Efficient comprehensive recovery method for low-grade complex lead-zinc oxide-kustemite

Abstract

The invention relates to a high-efficiency comprehensive recovery method for low-grade complex lead-zinc oxide-gold and silver ore. The method comprises the following steps: (1) two-stage selective grinding and grading; (2) pulse high-gradient strong magnetic separation; (3) extracting gold and silver from the gold-silver-containing iron ore concentrate cyanided carbon slurry; (4) flotation of lead, gold and silver from magnetic separation tailings; and (5) flotation of zinc from the floating lead tailings. According to the method, through two-section selective grinding classification and pulse high-gradient strong magnetic separation before flotation, over-grinding argillization of primary fine-fraction materials and slime is effectively prevented, micro-fine-particle hematite and limonite are separated preferentially, so that the adverse effect of the micro-fine materials on flotation is reduced, and the flotation efficiency is improved. And then, valuable metals in the magnetic separation tailings and the gold, silver, iron, lead and zinc-containing red and limonite ore concentrates are recycled through a multi-stage flotation technology and a cyaniding carbon slurry technology, comprehensive recycling of gold, silver, iron, lead and zinc in the low-grade complex lead-zinc oxide-gold and silver ore is achieved, and the efficient comprehensive recycling effect is remarkable. The problems that a single flotation process is low in recovery rate and high in recovery cost, and lead and zinc cannot be recovered are successfully solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of low-grade mineral recovery, and particularly relates to an efficient comprehensive recovery method for low-grade complex oxidized lead-zinc-gold-silver ore. Background Art

[0002] China is a country extremely rich in oxidized lead-zinc ore. However, with the development of lead-zinc-gold-silver ore deposits, the rich ore resources are decreasing day by day, the ore grade is gradually decreasing, and the complexity of oxidized ore is becoming increasingly prominent. Precious metals gold and silver are often associated with lead-zinc-gold-silver ore deposits, and their comprehensive development and utilization value is extremely high. However, the ore structure is complex, the gold and silver dissemination particle size is small, more exist in the form of inclusions, and the associated components are unstable, containing a large amount of clay, hematite, limonite and soluble salts.

[0003] At present, the separation and recovery of polymetallic oxidized lead-zinc ore mainly adopts the grinding-dispersant enhanced dispersion whole-slurry flotation process. However, this method has many problems: First, the content of soluble ions and slime in the ore is high, and it is difficult to effectively disperse the slurry even with a large amount of dispersant, resulting in high consumption of flotation reagents and difficult improvement of flotation indexes (grade and recovery rate); Second, for ores with fine-grained or complex dissemination, pre-desliming will cause a large amount of valuable minerals to be lost. In addition, when recovering precious metals by fine grinding-carbon leaching method, due to the interference of non-ferrous metal minerals, the gold and silver recovery rates are low, the production cost is high, and valuable components such as lead and zinc are difficult to be effectively recovered, resulting in resource waste and environmental pollution risks.

[0004] Therefore, it has become an inevitable trend to develop a new beneficiation process for oxidized lead-zinc-gold-silver ore with short process, low cost, less pollution or no pollution. Summary of the Invention

[0005] In order to overcome the deficiencies and defects of the prior art, the present invention provides an efficient comprehensive recovery method for low-grade complex oxidized lead-zinc-gold-silver ore. Fully based on the ore properties, two-stage selective crushing, grinding and classification, pulsed high-gradient high-intensity magnetic separation, fine grinding-cyanide carbon slurry and multi-stage flotation are combined to gradually reduce the influence of fine-grained materials on flotation and improve the comprehensive recovery rate of the ore.

