High-efficiency comprehensive recovery system for low-grade complex lead-zinc oxide-gold and silver ore

Abstract

The efficient comprehensive recovery system comprises a semi-autogenous mill, a discharge port of the semi-autogenous mill is connected to a feed port of a 1 # grading cyclone through a 1 # ore pulp pump, a sand settling port of the 1 # grading cyclone is connected to a feed port of a 1 # ball mill, and a sand settling port of the 1 # ball mill is connected to a feed port of a 2 # ball mill. A discharge port of the 1 # ball mill is connected to a feed port of the 2 # grading cyclone through the 2 # ore pulp pump, and a sand settling port of the 2 # grading cyclone is connected to a feed port of the 2 # ball mill; overflow ports of the 1 # grading cyclone and the 2 # grading cyclone are connected to a feeding port of the pulse high-gradient high-intensity magnetic separator, a concentrate outlet and a tailing outlet of the pulse high-gradient high-intensity magnetic separator are connected to a feeding port of the 2 # ball mill and a feeding port of the gold-silver-lead mixed floating system respectively, and a discharging port of the 2 # ball mill is connected to the cyaniding carbon slurry system; and a tailing outlet of the gold-silver-lead mixed flotation system is connected to the zinc flotation system. The comprehensive recovery device can realize comprehensive recovery of gold, silver, iron, lead and zinc in the low-grade complex lead-zinc oxide-gold and silver ore, and is remarkable in efficient comprehensive recovery effect.

Description

Technical Field

[0001] This utility model belongs to the field of low-grade mineral recovery technology, specifically relating to a high-efficiency comprehensive recovery system for low-grade complex oxidized lead-zinc-gold-silver ores. Background Technology

[0002] my country is a country with extremely rich oxidized lead-zinc ore deposits. However, with the development of lead-zinc-gold-silver deposits, rich ore resources are decreasing, ore grades are gradually decreasing, and the complexity of oxidized ores is becoming increasingly prominent. Lead-zinc-gold-silver deposits often contain precious metals such as gold and silver, which have extremely high comprehensive development and utilization value. However, the ore structure is complex, the gold and silver are embedded in small grains, mostly existing as inclusions, and the associated components are unstable, containing large amounts of clay, hematite, limonite, and soluble salts.

[0003] Currently, the separation and recovery of polymetallic oxide lead-zinc ores mainly employs the grinding-dispersant enhanced dispersion whole-slurry flotation process. However, this method has several problems: First, the high content of soluble ions and slime in the ore makes it difficult to effectively disperse the slurry even with large amounts of dispersant, resulting in high consumption of flotation reagents and difficulty in improving flotation indicators (grade and recovery rate). Second, for finely or complexly disseminated ores, pre-desliming leads to the loss of a large amount of valuable minerals. In addition, when using the fine grinding-carbon leaching method to recover precious metals, the interference of non-ferrous metal minerals results in low gold and silver recovery rates, high production costs, and difficulty in effectively recovering valuable components such as lead and zinc, leading to resource waste and environmental pollution risks.

[0004] Therefore, developing short-process, low-cost, and low- or pollution-free lead-zinc-gold-silver ore recovery systems has become an inevitable trend. Utility Model Content

[0005] To overcome the shortcomings and defects of existing technologies, this utility model provides a high-efficiency comprehensive recovery system for low-grade complex oxidized lead-zinc-gold-silver ores. Based on the ore properties, it adopts a combination of a two-stage selective closed-circuit crushing and classifying system, a pulsed high-gradient magnetic separator, a cyanide carbon-in-pulp system, and a multi-stage flotation system to gradually reduce the impact of fine particles on flotation and improve the overall ore recovery rate.

[0006] To achieve the above objectives, this utility model provides a high-efficiency integrated recovery system for low-grade complex oxide lead-zinc-gold-silver ore, comprising a semi-autogenous mill. The discharge port of the semi-autogenous mill is connected to the inlet of a No. 1 classifying hydrocyclone via a No. 1 slurry pump. The underflow port of the No. 1 classifying hydrocyclone is connected to the inlet of a No. 1 ball mill. The discharge port of the No. 1 ball mill is connected to the inlet of a No. 2 classifying hydrocyclone via a No. 2 slurry pump. The underflow port of the No. 2 classifying hydrocyclone is connected to the inlet of the No. 2 ball mill. The overflow ports of both the No. 1 and No. 2 classifying hydrocyclones are connected to the inlet of a pulse high-gradient magnetic separator. The concentrate outlet and tailings outlet of the pulse high-gradient magnetic separator are respectively connected to the inlets of the No. 2 ball mill and the gold-silver-lead mixed flotation system. The discharge port of the No. 2 ball mill is connected to a cyanide carbon-in-pulp system. The tailings outlet of the gold-silver-lead mixed flotation system is connected to a zinc flotation system.

