Organic inhibitor for galena and application thereof

Abstract

The invention discloses an organic inhibitor for galena and application of the organic inhibitor. The inhibitor is 3-mercapto-1 sodium propane sulfonate (MPS). Aiming at the characteristics of close copper and lead symbiosis, high iron and zinc content and fine disseminated particle size of raw ore, the method adopts the technological process of'copper and lead partial bulk flotation tailing discarding-bulk concentrate regrinding-copper and lead separation flotation ', and comprises the following steps: firstly, in a bulk flotation section, utilizing a zinc sulfate and sodium sulfite combined reagent to efficiently inhibit sphalerite and pyrite under a weakly alkaline condition; a large number of gangue and zinc-sulfur minerals are thrown away in advance; the method comprises the following steps of: carrying out superfine regrinding dissociation on obtained bulk concentrate, then carrying out separation operation, and in a copper-lead separation section, replacing traditional dichromate with 3-mercapto-1 sodium propane sulfonate (MPS), carrying out a closed-loop process of one-roughing, three-refining and three-sweeping, and supplementing an inhibitor in fine selection operation, so that efficient inhibition of galena and preferable flotation of chalcopyrite are realized. The technological process is rigorous in design, the reagent system is green and environmentally friendly, and the resource recovery rate of the low-grade complex ore is remarkably increased.

Description

Technical Field

[0001] This invention relates to the field of mineral processing engineering technology, specifically to an organic inhibitor of galena and its application. Background Technology

[0002] Technical bottlenecks in copper-lead separation In the flotation process of polymetallic sulfide ores, copper-lead separation is a core challenge. Because chalcopyrite (CuFeS2) and galena (PbS) have similar surface physicochemical properties, and after mixed flotation using xanthate collectors, both surfaces adsorb a large amount of hydrophobic reagents, resulting in minimal difference in floatability. The traditional "lead-suppressing, copper-floating" process is acceptable for ores with relatively coarse particle sizes, but when dealing with fine-grained ores, the separation efficiency drops significantly due to substantial "mechanical entrainment" and "mutual inclusion" effects.

[0003] Limitations of existing technology Currently, industrial copper-lead separation mainly relies on chemical inhibitors, but existing technologies all have significant drawbacks: Dichromate process (Cr process): Potassium / sodium dichromate is a traditional and highly effective depressant for galena. However, it contains hexavalent chromium (Cr). 6+ Dichromates are classified as Group 1 carcinogens, are extremely toxic, difficult to degrade, and cause permanent pollution to water and soil. Their use is strictly limited and even prohibited.

[0004] Cyanide method (CN method): Although cyanide is effective in inhibiting secondary copper and zinc minerals, its highly toxic and volatile properties bring huge safety hazards and high management costs.

[0005] Sulphite / thiosulfate process: This is a non-toxic process, but its inhibitory effect is weak, and it is easily oxidized and degraded in the slurry. It often requires extremely high alkalinity (pH>12, with the addition of a large amount of lime) or heating to be effective. The high alkalinity environment not only inhibits the recovery of associated precious metals such as gold and silver (causing economic losses), but also leads to severe scaling in the beneficiation pipelines, clogging the equipment and increasing maintenance costs.

[0006] Conventional organic inhibitors (CMC, dextrin, etc.): Although environmentally friendly, they have poor selectivity, require large amounts, are prone to "running out of the tank", and are not very adaptable to fine-grained mineral mud.

[0007] The challenges of fine-grained mineral processing For ores that require a "mixed flotation-regrinding" process due to their fine particle size, while regrinding can improve the degree of liberation of monomers, it also generates a large amount of secondary slime. This fine slime has a large specific surface area and will non-selectively adsorb reagents, causing conventional depressants to become ineffective. Therefore, developing a novel environmentally friendly reagent and supporting process that can both disperse slime and strongly and specifically inhibit galena in a weakly alkaline environment (facilitating precious metal recovery) and with low toxicity (meeting environmental requirements) is a key technical problem that urgently needs to be solved in the mineral processing field.

