A high-efficiency comprehensive recovery method for low-grade complex lead-zinc-gold-silver oxide ore

Abstract

The present application relates to a kind of low-grade complex lead-zinc-gold-silver ore high-efficiency comprehensive recovery method, comprising: (1) two-stage selective crushing and grinding classification;(2) pulse high gradient magnetic separation;(3) gold-silver-containing iron concentrate cyanide carbon slurry gold-silver;(4) magnetic separation tailings flotation lead gold silver;(5) floatation lead tailings flotation zinc.The present application is classified by two-stage selective crushing and grinding and pulse high gradient magnetic separation before flotation, effectively prevent primary fine material and slime overgrinding and mud, and preferentially separate micro-fine hematite and limonite, to reduce the adverse effects of micro-fine material on flotation, then use multi-stage flotation and cyanide carbon slurry process to recover valuable metals in magnetic separation tailings and gold-silver-containing hematite and limonite concentrate respectively, realize comprehensive recovery of gold-silver-iron-lead-zinc in low-grade complex lead-zinc-gold-silver ore, and the high-efficiency comprehensive recovery effect is remarkable, successfully solve the problem of low recovery rate, high recovery cost and lead-zinc cannot be recovered in single flotation process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of low-grade mineral recovery, and particularly relates to a high-efficiency comprehensive recovery method for low-grade complex oxidized lead-zinc gold-silver ore. BACKGROUND

[0002] China is a country with extremely rich oxidized lead-zinc ore, however, with the development of lead-zinc gold-silver deposits, rich ore resources are decreasing, the ore grade is gradually reduced, and the complexity of oxidized ore is increasingly highlighted. The lead-zinc gold-silver deposit is often associated with noble metals gold and silver, and has extremely high comprehensive development and utilization value, but the ore structure is complex, the gold and silver are finely disseminated, more exist in inclusions, and the associated components are unstable, containing a large amount of clay, hematite, limonite and soluble salt.

[0003] At present, the separation and recovery of polymetallic oxidized lead-zinc ore mainly adopts the grinding-dispersant reinforced dispersion full-sliming ore pulp flotation process, however, this method has many problems: first, the content of soluble ions and slime in the ore is high, even if a large amount of dispersant is used, the ore pulp is difficult to be effectively dispersed, resulting in large consumption of flotation reagents, and the flotation index (grade and recovery rate) is difficult to improve; second, for the ore with fine or complex dissemination, pre-desliming will cause a large amount of valuable minerals to be lost. In addition, when fine grinding-carbon leaching method is used to recover noble metals, due to the interference of non-ferrous metal minerals, the gold and silver recovery rate is low, the production cost is high, and the valuable components such as lead and zinc are difficult to be effectively recovered, causing resource waste and environmental pollution risk.

[0004] Therefore, it is an inevitable trend to develop a new beneficiation process for oxidized lead-zinc gold-silver ore with short process, low cost, little pollution or no pollution. SUMMARY

[0005] In order to overcome the deficiencies and defects of the prior art, the application provides a high-efficiency comprehensive recovery method for low-grade complex oxidized lead-zinc gold-silver ore, which fully utilizes the ore properties, adopts two-stage selective crushing-grinding classification, pulse high-gradient magnetic separation and fine grinding-cyanide carbon pulp and multi-stage flotation combination, gradually reduces the influence of micro-fine particles on flotation, and improves the comprehensive recovery rate of the ore.

[0006] To achieve the above purpose, the application provides a high-efficiency comprehensive recovery method for low-grade complex oxidized lead-zinc gold-silver ore, which includes the following steps:

[0007] (1) Two-stage selective crushing and grinding classification: the ore to be treated is delivered to a semi-autogenous mill for one-stage coarse crushing and grinding to obtain slurry with a fineness of-10 mm, which is classified by a low-concentration classification cyclone to obtain coarse particle material of-10 mm to 0.074 mm and qualified fine particle material; the coarse particle material of-10 mm to 0.074 mm is delivered to a ball mill for two-stage fine grinding, and then classified by a classification cyclone to obtain qualified fine particle material and coarse particle material, which is returned to the ball mill for regrinding, and the qualified fine particle material obtained is-0.074 mm accounting for 70% to 80%;

[0008] This step utilizes the selective crushing and grinding of the semi-autogenous mill on the coarse particle material and the low grinding effect on the fine particle material, thereby reducing the generation of secondary slurry, and combining the φ350 mm classification cyclone for classification under low-concentration conditions to avoid the primary qualified fine particle material and slurry (especially low-hardness limonite) from entering the ball mill again to be ground finer to form a large amount of colloidal secondary slurry, affecting the subsequent recovery process, and also reducing the processing capacity of the ball mill and the grinding cost.

