Method for recovering silver, sulfur and zinc from lead-zinc mine tailings

Abstract

The application discloses a method for recovering silver, sulfur and zinc from lead-zinc tailings, which comprises the following steps: step A: silver-sulfur mixed flotation is carried out on the flotation tailings, and one-stage roughing, two-stage cleaning and two-stage scavenging are carried out, wherein silver-sulfur concentrates are obtained through two-stage cleaning, and silver-sulfur tailings are obtained through two-stage scavenging; and step B: zinc oxide flotation is carried out on the silver-sulfur tailings obtained in step A, and two-stage roughing, three-stage cleaning and one-stage scavenging are carried out, wherein zinc concentrates are obtained through three-stage cleaning, and tailings are obtained through scavenging. The valuable metals silver, sulfur and zinc are extracted from lead-zinc tailings, the resource utilization rate is improved, and through re-flotation of the tailings and development of a suitable flotation method, comprehensive recovery of noble metal elements in low-grade ores is realized, the silver-sulfur concentrates obtained contain 32.41% of S and 107.33 g / t of Ag, the zinc oxide concentrates contain 9.26% of Zn, the recovery rate of Zn can reach 49.76%, and the lead-zinc resource utilization is realized.

Description

Technical fields:

[0001] This invention relates to the field of lead-zinc mine tailings recovery, and specifically to a method for recovering silver, sulfur, and zinc from lead-zinc mine tailings. Background technology:

[0002] With the rapid development of modern industry and the continuous growth of non-ferrous metal production, the amount of tailings discharged from mines and beneficiation plants is increasing day by day. At the same time, with the increasing depletion of rich mineral resources and the increasing proportion of low-grade mineral resources being mined, the number of metal mines and beneficiation plants is increasing and their scale is expanding. As a result, the amount of tailings discharged from metal mines and beneficiation plants is increasing dramatically. However, some tailings are still rich in some valuable elements and have a certain recovery value.

[0003] In the beneficiation process of lead-zinc ore, a lead-zinc preferential flotation process is adopted. The tailings after flotation are discharged into a tailings pond. Ore samples from the tailings pond of the Erdaogou lead-zinc-silver polymetallic mine were mixed and reduced in size, and then sampled for analysis. The contents of Ag, S, and Zn in the tailings (hereinafter referred to as: samples) were 11.85 g / t, 1.85%, and 0.78%, respectively. The mineral composition of the samples is complex. The main metallic mineral is pyrite, followed by magnetite, hematite, and smithsonite; the gangue minerals are mainly quartz and calcite, followed by almandine and grossular. Zinc in the samples is mainly found in smithsonite, accounting for approximately 63% of the total Zn, with a small amount found in hemimorphite and zinc-iron spinel. The degree of liberation of smithsonite is approximately 75%. Silver was dispersed in the sample, with silver-bearing minerals mainly including argentite and tellurite, closely related to quartz, pyrite, and limonite. The former often existed as fine grains encapsulated by or closely associated with the latter. Sulfur in the sample mainly existed in the form of pyrite. Therefore, the tailings contained valuable elements such as silver, sulfur, and zinc, and had certain recovery value. Summary of the Invention:

[0004] The purpose of this invention is to provide a method for recovering silver, sulfur, and zinc from lead-zinc mine tailings.

[0005] This invention is implemented by the following technical solution:

[0006] A method for recovering silver, sulfur, and zinc from lead-zinc mine tailings includes the following steps:

[0007] Step A: The flotation tailings are subjected to silver-sulfur mixed flotation, which consists of one roughing stage, two cleaning stages, and two scavenging stages. The silver-sulfur concentrate is obtained from the secondary cleaning stage, and the silver-sulfur tailings are obtained from the secondary scavenging stage.

[0008] Step B: The silver-sulfur tailings obtained in Step A are subjected to zinc oxide flotation, which consists of two roughing stages, three cleaning stages, and one scavenging stage. The three cleaning stages yield zinc concentrate, and the scavenging stage yields tailings.

[0009] Preferably, in step A, 70-85 g / t of CuSO4, 80-120 g / t of butyl xanthate, 5-20 g / t of MIBC, and 30-40 g / t of water glass are added.

[0010] Preferably, in step B, 15000-19000 g / t of Na2S, 120-140 g / t of sodium hexametaphosphate, and 560-700 g / t of HN are added.

[0011] Preferably, 70-85 g / t of CuSO4 is added during the coarse selection process in step A.

[0012] Preferably, 60-80 g / t of butyl xanthate is added during the coarse selection process in step A, 20-25 g / t is added for the first-stage scavenging, and 10-15 g / t is added for the second-stage scavenging.