[0008] The following problems exist in the flotation separation process of existing low-grade, fine-grained complex copper-lead-zinc polymetallic sulfide ores: (1) Copper and lead minerals are closely associated and difficult to separate by conventional grinding, resulting in difficult separation and serious mutual inclusion in the concentrate; (2) Traditional copper-lead separation processes rely on dichromates (to inhibit galena) or cyanides (to inhibit sphalerite), which are highly toxic, cause serious environmental pollution, and have high subsequent water treatment costs. (3) Existing chromium-free separation processes (such as the sulfite process) often require high alkalinity or complex high-temperature heating processes, which are not conducive to the recovery of associated gold and silver, and have insufficient selective inhibition of fine-grained galena. Summary of the Invention

[0009] To address the aforementioned technical problems, this invention provides a clean and efficient mineral processing method utilizing regrinding in conjunction with the green organic inhibitor sodium 3-mercapto-1-propanesulfonate, aiming to achieve complete separation of copper and lead under weakly alkaline conditions. This invention proposes a novel clean separation method combining ultrafine regrinding with the green inhibitor sodium 3-mercapto-1-propanesulfonate, aiming to solve the aforementioned industry pain points.

[0010] The organic inhibitor of the present invention is sodium 3-mercapto-1-propanesulfonate, which is used to inhibit galena in copper-lead separation.

[0011] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The process adopts a "copper-lead partial mixed flotation tailings removal - mixed concentrate regrinding - copper-lead separation flotation" flow. First, in the mixed flotation section, zinc sulfate and sodium sulfite are used as a combination reagent to suppress sphalerite and pyrite under weakly alkaline conditions, thus pre-removing a large amount of gangue and zinc-sulfur minerals. The resulting mixed concentrate is then regrinded and liberated before entering the separation operation. In the copper-lead separation section, sodium 3-mercapto-1-propanesulfonate is used as a depressant. Through a closed-loop process of "one roughing, three cleaning, and three scavenging", and additional depressant is added during the cleaning operation, efficient suppression of galena and optimized flotation of chalcopyrite are achieved.

[0012] The specific steps are as follows: (1) Grinding: After crushing the raw ore, ball milling is carried out to control the grinding fineness to 65% to 75% of the total fineness, which is -0.074 mm. This fineness is intended to ensure that the copper and lead minerals are separated from the gangue as an aggregate and to avoid excessive crushing leading to mud formation. (2) Copper-lead mixed flotation tailings: pH adjuster, zinc-sulfur inhibitor, mixed collector and frother are added to the slurry after grinding. After a closed-circuit process of roughing, cleaning and scavenging, copper-lead mixed rough concentrate and zinc-sulfur tailings are obtained. The synergistic effect of zinc sulfate and sodium sulfite is used to strongly inhibit high-iron sphalerite and pyrite, and a large amount of qualified tailings are discarded in advance to enrich copper-lead mixed concentrate. (3) Regrinding of mixed rough concentrate: After the copper-lead mixed rough concentrate obtained in step (2) is concentrated and dehydrated, it is sent to a regrinding mill for ultrafine grinding. The regrinding fineness is controlled to be -0.038mm, accounting for 90% to 95%. This step is the physical key. The old reagent film on the surface of the mineral is removed by strong scrubbing, and the intergrowth of fine-grained chalcopyrite and galena is fully opened to expose the fresh surface, creating physical conditions for subsequent separation. (4) Copper-lead separation flotation: pH adjuster, galena inhibitor, copper collector and frother are added to the refractory slurry. After one roughing, three cleaning and three scavenging closed-circuit process, the froth product is copper concentrate and the bottom flow product is lead concentrate. (5) Zinc flotation: The zinc-containing sulfur tailings generated in step (2) are activated, zinc collectors are added, and zinc flotation is carried out to recover zinc concentrate.

[0013] The zinc-sulfur inhibitor in step (2) is a combination of zinc sulfate and sodium sulfite, with zinc sulfate at 1000-2000 g / t and sodium sulfite at 300-1600 g / t, and the ratio of the two is 1:(0.3-0.8); the mixed collector is a combination of ethyl thiocyanate and butyl xanthate, with each at 30-50 g / t.

