Flotation separation method for lead-zinc sulfide ore mixed rough concentrate

Abstract

The invention discloses a flotation separation method for lead-zinc sulfide ore mixed rough concentrate, and belongs to the technical field of mineral processing. Aiming at the lead-zinc sulfide ore mixed rough concentrate, firstly, the rough concentrate is ground to a certain fineness and then is subjected to solid-liquid separation; secondly, water and acid are added into the filter cake after ore grinding for size mixing to a certain concentration and a certain pH value; and then glutathione is adopted as a selective inhibitor of sphalerite in the lead-zinc bulk concentrate for the ore pulp, then galena in the bulk concentrate is subjected to flotation, lead-zinc separation is conducted through a proper flotation technology, and lead concentrate and zinc concentrate with the low lead-zinc mutual content are obtained. According to the method, the lead-zinc separation problem caused by good floatability of galena and sphalerite in the lead-zinc bulk concentrate is effectively solved, meanwhile, it is guaranteed that the lead and zinc have the high recovery rate, and a new method is provided for efficient flotation separation of the lead-zinc bulk concentrate.

Description

Technical Field

[0001] This invention belongs to the field of mineral processing technology and relates to a flotation separation method for mixed lead-zinc sulfide ore rough and concentrate. Background Technology

[0002] Lead and zinc are important non-ferrous strategic metals in my country. In nature, galena is the main lead sulfide mineral, and sphalerite is the main zinc sulfide mineral. Galena and sphalerite often occur in close association, forming lead-zinc sulfide ores. In the beneficiation process, to reduce production costs and simplify the process, a mixed flotation process is often used to obtain a mixed lead-zinc concentrate. However, galena and sphalerite are both sulfide ores with similar crystal structures and similar natural floatability. Moreover, in actual ores, sphalerite is often activated by unavoidable ions such as lead and copper ions in the slurry, further increasing its floatability. This makes the separation of the two a long-standing technical challenge in the beneficiation field.

[0003] The key to achieving efficient lead-zinc separation lies in finding a highly effective depressant that can selectively suppress sphalerite while maximizing the floatability of galena. Currently, the commonly used industrial lead-zinc separation process is the zinc-suppression and lead-flotation process. The core of this process is using a depressant to suppress sphalerite, followed by the flotation of galena. Traditional sphalerite depressants mainly include combinations of cyanide, zinc sulfate, and sulfites, or a combination of zinc sulfate and cyanide. However, cyanide is strictly limited due to its high toxicity, and the inhibitory effect of the zinc sulfate and sulfite combination is weak, especially for strongly activated sphalerite, often requiring increased depressant dosage, and the separation effect is unsatisfactory, resulting in high lead-zinc content in the concentrate and low recovery rates. In addition, there is a lead-suppression and zinc-flotation process for lead-zinc separation, but this method is less commonly used and also faces the challenge of lacking efficient and environmentally friendly depressants.

[0004] In summary, existing lead-zinc separation technologies generally suffer from problems such as poor inhibitor selectivity, low separation efficiency, poor concentrate quality, and environmental pollution. Especially today, with increasingly stringent environmental requirements, developing a new, efficient, and green inhibitor and corresponding separation process to achieve clean and efficient separation of mixed lead-zinc concentrates is of vital importance for improving the comprehensive utilization of resources and promoting the sustainable development of the non-ferrous metals industry. Summary of the Invention

[0005] To overcome the problems in the prior art, the present invention uses glutathione as an inhibitor to selectively inhibit sphalerite in a lead-zinc mixed concentrate, and then performs flotation on galena in the mixed concentrate to separate lead and zinc, thereby obtaining high-quality lead concentrate and zinc concentrate with low lead and zinc content, while both lead and zinc have high recovery rates.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution: This invention proposes a flotation separation method for mixed lead-zinc sulfide ore rough concentrate. First, the mixed lead-zinc sulfide ore rough concentrate is regrinded. Water and acid are added to the regrinded slurry to adjust the slurry concentration and pH. Then, lead and zinc are separated from the mixed concentrate by flotation. Glutathione is used as an inhibitor of sphalerite in the mixed lead-zinc concentrate during flotation to obtain high-quality lead concentrate and zinc concentrate with low lead and zinc content.