[0006] To achieve the above object, an efficient comprehensive recovery method for low-grade complex oxidized lead-zinc-gold-silver ore provided by the present invention includes the following steps: (1) Two-stage selective grinding and classification: The ore to be processed is transported to a semi-autogenous mill for the first-stage coarse grinding to obtain a slurry with a fineness of -10 mm. After low-concentration classification by a hydrocyclone, -10 mm to 0.074 mm coarse-grained materials and qualified fine-grained materials are obtained. The -10 mm to 0.074 mm coarse-grained materials are transported to a ball mill for the second-stage fine grinding, and then classified by a hydrocyclone to obtain qualified fine-grained materials and coarse-grained materials. The coarse-grained materials are returned to the ball mill for re-grinding. The obtained qualified fine-grained materials have 70% - 80% of -0.074 mm. This step takes advantage of the characteristics of the semi-autogenous mill that selectively grinds large particles and has a low grinding effect on fine particles, which can reduce the generation of secondary slime. At the same time, combined with a φ350 mm hydrocyclone for classification under low-concentration conditions, it can prevent the original qualified fine-grained materials and slime (especially low-hardness limonite) from re-entering the ball mill and being ground finer, forming a large amount of colloidal secondary slime, which affects the subsequent recovery process. At the same time, it can also reduce the throughput of the ball mill and reduce the grinding cost.

[0007] (2) Pulse high-gradient high-intensity magnetic separation: The qualified fine-grained materials obtained in step (1) are transported to a pulse high-gradient high-intensity magnetic separation system for magnetic separation to pre-recover fine-grained hematite and limonite, and obtain a gold-silver-iron concentrate (containing hematite and limonite) and magnetic separation tailings. This step pre-recovers fine-grained hematite and limonite by pulse high-gradient high-intensity magnetic separation according to the wrapping effect of hematite and limonite on gold and silver. It not only realizes the recovery of gold and silver wrapped by them, but also reduces the content of fine-grained materials, which is beneficial to the subsequent flotation recovery.

[0008] (3) Cyanidation carbon-in-pulp extraction of gold and silver from the gold-silver-iron concentrate: After the gold-silver-iron concentrate obtained in step (2) is finely ground to 80% - 90% of -0.037 mm, it is transported to a cyanidation carbon-in-pulp system, lime is added to adjust the pulp to a pH of 10.5 - 11.5, and a sodium cyanide solution is added to leach gold and silver. Gold-loaded activated carbon and iron concentrate (containing hematite and limonite) are obtained through activated carbon adsorption. Before the cyanidation carbon-in-pulp leaching of gold and silver in this step, the ball mill is used again to selectively grind the gold-loaded hematite and limonite, so that the wrapped gold and silver are fully exposed, which can improve the leaching and adsorption effect of gold and silver by the cyanidation carbon-in-pulp method, improve the recovery rate of gold and silver, and at the same time obtain qualified hematite and limonite concentrates.

[0009] (4) Flotation of lead, gold and silver from the magnetic separation tailings: The magnetic separation tailings obtained in step (2) are transported to a gold-silver-lead bulk flotation system. After one roughing, three cleanings and two scavengings, a gold-silver-lead concentrate and lead flotation tailings are obtained. Among them, a regulator is added during one roughing and two scavengings to enhance the floatability of minerals. In this step, a regulator is used to strengthen the activation of lead oxide minerals during the flotation process, changing the chemical composition of the surface of lead oxide minerals, making the mineral surface more likely to react with the collector. Then, through the collector combination, the synchronous collection of lead sulfide and lead oxide minerals is achieved using the synergistic effect, and the recovery rate is relatively high.

[0010] (5)Flotation of zinc from lead flotation tailings: The lead flotation tailings obtained in step (4) are transported to the zinc flotation system, and after one rough selection, three fine selections, and two scavenging selections, zinc concentrate containing gold and silver and tailings are obtained; among them, an activator is added during one rough selection and two scavenging selections to enhance the floatability of minerals.

[0011] Furthermore, in step (1), the grinding concentration of the first-stage coarse crushing and grinding is 70% - 75%, and the classification concentration is 35% - 40%; the grinding concentration of the second-stage fine grinding is 65% - 70%, and the classification concentration is 50% - 55%; the diameters of the two-stage classification cyclones are both φ350mm.

[0012] Furthermore, in step (2), the background magnetic induction intensity is 1.3 - 1.4, the diameter of the magnetic medium is 1.0mm, the pulse intensity is 200 - 300 times / minute, the stroke is 15cm - 20cm, and the magnetic separation concentration is 28% - 30%.

[0013] Furthermore, in step (3), the concentration of the sodium cyanide solution is 0.5‰ - 0.7‰; the leaching pulp concentration is 30% - 40%.