[0007] Furthermore, preferably, the diameter of the No. 1 and No. 2 cyclone separators is φ350mm.

[0008] Furthermore, preferably, both the gold-silver-lead mixed flotation system and the zinc flotation system include two mixing tanks, one rougher flotation machine, three cleaner flotation machines, and two scavenger flotation machines.

[0009] The beneficial effects of this invention are as follows: Before flotation, the minerals are selectively coarsely and finely ground using a two-stage selective crushing and classifying closed-circuit system. This avoids the over-grinding and mudding of primary fine-grained materials and slime, which would affect subsequent flotation. Then, a pulsed high-gradient magnetic separator is used to preferentially separate fine-grained hematite and limonite, further reducing the adverse effects of fine materials on flotation. Subsequently, a multi-stage flotation system and a cyanide carbon-in-pulp system are used to recover valuable metals from the magnetic separation tailings and gold- and silver-bearing hematite and limonite concentrates, respectively. This achieves the recovery of gold, silver, iron, lead, and zinc from low-grade complex oxidized lead-zinc-gold-silver ores, with gold recovery rates of over 82%, silver over 81%, iron over 72%, lead over 75%, and zinc over 60%. The comprehensive and efficient resource recovery effect is significant, successfully solving the problems of low recovery rate, high recovery cost, and failure to recover lead and zinc in single flotation processes. Moreover, this method is highly adaptable, simple and environmentally friendly, and has stable process indicators, providing guidance for the comprehensive utilization of resources in low-grade complex oxidized lead-zinc-gold-silver ores. Attached Figure Description

[0010] Figure 1 This is an equipment diagram illustrating the efficient integrated recovery system for low-grade complex oxidized lead-zinc-gold-silver ores according to this utility model.

[0011] In the diagram: 1-Semi-autogenous mill, 2-1# slurry pump, 3-1# classifying hydrocyclone, 4-1# ball mill, 5-2# slurry pump, 6-2# classifying hydrocyclone, 7-Pulse high gradient magnetic separator, 8-2# ball mill, 9-Cyanide carbon-in-pulse system, 10-Gold, silver and lead mixed flotation system, 11-Zinc flotation system. Detailed Implementation

[0012] To make the technical problems and solutions solved by this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0013] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0014] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0015] like Figure 1 As shown, this utility model provides a high-efficiency integrated recovery system for low-grade complex oxide lead-zinc-gold-silver ore, including a semi-autogenous mill 1. The discharge port of the semi-autogenous mill 1 is connected to the inlet of a classifying hydrocyclone 3 via a 1# slurry pump 2. The underflow port of the classifying hydrocyclone 3 is connected to the inlet of a ball mill 4. This part constitutes a first-stage selective grinding and classification closed-loop system. The discharge port of the ball mill 4 is connected to the inlet of a second-stage classifying hydrocyclone 6 via a 2# slurry pump 5. The underflow port of the second-stage classifying hydrocyclone 6 is connected to the inlet of the ball mill 4. This part constitutes a second-stage selective grinding and classification closed-loop system.

[0016] The overflow ports of the #1 classifying hydrocyclone 3 and the #2 classifying hydrocyclone 6 are both connected to the feed port of the pulse high gradient magnetic separator 7. The concentrate outlet and tailings outlet of the pulse high gradient magnetic separator 7 are connected to the feed ports of the #2 ball mill 8 and the gold-silver-lead mixed flotation system 10, respectively. The discharge port of the #2 ball mill 8 is connected to the cyanide carbon slurry system 9. The tailings outlet of the gold-silver-lead mixed flotation system 10 is connected to the zinc flotation system 11.

[0017] Preferably, the diameter of the above-mentioned No. 1 cyclone separator 3 and No. 2 cyclone separator 6 is φ350mm.