[0014] The galena inhibitor in step (4) is sodium 3-mercapto-1-propanesulfonate, with a dosage of 700-900 g / t; the copper collector is an ester collector or a thiouric ester collector, with a dosage of 10-15 g / t.

[0015] In step (4), the pH value of the slurry for copper-lead separation flotation is controlled within a weakly alkaline range of 8.5 to 9.5, and there is no need to add dichromate.

[0016] In the three refining operations in step (4), 30-60 g / t of sodium 3-mercapto-1 propane sulfonate is added in the first refining operation to enhance the inhibitory effect on galvanite.

[0017] The core principle of this invention: This invention abandons the traditional oxidizing inhibitor (dichromate) in the copper-lead separation section and innovatively constructs an "organic" inhibition system: The role of sodium 3-mercapto-1-propanesulfonate (MPS): Sodium 3-mercapto-1-propanesulfonate is an organic compound containing mercapto (-SH) and sulfonic acid (-SO3Na) groups. The mercapto group has strong thiophilicity, enabling it to specifically chemisorb lead ions (Pb²⁺) on the surface of galena (PbS), forming stable thiolate bonds. This creates a hydrophobic film on the galena surface, inhibiting its floatability. Simultaneously, the presence of the sulfonic acid group increases the molecule's water solubility, aiding in uniform dispersion in the slurry, and may further enhance the inhibition effect on galena through electrostatic repulsion. In contrast, the surface of chalcopyrite (CuFeS2) is mainly composed of Cu⁺ and Fe²⁺, whose electronic structure and lattice energy differ fundamentally from Pb²⁺. This results in a weaker adsorption capacity of sodium 3-mercapto-1-propanesulfonate for chalcopyrite, with less impact on flotation recovery, thus achieving selective inhibition of galena.

[0018] Synergistic effect of regrinding: regrinding not only achieves monomer dissociation, but more importantly, it removes the collector adsorbed on the surface of galena in the mixed flotation stage, allowing MPS to act directly on the exposed galena surface and significantly improving reagent efficiency.

[0019] Compared with the prior art, the present invention has the following significant advantages: (1) Significant environmental benefits: The entire process of this invention does not use highly toxic agents such as dichromate and cyanide. The organic inhibitor MPS of this invention is non-toxic and biodegradable, which completely solves the environmental pain points of traditional processes.

[0020] (2) High separation efficiency and excellent indicators: For difficult-to-process ores with extremely low raw ore grade (Cu 0.33%, Pb 0.24%), through the dual means of "re-grinding + organic inhibitor", not only was a copper concentrate with grade >26% obtained, but the lead content in the copper concentrate was also controlled at about 2.15%, and the copper recovery rate was maintained at more than 85%, achieving precise separation of "copper preservation and lead suppression".

[0021] (3) High recovery rate of associated metals: The separation operation of the present invention is carried out under weakly alkaline conditions of around pH 9, which avoids the inhibitory effect of high alkalinity (pH>12) on associated precious metals such as gold and silver, which is conducive to improving the overall economic benefits of the mine.

[0022] (4) Strong process stability: The present invention adopts a closed-loop process of “one roughing, three refining, three sweeping” and step-by-step return of middlings, which can effectively adapt to the fluctuation of the properties of the raw ore, has strong resistance to mud formation, and is easy to implement in industrial applications. Attached Figure Description

[0023] Figure 1This is a flow chart of the mineral processing technology provided in the embodiments of the present invention. Detailed Implementation

[0024] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. These embodiments are only used to specifically illustrate the present invention, and the scope of protection of the present invention is not limited to the content described.

[0025] Example 1: 1. Ore properties The test ore sample was taken from a difficult-to-process copper-lead-zinc sulfide ore in Yunnan Province. The multi-element analysis results of the raw ore are shown in Table 1. The ore has complex properties, with extremely high iron content, low copper and lead grades, and dense coexistence.

[0026] Table 1. Results of multi-element analysis of raw ore (mass fraction, %)

[0027] 2. Process flow and operating procedures As shown in the attached document Figure 1 The process flow shown was subjected to a closed-circuit test.