[0014] Furthermore, in step (4), the reagents used in one rough selection are: the dosage of the regulator sodium carbonate is 1500g / t, the dosage of sodium sulfide is 300g / t - 500g / t, the dosage of the inhibitor zinc sulfate is 1000g / t - 1500g / t, the dosage of sodium sulfite is 500g / t - 800g / t, the dosage of the collector ethyl thionocarbamate + isobutyl xanthate is 60g / t - 80g / t, and the dosage of the frother No. 2 oil is 40g / t - 60g / t; the reagents used in all three fine selections are: the dosage of the inhibitor zinc sulfate is 300g / t - 500g / t, the dosage of sodium sulfite is 200g / t - 300g / t; the reagents used in both scavenging selections are: the dosage of the regulator sodium sulfide is 100g / t - 200g / t, the dosage of the collector isobutyl xanthate is 20g / t - 30g / t, and the dosage of the frother No. 2 oil is 20g / t - 30g / t.

[0015] Furthermore, in step (5), the reagents used in one rough selection are: the dosage of the activator copper sulfate is 80g / t - 100g / t, the dosage of the collector butyl xanthate is 80g / t - 100g / t, and the dosage of the frother No. 2 oil is 40g / t - 60g / t; the reagents used in both scavenging selections are: the dosage of the activator copper sulfate is 30g / t - 40g / t, the dosage of the collector butyl xanthate is 40g / t - 60g / t, and the dosage of the frother No. 2 oil is 20g / t - 30g / t.

[0016] Advantages of the present invention: Before flotation, the present invention first performs two-stage selective grinding and classification on the ore to perform selective coarse grinding and fine grinding on the ore, avoiding over-grinding and slime formation of the primary fine-grained materials and ore slime, which affect subsequent flotation. Then, pulsed high-gradient high-intensity magnetic separation is used to preferentially separate fine-grained hematite and limonite, further reducing the adverse effects of fine materials on flotation. Subsequently, multi-stage flotation and cyanide carbon slurry processes are respectively used to recover valuable metals in the magnetic separation tailings and gold- and silver-bearing hematite and limonite concentrates, realizing the comprehensive recovery of gold, silver, iron, lead, and zinc in low-grade complex oxidized lead-zinc-gold-silver ores. Moreover, the gold recovery rate is over 82%, the silver recovery rate is over 81%, the iron recovery rate is over 72%, the lead recovery rate is over 75%, and the zinc recovery rate is over 60%. The effect of efficient comprehensive resource recovery is remarkable, successfully solving the problems of low recovery rate, high recovery cost, and non-recovery of lead and zinc in a single flotation process. Moreover, this method has strong adaptability, a simple and environmentally friendly process, and stable process indexes, and has guiding significance for the comprehensive utilization of resources of low-grade complex oxidized lead-zinc-gold-silver ores. Description of the Drawings

[0017] Figure 1 is a flow chart of an efficient comprehensive recovery method for a low-grade complex oxidized lead-zinc-gold-silver ore of the present invention. Detailed Embodiments

[0018] In order to make the technical problems and technical solutions solved by the present invention clearer, the present invention will be further described in detail below with reference to the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Example 1

[0019] Original ore 1#: A low-grade complex oxidized lead-zinc-gold-silver ore, the chemical analysis of its main elements is: Pb 3.21%, Zn 0.68%, Au 1.25%, Ag 45.38, Fe 26.61% 、 S 2.34%, and the proportion of lead in sulfides is 50.65% and the proportion of zinc is 60.98%.

[0020] The main metal minerals in the ore are hematite, limonite, siderite, galena, cerussite, sphalerite, pyrrhotite, pyrite, and chalcopyrite. Among them, hematite and limonite have relatively high contents, and galena, cerussite, and sphalerite have relatively lower contents; the main gangue minerals are dolomite, quartz, calcite, kaolinite, and carbonate. Among them, dolomite, calcite, and quartz have relatively high contents, and kaolinite has relatively lower contents.

