Combined inhibitor for sphalerite in lead-zinc separation and application of combined inhibitor

Abstract

The invention discloses a combined inhibitor for sphalerite in lead-zinc separation and application of the combined inhibitor. The combined inhibitor comprises caramel pigment and zinc sulfate, the combined inhibitor is used for flotation separation of galena and sphalerite as a sphalerite inhibitor. The method comprises the following steps: crushing and grinding raw ore to achieve monomer dissociation between the minerals, mixing the pulp to obtain ore pulp to be floated, and sequentially adding a combined inhibitor caramel pigment and zinc sulfate, a collecting agent and a foaming agent into the ore pulp to carry out lead flotation operation to obtain lead concentrate and lead tailings. And an activating agent, a collecting agent and a foaming agent are sequentially added into the lead tailings for zinc flotation operation, and zinc concentrate and zinc tailings are obtained. The combined inhibitor has a strong inhibition effect on sphalerite and can effectively realize flotation separation of galena and sphalerite, the zinc sulfate is added to inhibit the sphalerite, the inhibition of caramel pigment on the sphalerite is enhanced, the use amount of the caramel pigment is reduced, and the mineral separation cost is reduced while the separation effect of lead-zinc sulfide ore is improved.

Description

Technical Field

[0001] The invention relates to a combined inhibitor of sphalerite in lead-zinc separation and application thereof, belonging to the technical field of mineral processing agents. Background Art

[0002] Lead and zinc are important nonferrous metal raw materials, playing a crucial role in national economic development. Galena and sphalerite are the primary resources for lead and zinc separation and extraction. Galena naturally floats better than sphalerite, so separation of galena and sphalerite typically prioritizes galena over sphalerite. However, with rapid economic development, the demand for lead and zinc concentrates continues to increase, leading to resource depletion and an increasingly dilute ore. The separation of fine lead-zinc sulfide ores requires extensive grinding, which results in excessively small particle size, significantly reducing the floatation rate.

[0003] Sphalerite inhibitors are mainly divided into organic inhibitors and inorganic inhibitors. Inorganic inhibitors for sphalerite mainly include cyanide, zinc sulfate, and sodium sulfite. These inorganic inhibitors can significantly increase the hydrophilicity of the sphalerite surface. However, they are toxic, require large dosages, and have adverse environmental impacts. Organic inhibitors for sphalerite offer advantages such as a wide variety and environmental friendliness. Examples include dextrin, tannin, lignin sulfonate, starch, and sodium humate. Mineral processing workers have discovered that combining inorganic and organic inhibitors can leverage the advantages of each, further enhancing the inhibitory effect on sphalerite. The development of new combined inhibitors is of great significance for improving copper-zinc separation reagent systems, saving reagent costs, increasing the utilization rate of copper and zinc metal resources, and reducing environmental pollution. Summary of the Invention

[0004] In response to the deficiencies in the prior art, the present invention provides a combined inhibitor of sphalerite in lead-zinc separation. The combined inhibitor of the present invention comprises caramel pigment and conventional inhibitor zinc sulfate, is naturally degradable, and is environmentally friendly.

[0005] The combined depressant of the present invention is used as a sphalerite depressant for flotation separation of galena and sphalerite, wherein the mass ratio of caramel pigment to zinc sulfate is (3-5):1.

[0006] The present invention provides an application of the combined depressant in the flotation separation of lead-zinc sulfide ores, and the specific steps are as follows:

[0007] (1) Crushing and grinding the raw ore until the monomers between the minerals are dissociated and then slurry is prepared;

[0008] (2) adding a combined inhibitor, caramel pigment and zinc sulfate, a collector, and a frother to the slurry in sequence to perform lead flotation to obtain lead concentrate and lead tailings;

[0009] (3) Adding an activator, a collector, and a frother to the lead tailings in sequence to carry out zinc flotation operations to obtain zinc concentrate and tailings.

[0010] In step (1) of the present invention, the ore is ground to a particle fineness of -0.074 mm, accounting for 78% to 82%.