[0009] (2) Pulsed high-gradient magnetic separation: the qualified fine particle material obtained in step (1) is delivered to a pulsed high-gradient magnetic separation system for magnetic separation to pre-recover micro-fine particle hematite and limonite, and obtain gold-silver-iron-containing concentrate (containing hematite and limonite) and magnetic separation tailings;

[0010] This step pre-recover micro-fine particle hematite and limonite by pulsed high-gradient magnetic separation according to the wrapping effect of hematite and limonite on gold and silver, which not only realizes the recovery of gold and silver wrapped by them, but also reduces the content of micro-fine particle material, which is beneficial to subsequent flotation recovery.

[0011] (3) Cyanide carbon-in-pulp gold and silver extraction from gold-silver-iron-containing concentrate: after the gold-silver-iron-containing concentrate obtained in step (2) is finely ground to-0.037 mm accounting for 80% to 90%, it is delivered to a cyanide carbon-in-pulp system, lime is added for slurry adjustment to pH 10.5 to 11.5, sodium cyanide solution is added for gold and silver leaching, and gold and silver-loaded activated carbon and iron concentrate (containing hematite and limonite) are obtained by activated carbon adsorption;

[0012] This step utilizes the selective fine grinding of gold and silver-loaded hematite and limonite by the ball mill again before cyanide carbon-in-pulp gold and silver leaching to fully expose the wrapped gold and silver, thereby improving the cyanide carbon-in-pulp gold and silver leaching and adsorption effect and increasing the gold and silver recovery rate, and obtaining qualified hematite and limonite concentrate.

[0013] (4) Flotation of lead, gold and silver from magnetic separation tailings: the magnetic separation tailings obtained in step (2) are delivered to a gold-silver-lead flotation system, and after one-stage roughing, three-stage cleaning, and two-stage scavenging, gold-silver-lead-containing concentrate and lead flotation tailings are obtained; during the one-stage roughing and two-stage scavenging, an adjusting agent is added to enhance the floatability of the minerals;

[0014] The step uses the modifier to strengthen and activate the oxidized lead mineral in the flotation process, changes the chemical composition of the oxidized lead mineral surface, makes the mineral surface more easily react with the collector, and then realizes the synchronous collection of the lead sulfide and the oxidized lead mineral by using the synergistic effect of the collector combination, and the recovery rate is higher.

[0015] (5) Flotation of lead tailings for zinc: the lead tailings obtained in step (4) are transported to a zinc flotation system, and after one roughing, three times of cleaning, and two times of scavenging, a gold-silver-zinc concentrate and tailings are obtained; the activator is added during the one roughing and the two times of scavenging to enhance the floatability of the mineral.

[0016] Further, in step (1), the grinding concentration of the first rough grinding is 70% to 75%, and the classification concentration is 35% to 40%; the grinding concentration of the second 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.

[0017] Further, in step (2), 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 per minute, the stroke is 15 cm to 20 cm, and the magnetic separation concentration is 28% to 30%.

[0018] Further, in step (3), the concentration of the sodium cyanide solution is 0.5‰ to 0.7‰; and the leaching slurry concentration is 30% to 40%.

[0019] Further, in step (4), the reagents used in the one roughing are: the modifier sodium carbonate is used in an amount of 1500 g / t, the sodium sulfide is used in an amount of 300 g / t to 500 g / t, the depressant zinc sulfate is used in an amount of 1000 g / t to 1500 g / t, the sodium sulfite is used in an amount of 500 g / t to 800 g / t, the collector ethylthiuram + isobutyl xanthate is used in an amount of 60 g / t to 80 g / t, and the frother 2# oil is used in an amount of 40 g / t to 60 g / t; the reagents used in the three times of cleaning are: the depressant zinc sulfate is used in an amount of 300 g / t to 500 g / t, and the sodium sulfite is used in an amount of 200 g / t to 300 g / t; the reagents used in the two times of scavenging are: the modifier sodium sulfide is used in an amount of 100 g / t to 200 g / t, the collector isobutyl xanthate is used in an amount of 20 g / t to 30 g / t, and the frother 2# oil is used in an amount of 20 g / t to 30 g / t.