[0018] Preferably, both the gold-silver-lead mixed flotation system 10 and the zinc flotation system 11 include two slurry mixing tanks, one rougher flotation machine, three cleaner flotation machines, and two scavenger flotation machines. The two slurry mixing tanks are connected between this system and the previous equipment to buffer or adjust the slurry. The concentrate outlet of the rougher flotation machine is sequentially connected to the three cleaner flotation machines, and the tailings outlet of the rougher flotation machine is sequentially connected to the two scavenger flotation machines. The tailings from each flotation machine can be returned to the previous flotation machine for recirculation. This part is a conventional structure for multi-stage flotation and will not be described in detail here.

[0019] It should be noted that the above-mentioned equipment are all existing equipment, and this application only relates to the application of these existing equipment, and does not involve any improvement of their structure.

[0020] The specific working principle of the above system for recovering low-grade complex oxidized lead-zinc-gold-silver ores is as follows:

[0021] (1) Two-stage selective grinding and classification: The ore to be processed is transported to the semi-autogenous mill 1 for coarse grinding to obtain a slurry with a fineness of -10mm. The slurry is then transported to the classifier hydrocyclone 3 via the 1# slurry pump 2 for low-concentration classification to obtain coarse particles of -10mm to 0.074mm and qualified fine particles. The coarse particles of -10mm to 0.074mm are transported from the sand outlet of the 1# classifier hydrocyclone 3 to the ball mill 4 for fine grinding in the second stage. After fine grinding, the slurry is transported to the 2# classifier hydrocyclone 6 via the 2# slurry pump 5 for classification to obtain qualified fine particles and coarse particles. The coarse particles are returned to the ball mill 4 via the sand outlet of the 2# classifier hydrocyclone 6 for further grinding. This cycle continues until the material is ground to qualified fine particles with -0.074mm accounting for 70% to 80%.

[0022] (2) Pulse high gradient strong magnetic separation: The qualified fine-grained material obtained in step (1) is transported to the pulse high gradient strong magnetic separator 7 for magnetic separation. The fine-grained hematite and limonite are pre-magnetically separated and recovered to obtain gold and silver iron concentrate (containing hematite and limonite) and magnetic separation tailings.

[0023] (3) Gold and silver iron concentrate cyanide carbon slurry extraction: The gold and silver iron concentrate obtained in step (2) is transported to ball mill 8 for fine grinding. After fine grinding to -0.037mm accounting for 80% to 90%, it is transported to cyanide carbon slurry system 9 for cyanide leaching. Gold and silver loaded activated carbon and iron concentrate are obtained by activated carbon adsorption.

[0024] (4) Magnetic tailings flotation of lead, gold and silver: The magnetic tailings obtained in step (2) are transported to the gold, silver and lead mixed flotation system 10. After one roughing, three cleaning and two scavenging, gold, silver and lead concentrate and lead flotation tailings are obtained.

[0025] (5) Zinc flotation from lead tailings: The lead tailings obtained in step (4) are transported to the zinc flotation system 11. After one roughing, three cleaning and two scavenging processes, gold, silver and zinc concentrate and tailings are obtained.

[0026] Application Example 1

[0027] Raw ore #1: A low-grade, complex oxidized lead-zinc-gold-silver ore. Its main element chemical analysis is as follows: Pb 3.21%, Zn 0.68%, Au 1.25%, Ag 45.38%, Fe 26.61%. 、 S 2.34%, of which lead accounted for 50.65% and zinc accounted for 60.98% of the sulfides.

[0028] The main metallic minerals in the ore are hematite, limonite, siderite, galena, cerussite, sphalerite, pyrrhotite, pyrite, and chalcopyrite. Among them, hematite and limonite are relatively abundant, followed by galena, cerussite, and sphalerite. The main gangue minerals are dolomite, quartz, calcite, kaolinite, and carbonates. Among them, dolomite, calcite, and quartz are relatively abundant, followed by kaolinite.