[0011] The lead flotation process in step (2) includes one roughing process, two scavenging processes, and two concentrating processes. The zinc flotation process in step (3) includes one roughing process, two scavenging processes, and two concentrating processes. The middlings are sequentially returned to the previous process, forming a closed circuit.

[0012] In step (2), the collector is ethyl xanthate, the foaming agent is 2# oil, wherein the amount of caramel pigment as the roughing combination inhibitor is 1500-2000 g / t, the amount of zinc sulfate is 400-500 g / t, the amount of ethyl xanthate is 300-350 g / t, and the amount of 2# oil is 30-35 g / t, the amount of caramel pigment as the combination inhibitor in the selection I is 750-1000 g / t, the amount of zinc sulfate is 200-250 g / t, the amount of ethyl xanthate in the scavenging I is 150-200 g / t, and the amount of 2# oil is 15-20 g / t; step In step (3), the activator is copper sulfate, the collector is butyl xanthate, and the foaming agent is 2# oil. The amount of copper sulfate used in the roughing process is 300-350 g / t, the amount of butyl xanthate used is 200-300 g / t, and the amount of 2# oil used is 20-30 g / t. The amount of copper sulfate used in the scavenging process I is 150-200 g / t, the amount of butyl xanthate used is 100-200 g / t, and the amount of 2# oil used is 10-15 g / t. The amount of copper sulfate used in the scavenging process II is 50-100 g / t, the amount of butyl xanthate used is 25-50 g / t, and the amount of 2# oil used is 5-10 g / t.

[0013] In the steps (2) and (3) of the present invention, the reagent is configured as a 1% mass concentration aqueous solution and added. Each roughing operation takes 5-6 minutes, each sweeping operation takes 4-5 minutes, and each fine selection operation takes 5-6 minutes.

[0014] No. 2 oil is added according to the weight required for the actual ore volume.

[0015] Principle of the present invention: The combined inhibitor of the present invention includes caramel pigment and zinc sulfate. The present invention mainly utilizes the synergistic inhibitory effect between caramel pigment and zinc sulfate. Caramel pigment belongs to the furanone class of organic compounds and contains a hydroxyl group. The double bond O atom can undergo a coordination reaction with the Zn site on the surface of sphalerite, and is stably adsorbed on the surface of sphalerite, thereby enhancing the hydrophilicity of the sphalerite surface. The coordination ability of caramel pigment with the Zn site is stronger than that of the Pb site on the surface of galena, so that the caramel pigment is less adsorbed on the surface of galena, increasing the difference in hydrophilicity between galena and sphalerite. In addition, zinc sulfate is hydrolyzed in the slurry to form zinc hydroxide colloid, which is adsorbed on the mineral surface, which not only enhances the hydrophilicity of the sphalerite surface, but also increases the active sites of zinc on the surface of sphalerite, increases the adsorption density of caramel pigment, prevents it from reacting with the collector, and further achieves the inhibition of sphalerite.

[0016] Beneficial effects of the present invention:

[0017] (1) The combined inhibitor provided by the present invention is composed of caramel pigment and zinc sulfate. The combined inhibitor has the advantages of good water solubility, wide source, and biodegradability, avoiding the problems of traditional inorganic inhibitors such as high toxicity and serious environmental pollution.

[0018] (2) The combined inhibitor of the present invention is combined in a certain proportion as a sphalerite inhibitor. Through the synergistic effect between the two agents, it is applied to the flotation separation of lead-zinc sulfide ores, with good separation effect and high concentrate grade, which is of great significance to the efficient recovery and utilization of lead-zinc sulfide ores. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is a process flow chart of an embodiment of the present invention. DETAILED DESCRIPTION

[0020] Example 1: This Example 1 conducted a flotation separation test on a lead-zinc sulfide ore from Inner Mongolia. The ore contained 2.13-2.18% Pb and 2.87-2.91% Zn. The lead in the ore existed primarily as galena, the zinc primarily as sphalerite, and the gangue minerals were primarily quartz.