[0021] As Figure 1 shown, the method of the present invention is used to recover the original ore 1#, and the specific steps are as follows: (1)Two-stage selective grinding and classification: The ore to be processed is transported to a semi-autogenous mill for the first-stage coarse grinding. The grinding concentration is controlled at 70% - 75%, and a slurry with a fineness of -10 mm is obtained. It is classified by a φ350 mm classification cyclone at a concentration of 35% - 40% to obtain coarse-grained materials with a size of -10 mm to 0.074 mm and qualified fine-grained materials; the coarse-grained materials with a size of -10 mm to 0.074 mm are transported to a ball mill for the second-stage fine grinding. The grinding concentration is controlled at 65% - 70%, and then it is classified by a φ350 mm classification cyclone at a concentration of 50% - 55% to obtain qualified fine-grained materials and coarse-grained materials. The coarse-grained materials are returned to the ball mill for re-grinding. The obtained qualified fine-grained materials have -0.074 mm accounting for 70% - 80% and a concentration of 28% - 30%. (2)Pulse high-gradient high-intensity magnetic separation: The qualified fine-grained materials obtained in step (1) are transported to a pulse high-gradient high-intensity magnetic separation system for magnetic separation. The fine-grained hematite and limonite are pre-magnetically separated and recovered to obtain a gold-silver-iron concentrate (containing hematite and limonite) and magnetic separation tailings; during this process, the background magnetic induction intensity is 1.3 - 1.4, the diameter of the magnetic medium is 1.0 mm, the pulse intensity is 200 - 300 times / minute, the stroke is 15 cm - 20 cm, and the magnetic separation concentration is 28% - 30%.

[0022] (3)Cyanidation carbon-in-pulp for gold and silver extraction from the gold-silver-iron concentrate: After the gold-silver-iron concentrate obtained in step (2) is finely ground to -0.037 mm accounting for 80% - 90%, it is transported to a cyanidation carbon-in-pulp system. Lime is added to adjust the pulp to a pH of 10.5 - 11.5, and a 0.5‰ sodium cyanide solution is added to leach gold and silver. The leaching pulp concentration is 30% - 40%, and gold-silver-loaded activated carbon and iron concentrate are obtained through activated carbon adsorption; (4)Flotation of lead, gold, and silver from the magnetic separation tailings: The magnetic separation tailings obtained in step (2) are transported to a gold-silver-lead bulk flotation system. After one roughing, three cleanings, and two scavengings, a gold-silver-lead concentrate and lead flotation tailings are obtained; among them, the reagents used in one roughing are: the dosage of the regulator sodium carbonate is 1500 g / t, the dosage of sodium sulfide is 300 g / t, the dosage of the inhibitor zinc sulfate is 1000 g / t, the dosage of sodium sulfite is 500 g / t, the dosage of the collector ethyl thionocarbamate + isobutyl xanthate is 60 g / t, and the dosage of the frother No. 2 oil is 40 g / t; the reagents used in the three cleanings are all: the dosage of the inhibitor zinc sulfate is 300 g / t, the dosage of sodium sulfite is 200 g / t; the reagents used in the two scavengings are all: the dosage of the regulator sodium sulfide is 100 g / t, the dosage of the collector isobutyl xanthate is 20 g / t, and the dosage of the frother No. 2 oil is 20 g / t.

[0023] (5) Flotation of zinc from lead flotation tailings: The lead flotation tailings obtained in step (4) are transported to the zinc flotation system, and after one rough selection, three fine selections, and two scavenging selections, zinc concentrate containing gold and silver and tailings are obtained. Among them, the reagents used in one rough selection are: the dosage of copper sulfate as an activator is 80 g / t, the dosage of butyl xanthate as a collector is 80 g / t, and the dosage of No. 2 oil as a foaming agent is 40 g / t. The reagents used in two scavenging selections are both: the dosage of copper sulfate as an activator is 30 g / t, the dosage of butyl xanthate as a collector is 40 g / t, and the dosage of No. 2 oil as a foaming agent is 20 g / t.

[0024] The test results obtained are as follows: the grades of the lead concentrate product containing gold and silver are Pb 61.25%, Au 26.45 g / t, and Ag 980.46 g / t respectively; the grades of the zinc concentrate product containing gold and silver are Zn 42.48%, Au 4.45 g / t, and Ag 228.46 g / t respectively; the grades of the activated carbon product carrying gold and silver are Au 750.45 g / t and Ag 3500.46 g / t respectively. Among them, the recovery rate of lead is 76.48%, the recovery rate of zinc is 60.58%, the comprehensive recovery rate of precious metal gold is 88.19%, the comprehensive recovery rate of silver is 89.66%, and the iron grade of the red and brown concentrate is 50.21% with a recovery rate of 72.66%. Example 2

[0025] Raw material 2#: A low-grade complex oxidized lead-zinc-gold-silver ore, the main element chemical analysis of which is: Pb 4.52%, Zn 0.75%, Au 1.42%, Ag 47.66, Fe 27.82%, S 2.19%. Among them, the proportion of lead in sulfides is 55.38%, and the proportion of zinc is 63.67%.

