A flotation method for zinc sulfide in acid leaching residue of oxygen-sulfur mixed zinc concentrate

Abstract

The invention discloses a flotation method for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate, belonging to the field of residue flotation. The method mainly includes the following steps: using the leaching residue of oxygen-sulfur mixed zinc concentrate as the raw ore, adopting sodium hexametaphosphate and acidified water glass as regulators, conducting roughing tests without adding collectors and frothers to obtain roughing concentrates and roughing tailings; adding acidified water glass, butyl xanthate, and No. 2 oil in sequence during the cleaning process; adding butyl xanthate during the scavenging process. Through a closed-circuit flotation process of one roughing, two cleanings, and one scavenging, with the middlings returned in sequence, the effective enrichment and recovery of zinc metal in the leaching residue can be achieved.

Description

Technical Field

[0001] The present invention relates to a flotation method for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate, belonging to the field of slag ore dressing. Background Art

[0002] Zinc has good rolling properties, wear resistance and corrosion resistance, and is widely used in many fields. At present, about 80% - 85% of the world's zinc is obtained by the hydrometallurgical zinc smelting process. However, statistics show that for every 1 ton of zinc produced, 0.85 - 1.2 tons of leaching residue will be generated. These leaching residues are relatively fine in particle size and often contain many useful components, mainly un-leached zinc, as well as valuable metals such as gold, silver, and lead, and have high recycling value.

[0003] Oxygen-sulfur mixed zinc concentrate is obtained by synchronously flotation of oxygen-sulfur mixed lead-zinc ore, which contains both zinc oxide and zinc sulfide. Since zinc sulfide is insoluble in acid, in the conventional hydrometallurgical zinc smelting process, it is inevitable that some zinc sulfide will enter the leaching residue. Returning these leaching residues directly to the original process will reduce the leaching efficiency, and direct stacking or burying treatment will not only cause waste of resources, but also pose risks such as the dissolution of heavy metal ions. Currently, the common treatment methods for zinc acid leaching residues mainly include pyrometallurgical and hydrometallurgical processes. However, these treatment processes often have problems such as complex processes and high energy consumption.

[0004] In recent years, researchers have tried to use flotation method to recover zinc sulfide in zinc acid leaching residue. Compared with the traditional pyrometallurgical and hydrometallurgical processes for treating zinc acid leaching residue, the flotation method has the advantages of simple process, large processing capacity, low production cost, high return rate, etc. However, due to a series of reactions that zinc materials undergo during the acid leaching process, the physical and chemical properties of each component in the acid leaching residue have changed significantly; in addition, a large amount of ore dressing reagents remaining in the synchronous flotation process will also interfere with the flotation process of the acid leaching residue. Summary of the Invention

[0005] To solve the above problems, starting from the perspective of full recovery of mineral resources, the present invention designs a flotation process for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate, providing ideas for scientifically and effectively developing and utilizing industrial zinc acid leaching residue, reducing environmental pollution, and increasing enterprise benefits.

[0006] The object of the present invention is mainly achieved through the following technical solutions:

[0007] The present invention provides a flotation method for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate. The acid leaching residue of oxygen-sulfur mixed zinc concentrate is slurried to obtain an acid leaching residue pulp. Sodium hexametaphosphate and acidified water glass are sequentially added to the acid leaching residue pulp for rough selection to obtain a rough concentrate and a rough tailing. The rough concentrate is subjected to cleaning to obtain a cleaning middling and a zinc concentrate, and the rough tailing is subjected to scavenging to obtain a scavenging middling and a tailing.

[0008] Furthermore, the flotation method includes one rough selection, one to two scavenging selections, and one cleaning selection, and the middlings from the scavenging selections and the cleaning selections are returned in sequence.

[0009] Furthermore, the concentration of the acid leaching residue pulp is 18-25%.

[0010] In the present invention, all the concentrations involved refer to mass concentrations.

[0011] Furthermore, during the rough selection process, the pH of the acid leaching residue pulp is controlled to be 4-8.

[0012] Furthermore, during the rough selection process, the dosage of sodium hexametaphosphate added is 800-1500 g / t, and the dosage of acidified sodium silicate is 4000-7000 g / t.

[0013] Furthermore, the time for the rough selection is 5-7 min.