[0021] Example 1-1 uses a combined inhibitor caramel pigment and zinc sulfate as a sphalerite inhibitor for lead and zinc separation, with a mass ratio of 3:1. Figure 1 The specific steps are as follows:

[0022] (1) crushing and grinding the lead-zinc sulfide ore to a fineness of -0.074 mm accounting for 78% to obtain a pulp to be flotated;

[0023] (2) adding a combined inhibitor of caramel pigment and zinc sulfate, a collector of ethyl xanthate, and a foaming agent of 2# oil to the ore pulp to be floated in step (1) in sequence to perform a lead roughing operation, wherein the roughing time is 7 minutes, and a lead rough concentrate and a lead rough tailing are obtained, wherein the amount of caramel pigment is 1500 g / t, the amount of zinc sulfate is 500 g / t, the amount of ethyl xanthate is 300 g / t, and the amount of 2# oil is 30 g / t;

[0024] (3) adding a combined inhibitor, caramel pigment and zinc sulfate, to the lead rough concentrate in step (2) to perform lead concentration I, wherein the amount of caramel pigment used is 750 g / t and the amount of zinc sulfate used is 250 g / t. The lead concentration I concentrate is subjected to a blank concentration again to obtain lead concentration II, thereby obtaining a final lead concentrate. Each concentration operation time is 6 minutes, wherein the middlings of lead concentration I and II are returned to the lead roughing and lead concentration I, respectively, to form a closed loop;

[0025] (4) Adding a collector ethyl xanthate and a foaming agent 2# oil to the lead rough tailings in step (2) to carry out lead scavenging I, with the amount of ethyl xanthate used being 150 g / t and the amount of 2# oil used being 15 g / t. The tailings of lead scavenging I are subjected to another blank scavenging, which is lead scavenging II. Each scavenging operation lasts for 5 minutes, wherein the middlings of lead scavenging I and II are returned to the lead roughing and lead scavenging I, respectively, to form a closed circuit;

[0026] (5) adding copper sulfate as an activator, butyl xanthate as a collector, and 2# oil as a foaming agent to the lead scavenging II tailings in step (4) in sequence to perform zinc roughing operation, the roughing time being 7 minutes, to obtain zinc rough concentrate and zinc rough tailings, wherein the amount of copper sulfate used is 300 g / t, the amount of butyl xanthate used is 200 g / t, and the amount of 2# oil used is 20 g / t;

[0027] (6) The zinc rough concentrate in step (5) is subjected to two blank concentrations, each concentration operation time is 6 minutes, to obtain the final zinc concentrate, wherein the middlings of zinc concentration I and II are returned to the zinc rougher and zinc concentration I respectively, forming a closed circuit;

[0028] (7) To the zinc rough tailings in step (5), activator copper sulfate, collector butyl xanthate and foaming agent 2# oil were added in sequence to carry out zinc scavenging I, wherein the amount of copper sulfate, the amount of butyl xanthate and the amount of 2# oil were 150 g / t, 100 g / t and 10 g / t, and the zinc scavenging I tailings were further added with activator copper sulfate, collector butyl xanthate and foaming agent 2# oil to carry out zinc scavenging II, wherein the amount of copper sulfate, the amount of butyl xanthate and the amount of 2# oil were 50 g / t, 25 g / t and 5 g / t, and each scavenging operation time was 5 minutes, wherein the middlings of zinc scavenging I and II were returned to zinc roughing and zinc scavenging I respectively, forming a closed circuit, and the product indicators are shown in Table 1.

[0029] Comparative Example 1-2: The conventional inhibitor zinc sulfate was used as the sphalerite inhibitor for lead-zinc separation, wherein the addition amount of zinc sulfate in lead roughing and lead concentration I was 2000 g / t and 1000 g / t, respectively. Other process conditions remained unchanged. The product indicators are shown in Table 1.