[0029] like Figure 1 As shown, the specific steps for recovering raw ore #1 using the system described in this utility model are as follows:

[0030] (1) Two-stage selective grinding and classification: The ore to be processed is transported to a semi-autogenous mill 1 for coarse grinding, with the grinding concentration controlled at 70% to 75%, to obtain a slurry with a fineness of -10 mm. The slurry is then transported to a classifying hydrocyclone 3 via a slurry pump 2, and classified at a concentration of 35% to 40% to obtain coarse particles of -10 mm to 0.074 mm and qualified fine particles. The coarse particles of -10 mm to 0.074 mm are transported from the sand outlet of the classifying hydrocyclone 3 to a ball mill 4 for fine grinding, with the grinding concentration controlled at 65% to 70%. After fine grinding, the slurry is transported to a classifying hydrocyclone 6 via a slurry pump 5, and classified at a concentration of 50% to 55% to obtain qualified fine particles and coarse particles. The coarse particles are then returned to the ball mill 4 for re-grinding. The qualified fine particles obtained are 70% to 80% of the particles with a fineness of -0.074 mm and a concentration of 28% to 30%.

[0031] (2) Pulse high gradient strong magnetic separation: The qualified fine-grained material obtained in step (1) is transported to the pulse high gradient strong magnetic separator 7 for magnetic separation. The fine-grained hematite and limonite are pre-magnetically separated and recovered to obtain gold-silver iron concentrate (containing hematite and limonite) and magnetic separation tailings. During this process, the background magnetic induction intensity is 1.3 to 1.4, the diameter of the magnetic medium is 1.0 mm, the pulse intensity is 200 to 300 times / minute, the stroke is 15 cm to 20 cm, and the magnetic separation concentration is 28% to 30%.

[0032] (3) Gold and silver extraction from gold and silver iron concentrate by cyanide carbon slurry: The gold and silver iron concentrate obtained in step (2) is transported to ball mill 8 for fine grinding. After fine grinding to -0.037mm accounting for 80% to 90%, it is transported to cyanide carbon slurry system 9. Lime is added to adjust the slurry to pH 10.5 to 11.5. 0.5‰ sodium cyanide solution is added to leach gold and silver. The concentration of the leaching slurry is 30% to 40%. Gold and silver loaded activated carbon and iron concentrate are obtained by activated carbon adsorption.

[0033] (4) Magnetic tailings flotation of lead, gold, and silver: The magnetic tailings obtained in step (2) are transported to the gold, silver, and lead mixed flotation system 10. After one roughing, three cleaning, and two scavenging processes, gold, silver, and lead concentrate and lead-containing tailings are obtained. The reagents used in the first roughing process are: sodium carbonate as a modifier at a dosage of 1500 g / t, sodium sulfide at a dosage of 300 g / t, zinc sulfate as a depressant at a dosage of 1000 g / t, and sodium sulfite at a dosage of 500 g / t. The dosage of collector ethyl thiocyanate + isobutyl xanthate was 60 g / t, and the dosage of frother 2# oil was 40 g / t. The reagents used in the three cleaning processes were: zinc sulfate inhibitor 300 g / t and sodium sulfite 200 g / t. The reagents used in the two scavenging processes were: sodium sulfide modifier 100 g / t, isobutyl xanthate collector 20 g / t, and frother 2# oil 20 g / t.

[0034] (5) Zinc flotation of lead tailings: The lead tailings obtained in step (4) are transported to the zinc flotation system 11. After one roughing, three cleaning and two scavenging processes, gold, silver and zinc concentrate and tailings are obtained. The reagents used in the first roughing process are: activator copper sulfate at 80g / t, collector butyl xanthate at 80g / t, and frother 2# oil at 40g / t. The reagents used in the two scavenging processes are: activator copper sulfate at 30g / t, collector butyl xanthate at 40g / t, and frother 2# oil at 20g / t.

[0035] The experimental results are as follows: the grades of gold, silver and lead concentrate products are Pb 61.25%, Au 26.45 g / t and Ag 980.46 g / t, respectively; the grades of gold, silver and zinc concentrate products are Zn 42.48%, Au 4.45 g / t and Ag 228.46 g / t, respectively; and the grades of gold and silver loaded activated carbon products are Au 750.45 g / t and Ag 3500.46 g / t, respectively. The lead recovery rate is 76.48%, the zinc recovery rate is 60.58%, the comprehensive gold recovery rate is 88.19%, and the comprehensive silver recovery rate is 89.66%. The iron grade of red and brown concentrates is 50.21%, and the recovery rate is 72.66%.