[0020] Further, in step (5), the reagents used in the one roughing are: the activator copper sulfate is used in an amount of 80 g / t to 100 g / t, the collector butyl xanthate is used in an amount of 80 g / t to 100 g / t, and the frother 2# oil is used in an amount of 40 g / t to 60 g / t; the reagents used in the two times of scavenging are: the activator copper sulfate is used in an amount of 30 g / t to 40 g / t, the collector butyl xanthate is used in an amount of 40 g / t to 60 g / t, and the frother 2# oil is used in an amount of 20 g / t to 30 g / t.

[0021] The beneficial effects of the present application: the present application first classifies the minerals by two-stage selective crushing and grinding before flotation, which avoids over-grinding of primary fine particles and slimes, and the subsequent flotation is affected by the over-grinding of slimes. The present application further reduces the adverse effects of fine materials on flotation by preferentially separating micro-fine hematite and limonite using pulse high-gradient magnetic separation. Subsequently, valuable metals in the tailings of magnetic separation and gold-silver-containing hematite and limonite concentrates are recovered using multi-stage flotation and carbon-in-pulp processes, respectively. The present application realizes the comprehensive recovery of gold, silver, iron, lead and zinc from low-grade complex oxidized lead-zinc-gold-silver ore, with a gold recovery rate of 82% or more, a silver recovery rate of 81% or more, an iron recovery rate of 72% or more, a lead recovery rate of 75% or more, and a zinc recovery rate of 60% or more. The present application has a remarkable effect of efficient comprehensive recovery of resources, successfully solves the problems of low recovery rate, high recovery cost and the inability to recover lead and zinc in single flotation process, and has strong adaptability, simple and environmentally friendly process, stable process indicators, and guiding significance for the comprehensive utilization of low-grade complex oxidized lead-zinc-gold-silver ore resources. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 is a flow chart of the present application, which is a method for efficient comprehensive recovery of low-grade complex oxidized lead-zinc-gold-silver ore. DETAILED DESCRIPTION

[0023] In order to make the technical problems and technical solutions of the present application clearer, the present application is further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the present application and do not limit the present application. Example 1

[0024] The raw ore 1# is a low-grade complex oxidized lead-zinc-gold-silver ore, and the 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 the proportion of lead in sulfide is 50.65%, and the proportion of zinc is 60.98%.

[0025] The main metallic minerals in the ore are hematite, limonite, siderite, galena, cerussite, sphalerite, pyrrhotite, pyrite and chalcopyrite, of which hematite and limonite have relatively high content, and galena, cerussite and sphalerite have relatively low content. The main gangue minerals are dolomite, quartz, calcite and kaolinite, of which dolomite, calcite and quartz have relatively high content, and kaolinite has relatively low content.

[0026] As shown in Figure 1 , the raw ore 1# is recovered by the method of the present application, and the specific steps are as follows:

[0027] (1) Two-stage selective crushing and grinding classification: the ore to be treated is delivered to a semi-autogenous mill for first-stage coarse crushing and grinding, the grinding concentration is controlled at 70%-75%, and a slurry with a fineness of -10 mm is obtained, which is classified by a φ350 mm classifying cyclone at a concentration of 35%-40%, to obtain coarse particle material of -10 mm-0.074 mm and qualified fine particle material; the coarse particle material of -10 mm-0.074 mm is delivered to a ball mill for second-stage fine grinding, the grinding concentration is controlled at 65%-70%, and then classified by a φ350 mm classifying cyclone at a concentration of 50%-55%, to obtain qualified fine particle material and coarse particle material, which is returned to the ball mill for regrinding, and the obtained qualified fine particle material is -0.074 mm, accounting for 70%-80%, and the concentration is 28%-30%;

[0028] (2) Pulsed high-gradient magnetic separation: the qualified fine particle material obtained in step (1) is delivered to a pulsed high-gradient magnetic separation system for magnetic separation, to pre-magnetically separate and recover micro-fine particle hematite and limonite, and obtain a gold-silver-iron-containing concentrate (containing hematite and limonite) and a magnetic separation tailing; in this process, the background magnetic induction intensity is 1.3-1.4, the magnetic medium diameter 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%.