[0030] Table 1 Flotation separation results of Example 1

[0031]

[0032] As can be seen from Table 1, under the condition of the lowest reagent dosage, the combined inhibitor caramel color and zinc sulfate reduced the zinc grade in the lead concentrate by 7.08 percentage points and increased the lead grade by 4.78 percentage points compared to zinc sulfate alone. At the same time, the lead recovery rate increased by 2.65 percentage points. This shows that under the same conditions, the combined inhibitor caramel color and zinc sulfate has a stronger inhibitory effect on sphalerite than zinc sulfate alone.

[0033] Example 2: This Example 2 conducted a flotation separation test on a lead-zinc sulfide ore in Yunnan. The raw ore contained 3.05-3.15% Pb and 4.40-4.50% Zn. The lead in the ore existed primarily as galena, the zinc primarily as sphalerite, and the gangue minerals primarily included quartz and dolomite.

[0034] Example 2-1 uses a combined inhibitor caramel pigment and zinc sulfate as a sphalerite inhibitor for lead and zinc separation, with a mass ratio of 5:1. Figure 1 The specific steps are as follows:

[0035] (1) crushing and grinding the lead-zinc sulfide ore to a fineness of -0.074 mm, accounting for 82%, to obtain a pulp to be flotated;

[0036] (2) adding a combined inhibitor of caramel pigment and zinc sulfate, a collector of ethyl xanthate, and a frother 2# oil to the slurry to be floated in step (1) in sequence to perform a lead roughing operation, with the roughing time being 7 minutes, to obtain a lead concentrate and a lead tailing. The amount of caramel pigment used is 2000 g / t, the amount of zinc sulfate used is 400 g / t, the amount of ethyl xanthate used is 350 g / t, and the amount of 2# oil used is 35 g / t;

[0037] (3) adding a combined inhibitor, caramel pigment and zinc sulfate, to the lead rough concentrate in step (2) to perform lead concentration I, wherein the amount of caramel pigment used is 1000 g / t and the amount of zinc sulfate used is 200 g / t, and the lead concentration I concentrate is subjected to a blank concentration again to obtain lead concentration II, thereby obtaining a final lead concentrate. Each concentration operation time is 6 minutes, wherein the middlings of lead concentration I and II are respectively returned to the lead roughing and lead concentration I, forming a closed loop;

[0038] (4) adding a collector ethyl xanthate and a foaming agent 2# oil to the lead rough tailings in step (2) to carry out lead scavenging I, wherein the amount of ethyl xanthate is 200 g / t and the amount of 2# oil is 20 g / t, and the lead scavenging I tailings are subjected to a blank scavenging again, namely lead scavenging II, and each scavenging operation time is 5 minutes, wherein the middlings of lead scavenging I and II are respectively returned to the lead roughing and lead scavenging I, forming a closed circuit;

[0039] (5) copper sulfate as an activator, butyl xanthate as a collector, and 2# oil as a foaming agent are sequentially added to the lead scavenging II tailings in step (4) to perform zinc roughing operation. The roughing time is 7 minutes to obtain zinc rough concentrate and zinc rough tailings. The amount of copper sulfate used is 350 g / t, the amount of butyl xanthate used is 300 g / t, and the amount of 2# oil used is 30 g / t;

[0040] (6) The zinc rough concentrate in step (5) is subjected to two blank concentrations, each concentration operation time is 6 minutes, to obtain the final zinc concentrate, wherein the middlings of zinc concentration I and II are returned to the zinc rougher and zinc concentration I respectively, forming a closed circuit;

[0041] (7) The zinc rough tailings in step (5) were sequentially added with copper sulfate as an activator, butyl xanthate as a collector, and 2# oil as a foaming agent to carry out zinc scavenging I, wherein the amount of copper sulfate, butyl xanthate, and 2# oil was 200 g / t, 200 g / t, and 15 g / t, respectively. The zinc scavenging I tailings were further added with copper sulfate as an activator, butyl xanthate as a collector, and 2# oil as a foaming agent to carry out zinc scavenging II, wherein the amount of copper sulfate, butyl xanthate, and 10 g / t, 2# oil were 100 g / t, 50 g / t, and 10 g / t, respectively. Each scavenging operation lasted 5 minutes, wherein the middlings from zinc scavenging I and II were returned to the zinc roughing and zinc scavenging I, respectively, to form a closed circuit. The product indicators are shown in Table 2.