[0026] The main metal minerals in the ore are hematite, limonite, siderite, galena, cerussite, sphalerite, pyrrhotite, pyrite, chalcopyrite. Among them, the relative contents of limonite and siderite are relatively high, and the relative contents of galena, cerussite, and sphalerite are the second; the main gangue minerals are dolomite, quartz, calcite, kaolinite, carbonate. Among them, the relative contents of dolomite, calcite, and quartz are relatively high, and the relative content of kaolinite is the second.

[0027] As Figure 1 shown, the method of the present invention is used to recover raw ore 2#, and the specific steps are as follows: (1)Two-stage selective grinding and classification: The ore to be processed is transported to a semi-autogenous mill for the first-stage coarse grinding. The grinding concentration is controlled at 70% - 75%, and a slurry with a fineness of -10 mm is obtained. It is classified by a φ350 mm hydrocyclone at a concentration of 35% - 40% to obtain coarse-grained materials with a size range of -10 mm to 0.074 mm and qualified fine-grained materials. The coarse-grained materials with a size range of -10 mm to 0.074 mm are transported to a ball mill for the second-stage fine grinding. The grinding concentration is controlled at 65% - 70%, and then it is classified by a φ350 mm hydrocyclone at a concentration of 50% - 55% to obtain qualified fine-grained materials and coarse-grained materials. The coarse-grained materials are returned to the ball mill for re-grinding. The obtained qualified fine-grained materials have 70% - 80% of -0.074 mm and a concentration of 28% - 30%. (2)Pulse high-gradient high-intensity magnetic separation: The qualified fine-grained materials obtained in step (1) are transported to a pulse high-gradient high-intensity magnetic separation system for magnetic separation. The fine-grained hematite and limonite are pre-magnetically separated and recovered to obtain a gold-silver-iron concentrate (containing hematite and limonite) and magnetic separation tailings. During this process, the background magnetic induction intensity is 1.3 - 1.4, the diameter of the magnetic medium is 1.0 mm, the pulse intensity is 200 - 300 times per minute, the stroke is 15 cm - 20 cm, and the magnetic separation concentration is 28% - 30%.

[0028] (3)Gold and silver extraction from the gold-silver-iron concentrate by cyanidation and carbon-in-pulp process: After the gold-silver-iron concentrate obtained in step (2) is finely ground to 80% - 90% of -0.037 mm, it is transported to a cyanidation and carbon-in-pulp system. Lime is added to adjust the pulp pH to 10.5 - 11.5, and a 0.6‰ sodium cyanide solution is added for gold and silver leaching. The leaching pulp concentration is 30% - 40%. Gold and silver are adsorbed by activated carbon to obtain gold-silver-loaded activated carbon and iron concentrate. (4)Flotation of lead, gold, and silver from the magnetic separation tailings: The magnetic separation tailings obtained in step (2) are transported to a gold-silver-lead bulk flotation system. After one roughing, three cleanings, and two scavengings, a gold-silver-lead concentrate and lead flotation tailings are obtained. Among them, the reagents used in one roughing are: the dosage of the regulator sodium carbonate is 1500 g / t, the dosage of sodium sulfide is 400 g / t, the dosage of the inhibitor zinc sulfate is 1200 g / t, the dosage of sodium sulfite is 600 g / t, the dosage of the collector ethyl thionocarbamate + isobutyl xanthate is 70 g / t, and the dosage of the frother No. 2 oil is 50 g / t. The reagents used in the three cleanings are: the dosage of the inhibitor zinc sulfate is 400 g / t, the dosage of sodium sulfite is 250 g / t. The reagents used in the two scavengings are: the dosage of the regulator sodium sulfide is 150 g / t, the dosage of the collector isobutyl xanthate is 25 g / t, and the dosage of the frother No. 2 oil is 25 g / t.