[0007] The specific steps of the method of the present invention are as follows: (1) The lead-zinc sulfide ore mixed rough concentrate is regrinded to obtain regrinded slurry, wherein the mass of mineral particles with a diameter of -74μm accounts for 80%-85% of the total mass of the mixed rough concentrate, the slurry concentration during regrinding is 65%~70%, and the mass of mineral particles with a diameter of -37μm accounts for more than 85% of the total mass of the mixed concentrate after regrinding; (2) The slurry obtained in step (1) is filtered and dewatered to obtain a refractory lead-zinc mixed coarse concentrate filter cake and filtrate. The filtration is carried out using a ceramic filter, and the moisture content of the filter cake is 10%-12%. (3) Add water to the lead-zinc mixed concentrate filter cake obtained in step (2) to adjust the slurry concentration to 15%-20%, and add sulfuric acid to adjust the pH to 5-6; (4) The lead-zinc mixed concentrate slurry after step (3) is subjected to a closed-circuit flotation process consisting of two lead roughing, two lead scavenging, and four lead cleaning to obtain lead concentrate. The underflow after lead scavenging is zinc concentrate. Lead roughing I: Add 200-300 g / t of glutathione zinc inhibitor, 100-150 g / t of collector mercaptobenzothiazole sodium, and 80-90 g / t of methyl isobutyl methanol frother to the slurry. Lead roughing I is carried out for 6-8 minutes to obtain lead roughing I concentrate and lead roughing I tailings. Lead roughing II: Add 100-150 g / t of glutathione, 50-80 g / t of collector mercaptobenzothiazole sodium, and 40-45 g / t of methyl isobutyl methanol to the lead roughing I tailings. Lead roughing II is carried out for 5-7 minutes to obtain lead roughing II concentrate and lead roughing II tailings. Lead scavenging I: Add 50-70 g / t of glutathione, 30-40 g / t of collector mercaptobenzothiazole sodium, and 20-25 g / t of methyl isobutyl methanol frother to the lead roughing II tailings. Methyl isobutyl methanol is used for lead scavenging I for 4-6 minutes to obtain lead scavenging I concentrate and lead scavenging I tailings. Lead scavenging II: 20-35 g / t glutathione, 15-20 g / t collector mercaptobenzothiazole sodium, and 10-15 g / t methyl isobutyl methanol are added to the lead scavenging I tailings. Lead scavenging II is carried out for 4-6 minutes to obtain lead scavenging II foam and lead scavenging II underflow. The lead scavenging II foam is returned to the lead scavenging I operation to form a closed loop. The lead scavenging II underflow is zinc concentrate. Lead rougher I concentrate and lead rougher II concentrate are mixed and then fed into lead refinement I. Lead refinement I: 30-40 g / t of glutathione and 200-300 g / t of water glass are added. Refinement I takes 7-9 minutes, yielding lead refinement I concentrate and lead refinement I underflow. The lead refinement I underflow and lead scavenging I concentrate are combined and returned to lead rougher I. Lead refinement II: 15-20 g / t of glutathione and 100-150 g / t of water glass are added to lead refinement I concentrate. Refinement II takes 6-8 minutes, yielding lead refinement II concentrate and lead refinement II underflow. The lead refinement II underflow is returned to lead refinement I. Lead refinement III: 10-15 g / t of glutathione is added to lead refinement II concentrate. Refinement III takes 5-6 minutes, yielding lead refinement III concentrate and lead refinement III underflow. The lead refinement III underflow is returned to lead refinement II. Lead refinement IV: No reagents are added, and the flotation time is 4-5 minutes. min, to obtain the final lead concentrate and lead refining IV underflow, the lead refining IV underflow is returned to lead refining III operation.

[0008] The feature of this invention is: a novel inhibitor of glutathione (C 10 H 17 The -COOH, -CN, and -NH active functional groups in the N3O6S molecule can undergo strong and specific chemisorption with Zn sites on the surface of sphalerite, forming R-COO-Zn complexes, which effectively inhibit the strong hydrophilicity of sphalerite. Meanwhile, glutathione hardly adsorbs on the surface of galena, thus not affecting its natural floatability. This excellent selectivity solves the separation problem caused by the similar floatability of galena and sphalerite.

[0009] Compared with the prior art, the present invention has the following significant advantages: 1. Highly selective inhibition of sphalerite is achieved: This invention uses glutathione as a novel inhibitor. The active functional groups in its molecule can specifically and firmly adsorb onto the surface of sphalerite, making it strongly hydrophilic and thus efficiently inhibiting it; while it hardly adsorbs onto the surface of galena, without affecting its natural floatability. This excellent selectivity can solve the separation problem caused by the similar floatability of galena and sphalerite.