[0029] (3) Cyanide carbon-in-pulp gold-silver extraction from the gold-silver-iron-containing concentrate: after the gold-silver-iron-containing concentrate obtained in step (2) is finely ground to -0.037 mm, accounting for 80%-90%, it is delivered to a cyanide carbon-in-pulp system, lime is added for slurry adjustment to a pH of 10.5-11.5, 0.5‰ sodium cyanide solution is added for gold-silver leaching, the leaching slurry concentration is 30%-40%, and gold-silver-loaded activated carbon and iron concentrate are obtained by activated carbon adsorption;

[0030] (4) Flotation of lead, gold and silver from the magnetic separation tailing: the magnetic separation tailing obtained in step (2) is delivered to a gold-silver-lead mixed flotation system, to obtain a gold-silver-lead-containing concentrate and a floating lead tailing through one-stage roughing, three-stage cleaning and two-stage scavenging; the reagents used in the one-stage roughing are: sodium carbonate 1500 g / t, sodium sulfide 300 g / t, zinc sulfate 1000 g / t, sodium sulfite 500 g / t, ethylthiuram + isobutyl xanthate 60 g / t, and 2# oil 40 g / t; the reagents used in the three-stage cleaning are: zinc sulfate 300 g / t, and sodium sulfite 200 g / t; and the reagents used in the two-stage scavenging are: sodium sulfide 100 g / t, isobutyl xanthate 20 g / t, and 2# oil 20 g / t.

[0031] (5) Zinc flotation of lead tailings: The lead tailings obtained in step (4) are transported to the zinc flotation system. 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 a dosage of 80 g / t, collector butyl xanthate at a dosage of 80 g / t, and frother 2# oil at a dosage of 40 g / t. The reagents used in the two scavenging processes are: activator copper sulfate at a dosage of 30 g / t, collector butyl xanthate at a dosage of 40 g / t, and frother 2# oil at a dosage of 20 g / t.

[0032] 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%. Example 2

[0033] 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.

[0034] 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.

[0035] like Figure 1 As shown, the method described in this invention is used to recover raw ore #2. The specific steps are as follows:

[0036] (1) Two-stage selective crushing and grinding classification: the ore to be treated is delivered to a semi-autogenous mill for first-stage coarse crushing and grinding, the grinding concentration is controlled at 70%-75%, and a slurry with a fineness of -10 mm is obtained, which is classified by a φ350 mm classifying cyclone at a concentration of 35%-40%, to obtain coarse particle material of -10 mm-0.074 mm and qualified fine particle material; the coarse particle material of -10 mm-0.074 mm is delivered to a ball mill for second-stage fine grinding, the grinding concentration is controlled at 65%-70%, and then classified by a φ350 mm classifying cyclone at a concentration of 50%-55%, to obtain qualified fine particle material and coarse particle material, which is returned to the ball mill for regrinding, and the obtained qualified fine particle material is -0.074 mm, accounting for 70%-80%, and the concentration is 28%-30%;

[0037] (2) Pulsed high-gradient magnetic separation: the qualified fine particle material obtained in step (1) is delivered to a pulsed high-gradient magnetic separation system for magnetic separation, to pre-magnetically separate and recover micro-fine particle hematite and limonite, and obtain a gold-silver-iron-containing concentrate (containing hematite and limonite) and a magnetic separation tailing; in this process, the background magnetic induction intensity is 1.3-1.4, the magnetic medium diameter is 1.0 mm, the pulse intensity is 200-300 times / min, the stroke is 15-20 cm, and the magnetic separation concentration is 28%-30%.