[0029] (5) Flotation of zinc from lead floatation tailings: The lead floatation tailings obtained in step (4) are transported to the zinc flotation system, and after one rough selection, three fine selections, and two scavenging selections, zinc concentrate containing gold and silver and tailings are obtained. Among them, the reagents used in one rough selection are: the dosage of copper sulfate as an activator is 90 g / t, the dosage of butyl xanthate as a collector is 90 g / t, and the dosage of No. 2 oil as a frother is 50 g / t. The reagents used in two scavenging selections are both: the dosage of copper sulfate as an activator is 35 g / t, the dosage of butyl xanthate as a collector is 50 g / t, and the dosage of No. 2 oil as a frother is 25 g / t.

[0030] The test results obtained are as follows: The grades of the lead concentrate product containing gold and silver are Pb 64.28%, Au 25.37 g / t, and Ag 994.55 g / t respectively. The grades of the zinc concentrate product containing gold and silver are Zn 42.69%, Au 5.64 g / t, and Ag 205.39 g / t respectively. The grades of the activated carbon product carrying gold and silver are Au 738.67 g / t and Ag 3629.49 g / t respectively. Among them, the lead recovery rate is 77.23%, the zinc recovery rate is 61.36%, the comprehensive recovery rate of precious metal gold is 89.45%, the comprehensive recovery rate of silver is 87.18%, and the iron grade of the red and brown concentrates is 48.57% with a recovery rate of 73.73%. Example 3

[0031] Raw material 3#: A low-grade complex oxidized lead-zinc-gold-silver ore, and its main element chemical analysis is: Pb 3.75%, Zn 0.78%, Au 1.42%, Ag 42.42, Fe 25.29% 、 S 2.71%, among which the proportion of lead in sulfides is 57.61% and the proportion of zinc is 66.95%.

[0032] The main metal minerals in the ore are hematite, limonite, siderite, galena, cerussite, sphalerite, pyrrhotite, pyrite, and chalcopyrite. Among them, the relative content of limonite is relatively large, and the relative contents of galena, cerussite, and sphalerite are the second. The main gangue minerals are dolomite, quartz, calcite, kaolinite, and carbonate. Among them, the relative contents of dolomite, calcite, and quartz are relatively large, and the relative content of kaolinite is the second.

[0033] As Figure 1 shown, the method described in the present invention is used to recover raw ore 2#, and the specific steps are as follows: (1) Two-stage selective crushing and classification: The ore to be processed is transported to the semi-autogenous mill for a first-stage coarse grinding, and the grinding concentration is controlled at 70% to 75% to obtain a slurry with a fineness of -10 mm. The slurry is classified at a concentration of 35% to 40% by a φ350mm classification cyclone to obtain a coarse-grained material of -10 mm to 0.074 mm and a qualified fine-grained material; the coarse-grained material of -10 mm to 0.074 mm is transported to the ball mill for a second-stage fine grinding, and the grinding concentration is controlled at 65% to 70%. The ore is then classified at a concentration of 50% to 55% by a φ350mm classification cyclone to obtain a qualified fine-grained material and a coarse-grained material. The coarse-grained material is returned to the ball mill for re-grinding, and the obtained qualified fine-grained material is -0.074 mm, accounting for 70% to 80%, and the concentration is 28% to 30%; (2) Pulse high gradient strong magnetic separation: The qualified fine-grained material obtained in step (1) is transported to a pulse high gradient strong magnetic separation system for magnetic separation, and the fine-grained hematite and limonite are pre-magnetically separated and recovered to obtain gold-silver-containing iron concentrate (including hematite and limonite) and magnetic separation tailings; in this process, the background magnetic induction intensity is 1.3-1.4, the diameter of the magnetic medium is 1.0 mm, the pulse intensity is 200-300 times / min, the stroke is 15 cm-20 cm, and the magnetic separation concentration is 28%-30%.

