanthate and 25 g / t of No. 2 oil and react with them for 3 minutes. After roughing, zinc roughing concentrate and zinc roughing tailings are obtained.

[0080] (2) Zinc scavenging: The zinc rougher tailings obtained in step (1) are scavenged three times. In the first scavenging, 200 g / t of copper sulfate is added to the pulp and reacted with the pulp for 3 minutes, 70 g / t of potassium butyl xanthate, and 15 g / t of No. 2 oil are added to the pulp and reacted with the pulp for 3 minutes; before the second scavenging, 100 g / t of copper sulfate is added to the pulp and reacted with the pulp for 3 minutes, 40 g / t of potassium butyl xanthate, and 10 g / t of No. 2 oil are added to the pulp and reacted with the pulp for 3 minutes; before the third scavenging, 50 g / t of copper sulfate is added to the pulp and reacted with the pulp for 3 minutes, 20 g / t of potassium butyl xanthate, and 5 g / t of No. 2 oil are added to the pulp and reacted with the pulp for 3 minutes to carry out scavenging. The concentrate from the first scavenging is returned to the zinc rougher, and the concentrates from the second and third scavenging are returned to the previous scavenging respectively. After the three scavengings are completed, zinc tailings are obtained.

[0081] (3) Zinc concentration: The zinc rougher concentrate obtained in step (1) is subjected to three rounds of concentration. Ferrous sulfate and baicalin are added before each round of concentration. The tailings of the first round of concentration are returned to the zinc rougher concentration, and the tailings of the second and third rounds of concentration are returned to the previous round of concentration. After the three rounds of concentration, the final zinc concentrate is obtained. The amount of ferrous sulfate added in the three rounds of concentration is 300 g / t, 150 g / t, and 75 g / t, respectively; the amount of baicalin added in the three rounds of concentration is 200 g / t, 100 g / t, and 50 g / t, respectively. Each agent is allowed to act for 3 minutes after addition.

[0082] (4) Sulfur roughing: 800 g / t of hydrogen peroxide was added to the zinc tailings obtained in step (2) and reacted with the pulp for 3 minutes, and 120 g / t of potassium butyl xanthate and 20 g / t of No. 2 oil were added to the pulp for 3 minutes to obtain sulfur roughing concentrate and sulfur roughing tailings.

[0083] (5) Sulfur concentration: The sulfur roughing concentrate obtained in step (4) is concentrated twice again, the tailings from the first concentration are returned to the sulfur roughing, and the tailings from the second concentration are returned to the first concentration operation. After the two concentrations are completed, the final sulfur concentrate is obtained.

[0084] (6) Sulfur scavenging: The sulfur roughing tailings obtained in step (4) are scavenged twice. During the first scavenging, 400 g / t of hydrogen peroxide is added to the sulfur roughing tailings to react with the slurry for 3 minutes, and 60 g / t of potassium butyl xanthate and 10 g / t of No. 2 oil are added to the slurry to react with the slurry for 3 minutes; during the second scavenging, 200 g / t of hydrogen peroxide is added to react with the slurry for 3 minutes, and 30 g / t of potassium butyl xanthate and 5 g / t of No. 2 oil are added to react with the slurry for 3 minutes; the concentrate from the first scavenging is returned to the sulfur roughing, and the concentrate from the second scavenging is returned to the previous scavenging. After the two scavengings are completed, sulfur tailings are obtained.

[0085] Table 13 shows the amount of collector used in each flotation operation, Table 14 shows the amount of activator used in each flotation operation, and Table 15 shows the final flotation test results.

[0086] Table 13 Inhibitor dosage for each operation (g / t)

[0087] inhibitors Zinc roughing Zinc Select I Zinc Select II Zinc Select III total Baicalin 400 200 100 50 750 Ferrous sulfate 600 300 150 75 1125

[0088] Table 14 Activator dosage for each operation (g / t)

[0089] Activator Sulfur roughing Sulfur Scavenging I Sulfur Sweep II total hydrogen peroxide 800 400 200 1400

[0090] Table 15 Flotation separation test results

[0091]

[0092] The zinc concentrate obtained had a Zn grade of 49.05%, a S grade of 30.21%, a Zn recovery rate of 91.29%, and a S recovery rate of 7.09%. The sulfur concentrate obtained had a Zn grade of 0.26%, a S grade of 49.18%, a Zn recovery rate of 3.81%, and a S recovery rate of 90.89%.

[0093] Comparative Example 3

[0094] For comparison, this comparative example differs from Example 3 in that lime is used as the depressant and sulfuric acid is used as the activator. The flotation steps and the amounts of other chemicals used are the same as those in Example 3. Table 16 shows the amount of depressant used in each flotation operation, Table 17 shows the amount of activator used in each flotation operation, and Table 8 shows the final flotation test results.

[0095] Table 16 Inhibitor dosage for each operation (g / t)

[0096] inhibitors Zinc roughing Zinc Select I Zinc Select II Zinc Select III total lime 5000 2500 1200 600 9300

[0097] Table 17 Activation dosage for each operation (g / t)

[0098] Activator Sulfur roughing Sulfur Selection I Sulfur Selection II total sulfuric acid 1000 500 250 1750

[0099] Table 18 Flotation separation test results

[0100]

[0101] The zinc concentrate obtained had a Zn grade of 42.07%, a S grade of 37.96%, a Zn recovery rate of 86.87%, and a S recovery rate of 9.89%. The sulfur concentrate obtained had a Zn grade of 0.48%, a S grade of 43.86%, a Zn recovery rate of 7.50%, and a S recovery rate of 86.44%.