[0038] (3) Cyanide carbon slurry gold-silver extraction from the gold-silver-iron-containing concentrate: after the gold-silver-iron-containing concentrate obtained in step (2) is finely ground to -0.037 mm, accounting for 80%-90%, it is delivered to a cyanide carbon slurry system, lime is added for slurry adjustment to a pH of 10.5-11.5, 0.6‰ sodium cyanide solution is added for gold-silver leaching, the leaching slurry concentration is 30%-40%, and gold-silver-loaded activated carbon and iron concentrate are obtained by activated carbon adsorption;

[0039] (4) Flotation of lead, gold and silver from the magnetic separation tailing: the magnetic separation tailing obtained in step (2) is delivered to a gold-silver-lead mixed flotation system, to obtain a gold-silver-lead-containing concentrate and a floating lead tailing through one-stage roughing, three-stage cleaning and two-stage scavenging; the reagents used in the one-stage roughing are: sodium carbonate 1500 g / t, sodium sulfide 400 g / t, zinc sulfate 1200 g / t, sodium sulfite 600 g / t, ethylthiuram + isobutyl xanthate 70 g / t, and 2# oil 50 g / t; the reagents used in the three-stage cleaning are: zinc sulfate 400 g / t, and sodium sulfite 250 g / t; and the reagents used in the two-stage scavenging are: sodium sulfide 150 g / t, isobutyl xanthate 25 g / t, and 2# oil 25 g / t.

[0040] (5) Floatation of zinc from lead floatation tailings: the lead floatation tailings obtained in step (4) are transported to a zinc floatation system, and after one rough selection, three times of selection, and two times of scavenging, a gold-silver-zinc concentrate and tailings are obtained; the reagents used in the one rough selection are as follows: the dosage of the activator copper sulfate is 90 g / t, the dosage of the collector butyl xanthate is 90 g / t, and the dosage of the frother 2# oil is 50 g / t; the reagents used in the two times of scavenging are as follows: the dosage of the activator copper sulfate is 35 g / t, the dosage of the collector butyl xanthate is 50 g / t, and the dosage of the frother 2# oil is 25 g / t.

[0041] The test results are as follows: the grade of the gold-silver-lead concentrate product is Pb 64.28%, Au 25.37 g / t, and Ag 994.55 g / t, the grade of the gold-silver-zinc concentrate product is Zn 42.69%, Au 5.64 g / t, and Ag 205.39 g / t, and the grade of the gold-silver-loaded activated carbon product is Au 738.67 g / t and Ag 3629.49 g / t, wherein the lead recovery rate is 77.23%, the zinc recovery rate is 61.36%, the comprehensive recovery rate of the noble metal gold is 89.45%, the comprehensive recovery rate of the noble metal silver is 87.18%, the grade of the red and brown concentrate iron is 48.57%, and the recovery rate is 73.73%. Example 3

[0042] Raw material 3#: a low-grade complex oxidized lead-zinc-gold-silver ore, the main element chemical analysis of which is as follows: Pb 3.75%, Zn 0.78%, Au 1.42%, Ag 42.42, and Fe 25.29% 、 S 2.71%, wherein the proportion of lead in the sulfide is 57.61%, and the proportion of zinc is 66.95%.

[0043] The main metal minerals in the ore are hematite, limonite, siderite, galena, cerusite, sphalerite, pyrrhotite, pyrite, and chalcopyrite, wherein the relative content of limonite is relatively high, and the relative content of galena, cerusite, and sphalerite is relatively low; the main gangue minerals are dolomite, quartz, calcite, and kaolinite, wherein the relative content of dolomite, calcite, and quartz is relatively high, and the relative content of kaolinite is relatively low.

[0044] As shown in Figure 1 , the raw ore 2# is recovered by using the method of the present application, and the specific steps are as follows:

[0045] (1) Two-stage selective crushing and grinding classification: the ore to be treated is delivered to a semi-autogenous mill for first-stage coarse crushing and grinding, the grinding concentration is controlled at 70%-75%, and a slurry with a fineness of -10 mm is obtained, which is classified by a φ350 mm classifying cyclone at a concentration of 35%-40%, to obtain coarse particle material of -10 mm-0.074 mm and qualified fine particle material; the coarse particle material of -10 mm-0.074 mm is delivered to a ball mill for second-stage fine grinding, the grinding concentration is controlled at 65%-70%, and then classified by a φ350 mm classifying cyclone at a concentration of 50%-55%, to obtain qualified fine particle material and coarse particle material, which is returned to the ball mill for regrinding, and the obtained qualified fine particle material is -0.074 mm, accounting for 70%-80%, and the concentration is 28%-30%;