[0034] (3) Extracting gold and silver from gold-silver iron concentrate with cyanide carbon slurry: The gold-silver iron concentrate obtained in step (2) is finely ground to -0.037 mm, accounting for 80% to 90%, and then transported to a cyanide carbon slurry system, lime is added to adjust the slurry to a pH of 10.5 to 11.5, and 0.7‰ sodium cyanide solution is added to leach gold and silver, and the leaching slurry concentration is 30% to 40%. After adsorption on activated carbon, gold-silver loaded activated carbon and iron concentrate are obtained; (4) Magnetic separation tailings flotation of lead, gold and silver: The magnetic separation tailings obtained in step (2) are transported to a gold, silver and lead mixed flotation system, and after one roughing selection, three cleaning selections and two scavenging selections, gold, silver and lead concentrates and floating lead tailings are obtained; wherein the reagents used in the first roughing selection are: the adjustment agent sodium carbonate is used in an amount of 1500g / t, the sodium sulfide is used in an amount of 500g / t, the inhibitor zinc sulfate is used in an amount of 1500g / t, and the sodium sulfite is used in an amount of 800g / t. / t, the dosage of collector ethylthiocyanate + isobutyl xanthate is 80g / t, and the dosage of foaming agent 2# oil is 60g / t; the reagents used in the three concentrations are: the inhibitor zinc sulfate dosage is 500g / t, the dosage of sodium sulfite is 300g / t; the reagents used in the two sweeps are: the dosage of adjusting agent sodium sulfide is 200g / t, the dosage of collector isobutyl xanthate is 30g / t, and the dosage of foaming agent 2# oil is 30g / t.

[0035] (5)Flotation of zinc from lead floatation tailings: The lead floatation tailings obtained in step (4) are transported to the zinc flotation system, and after one rough selection, three fine selections, and two scavenging selections, zinc concentrate containing gold, silver, and zinc and tailings are obtained. Among them, the reagents used in one rough selection are: the dosage of copper sulfate as an activator is 100 g / t, the dosage of butyl xanthate as a collector is 100 g / t, and the dosage of No. 2 oil as a frother is 60 g / t. The reagents used in two scavenging selections are both: the dosage of copper sulfate as an activator is 40 g / t, the dosage of butyl xanthate as a collector is 60 g / t, and the dosage of No. 2 oil as a frother is 30 g / t.

[0036] The test results obtained are as follows: The grades of the lead concentrate product containing gold, silver, and lead are Pb 63.46%, Au 28.39 g / t, and Ag 1029.15 g / t respectively. The grades of the zinc concentrate product containing gold, silver, and zinc are Zn 44.39%, Au 4.82 g / t, and Ag 199.78 g / t respectively. The grades of the activated carbon product carrying gold and silver are Au 700.73 g / t and Ag 3497.64 g / t respectively. Among them, the recovery rate of lead is 75.81%, the recovery rate of zinc is 64.25%, the comprehensive recovery rate of precious metal gold is 88.26%, and the comprehensive recovery rate of silver is 86.79%. The iron grades of the red and brown concentrates are 49.57% and the recovery rate is 78.41%.

[0037] Based on the above embodiments, by using the method described in the present invention to recover and process this type of low-grade complex oxidized lead-zinc-gold-silver ore, recovery indexes with a gold recovery rate of more than 88%, a silver recovery rate of more than 86%, an iron recovery rate of more than 72%, a lead recovery rate of more than 75%, and a zinc recovery rate of more than 60% can be obtained. It can be seen that the effect of efficient comprehensive resource recovery is remarkable. Moreover, this method has strong adaptability to this type of ore, a simple and environmentally friendly process, and stable process indexes, which has guiding significance for the comprehensive utilization of resources of low-grade complex oxidized lead-zinc-gold-silver ore.