[0014] Furthermore, the rough concentrate is slurried to obtain a rough concentrate pulp, and acidified sodium silicate, butyl xanthate, and No. 2 oil are sequentially added to the rough concentrate pulp for scavenging selection to obtain scavenging middlings and zinc concentrate.

[0015] Furthermore, the time for the scavenging selection is 3-4 min.

[0016] Furthermore, sodium hydroxide is used to adjust the pH of the rough concentrate pulp to 8-9.

[0017] Furthermore, the concentration of the rough concentrate pulp is 18-25%.

[0018] Furthermore, during the first scavenging selection process, the dosage of acidified sodium silicate is 80-150 g / t, the dosage of butyl xanthate is 40-65 g / t, and the dosage of No. 2 oil is 15-30 g / t. During the second scavenging selection process, 15-30 g / t of No. 2 oil is replenished.

[0019] Furthermore, the rough tailings are slurried to obtain a rough tailings pulp, and butyl xanthate is added to the rough tailings pulp for cleaning selection to obtain cleaning middlings and tailings.

[0020] Furthermore, the time for the cleaning selection is 3-4 min.

[0021] Furthermore, sodium hydroxide is used to adjust the pH of the rough tailings pulp to 8-9.

[0022] Furthermore, the concentration of the rough tailings pulp is 20-32%.

[0023] Furthermore, during the cleaning selection process, the dosage of butyl xanthate is 15-30 g / t.

[0024] Principle and Advantages

[0025] The principle of the present invention is as follows: In the present invention, the acid leaching residue is directly used as the raw material for flotation. Since the acid leaching residue is the product of acid leaching treatment of oxygen-sulfur mixed zinc concentrate, its particle size is relatively fine. Therefore, in the present invention, there is no need to grind the feed. In addition, since a large amount of collector usually remains on the surface of the acid leaching residue, during the roughing process, the zinc sulfide component in the residue can still float. Therefore, without removing the medicine, only sodium hexametaphosphate and acidified sodium silicate are added during the roughing process to inhibit the calcium-containing and silicon-containing gangue in the residue, and there is no need to add a collector; the tailings of the roughing are scavenged, and butyl xanthate is added to fully recover the zinc sulfide in the acid leaching residue; during the cleaning process, acidified sodium silicate, butyl xanthate and No. 2 oil are added to further purify the roughing concentrate.

[0026] Compared with the traditional pyrometallurgical and hydrometallurgical processes for treating zinc acid leaching residue, the advantages of the present invention are as follows:

[0027] 1) The present invention uses a flotation process to recover zinc sulfide from zinc acid leaching residue, with a simple principle, large processing capacity, low production cost and high return rate.

[0028] 2) The present invention directly uses the acid leaching residue of oxygen-sulfur mixed zinc concentrate as the raw ore, and recovers zinc sulfide therein through a flotation process, without the need for grinding and medicine removal processes, with a simple process and easy operation.

[0029] 3) The present invention does not need to add a collector during the roughing process, and the reagent cost is low. Brief Description of the Drawings

[0030] Figure 1 is the flow chart of the flotation process of the present invention.

[0031] Figure 2 is the X-ray diffraction (XRD) analysis result of zinc acid leaching residue in a certain place in Yunnan. The main metal minerals are sphalerite and galena, and the gangue components are mainly gypsum dihydrate and quartz. Detailed Embodiments

[0032] The present invention will be further described below in conjunction with specific embodiments. It should be noted that the specific embodiments described here are only used to explain the present invention and are not used to limit the present invention.

[0033] Example 1

[0034] Select the acid leaching residue of oxygen-sulfur mixed zinc concentrate in a certain place in Yunnan as the research object. The multi-element analysis results and zinc phase analysis results are shown in Table 1 and Table 2 respectively:

[0035] Table 1 Multi-element analysis results of acid leaching residue samples in a certain place in Yunnan

[0036]

[0037] Table 2 Analysis Results of Zinc Phase in Acid Leaching Residue Samples from a Certain Place in Yunnan

[0038]

[0039]

[0040] As Figure 1 shown, a flotation process for zinc sulfide in an oxygen-sulfur mixed zinc concentrate acid leaching residue, the specific steps are as follows:

[0041] 1. Pulp preparation: For the roughing flotation test, a 0.5L flotation machine is used, and for the cleaning and scavenging tests, a 0.25L flotation machine is used. Each test takes 100g of zinc acid leaching residue, and the roughing pulp concentration is 20%.