[0036] Application Example 2

[0037] Raw material #2: A low-grade complex oxidized lead-zinc-gold-silver ore. Its main element chemical analysis is as follows: Pb 4.52%, Zn 0.75%, Au 1.42%, Ag 47.66%, Fe 27.82%, S 2.19%, of which lead accounts for 55.38% and zinc accounts for 63.67% of the sulfides.

[0038] The main metallic minerals in the ore are hematite, limonite, siderite, galena, cerussite, sphalerite, pyrrhotite, pyrite, and chalcopyrite. Among them, limonite and siderite are relatively abundant, followed by galena, cerussite, and sphalerite. The main gangue minerals are dolomite, quartz, calcite, kaolinite, and carbonates. Among them, dolomite, calcite, and quartz are relatively abundant, followed by kaolinite.

[0039] like Figure 1 As shown, the method described in this utility model is used to recover raw ore #2. The specific steps are as follows:

[0040] (1) Two-stage selective grinding and classification: The ore to be processed is transported to a semi-autogenous mill 1 for coarse grinding, with the grinding concentration controlled at 70% to 75%, to obtain a slurry with a fineness of -10 mm. The slurry is then transported to a classifying hydrocyclone 3 via a slurry pump 2, and classified at a concentration of 35% to 40% to obtain coarse particles of -10 mm to 0.074 mm and qualified fine particles. The coarse particles of -10 mm to 0.074 mm are transported from the sand outlet of the classifying hydrocyclone 3 to a ball mill 4 for fine grinding, with the grinding concentration controlled at 65% to 70%. After fine grinding, the slurry is transported to a classifying hydrocyclone 6 via a slurry pump 5, and classified at a concentration of 50% to 55% to obtain qualified fine particles and coarse particles. The coarse particles are then returned to the ball mill 4 for re-grinding. The qualified fine particles obtained are 70% to 80% of the particles with a fineness of -0.074 mm and a concentration of 28% to 30%.

[0041] (2) Pulse high gradient strong magnetic separation: The qualified fine-grained material obtained in step (1) is transported to the pulse high gradient strong magnetic separator 7 for magnetic separation. The fine-grained hematite and limonite are pre-magnetically separated and recovered to obtain gold-silver iron concentrate (containing hematite and limonite) and magnetic separation tailings. During this process, the background magnetic induction intensity is 1.3 to 1.4, the diameter of the magnetic medium is 1.0 mm, the pulse intensity is 200 to 300 times / minute, the stroke is 15 cm to 20 cm, and the magnetic separation concentration is 28% to 30%.

[0042] (3) Gold and silver extraction from gold and silver iron concentrate by cyanide carbon slurry: The gold and silver iron concentrate obtained in step (2) is transported to ball mill 8 for fine grinding. After fine grinding to -0.037mm accounting for 80% to 90%, it is transported to cyanide carbon slurry system 9. Lime is added to adjust the slurry to pH 10.5 to 11.5. 0.6‰ sodium cyanide solution is added to leach gold and silver. The concentration of the leaching slurry is 30% to 40%. Gold and silver loaded activated carbon and iron concentrate are obtained by activated carbon adsorption.

[0043] (4) Magnetic tailings flotation of lead, gold, and silver: The magnetic tailings obtained in step (2) are transported to the gold, silver, and lead mixed flotation system 10. After one roughing, three cleaning, and two scavenging processes, gold, silver, and lead concentrate and lead-containing tailings are obtained. The reagents used in the first roughing process are: sodium carbonate as a modifier at a dosage of 1500 g / t, sodium sulfide at a dosage of 400 g / t, zinc sulfate as a depressant at a dosage of 1200 g / t, and sodium sulfite at a dosage of 600 g / t. The dosage of the collector ethyl thiocyanate + isobutyl xanthate was 70 g / t, and the dosage of the frother 2# oil was 50 g / t. The reagents used in the three cleaning processes were: zinc sulfate inhibitor at 400 g / t and sodium sulfite at 250 g / t. The reagents used in the two scavenging processes were: sodium sulfide modifier at 150 g / t, isobutyl xanthate collector at 25 g / t, and frother 2# oil at 25 g / t.

[0044] (5) Zinc flotation of lead tailings: The lead tailings obtained in step (4) are transported to the zinc flotation system 11. After one roughing, three cleaning and two scavenging processes, gold, silver and zinc concentrate and tailings are obtained. The reagents used in the first roughing process are: 90 g / t of copper sulfate activator, 90 g / t of butyl xanthate collector, and 50 g / t of frother 2# oil. The reagents used in the two scavenging processes are: 35 g / t of copper sulfate activator, 50 g / t of butyl xanthate collector, and 25 g / t of frother 2# oil.