[0010] 2. High separation efficiency and high-quality concentrate: Through the synergistic effect of pretreatment ("regrinding-filtration-removal") and "glutathione inhibition" of the rough concentrate, this invention achieves highly efficient separation of lead and zinc. The zinc content in the resulting lead concentrate is significantly reduced, and the lead content in the zinc concentrate is also effectively controlled, resulting in high-quality lead and zinc concentrates with low intermetallic content, thus greatly enhancing product value.

[0011] 3. High metal recovery rate: Due to the non-inhibitory effect of glutathione on galena and the elimination of the activation effect of inevitable ions on sphalerite by pretreatment, galena is fully floated during flotation, ensuring a high lead recovery rate. Simultaneously, the effectively inhibited sphalerite remains in the tailings (i.e., zinc concentrate), also ensuring a high zinc recovery rate.

[0012] 4. Green and environmentally friendly, safe and non-toxic: The core inhibitor glutathione is a naturally occurring bioactive molecule that is easily biodegradable and harmless to the environment. It completely eliminates the dependence on highly toxic agents such as cyanide, which is in line with the development trend of green mineral processing and greatly reduces environmental and production safety risks.

[0013] 5. Strong process adaptability and controllable cost: The process flow of this invention is simple and the operating conditions are mild. The "regrinding, filtration, and de-drug removal" step can effectively remove residual reagents and unavoidable ions from the slurry, creating optimal conditions for efficient glutathione inhibition. Furthermore, the filtrate can be treated and recycled, reducing operating costs. This process provides a reliable new approach to solving the problem of separating complex and difficult-to-process lead-zinc mixed concentrates. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0015] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the scope of protection of the present invention is not limited to the content described.

[0016] In the embodiments and comparative examples of this invention, three kinds of lead-zinc sulfide ore mixed rough concentrates produced in Yunnan were selected respectively. The three kinds of mixed rough concentrates were numbered as samples 1-3. The lead mineral in the three kinds of mixed rough concentrates is mainly galena (PbS), the zinc mineral is mainly sphalerite (ZnS), and it also contains a very small amount of impurity minerals such as pyrite and quartz. Example 1

[0017] In this embodiment, flotation separation was performed on a mixed rough concentrate of lead-zinc sulfide ore No. 1. The lead grade of sample No. 1 was 28.94%, and the zinc grade was 20.61%. (1) The No. 1 lead-zinc sulfide ore mixed rough concentrate (80% of which is -74μm) was regrinded. The slurry concentration during regrinding was 70%, and the fineness of the regrinded lead-zinc mixed concentrate was -37μm, accounting for 85%.

[0018] (2) A ceramic filter was used to filter and dewater the refractory slurry obtained in step (1) to obtain a refractory lead-zinc mixed coarse concentrate filter cake and filtrate. The filter cake had a moisture content of 10%.

[0019] (3) Add water to the lead-zinc mixed concentrate filter cake obtained in step (2) to adjust the slurry concentration to 20%, and add sulfuric acid to adjust the slurry pH to 5.

[0020] (4) The lead-zinc mixed concentrate slurry obtained in step (3) is subjected to a zinc-suppressing flotation process, using glutathione as an inhibitor for sphalerite, sodium mercaptobenzothiazole as a collector for galena, and methyl isobutyl methanol as a frother. The process involves two lead roughing stages, two lead scavenging stages, and four lead cleaning stages in a closed-circuit flotation process to obtain lead concentrate. The underflow after lead scavenging is zinc concentrate. The flotation process is shown in [link to flotation process]. Figure 1 The dosing regime and stirring time for each operation in the flotation process are shown in Table 1.

[0021] The lead-zinc flotation separation results of Example 1 are shown in Table 2. Example 2

[0022] In this embodiment, the mixed rough concentrate of No. 2 lead-zinc sulfide ore was separated by flotation. The lead grade of No. 2 sample was 25.19% and the zinc grade was 26.48%.

[0023] (1) The No. 2 lead-zinc sulfide ore mixed rough concentrate (85% of which are -74μm) was regrinded. The slurry concentration during regrinding was 67%, and the fineness of the regrinded lead-zinc mixed concentrate was 95% -37μm.

[0024] (2) A ceramic filter was used to filter and dewater the refractory slurry obtained in step (1) to obtain a refractory lead-zinc mixed coarse concentrate filter cake and filtrate. The filter cake had a moisture content of 11%.

[0025] (3) Add water to the lead-zinc mixed concentrate filter cake obtained in step (2) to adjust the slurry concentration to 17%, and add sulfuric acid to adjust the slurry pH to 6.