[0013] Preferably, 5-10 g / t of MIBC is added during the coarse selection process in step A, and 5-10 g / t is added as a supplement during the primary scavenging process.

[0014] Preferably, 20-25 g / t of water glass is added during the primary refining process in step A, and 10-15 g / t is added during the secondary refining process.

[0015] Preferably, in step B, 15000-15020 g / t of Na2S is added during the first roughing stage, 2000-2020 g / t is added during the second roughing stage, 1000-1020 g / t is added during the first scavenging stage, 500-520 g / t is added during the first cleaning stage, 300-320 g / t is added during the second cleaning stage, and 100 g / t is added during the third cleaning stage.

[0016] Preferably, 100-110 g / t of sodium hexametaphosphate is added during the primary coarse selection process in step B, and 20-30 g / t is added as a supplementary agent during the primary fine selection process.

[0017] Preferably, in step B, 250-300 g / t of HN is added during the first coarse selection process, 120-150 g / t of HN is added during the second coarse selection, 80-100 g / t of HN is added during the first scavenging selection, 60-70 g / t of HN is added during the first fine selection, 40-45 g / t of HN is added during the second fine selection, and 30-35 g / t of HN is added during the third fine selection.

[0018] Advantages of this invention: This invention extracts valuable metallic silver, sulfur, and zinc from lead-zinc tailings, improving resource utilization. By re-flotating the tailings and developing a suitable flotation method, it achieves comprehensive recovery of precious metal elements from low-grade ores. The obtained silver-sulfur concentrate contains 32.41% S and 107.33 g / t Ag, respectively, and the zinc oxide concentrate contains 9.26% Zn. The Zn recovery rate can reach 49.76%, realizing the resource utilization of lead-zinc ore. Attached image description:

[0019] Figure 1 This is a process flow diagram of the present invention;

[0020] Figure 2 This is a process flow diagram for the copper sulfate dosage test.

[0021] Figure 3 This is a process flow diagram for the dosage conditions test of Dinghuang medicine;

[0022] Figure 4 This is a process flow diagram for the sulfidation flotation test;

[0023] Figure 5 This is a process flow diagram for the Na2S dosage condition test;

[0024] Figure 6 This is a process flow diagram for inhibitor condition testing;

[0025] Figure 7 This is a process flow diagram for the collector dosage condition test. Detailed implementation method:

[0026] The following description, in conjunction with examples and experimental procedures, provides further details.

[0027] Chemical multi-element analysis was performed on ore samples from the tailings dam of the Erdaogou lead-zinc-silver polymetallic mine. The results are shown in Table 1.

[0028] Table 1. Chemical multi-element analysis results of the ore (%)

[0029] content 0.11 0.78 7.59 1.85 40.61 11.85 Components <![CDATA[Al2O3]]> MgO CaO <![CDATA[K2O]]> <![CDATA[Na2O]]> Au(g / t) content 9.26 3.25 19.51 1.42 0.91 <0.1

[0030] The main objective was to recover Zn, S, and Ag, with grades of 0.78%, 1.85%, and 11.85 g / t, respectively. Analysis of the distribution characteristics of the main minerals in the tailings revealed that zinc was primarily found in smithsonite, accounting for approximately 63% of the total Zn, with smaller amounts found in hemimorphite and zinc-iron spinel. The degree of liberation of smithsonite was approximately 75%. Silver was relatively dispersed, with silver-bearing minerals mainly including argentite and tellurite. Sulfur mainly existed in the form of pyrite.

[0031] After conducting a process mineralogical study of the tailings, flotation tests were performed using the obtained data, as follows:

[0032] 1. Silver-sulfur flotation test

[0033] (1) Test on copper sulfate dosage conditions

[0034] The experimental process flow for copper sulfate dosage conditions is as follows: Figure 2 The test results are shown in Table 2;

[0035] Table 2. Results of the test on copper sulfate dosage conditions (%)

[0036]

[0037]

[0038] As can be seen from the experimental results in Table 2, with the increase of copper sulfate dosage, the grade and recovery of S and Ag in sulfur concentrate first rise and then slow down. The appropriate copper sulfate dosage is 80 g / t ±.

[0039] (2) Dosage conditions test of clove and huang medicine

[0040] The process flow for the dosage condition test of clove and rhubarb is as follows: Figure 3 The test results are shown in Table 3;

[0041] Table 3 Results of the test on dosage conditions of benzoyl peroxide (%)

[0042]

[0043] As shown in Table 3, with the increase of the amount of butyl xanthan gum used, the yield of sulfur concentrate increased, the grade of S and Ag decreased, and the overall recovery rate increased. Taking all factors into consideration, the appropriate amount of butyl xanthan gum used is about 120 g / t.