[0042] Comparative Example 2-2: The conventional inhibitor zinc sulfate was used as the sphalerite inhibitor for lead-zinc separation, wherein the addition amount of zinc sulfate in lead roughing and lead concentration I was 2500 g / t and 1500 g / t, respectively. Other process conditions remained unchanged. The product indicators are shown in Table 2.

[0043] Table 2 Flotation separation results of Example 2

[0044]

[0045] Table 2 shows that, under the lowest reagent dosage conditions, the combined inhibitors of caramel color and zinc sulfate reduced the zinc grade in the lead concentrate by 3.66 percentage points, increased the lead grade by 6.14 percentage points, and improved the lead recovery by 3.49 percentage points compared to zinc sulfate alone. This indicates that under the same conditions, the combined inhibitors of caramel color and zinc sulfate are more effective in inhibiting sphalerite than zinc sulfate alone.

[0046] Example 3: This Example 3 conducted a flotation separation test on a lead-zinc sulfide ore in Yunnan. The ore contained 2.90-2.95% Pb and 2.77-2.82% Zn. The lead in the ore existed primarily as galena, the zinc primarily as sphalerite, and the gangue mineral was primarily quartz.

[0047] Example 3: Combined inhibitor caramel pigment and zinc sulfate are used as sphalerite inhibitors for lead and zinc separation. The mass ratio of the two is 4:1. Figure 1 The specific steps are as follows:

[0048] (1) crushing and grinding the lead-zinc sulfide ore to a fineness of -0.074 mm, accounting for 80%, to obtain a pulp to be flotated;

[0049] (2) adding a combined inhibitor of caramel pigment and zinc sulfate, a collector of ethyl xanthate, and a frother 2# oil to the slurry to be floated in step (1) in sequence to perform a lead roughing operation, with the roughing time being 7 minutes, to obtain a lead concentrate and a lead tailing. The amount of caramel pigment used is 1800 g / t, the amount of zinc sulfate used is 450 g / t, the amount of ethyl xanthate used is 325 g / t, and the amount of 2# oil used is 32 g / t;

[0050] (3) adding a combined inhibitor, caramel pigment and zinc sulfate, to the lead rough concentrate in step (2) to perform lead concentration I, wherein the amount of caramel pigment used is 900 g / t and the amount of zinc sulfate used is 225 g / t. The lead concentration I concentrate is subjected to a blank concentration again to obtain lead concentration II, thereby obtaining a final lead concentrate. Each concentration operation time is 6 minutes, wherein the middlings of lead concentration I and II are respectively returned to the lead roughing and lead concentration I, forming a closed loop;

[0051] (4) adding a collector ethyl xanthate and a foaming agent 2# oil to the lead rough tailings in step (2) to carry out lead scavenging I, wherein the amount of ethyl xanthate used is 175 g / t and the amount of 2# oil used is 17 g / t, and the lead scavenging I tailings are subjected to a blank scavenging again, namely lead scavenging II, and each scavenging operation time is 5 minutes, wherein the middlings of lead scavenging I and II are respectively returned to the lead roughing and lead scavenging I, forming a closed circuit;

[0052] (5) copper sulfate as an activator, butyl xanthate as a collector, and 2# oil as a foaming agent are sequentially added to the lead scavenging II tailings in step (4) to perform zinc roughing operation. The roughing time is 7 minutes to obtain zinc rough concentrate and zinc rough tailings. The amount of copper sulfate used is 325 g / t, the amount of butyl xanthate used is 250 g / t, and the amount of 2# oil used is 25 g / t;