[0026] (4) The lead-zinc mixed concentrate slurry obtained in step (3) is subjected to a zinc-suppressing flotation process, using glutathione as an inhibitor for sphalerite, sodium mercaptobenzothiazole as a collector for galena, and methyl isobutyl methanol as a frother. The process involves two lead roughing stages, two lead scavenging stages, and four lead cleaning stages in a closed-circuit flotation process to obtain lead concentrate. The underflow after lead scavenging is zinc concentrate. The flotation process is shown in [link to flotation process]. Figure 1 The dosing regime and stirring time for each operation in the flotation process are shown in Table 1.

[0027] The lead-zinc flotation separation results of Example 2 are shown in Table 2. Example 3

[0028] In this embodiment, the mixed rough concentrate of No. 3 lead-zinc sulfide ore was separated by flotation. The lead grade of No. 3 sample was 22.20%, and the zinc grade was 28.48%.

[0029] (1) The No. 3 lead-zinc sulfide ore mixed rough concentrate (-74μm accounts for 83%) was regrinded. The slurry concentration during regrinding was 65%, and the fineness of the regrinded lead-zinc mixed concentrate was -37μm accounting for 90%.

[0030] (2) A ceramic filter was used to filter and dewater the refractory slurry obtained in step (1) to obtain a refractory lead-zinc mixed coarse concentrate filter cake and filtrate. The filter cake had a moisture content of 12%.

[0031] (3) Add water to the lead-zinc mixed concentrate filter cake obtained in step (2) to adjust the slurry concentration to 15%, and add sulfuric acid to adjust the slurry pH to 5.5.

[0032] (4) The lead-zinc mixed concentrate slurry obtained in step (3) is subjected to a zinc-suppressing flotation process, using glutathione as an inhibitor for sphalerite, sodium mercaptobenzothiazole as a collector for galena, and methyl isobutyl methanol as a frother. The process involves two lead roughing stages, two lead scavenging stages, and four lead cleaning stages in a closed-circuit flotation process to obtain lead concentrate. The underflow after lead scavenging is zinc concentrate. The flotation process is shown in [link to flotation process]. Figure 1 The dosing regime and stirring time for each operation in the flotation process are shown in Table 1.

[0033] The lead-zinc flotation separation results of Example 3 are shown in Table 2. Comparative Example

[0034] This comparative example employs a traditional zinc-suppressing and lead-floating process to separate lead and zinc in No. 2 lead-zinc mixed rough concentrate. Specifically, zinc sulfate and sodium sulfite are used as inhibitors for sphalerite, ethyl thiocyanate is used as a collector for galena, and methyl isobutyl alcohol is used as a frother. The experimental procedure is similar to... Figure 1 To maintain consistency, the experimental reagent regime is shown in the table, and the flotation results of lead concentrate and zinc concentrate are shown in the comparative examples in Table 2.

[0035] Table 1. Reagent dosage for each flotation operation in Examples 1-3 and the comparative example.

[0036] Table 2 shows the lead-zinc flotation separation effect obtained in Examples 1-3 using the process of the present invention.

[0037] As shown in Table 2, compared with the comparative examples, in Examples 1 to 3 of this invention, the lead grade of the obtained lead concentrate can reach over 45%, the lead recovery rate can reach over 91%, and the content of harmful impurities (Zn) in the lead concentrate can be reduced to below 5%; the zinc grade of the obtained zinc concentrate can reach over 45%, the zinc recovery rate can reach over 88%, and the content of harmful impurities (Pb) in the zinc concentrate can be reduced to below 5%, all meeting the relevant quality standards for lead and zinc concentrates. This demonstrates that this invention can effectively achieve efficient separation of galena and sphalerite in lead-zinc mixtures, significantly improving the quality of lead and zinc concentrates while ensuring high lead and zinc recovery rates, fundamentally solving the problem of flotation separation of lead-zinc mixed concentrates.

[0038] In summary, by using glutathione as an inhibitor and combining the synergistic effect of the descaling and flotation processes, this invention significantly improves the separation of galena and sphalerite, greatly enhances the quality of lead and zinc concentrate products, increases the recovery rate of lead and zinc, and effectively solves the lead-zinc separation problem.