[0044] (3) Silver-sulfur flotation open-circuit test

[0045] An open-circuit test of silver-sulfur flotation was conducted, and the test results are shown in Table 4.

[0046] Table 4. Results of open-circuit tests for silver-sulfur flotation (%)

[0047]

[0048] As shown in Table 5, after one stage of roughing, two stages of cleaning, and two stages of scavenging, the sulfur concentrate obtained contained 42.16% S and 143.29 g / t of Ag, with recovery rates of 53.33% and 28.02%, respectively; the sulfur tailings contained 0.21% S and 7.71 g / t of Ag, with recovery rates of 10.44% and 59.26%, respectively.

[0049] 2. Zinc oxide flotation test

[0050] (1) Sulfide flotation test

[0051] Using tailings obtained through silver-sulfur flotation as the research object, a sulfidation flotation experiment was conducted to recover zinc oxide. The process flow of the sulfidation flotation experiment is shown below. Figure 4 The test results are shown in Table 5;

[0052] Table 5 Results of sulfidation flotation tests (%)

[0053]

[0054]

[0055] As shown in Table 5, under the same dosage conditions, HN and octadecylamine have relatively strong collecting ability, while mixed amine and dodecylamine have relatively weaker ability. Dodecylamine and mixed collection have relatively good selectivity. Overall, mixed collection has both good collecting ability and selectivity. For the flotation recovery of zinc oxide from silver-sulfur flotation tailings, the experimental indicators obtained by the sulfide-amine method are relatively good. Therefore, this process was selected for flotation.

[0056] (2) Na2S dosage condition test

[0057] The process flow for the Na2S dosage condition test is as follows: Figure 5 The test results are shown in Table 6;

[0058] Table 6. Results of Na2S Dosage Condition Tests (%)

[0059]

[0060]

[0061] As can be seen from the test results in Table 6, with the increase of Na2S dosage, the zinc concentrate yield first increases and then decreases, the grade generally shows an upward trend, and the recovery first increases and then decreases. Taking all factors into consideration, the appropriate Na2S dosage is 15000g / t.

[0062] (3) Inhibitor conditioned study

[0063] The process flow for inhibitor condition testing is as follows: Figure 6 The test results are shown in Table 7;

[0064] Table 7 Results of Inhibitor Conditioning Tests (%)

[0065]

[0066]

[0067] As can be seen from the experimental results in Table 7, among the five inhibitors, sodium hexametaphosphate has a relatively good selective inhibition effect on gangue minerals. With the increase of sodium hexametaphosphate dosage, the Zn recovery rate of zinc concentrate generally shows a downward trend, while the grade shows an upward trend. Taking all factors into consideration, the appropriate dosage of sodium hexametaphosphate is about 140 g / t.

[0068] (4) Test on the dosage conditions of the collector

[0069] The process flow for the collector dosage condition test is as follows: Figure 7 The test results are shown in Table 8;

[0070] Table 8 Results of the test on the dosage conditions of the collector (%)

[0071]

[0072]

[0073] As shown in Table 8, under the same conditions, with the increase of collector dosage, the yield of zinc concentrate shows an upward trend, the grade shows a downward trend, and the recovery rate shows an overall upward trend. Taking all factors into consideration, the appropriate HN collector dosage for zinc oxide roughing is about 300 g / t.

[0074] (5) Test on the dosage conditions of the collector

[0075] Open-circuit tests of zinc oxide flotation were conducted on silver-sulfur flotation tailings. The test results are shown in Table 9.

[0076] Table 9 Results of open-circuit test for zinc oxide flotation (%)

[0077]

[0078] As shown in Table 9, the zinc concentrate obtained from silver-sulfur flotation tailings after one roughing and three cleaning processes contained 10.51% Zn, with a recovery rate of 40.66%. The zinc concentrate obtained after two cleaning processes contained 10.09% Zn, with a recovery rate of 44.12%. The total tailings obtained after one scavenging process contained only 0.27% Zn, and further increasing the number of scavenging processes would not significantly improve the Zn recovery rate.