[0028] (1) Grinding and copper-lead mixed flotation Grinding: 70% of the raw ore is ground to -0.074mm.

[0029] Mixed coarse selection: Add the following ingredients sequentially to the mixing tank: pH adjuster: lime, to adjust pH to 9.0; Inhibitor: Zinc sulfate 1500g / t + sodium sulfite 500g / t (strong inhibitor of sphalerite and pyrite); Collector: Ethyl thiocyanate + butyl xanthate (1:1) 40g / t; Foaming agent: No. 2 oil 15g / t.

[0030] Mixed Concentrate I and II: The tailings from Mixed Concentrate I are returned to the mixed roughing process, and the tailings from Concentrate II are returned to Mixed Concentrate I. The mixed concentrate is a copper-lead mixed roughing concentrate.

[0031] Mixed scavenging I and II: The foam from mixed scavenging I is returned to the mixed roughing process, the foam from mixed scavenging II is returned to mixed scavenging I, and the underflow from mixed scavenging II is used as zinc-sulfur tailings.

[0032] Objective: To maximize the recovery of copper and lead, and remove zinc and sulfur.

[0033] (2) Regrinding and de-processing of mixed concentrate The copper-lead mixed concentrate produced by Mixed Selection II is concentrated, and activated carbon is added to adsorb residual xanthate before being fed into a vertical stirred mill.

[0034] Re-grinding fineness: 90% is controlled at -0.038mm to ensure complete dissociation of copper-lead intergrowth.

[0035] Copper-lead separation flotation (core of this invention) Separation and coarse selection: Dosing point: the mixing tank after regrinding.

[0036] Added reagents: lime (to adjust pH to 9.0), sodium 3-mercapto-1-propanesulfonate (MPS) 800g / t, Z-200 12g / t.

[0037] Function: MPS inhibits galena, Z-200 selectively collects chalcopyrite.

[0038] Separate Selection I: Dosing point: Selective I, before feed inlet.

[0039] Addition of reagent: 40g / t of MPS.

[0040] Function: To enhance inhibition and cleanse entrained galena.

[0041] Separation and Refinement II and III: Multi-stage refinement to ensure the grade of copper concentrate. Separation and Refinement III concentrate is copper concentrate.

[0042] Separate scavenging stages I, II, and III: multi-stage scavenging ensures high copper recovery. The underflow from scavenging stage III is lead concentrate (suppressed galena).

[0043] Zinc flotation The underflow from the mixed scavenging II process was subjected to conventional zinc flotation (pH adjusted to 11 with lime, activated with copper sulfate, and collected with butyl xanthate) to obtain zinc concentrate.

[0044] Mineral processing index results The results of the full-process closed-loop test are shown in Table 2.

[0045] Table 2 Closed-Circuit Process Mineral Processing Indicators

[0046] 4. Results Analysis (1) Quality of copper concentrate: With a copper grade of only 0.33% in the raw ore, a high-quality copper concentrate with a grade of 26.12% was obtained, with a lead content of only 2.15% and a zinc content of 3.20%. This indicates that the combination of "zinc sulfate + sodium sulfite for flotation" and "MPS for separation" was extremely successful, effectively shielding the interference of high zinc, high iron and lead minerals.

[0047] (2) Where does the lead go? Because the lead grade of the raw ore is extremely low (0.24%), it is difficult to enrich it to a high grade. However, this process still enriches it to 32.50%, mainly as a lead-rich mineral product. And most importantly, it does not pollute the copper concentrate.

[0048] (3) Process advantages: The setting of three cleaning and three sweeping makes the system stable despite the large amount of medium ore circulation, which proves that the reagent has good anti-mudification and anti-circulation accumulation capabilities. Comparative Examples

[0049] If the separation section is not regrinded and flotation is carried out directly with reagents, the lead content in the copper concentrate increases to 8.4%, the zinc content increases to 6.5%, and the copper recovery rate decreases to 72%. This proves the necessity of step S3 (regrinding) in this invention for difficult-to-process ores. Example 2

[0050] (1) Grinding and copper-lead mixed flotation Grinding: 65% of the raw ore is ground to -0.074mm.