[0039] Finally, the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A flotation separation method for a mixed lead-zinc sulfide ore rough and concentrate, characterized in that, First, the mixed lead-zinc sulfide ore concentrate is regrinded; then, water and acid are added to the regrinded slurry to adjust the slurry concentration and pH; then, lead and zinc are separated from the mixed concentrate by flotation. Glutathione is used as an inhibitor of sphalerite in the mixed lead-zinc concentrate during flotation to obtain high-quality lead concentrate and zinc concentrate with low lead-zinc content.

2. The flotation separation method for a mixed rough and concentrate of lead-zinc sulfide ore according to claim 1, characterized in that: The specific steps are as follows: (1) The lead-zinc sulfide ore mixed with coarse concentrate is regrinded to obtain regrinded slurry; (2) The slurry obtained in step (1) is filtered and dewatered to obtain a refmilled lead-zinc mixed coarse concentrate filter cake and filtrate; (3) Add water to the lead-zinc mixed concentrate filter cake obtained in step (2) to adjust the slurry concentration to 15%-20%, and add acid to adjust the pH to 5-6; (4) The lead-zinc mixed concentrate slurry after step (3) is subjected to a closed-circuit flotation process consisting of two lead roughing, two lead scavenging, and four lead cleaning to obtain lead concentrate. The underflow after lead scavenging is zinc concentrate.

3. The flotation separation method for a mixed lead-zinc sulfide ore rough and concentrate according to claim 2, characterized in that: In step (1), in the mixed lead-zinc sulfide ore concentrate, the mineral particles with a diameter of -74μm account for 80%-85% of the total mass of the mixed concentrate, the slurry concentration during regrinding is 65%~70%, and in the regrinded lead-zinc mixed concentrate, the mineral particles with a diameter of -37μm account for more than 85% of the total mass of the mixed concentrate.

4. The flotation separation method for a mixed rough and concentrate of lead-zinc sulfide ore according to claim 2, characterized in that: In step (2), a ceramic filter is used for filtration, and the moisture content of the filter cake is 10%-12%.

5. The flotation separation method for a mixed rough concentrate of lead-zinc sulfide ore according to claim 2, characterized in that: In step (4), lead roughing I: 200-300 g / t of glutathione zinc inhibitor, 100-150 g / t of collector mercaptobenzothiazole sodium, and 80-90 g / t of methyl isobutyl methanol frother are added to the slurry. Lead roughing I is carried out for 6-8 minutes to obtain lead roughing I concentrate and lead roughing I tailings. Lead roughing II: 100-150 g / t of glutathione, 50-80 g / t of collector mercaptobenzothiazole sodium, and 40-45 g / t of methyl isobutyl methanol are added to the lead roughing I tailings. Lead roughing II is carried out for 5-7 minutes to obtain lead roughing II concentrate and lead roughing II tailings. Lead scavenging I: 50-70 g / t of glutathione, 30-40 g / t of collector mercaptobenzothiazole sodium, and 20-25 g / t of methyl isobutyl methanol are added to the lead roughing II tailings. Methyl isobutyl methanol is used for lead scavenging I for 4-6 minutes to obtain lead scavenging I concentrate and lead scavenging I tailings. Lead scavenging II: 20-35 g / t glutathione, 15-20 g / t collector mercaptobenzothiazole sodium, and 10-15 g / t methyl isobutyl methanol are added to the lead scavenging I tailings. Lead scavenging II is carried out for 4-6 minutes to obtain lead scavenging II foam and lead scavenging II underflow. The lead scavenging II foam is returned to the lead scavenging I operation to form a closed loop. The lead scavenging II underflow is zinc concentrate. Lead rougher I concentrate and lead rougher II concentrate are mixed and then fed into lead refinement I. Lead refinement I: 30-40 g / t of glutathione and 200-300 g / t of water glass are added. Refinement I takes 7-9 minutes, yielding lead refinement I concentrate and lead refinement I underflow. The lead refinement I underflow and lead scavenging I concentrate are combined and returned to lead rougher I. Lead refinement II: 15-20 g / t of glutathione and 100-150 g / t of water glass are added to lead refinement I concentrate. Refinement II takes 6-8 minutes, yielding lead refinement II concentrate and lead refinement II underflow. The lead refinement II underflow is returned to lead refinement I. Lead refinement III: 10-15 g / t of glutathione is added to lead refinement II concentrate. Refinement III takes 5-6 minutes, yielding lead refinement III concentrate and lead refinement III underflow. The lead refinement III underflow is returned to lead refinement II. Lead refinement IV: No reagents are added, and the flotation time is 4-5 minutes. min, to obtain the final lead concentrate and lead refining IV underflow, the lead refining IV underflow is returned to lead refining III operation.

Images