[0042] 2. Roughing test: Sodium hexametaphosphate 1000g / t and acidified water glass 5000g / t are added in sequence. After 1 roughing, roughing concentrate and roughing tailings are obtained;

[0043] 3. The first cleaning test: Appropriate sodium hydroxide, acidified water glass 100g / t, butyl xanthate 50g / t, and No. 2 oil 20g / t are added to the roughing concentrate pulp for the first cleaning to obtain concentrate and middling M1. 20g / t of No. 2 oil is added to the obtained concentrate pulp for the second cleaning to obtain the final zinc concentrate and middling M2;

[0044] 4. Scavenging test: Appropriate sodium hydroxide and 20g / t of No. 2 oil are added to the roughing tailings pulp for the scavenging test to obtain the final tailings and middling M3.

[0045] Specifically, in step 2, the pH of the roughing test pulp is about 5.5.

[0046] Specifically, in steps 3 and 4, appropriate sodium hydroxide is added during the cleaning and scavenging tests to adjust the pulp pH to 8 - 9.

[0047] Specifically, in steps 2, 3, and 4, the flotation time for roughing and scavenging tests is 5min, and the time for each cleaning test is 3min.

[0048] Specifically, in steps 2, 3, and 4, middling M1 and M3 are returned to the roughing process, and middling M2 is returned to the first cleaning process.

[0049] Specifically, in step 2 or 4, the acidified water glass is self-made sulfated water glass.

[0050] Comparative Example 1

[0051] Comparative Example 1: The inhibitor acidified sodium silicate was replaced with sodium silicate, and the dosage remained unchanged, i.e., the dosage of sodium silicate in rough selection was 5000 g / t, and the dosage of sodium silicate in the first stage of cleaning was 100 g / t. Other experimental steps and feed properties were the same as those in Example 1.

[0052] Comparative Example 2

[0053] Comparative Example 2: The inhibitor acidified sodium silicate was replaced with a common silicon-containing gangue inhibitor sodium fluorosilicate. The dosage of sodium fluorosilicate in rough selection was 3000 g / t, and the dosage of sodium fluorosilicate in the first stage of cleaning was 60 g / t. Other experimental steps and feed properties were the same as those in Example 1.

[0054] Comparative Example 3

[0055] Comparative Example 3: In the first stage of cleaning, 200 g / t of copper sulfate was added as an activator before adding butyl xanthate. Other experimental steps and feed properties were the same as those in Example 1.

[0056] Comparative Example 4

[0057] Comparative Example 4: Before the rough selection experiment, the zinc acid leaching residue was subjected to mechanical grinding for de-drug treatment. The acid leaching residue pulp was added into the mill, and 500 g / t of activated carbon was added, followed by weak-intensity grinding for 10 min. Then, 500 g / t of butyl xanthate was added in the subsequent rough selection process. Other experimental steps and feed properties were the same as those in Example 1.

[0058] Table 3 shows the results of the closed-circuit flotation tests for Example 1, Comparative Example 1, Comparative Example 2, Comparative Example 3, and Comparative Example 4.

[0059] Table 3 Results of Closed-Circuit Flotation Tests

[0060]

[0061] Compared with Comparative Example 1, the zinc grade of zinc concentrate obtained by using the test process and reagent system described in Example 1 of the present invention increased by 6.53%. Although the recovery rate decreased by 6%, the calcium grade decreased by 3.05% and the silicon grade decreased by 1.84%, and the quality of zinc concentrate was improved. Compared with Comparative Example 2, the zinc grade of the concentrate obtained in Example 1 increased by 2.8%, the recovery rate increased by 3.33%, and the calcium and silicon grades decreased by 1.14% and 1.71% respectively. Compared with Comparative Example 3, the zinc grade of the concentrate obtained in Example 1 increased by 3.27%, the recovery rate only decreased by 1.55%, and the calcium and silicon grades decreased by 2.06% and 5.02% respectively. Compared with Comparative Example 4, the zinc grade of the concentrate obtained in Example 1 increased by 4.28%. Although the zinc recovery rate decreased by 6.16%, the calcium grade and recovery rate decreased by 4.04% and 10% respectively, and the silicon grade and recovery rate decreased by 6.02% and 16% respectively. The gangue components in the slag were fully inhibited, and there was no grinding and drug removal process in Example 1, the process was simple and the cost was lower.