[0045] The experimental results are as follows: the grades of gold, silver and lead concentrate products are Pb 64.28%, Au 25.37 g / t and Ag 994.55 g / t, respectively; the grades of gold, silver and zinc concentrate products are Zn 42.69%, Au 5.64 g / t and Ag 205.39 g / t, respectively; and the grades of gold and silver loaded activated carbon products are Au 738.67 g / t and Ag 3629.49 g / t, respectively. The lead recovery rate is 77.23%, the zinc recovery rate is 61.36%, the comprehensive recovery rate of precious metals gold is 89.45%, and the comprehensive recovery rate of silver is 87.18%. The iron grade of red and brown concentrates is 48.57%, and the recovery rate is 73.73%.

[0046] Application Example 3

[0047] Raw material #3: A low-grade, complex oxide lead-zinc-gold-silver ore, with the following main element chemical analysis: Pb 3.75%, Zn 0.78%, Au 1.42%, Ag 42.42%, Fe 25.29%. 、 S 2.71%, of which lead accounted for 57.61% and zinc accounted for 66.95% of the sulfides.

[0048] The main metallic minerals in the ore are hematite, limonite, siderite, galena, cerussite, sphalerite, pyrrhotite, pyrite, and chalcopyrite. Limonite is relatively abundant, followed by galena, cerussite, and sphalerite. The main gangue minerals are dolomite, quartz, calcite, kaolinite, and carbonates. Dolomite, calcite, and quartz are relatively abundant, followed by kaolinite.

[0049] like Figure 1 As shown, the method described in this utility model is used to recover raw ore #2. The specific steps are as follows:

[0050] (1) Two-stage selective grinding and classification: The ore to be processed is transported to a semi-autogenous mill 1 for coarse grinding, with the grinding concentration controlled at 70% to 75%, to obtain a slurry with a fineness of -10 mm. The slurry is then transported to a classifying hydrocyclone 3 via a slurry pump 2, and classified at a concentration of 35% to 40% to obtain coarse particles of -10 mm to 0.074 mm and qualified fine particles. The coarse particles of -10 mm to 0.074 mm are transported from the sand outlet of the classifying hydrocyclone 3 to a ball mill 4 for fine grinding, with the grinding concentration controlled at 65% to 70%. After fine grinding, the slurry is transported to a classifying hydrocyclone 6 via a slurry pump 5, and classified at a concentration of 50% to 55% to obtain qualified fine particles and coarse particles. The coarse particles are then returned to the ball mill 4 for re-grinding. The qualified fine particles obtained are 70% to 80% of the particles with a fineness of -0.074 mm and a concentration of 28% to 30%.

[0051] (2) Pulse high gradient strong magnetic separation: The qualified fine-grained material obtained in step (1) is transported to the pulse high gradient strong magnetic separator 7 for magnetic separation. The fine-grained hematite and limonite are pre-magnetically separated and recovered to obtain gold-silver iron concentrate (containing hematite and limonite) and magnetic separation tailings. During this process, the background magnetic induction intensity is 1.3 to 1.4, the diameter of the magnetic medium is 1.0 mm, the pulse intensity is 200 to 300 times / minute, the stroke is 15 cm to 20 cm, and the magnetic separation concentration is 28% to 30%.

[0052] (3) Gold and silver extraction from gold and silver iron concentrate by cyanide carbon slurry: The gold and silver iron concentrate obtained in step (2) is transported to ball mill 8 for fine grinding. After fine grinding to -0.037mm accounting for 80% to 90%, it is transported to cyanide carbon slurry system 9. Lime is added to adjust the slurry to pH 10.5 to 11.5. 0.7‰ sodium cyanide solution is added to leach gold and silver. The concentration of the leaching slurry is 30% to 40%. Gold and silver loaded activated carbon and iron concentrate are obtained by activated carbon adsorption.