[0046] (2) Pulsed high-gradient magnetic separation: the qualified fine particle material obtained in step (1) is delivered to a pulsed high-gradient magnetic separation system for magnetic separation, to pre-magnetically separate and recover micro-fine particle hematite and limonite, and obtain a gold-silver-iron-containing concentrate (containing hematite and limonite) and a magnetic separation tailing; in this process, the background magnetic induction intensity is 1.3-1.4, the magnetic medium diameter is 1.0 mm, the pulse intensity is 200-300 times / min, the stroke is 15-20 cm, and the magnetic separation concentration is 28%-30%.

[0047] (3) Cyanide carbon-in-pulp gold-silver extraction from the gold-silver-iron-containing concentrate: after the gold-silver-iron-containing concentrate obtained in step (2) is finely ground to -0.037 mm, accounting for 80%-90%, it is delivered to a cyanide carbon-in-pulp system, lime is added for slurry adjustment to a pH of 10.5-11.5, 0.7‰ sodium cyanide solution is added for gold-silver leaching, the leaching slurry concentration is 30%-40%, and gold-silver-loaded activated carbon and iron concentrate are obtained by activated carbon adsorption;

[0048] (4) Flotation of lead, gold and silver from the magnetic separation tailing: the magnetic separation tailing obtained in step (2) is delivered to a gold-silver-lead mixed flotation system, to obtain a gold-silver-lead-containing concentrate and a floating lead tailing through one-stage roughing, three-stage cleaning and two-stage scavenging; the reagents used in the one-stage roughing are: sodium carbonate 1500 g / t, sodium sulfide 500 g / t, zinc sulfate 1500 g / t, sodium sulfite 800 g / t, ethylthiuram + isobutyl xanthate 80 g / t, and 2# oil 60 g / t; the reagents used in the three-stage cleaning are: zinc sulfate 500 g / t, and sodium sulfite 300 g / t; and the reagents used in the two-stage scavenging are: sodium sulfide 200 g / t, isobutyl xanthate 30 g / t, and 2# oil 30 g / t.

[0049] (5) Floatation of zinc from lead floatation tailings: the lead floatation tailings obtained in step (4) are transported to a zinc floatation system, and after one rough selection, three times of fine selection, and two times of scavenging, a gold-silver-zinc concentrate and tailings are obtained; the reagents used in the one rough selection are as follows: the dosage of the activator copper sulfate is 100 g / t, the dosage of the collector butyl xanthate is 100 g / t, and the dosage of the frother 2# oil is 60 g / t; the reagents used in the two times of scavenging are as follows: the dosage of the activator copper sulfate is 40 g / t, the dosage of the collector butyl xanthate is 60 g / t, and the dosage of the frother 2# oil is 30 g / t.

[0050] The test results are as follows: the grade of the gold-silver-lead concentrate product is Pb 63.46%, Au 28.39 g / t, and Ag 1029.15 g / t, the grade of the gold-silver-zinc concentrate product is Zn 44.39%, Au 4.82 g / t, and Ag 199.78 g / t, and the grade of the gold-silver-loaded activated carbon product is Au 700.73 g / t and Ag 3497.64 g / t, wherein the lead recovery rate is 75.81%, the zinc recovery rate is 64.25%, the comprehensive gold recovery rate is 88.26%, and the comprehensive silver recovery rate is 86.79%; the grade of the red and brown concentrate is 49.57%, and the recovery rate is 78.41%.

[0051] In summary of the above examples, the method described in the present application is used to recover and process the low-grade complex oxidized lead-zinc-gold-silver ore, and the recovery indexes of gold recovery rate of more than 88%, silver recovery rate of more than 86%, iron recovery rate of more than 72%, lead recovery rate of more than 75%, and zinc recovery rate of more than 60% are obtained, which shows that the resource efficient comprehensive recovery effect is remarkable, the method has strong adaptability to the ore, the process is simple, environmental protection, and the process indexes are stable, and the method has guiding significance for the resource comprehensive utilization of the low-grade complex oxidized lead-zinc-gold-silver ore.