[0053] (6) The zinc rough concentrate in step (5) is subjected to two blank concentrations, each concentration operation time is 6 minutes, to obtain the final zinc concentrate, wherein the middlings of zinc concentration I and II are returned to the zinc rougher and zinc concentration I respectively, forming a closed circuit;

[0054] (7) To the zinc rough tailings in step (5), activator copper sulfate, collector butyl xanthate and foaming agent 2# oil were added in sequence to carry out zinc scavenging I, wherein the amount of copper sulfate, butyl xanthate and 2# oil was 175 g / t, 150 g / t and 12 g / t, respectively. Activator copper sulfate, collector butyl xanthate and foaming agent 2# oil were added to the zinc scavenging I tailings to carry out zinc scavenging II, wherein the amount of copper sulfate, butyl xanthate and 2# oil were 75 g / t, 38 g / t and 7 g / t, respectively. Each scavenging operation lasted 5 minutes, wherein the middlings from zinc scavenging I and II were returned to zinc roughing and zinc scavenging I, respectively, to form a closed circuit. The product indicators are shown in Table 3.

[0055] Table 3 Flotation separation results of Example 3

[0056]

[0057]

Claims

1. A combined inhibitor of sphalerite in lead-zinc separation, characterized in that: The combination inhibitor includes caramel color and zinc sulfate.

2. The combined inhibitor of sphalerite in lead-zinc separation according to claim 1, characterized in that: The mass ratio of caramel pigment and zinc sulfate is (3-5):

1.

3. The combined inhibitor of sphalerite in lead-zinc separation according to claim 1, characterized in that: The combined depressant is used as a sphalerite depressant for flotation separation of galena and sphalerite.

4. A use of the combined inhibitor of sphalerite in lead-zinc separation according to claims 1 to 3, characterized in that: The specific steps are as follows: (1) Crushing and grinding the raw ore until the monomers between the minerals are dissociated and then slurry is prepared; (2) adding a combined inhibitor, caramel pigment and zinc sulfate, a collector, and a frother to the slurry in sequence to perform lead flotation to obtain lead concentrate and lead tailings; (3) Adding an activator, a collector, and a frother to the lead tailings in sequence to carry out zinc flotation operations to obtain zinc concentrate and tailings.

5. The use of the combined inhibitor of sphalerite in lead-zinc separation according to claim 4, characterized in that: Step (1) grinding the ore to a particle fineness of -0.074 mm, accounting for 78% to 82%.

6. The use of the combined inhibitor of sphalerite in lead-zinc separation according to claim 4, characterized in that: The lead flotation operation in step (2) includes one roughing, two scavenging and two concentrating operations, and the zinc flotation operation in step (3) includes one roughing, two scavenging and two concentrating operations.

7. The use of the combined inhibitor of sphalerite in lead-zinc separation according to claim 6, characterized in that: In step (2), the collector is ethyl xanthate, the foaming agent is 2# oil, wherein the amount of caramel pigment as the roughing combination inhibitor is 1500-2000 g / t, the amount of zinc sulfate is 400-500 g / t, the amount of ethyl xanthate is 300-350 g / t, and the amount of 2# oil is 30-35 g / t, the amount of caramel pigment as the combination inhibitor in the selection I is 750-1000 g / t, the amount of zinc sulfate is 200-250 g / t, the amount of ethyl xanthate in the scavenging I is 150-200 g / t, and the amount of 2# oil is 15-20 g / t; step In step (3), the activator is copper sulfate, the collector is butyl xanthate, and the foaming agent is 2# oil. The amount of copper sulfate used in the roughing process is 300-350 g / t, the amount of butyl xanthate used is 200-300 g / t, and the amount of 2# oil used is 20-30 g / t. The amount of copper sulfate used in the scavenging process I is 150-200 g / t, the amount of butyl xanthate used is 100-200 g / t, and the amount of 2# oil used is 10-15 g / t. The amount of copper sulfate used in the scavenging process II is 50-100 g / t, the amount of butyl xanthate used is 25-50 g / t, and the amount of 2# oil used is 5-10 g / t.

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