[0051] Mixed coarse selection: Add the following ingredients sequentially to the mixing tank: pH adjuster: lime, to adjust pH to 8.5; Inhibitor: 1000g / t zinc sulfate + 300g / t sodium sulfite (strong inhibitor of sphalerite and pyrite) Collector: Ethyl thiocyanate + butyl xanthate (1:1) 30g / t; Foaming agent: No. 2 oil 12g / t.

[0052] Mixed Concentrate I and II: The tailings from Mixed Concentrate I are returned to the mixed roughing process, and the tailings from Concentrate II are returned to Mixed Concentrate I. The mixed concentrate is a copper-lead mixed roughing concentrate.

[0053] Mixed scavenging I and II: The foam from mixed scavenging I is returned to the mixed roughing process, the foam from mixed scavenging II is returned to mixed scavenging I, and the underflow from mixed scavenging II is used as zinc-sulfur tailings.

[0054] Objective: To maximize the recovery of copper and lead, and remove zinc and sulfur.

[0055] (2) Regrinding and de-processing of mixed concentrate The copper-lead mixed concentrate produced by Mixed Selection II is concentrated, and activated carbon is added to adsorb residual xanthate before being fed into a vertical stirred mill.

[0056] Re-grinding fineness: 90% is controlled at -0.038mm to ensure complete dissociation of copper-lead intergrowth.

[0057] Copper-lead separation flotation (core of this invention) Separation and coarse selection: Dosing point: the mixing tank after regrinding.

[0058] Added reagents: lime (to adjust pH to 8.5), sodium 3-mercapto-1-propanesulfonate (MPS) 700g / t, Z-200 10g / t.

[0059] Functions: MPS selectively inhibits galena, Z-200 precisely collects chalcopyrite, the weakly alkaline pH environment avoids the inhibition of precious metals, and the reagent adsorption efficiency is adapted to low dissociation slurries.

[0060] Separate Selection I: Dosing point: Selective I, before feed inlet.

[0061] Addition of reagent: Add 30g / t of MPS.

[0062] Function: Enhances the inhibition of slight galena inclusions in low-dissociation slurries, cleans foamy products, and reduces lead intermingling in copper concentrate.

[0063] Separation and Refinement II and III: No additional reagents are added; a multi-stage closed-loop refinement process is adopted: tailings from Refinement II are returned to Refinement I, and tailings from Refinement III are returned to Refinement II. Function: To purify chalcopyrite foam in stages, ensuring that the grade of copper concentrate meets the standards, and the final foam product of the third stage is copper concentrate.

[0064] Separation of Scavenging I, II, and III: No additional reagents are added; a multi-stage closed-loop scavenging process is adopted: Scavenging I foam is returned to the separation roughing stage; Scavenging II foam is returned to Scavenging I; Scavenging III foam is returned to Scavenging II. Function: To recover chalcopyrite that has not been fully collected in the underflow of the scavenging tank in stages, ensuring copper recovery rate. The final underflow product of the scavenging III tank is suppressed lead concentrate.

[0065] (4) Zinc flotation: The underflow from the mixed scavenging II process was subjected to conventional zinc flotation (pH adjusted to 11 with lime, activated with copper sulfate, and collected with butyl xanthate) to obtain zinc concentrate.

[0066] Mineral processing index results The results of the full-process closed-loop test are shown in Table 3.

[0067] Table 3 Closed-Circuit Process Mineral Processing Indicators

[0068] Results Analysis The grinding fineness was at the lower limit, the mineral liberation degree was slightly low, and with the addition of low-dose reagents, the copper concentrate grade and recovery rate were slightly lower than in Example 1, and the lead content in the copper concentrate increased slightly, but was still far better than the control group without regrinding; the lead concentrate grade decreased slightly, and the lead loss rate in the tailings was slightly higher, but the overall indicators still met the requirements of industrial mineral processing, verifying the adaptability of this process at low grinding fineness. Example 3

[0069] As shown in the attached document Figure 1 The process flow shown was subjected to a closed-circuit test.

[0070] (1) Grinding and copper-lead mixed flotation Grinding: 75% of the raw ore is ground to -0.074mm.