[0052] The present application is described in detail through specific and preferred examples, but those skilled in the art should understand that the present application is not limited to the above examples, and any modification, equivalent replacement, etc. made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for efficient comprehensive recovery of low-grade complex lead-zinc-gold-silver oxide ore, characterized in that, It comprises the following steps: (1) two-stage selective crushing and grinding classification: the ore to be treated is delivered to a semi-autogenous mill for one-stage coarse crushing and grinding to obtain slurry with a fineness of -10 mm, which is classified by a low-concentration classifier to obtain coarse material of -10 mm to 0.074 mm and qualified fine material; the coarse material of -10 mm to 0.074 mm is delivered to a ball mill for two-stage fine grinding, and then classified by a classifier to obtain qualified fine material and coarse material, which is returned to the ball mill for regrinding, and the qualified fine material obtained has a fineness of -0.074 mm accounting for 70% to 80%; (2) pulse high-gradient magnetic separation: the qualified fine material obtained in step (1) is delivered to a pulse high-gradient magnetic separation system for magnetic separation, and the fine hematite and limonite are pre-magnetic separated and recovered to obtain a gold-silver-iron-containing concentrate (containing hematite and limonite) and a magnetic separation tailing; (3) cyanidation carbon-in-pulp gold-silver extraction from the gold-silver-iron-containing concentrate: after the gold-silver-iron-containing concentrate obtained in step (2) is finely ground to a fineness of -0.037 mm accounting for 80% to 90%, it is delivered to a cyanidation carbon-in-pulp system, lime is added for slurry adjustment to a pH of 10.5 to 11.5, sodium cyanide solution is added for gold and silver leaching, and gold-silver-loaded activated carbon and iron concentrate are obtained by activated carbon adsorption; (4) flotation of lead, gold and silver from the magnetic separation tailing: the magnetic separation tailing obtained in step (2) is delivered to a gold-silver-lead bulk flotation system, and after one-stage roughing, three-stage cleaning and two-stage scavenging, a gold-silver-lead-containing concentrate and a lead flotation tailing are obtained; during the one-stage roughing and the two-stage scavenging, an adjusting agent is added to enhance the floatability of the minerals; the reagents used in the one-stage roughing are: adjusting agent sodium carbonate 1500 g / t, sodium sulfide 300 g / t to 500 g / t, depressant zinc sulfate 1000 g / t to 1500 g / t, sodium sulfite 500 g / t to 800 g / t, collector ethylthiuram + isobutyl xanthate 60 g / t to 80 g / t, and frother 2# oil 40 g / t to 60 g / t; the reagents used in the three-stage cleaning are: depressant zinc sulfate 300 g / t to 500 g / t, and sodium sulfite 200 g / t to 300 g / t; the reagents used in the two-stage scavenging are: adjusting agent sodium sulfide 100 g / t to 200 g / t, collector isobutyl xanthate 20 g / t to 30 g / t, and frother 2# oil 20 g / t to 30 g / t; (5) Floatation of zinc from lead floatation tailings: the lead floatation tailings obtained in step (4) are transported to a zinc floatation system, and after one rough selection, three fine selections and two sweep selections, a gold-silver-zinc concentrate and tailings are obtained; in the one rough selection and the two sweep selections, an activator is added to enhance the floatability of the minerals; the reagents used in the one rough selection are: the amount of the activator copper sulfate is 80-100 g / t, the amount of the collector butyl xanthate is 80-100 g / t, and the amount of the frother 2# oil is 40-60 g / t; the reagents used in the two sweep selections are: the amount of the activator copper sulfate is 30-40 g / t, the amount of the collector butyl xanthate is 40-60 g / t, and the amount of the frother 2# oil is 20-30 g / t.

2. The method according to claim 1, characterized in that, In step (1), the grinding concentration of the first rough grinding is 70-75%, and the classification concentration is 35-40%; the grinding concentration of the second fine grinding is 65-70%, and the classification concentration is 50-55%; the diameters of the two-stage classification cyclones are both φ350 mm.

3. The method 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 15-20 cm, and the magnetic separation concentration is 28-30%.

4. The method according to claim 1, characterized in that, In step (3), the concentration of the sodium cyanide solution is 0.5-0.7 ‰; the leaching slurry concentration is 30-40%.

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