[0038] The present invention has been described in detail through specific and preferred embodiments above. However, those skilled in the art should understand that the present invention is not limited to the above-described embodiments. Any modifications, equivalent replacements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A high-efficiency comprehensive recovery method for low-grade complex oxidized lead-zinc-gold-silver ore, characterized in that: The steps include: (1) Two-stage selective crushing and classification: The ore to be processed is transported to the semi-autogenous mill for a first-stage coarse crushing to obtain a slurry with a fineness of -10 mm. After low-concentration classification by a grading cyclone, coarse particles of -10 mm to 0.074 mm and qualified fine particles are obtained. The coarse particles of -10 mm to 0.074 mm are transported to the ball mill for a second-stage fine grinding, and then classified by a grading cyclone to obtain qualified fine particles and coarse particles. The coarse particles are returned to the ball mill for re-grinding. The qualified fine particles obtained are -0.074 mm, accounting for 70% to 80%; (2) Pulse high gradient strong magnetic separation: The qualified fine-grained material obtained in step (1) is transported to a pulse high gradient strong magnetic separation system for magnetic separation, and fine-grained hematite and limonite are pre-magnetically separated and recovered to obtain gold-silver-containing iron concentrate (including hematite and limonite) and magnetic separation tailings; (3) Extracting gold and silver from gold-silver iron concentrate by cyanide carbon slurry: After the gold-silver iron concentrate obtained in step (2) is finely ground to -0.037 mm, accounting for 80% to 90%, it is transported to a cyanide carbon slurry system, lime is added to adjust the slurry to a pH of 10.5 to 11.5, sodium cyanide solution is added to leach gold and silver, and gold-silver loaded activated carbon and iron concentrate are obtained by adsorption on activated carbon; (4) Magnetic separation tailings flotation of lead, gold and silver: The magnetic separation tailings obtained in step (2) are transported to a gold, silver and lead mixed flotation system, and after one roughing selection, three cleaning selections and two scavenging selections, gold, silver and lead concentrates and floating lead tailings are obtained; wherein, during the one roughing selection and two scavenging selections, an adjusting agent is added to enhance the floatability of the mineral; (5) Flotation of zinc from floating lead tailings: The floating lead tailings obtained in step (4) are transported to a zinc flotation system, and after one roughing, three cleaning and two scavenging processes, gold, silver and zinc concentrate and tailings are obtained; wherein, an activator is added during the one roughing and two scavenging processes to enhance the floatability of the mineral.

2. The method for the efficient comprehensive recovery of low-grade complex oxidized lead-zinc-gold-silver ore according to claim 1, characterized in that: In step (1), the grinding concentration of the first stage coarse grinding is 70% to 75%, and the classification concentration is 35% to 40%; the grinding concentration of the second stage fine grinding is 65% to 70%, and the classification concentration is 50% to 55%; the diameters of the two-stage classification cyclones are both φ350 mm.

3. The method for efficient comprehensive recovery of low-grade complex oxidized lead-zinc-gold-silver ore according to claim 1, characterized in that: In step (2), the background magnetic induction intensity is 1.3-1.4, the diameter of the magnetic medium is 1.0 mm, the pulse intensity is 200-300 times / min, the stroke is 15 cm-20 cm, and the magnetic separation concentration is 28%-30%.

4. The method for efficient comprehensive recovery of low-grade complex oxidized lead-zinc-gold-silver ore according to claim 1, characterized in that: The concentration of the sodium cyanide solution in step (3) is 0.5‰ to 0.7‰; the concentration of the leaching slurry is 30% to 40%.

5. The method for the efficient comprehensive recovery of low-grade complex oxidized lead-zinc-gold-silver ore according to claim 1, characterized in that: The reagents used for the primary roughing in step (4) are: the adjusting agent sodium carbonate is used in an amount of 1500g / t, the sodium sulfide is used in an amount of 300g / t to 500g / t, the inhibitor zinc sulfate is used in an amount of 1000g / t to 1500g / t, the sodium sulfite is used in an amount of 500g / t to 800g / t, the collector ethylthiocyanate + isobutyl xanthate is used in an amount of 60g / t to 80g / t, and the foaming agent 2# oil is used in an amount of 40g / t ~60g / t; the reagents used in the three selections are: the inhibitor zinc sulfate dosage is 300g / t~500g / t, the sodium sulfite dosage is 200g / t~300g / t; the reagents used in the two sweeps are: the adjusting agent sodium sulfide dosage is 100g / t~200g / t, the collecting agent isobutyl xanthate dosage is 20g / t~30g / t, and the foaming agent 2# oil dosage is 20g / t~30g / t.

6. The method for efficient comprehensive recovery of low-grade complex oxidized lead-zinc-gold-silver ore according to claim 1, characterized in that: The reagents used in the first roughing selection in step (5) are: activator copper sulfate in an amount of 80 g / t to 100 g / t, collector butyl xanthate in an amount of 80 g / t to 100 g / t, and foaming agent 2# oil in an amount of 40 g / t to 60 g / t; the reagents used in the two sweeping selections are: activator copper sulfate in an amount of 30 g / t to 40 g / t, collector butyl xanthate in an amount of 40 g / t to 60 g / t, and foaming agent 2# oil in an amount of 20 g / t to 30 g / t.

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