[0062] Therefore, the experimental method described in Example 1 can efficiently recover zinc sulfide in zinc acid leaching residue. In addition, the main gangue components, gypsum dihydrate and quartz (see Figure 2 ) were well inhibited, and good separation indexes were achieved. When acidified sodium silicate was replaced by sodium silicate or sodium fluorosilicate, although the zinc recovery rate of the concentrate increased slightly, a large amount of gangue floated up and the quality of the concentrate decreased. Using copper sulfate for activation and cleaning would activate the flotation of gangue minerals gypsum dihydrate and quartz, which was not beneficial to zinc flotation; using pre-mechanical drug removal - butyl xanthate flotation was not conducive to the inhibition of gangue components.

[0063] The flotation method of the present invention has a simple process flow, low reagent cost, high recovery rate of zinc sulfide in the concentrate, and low content of gangue components, and is particularly suitable for the recovery of zinc sulfide components in the acid leaching residue obtained after acid leaching of oxygen-sulfur mixed zinc concentrate to recover zinc oxide.

Claims

1. A flotation method for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate, characterized in that: The acid-leaching residue of oxygen-sulfur mixed zinc concentrate is slurried to obtain an acid-leaching residue pulp. Sodium hexametaphosphate and acidified water glass are successively added to the acid-leaching residue pulp for rough selection to obtain a rough concentrate and a rough tailing. The rough concentrate is subjected to cleaning to obtain a cleaning middling and a zinc concentrate, and the rough tailing is subjected to scavenging to obtain a scavenging middling and a tailing; without removing the reagent, only sodium hexametaphosphate and acidified water glass are added during the rough selection process to inhibit the calcium-containing and silicon-containing gangue in the acid-leaching residue of oxygen-sulfur mixed zinc concentrate, and no collector needs to be added. When the rough concentrate is subjected to cleaning, acidified water glass, butyl xanthate and No. 2 oil are added. When the rough tailing is subjected to scavenging, butyl xanthate is added.

2. The flotation method of zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 1, characterized in that: The flotation method includes 1 rough selection, 1 - 2 cleanings and 1 scavenging, and the cleaning middling and the scavenging middling are returned in sequence.

3. The flotation method of zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 1 or 2, characterized in that: The concentration of the acid-leaching residue pulp is 18 - 25%; during the rough selection process, the pH of the acid-leaching residue pulp is controlled to be 4 - 8.

4. The flotation method of zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 1 or 2, characterized in that: During the rough selection process, the dosage of sodium hexametaphosphate added is 800 - 1500 g / t, and the dosage of acidified water glass is 4000 - 7000 g / t.

5. The flotation method of zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 1 or 2, characterized in that: The rough concentrate is slurried to obtain a rough concentrate pulp. Acidified water glass, butyl xanthate and No. 2 oil are successively added to the rough concentrate pulp for cleaning to obtain a cleaning middling and a zinc concentrate.

6. The flotation method of zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 5, characterized in that: Sodium hydroxide is used to adjust the pH of the rough concentrate pulp to 8 - 9, and the concentration of the rough concentrate pulp is 18 - 25%.

7. A flotation method for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 5, characterized in that: During the first cleaning process, the dosage of acidified water glass is 80 - 150 g / t, the dosage of butyl xanthate is 40 - 65 g / t, and the dosage of No. 2 oil is 15 - 30 g / t. During the second cleaning process, 15 - 30 g / t of No. 2 oil is supplemented.

8. A flotation method for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 1 or 2, characterized in that: The rough tailing is slurried to obtain a rough tailing pulp. Butyl xanthate is added to the rough tailing pulp for scavenging to obtain a scavenging middling and a tailing.

9. A flotation method for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 8, characterized in that: Sodium hydroxide is used to adjust the pH of the rough tailing pulp to 8 - 9; the concentration of the rough tailing pulp is 20 - 32%.

10. A flotation method for zinc sulfide in the acid leaching residue of oxygen-sulfur mixed zinc concentrate according to claim 8, characterized in that: During the scavenging process, the dosage of butyl xanthate is 15 - 30 g / t.

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