[0079] Based on extensive conditional experiments, and considering the comprehensive recovery of silver, sulfur, and zinc from tailings discharged from the Erdaogou plant, a recommended flotation process is the sequential flotation of silver-sulfur and zinc oxide. The flotation process is detailed in the following flow chart. Figure 1 ;

[0080] The steps include the following:

[0081] Step A: The flotation tailings are subjected to silver-sulfur mixed flotation, consisting of one roughing stage, two cleaning stages, and two scavenging stages. The two cleaning stages yield silver-sulfur concentrate, while the two scavenging stages yield silver-sulfur tailings. During the roughing stage in Step A, 80 g / t of CuSO4 is added. During the roughing stage in Step A, 60 g / t of butyl xanthate is added, with an additional 20 g / t added during the first scavenging stage and 10 g / t added during the second scavenging stage. During the roughing stage in Step A, 5 g / t of MIBC is added, with an additional 5 g / t added during the first scavenging stage. During the first cleaning stage in Step A, 20 g / t of water glass is added, with an additional 10 g / t added during the second cleaning stage.

[0082] Step B: The silver-sulfur tailings obtained in Step A are subjected to zinc oxide flotation, consisting of two roughing stages, three cleaning stages, and one scavenging stage. The three cleaning stages yield zinc concentrate, and the scavenging stage yields tailings. During the first roughing stage in Step B, 15000 g / t of Na₂S is added; during the second roughing stage, 2000 g / t is added; during the first scavenging stage, 1000 g / t is added; during the first cleaning stage, 500 g / t is added; during the second cleaning stage, 300 g / t is added; and during the third cleaning stage, 100 g / t is added. During the first roughing stage in Step B, 100 g / t of sodium hexametaphosphate is added; and during the first cleaning stage, 20 g / t is added. During the first roughing stage in Step B, 250 g / t of hydrogen nitrate (HN) is added; during the second roughing stage, 120 g / t of HN is added; during the first scavenging stage, 80 g / t of HN is added; during the first cleaning stage, 60 g / t of HN is added; during the second cleaning stage, 40 g / t of HN is added; and during the third cleaning stage, 30 g / t of HN is added.

[0083] The test parameters for flotation based on the above process flow are shown in Table 10.

[0084] Table 10 Test Indicators (%)

[0085]

[0086]

[0087] As shown in Table 10, the silver-sulfur concentrate contained 32.41% S and 107.33 g / t Ag, respectively, and the zinc oxide concentrate contained 9.26% Zn, with a Zn recovery rate of 49.76%.

[0088] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for recovering silver, sulfur, and zinc from lead-zinc mine tailings, characterized in that, The steps include the following: Step A: The flotation tailings are subjected to silver-sulfur mixed flotation, which consists of one roughing stage, two cleaning stages, and two scavenging stages. The silver-sulfur concentrate is obtained from the secondary cleaning stage, and the silver-sulfur tailings are obtained from the secondary scavenging stage. Step B: The silver-sulfur tailings obtained in Step A are subjected to zinc oxide flotation, which consists of two roughing stages, three cleaning stages, and one scavenging stage. The three cleaning stages yield zinc concentrate, and the scavenging stage yields tailings. In step A, add 70-85 g / t of CuSO4, 80-120 g / t of butyl xanthate, 5-20 g / t of MIBC, and 30-40 g / t of water glass. Specifically, in step A, 70-85 g / t of CuSO4 is added during the roughing process; 60-80 g / t of butyl xanthate is added during the roughing process, with 20-25 g / t added for the first-stage scavenging and 10-15 g / t added for the second-stage scavenging; 5-10 g / t of MIBC is added during the roughing process, with 5-10 g / t added for the first-stage scavenging; and 20-25 g / t of water glass is added during the first-stage cleaning process, with 10-15 g / t added for the second-stage cleaning. In step B, add 15000-19000 g / t of Na2S, 120-140 g / t of sodium hexametaphosphate, and 560-700 g / t of HN. Specifically, in step B, 15000-15020 g / t of Na₂S is added during the first roughing stage; 2000-2020 g / t is added during the second roughing stage; 1000-1020 g / t is added during the first scavenging stage; 500-520 g / t is added during the first cleaning stage; 300-320 g / t is added during the second cleaning stage; and 100 g / t is added during the third cleaning stage. In step B, 100-110 g / t of sodium hexametaphosphate is added during the first roughing stage; and 20-30 g / t of sodium hexametaphosphate is added during the first cleaning stage. In step B, 250-300 g / t of HN is added during the first roughing stage; 120-150 g / t of HN is added during the second roughing stage; 80-100 g / t of HN is added during the first scavenging stage; 60-70 g / t of HN is added during the first cleaning stage; 40-45 g / t of HN is added during the second cleaning stage; and HN is added during the third cleaning stage. 30-35g / t.

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