[0053] (4) Magnetic tailings flotation of lead, gold, and silver: The magnetic tailings obtained in step (2) are transported to the gold, silver, and lead mixed flotation system 10. After one roughing, three cleaning, and two scavenging processes, gold, silver, and lead concentrate and lead tailings are obtained. The reagents used in the first roughing process are: sodium carbonate as a modifier at a dosage of 1500 g / t, sodium sulfide at a dosage of 500 g / t, zinc sulfate as a depressant at a dosage of 1500 g / t, and sodium sulfite at a dosage of 800 g / t. The dosage of collector ethyl thiocyanate + isobutyl xanthate was 80 g / t, and the dosage of frother 2# oil was 60 g / t. The reagents used in the three cleaning processes were: zinc sulfate inhibitor 500 g / t and sodium sulfite 300 g / t. The reagents used in the two scavenging processes were: sodium sulfide modifier 200 g / t, isobutyl xanthate collector 30 g / t, and frother 2# oil 30 g / t.

[0054] (5) Zinc flotation of lead tailings: The lead tailings obtained in step (4) are transported to the zinc flotation system 11. After one roughing, three cleaning and two scavenging processes, gold, silver and zinc concentrate and tailings are obtained. The reagents used in the first roughing process are: 100 g / t of copper sulfate activator, 100 g / t of butyl xanthate collector, and 60 g / t of frother 2# oil. The reagents used in the two scavenging processes are: 40 g / t of copper sulfate activator, 60 g / t of butyl xanthate collector, and 30 g / t of frother 2# oil.

[0055] The experimental results are as follows: the grades of gold, silver and lead concentrate products are Pb 63.46%, Au 28.39 g / t and Ag 1029.15 g / t, respectively; the grades of gold, silver and zinc concentrate products are Zn 44.39%, Au 4.82 g / t and Ag 199.78 g / t, respectively; and the grades of gold and silver loaded activated carbon products are Au 700.73 g / t and Ag 3497.64 g / t, respectively. The lead recovery rate is 75.81%, the zinc recovery rate is 64.25%, and the comprehensive recovery rate of precious metals is 88.26% for gold and 86.79% for silver. The iron grade of red and brown concentrates is 49.57%, and the recovery rate is 78.41%.

[0056] In summary, the present invention, when used to recover this type of low-grade complex oxidized lead-zinc-gold-silver ore, achieves recovery rates of over 88% for gold, over 86% for silver, over 72% for iron, over 75% for lead, and over 60% for zinc. This demonstrates a significant and efficient comprehensive resource recovery effect. Furthermore, the system exhibits strong adaptability to this type of ore, a simple and environmentally friendly structure, and stable process indicators, providing guidance for the comprehensive utilization of low-grade complex oxidized lead-zinc-gold-silver ore resources.

[0057] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications or equivalent substitutions made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A highly efficient integrated recovery system for low-grade complex oxidized lead-zinc-gold-silver ores, characterized in that: The system includes a semi-autogenous mill (1), the outlet of which is connected to the inlet of a classifying hydrocyclone (3) via a slurry pump (2), the underflow port of the classifying hydrocyclone (3) is connected to the inlet of a ball mill (4), the outlet of the ball mill (4) is connected to the inlet of a classifying hydrocyclone (6) via a slurry pump (5), and the underflow port of the classifying hydrocyclone (6) is connected to the inlet of the ball mill (4). The overflow ports of the No. 1 classifying hydrocyclone (3) and the No. 2 classifying hydrocyclone (6) are both connected to the feed port of the pulse high gradient magnetic separator (7). The concentrate outlet and tailings outlet of the pulse high gradient magnetic separator (7) are respectively connected to the feed ports of the No. 2 ball mill (8) and the gold-silver-lead mixed flotation system (10). The discharge port of the No. 2 ball mill (8) is connected to the cyanide carbon slurry system (9). The tailings outlet of the gold-silver-lead mixed flotation system (10) is connected to the zinc flotation system (11).

2. The efficient integrated recovery system for low-grade complex oxidized lead-zinc-gold-silver ores according to claim 1, characterized in that: The diameter of the No. 1 grade hydrocyclone (3) and the No. 2 grade hydrocyclone (6) is φ350mm.

3. The efficient integrated recovery system for low-grade complex oxidized lead-zinc-gold-silver ores according to claim 1, characterized in that: The gold, silver and lead mixed flotation system (10) and the zinc flotation system (11) both include two mixing tanks, one rougher flotation machine, three cleaner flotation machines, and two sweeper flotation machines.

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