[0102] Tests have shown that the inhibitor used in the present invention has a stronger inhibitory effect on pyrite than lime under optimal dosage conditions, and both the concentrate grade and recovery rate have been significantly improved. The dosage of the activator used in the present invention is much lower than that of sulfuric acid, and the activation effect on pyrite is obvious, and the sulfur concentrate grade and recovery rate are significantly improved. The organic inhibitor and its combined inhibitor described in the present invention have stable properties, good inhibitory effect, small dosage, safe use, strong adaptability, and broad application prospects. The activator has low cost, low dosage, strong applicability, and is non-toxic and environmentally friendly.

[0103] The contents illustrated in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various simple modifications, equivalent changes and modifications to the present invention made by those skilled in the art all fall within the scope defined by the claims attached to this application.

Claims

1. A method for separating sphalerite and pyrite from lead tailings by flotation, characterized in that: The mixed system of ferrous sulfate and baicalin is an inhibitor of pyrite, and hydrogen peroxide is an inhibitor of pyrite decomposition; The specific steps are as follows: (1) Zinc roughing: ferrous sulfate, baicalin, copper sulfate, potassium butyl xanthate and No. 2 oil are sequentially added to the lead tailings for roughing to obtain zinc roughing concentrate and zinc roughing tailings; (2) Zinc scavenging: copper sulfate, potassium butyl xanthate and No. 2 oil are added to the zinc roughing tailings obtained in step (1) to carry out scavenging for three times, and the scavenged concentrate from the first scavenging operation is returned to the zinc roughing operation, and the other scavenged concentrates are returned to the previous level in turn to finally obtain zinc tailings; (3) Zinc concentration: adding ferrous sulfate and baicalin to the zinc rougher concentrate obtained in step (1) to inhibit pyrite, and performing three concentrations, returning the concentrated tailings of the first concentration operation to the zinc rougher operation, and returning the tailings of other concentration operations to the previous level in turn, and performing three concentrations to obtain the final zinc concentrate; (4) Sulfur roughing: adding hydrogen peroxide, potassium butyl xanthate and No. 2 oil to the zinc tailings obtained in step (2) to perform a roughing operation to obtain a sulfur roughing concentrate and sulfur roughing tailings; (5) Sulfur concentration: The sulfur roughing concentrate obtained in step (4) is concentrated twice again, and the tailings from the first concentration are returned to the sulfur roughing operation, and the tailings from the second concentration are returned to the first concentration operation; (6) Sulfur scavenging: hydrogen peroxide, potassium butyl xanthate and No. 2 oil are added to the sulfur roughing tailings obtained in step (4) to carry out two scavenging operations, the scavenged concentrate from the first scavenging operation is returned to the sulfur roughing operation, and the scavenged concentrate from the second scavenging operation is returned to the first scavenging operation. After the two scavenging operations are completed, sulfur tailings are obtained.

2. The method for separating sphalerite and pyrite from lead tailings by flotation according to claim 1, wherein: In step (1), the amount of ferrous sulfate is 400-600 g / t, the amount of baicalin is 300-400 g / t, the amount of copper sulfate is 300-500 g / t, the amount of potassium butyl xanthate is 100-140 g / t, and the amount of No. 2 oil is 20-25 g / t.

3. The method for separating sphalerite and pyrite from lead tailings by flotation according to claim 1, wherein: During the first sweep in step (2), the amount of copper sulfate used is 150-200 g / t, the amount of potassium butyl xanthate used is 50-70 g / t, and the amount of No. 2 oil used is 10-15 g / t; during the second sweep, the amount of copper sulfate used is 70-100 g / t, the amount of potassium butyl xanthate used is 20-40 g / t, and the amount of No. 2 oil used is 5-10 g / t; during the third sweep, the amount of copper sulfate used is 30-50 g / t, the amount of potassium butyl xanthate used is 10-20 g / t, and the amount of No. 2 oil used is 1-5 g / t.

4. The method for separating sphalerite and pyrite from lead tailings by flotation according to claim 1, wherein: In step (3), during the first selection, the amount of ferrous sulfate is 200-300 g / t, and the amount of baicalin is 150-200 g / t; during the second selection, the amount of ferrous sulfate is 100-150 g / t, and the amount of baicalin is 80-100 g / t; during the third selection, the amount of ferrous sulfate is 50-75 g / t, and the amount of baicalin is 40-50 g / t.

5. The method for separating sphalerite and pyrite from lead tailings by flotation according to claim 1, wherein: In step (4), the amount of hydrogen peroxide used is 600-800 g / t, the amount of potassium butyl xanthate used is 80-120 g / t, and the amount of No. 2 oil used is 15-20 g / t.

6. The method for separating sphalerite and pyrite from lead tailings by flotation according to claim 1, wherein: During the first sweep in step (6), the amount of hydrogen peroxide used is 300-400 g / t, the amount of potassium butyl xanthate used is 40-60 g / t, and the amount of No. 2 oil used is 7-10 g / t; during the second sweep, the amount of hydrogen peroxide used is 150-200 g / t, the amount of potassium butyl xanthate used is 20-30 g / t, and the amount of No. 2 oil used is 3-5 g / t.

7. The method for separating sphalerite and pyrite from lead tailings by flotation according to claim 1, wherein: In each step, each agent was added and allowed to react for at least 3 minutes before the next agent was added.

Images