[0071] Mixed coarse selection: Add the following ingredients sequentially to the mixing tank: pH adjuster: lime, to adjust pH to 9.5; Inhibitor: 2000g / t zinc sulfate + 1600g / t sodium sulfite (strong inhibitor of sphalerite and pyrite) Collector: Ethyl thiocyanate + butyl xanthate (1:1) 50g / t; Foaming agent: No. 2 oil 18g / t.

[0072] Mixed Concentrate I and II: The tailings from Mixed Concentrate I are returned to the mixed roughing process, and the tailings from Concentrate II are returned to Mixed Concentrate I. The mixed concentrate is a copper-lead mixed roughing concentrate.

[0073] Mixed scavenging I and II: The foam from mixed scavenging I is returned to the mixed roughing process, the foam from mixed scavenging II is returned to mixed scavenging I, and the underflow from mixed scavenging II is used as zinc-sulfur tailings.

[0074] Objective: To maximize the recovery of copper and lead, and remove zinc and sulfur.

[0075] (2) Regrinding and de-processing of mixed concentrate The copper-lead mixed concentrate produced by Mixed Selection II is concentrated, and activated carbon is added to adsorb residual xanthate before being fed into a vertical stirred mill.

[0076] Re-grinding fineness: controlled at -0.038mm for 95% to ensure complete dissociation of copper-lead intergrowth.

[0077] Copper-lead separation flotation (core of this invention) Separation and coarse selection: Dosing point: the mixing tank after regrinding.

[0078] Added reagents: lime (to adjust pH to 9.5), sodium 3-mercapto-1-propanesulfonate (MPS) 900g / t, Z-200 15g / t.

[0079] Function: For ultrafine mineral slurries with high dissociation, increasing the amount of MPS ensures sufficient adsorption and inhibition on the surface of galena, increasing the amount of Z-200 enhances the selective collection of chalcopyrite, adapts to the characteristics of fine-grained minerals with large specific surface area, and improves separation efficiency.

[0080] Separate Selection I: Dosing point: Selective I, before feed inlet.

[0081] Addition of reagent: Add 50g / t of MPS.

[0082] Function: To perform secondary strengthening and suppression of ultrafine-grained galena that is easily mechanically entrained, to deeply clean lead impurities in the foam, to further reduce lead intermingling in copper concentrate, and to ensure high concentrate grade.

[0083] Separation and Refinement II and III: No additional reagents are added; a multi-stage closed-loop refinement process is adopted: tailings from Refinement II are returned to Refinement I, and tailings from Refinement III are returned to Refinement II. Function: To refine chalcopyrite foam with high degree of dissociation step by step, maximize the grade of copper concentrate, and select the final foam product as copper concentrate.

[0084] Separation of Scavenging I, II, and III: No additional reagents are added; a multi-stage closed-loop scavenging process is adopted: Scavenging I foam is returned to the separation roughing stage; Scavenging II foam is returned to Scavenging I; Scavenging III foam is returned to Scavenging II. Function: For ultrafine chalcopyrite that is easily lost, the target mineral is recovered in the underflow of the scavenging tank in stages to maximize the copper recovery rate. The final underflow product of the scavenging III is the suppressed lead concentrate.

[0085] Zinc flotation The underflow from the mixed scavenging II process was subjected to conventional zinc flotation (pH adjusted to 11 with lime, activated with copper sulfate, and collected with butyl xanthate) to obtain zinc concentrate.

[0086] Mineral processing index results The results of the full-process closed-loop test are shown in Table 4.

[0087] Table 4 Closed-Circuit Process Mineral Processing Indicators

[0088] Results analysis: The grinding fineness was set to the upper limit, resulting in the most complete dissociation of copper-lead intergrowths. Combined with high-dose, appropriately matched reagents, the optimal ore selection indicators were achieved: the copper concentrate grade was increased to 27.58%, the lead intercalation content was reduced to 1.82% (the lowest in the example), and the copper recovery rate increased to 88.65%; the lead concentrate grade was increased to 34.26%, and the recovery rate was 63.55% (the highest in the example); the zinc concentrate grade and recovery rate were both optimal, and the tailings metal loss rate was significantly reduced, fully demonstrating the process advantages of ultrafine grinding + precise reagent dosage matching.

[0089] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. An organic inhibitor of galena, characterized in that, The organic inhibitor is sodium 3-mercapto-1-propanesulfonate, which is used to inhibit galena in copper-lead separation.

2. The organic inhibitor for galena as described in claim 1 is applied to the flotation separation of complex copper-lead-zinc polymetallic sulfide ores, characterized in that, The process adopts a "copper-lead partial mixed flotation tailings removal - mixed concentrate regrinding - copper-lead separation flotation" flow. First, in the mixed flotation section, zinc sulfate and sodium sulfite are used as a combination reagent to suppress sphalerite and pyrite under weakly alkaline conditions, thus pre-removing a large amount of gangue and zinc-sulfur minerals. The resulting mixed concentrate is then regrinded and liberated before entering the separation operation. In the copper-lead separation section, sodium 3-mercapto-1-propanesulfonate is used as a depressant. Through a closed-loop process of "one roughing, three cleaning, and three scavenging", and additional depressant is added during the cleaning operation, efficient suppression of galena and optimized flotation of chalcopyrite are achieved.

3. The organic inhibitor for galena according to claim 2 is applied to the flotation separation of complex copper-lead-zinc polymetallic sulfide ores, characterized in that: The specific steps are as follows: (1) Grinding: After crushing the raw ore, ball milling is performed to control the grinding fineness to be -0.074 mm, accounting for 65% to 75%; (2) Copper-lead mixed flotation tailings: pH adjuster, zinc-sulfur inhibitor, mixed collector and frother are added to the slurry after grinding. After a closed-circuit process of roughing, cleaning and scavenging, copper-lead mixed rough concentrate and zinc-sulfur tailings are obtained. (3) Regrinding of mixed rough concentrate: After the copper-lead mixed rough concentrate obtained in step (2) is concentrated and dehydrated, it is sent to a regrinding mill for ultrafine grinding, and the fineness of the regrinding is controlled to be -0.038mm, accounting for 90% to 95%; (4) Copper-lead separation flotation: pH adjuster, galena inhibitor, copper collector and frother are added to the refractory slurry. After one roughing, three cleaning and three scavenging closed-circuit process, the froth product is copper concentrate and the bottom flow product is lead concentrate. (5) Zinc flotation: The zinc-containing sulfur tailings generated in step (2) are activated, zinc collectors are added, and zinc flotation is carried out to recover zinc concentrate.

4. The method for applying the organic inhibitor of galena according to claim 3 to the flotation separation of complex copper-lead-zinc polymetallic sulfide ores, characterized in that: The pH adjuster in step (2) is lime, which adjusts the pH to 8.5-9.

5. The zinc-sulfur inhibitor in step (2) is a combination of zinc sulfate and sodium sulfite, with zinc sulfate at 1000-2000 g / t and sodium sulfite at 300-1600 g / t, and the ratio of the two is 1:(0.3-0.8). The mixed collector is a combination of ethyl thiocyanate and butyl xanthate, with a dosage of 30-50 g / t.

5. The method for applying the organic inhibitor of galena according to claim 3 to the flotation separation of complex copper-lead-zinc polymetallic sulfide ores, characterized in that: The galena inhibitor in step (4) is sodium 3-mercapto-1-propanesulfonate, 700-900 g / t; the copper collector is an ester collector or a thiouric ester collector, with a dosage of 10-15 g / t.

6. The method for applying the organic inhibitor of galena according to claim 3 to the flotation separation of complex copper-lead-zinc polymetallic sulfide ores, characterized in that: In step (4), the pH value of the slurry for copper-lead separation flotation is controlled within a weakly alkaline range of 8.5 to 9.5, and there is no need to add dichromate.

7. The method for applying the organic inhibitor of galena according to claim 3 to the flotation separation of complex copper-lead-zinc polymetallic sulfide ores, characterized in that: In the three refining operations in step (4), 30-60 g / t of sodium 3-mercapto-1 propanesulfonate is added in the first refining operation to enhance the inhibitory effect on galvanite.

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