Method for comprehensively recovering valuable elements from lead-zinc-gold-silver concentrate

Abstract

The invention belongs to the technical field of comprehensive recovery of complex multi-metal gold and silver concentrates, and particularly relates to a method for comprehensively recovering valuable elements from lead-zinc-gold and silver concentrates, which comprises the following steps: (1) carrying out ore grinding treatment and sulfur suppression treatment on the lead-zinc-gold and silver concentrates, and then carrying out flotation operation to obtain lead-zinc mixed gold and silver concentrates and flotation tailings; (2) the lead-zinc mixed gold and silver concentrate is subjected to cyanidation leaching treatment, and leaching liquid containing gold and silver and leaching residues are obtained through separation; (3) the flotation tailings are subjected to fine grinding treatment and cyanidation leaching, and leaching liquid containing gold and silver and leaching residues are obtained; (4) mixing the leaching residues with sulfur-containing gold concentrate, then carrying out oxidizing roasting, and carrying out acid leaching treatment on roasting residues to obtain acid leaching liquid and acid leaching residues; and (5) carrying out fine grinding on the acid leaching residues, and carrying out secondary cyanidation leaching. According to the method, the lead-zinc-gold-silver bulk concentrate is treated by adopting a cyaniding sulfur suppression flotation process, so that the problem of low lead-zinc recovery rate caused by over-fine grinding, mineral argillization and serious oxidation of the traditional cyaniding tailings is solved.

Description

Technical Field

[0001] This invention relates to a method for the comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates, belonging to the technical field of comprehensive recovery of complex polymetallic gold-silver concentrates. Background Technology

[0002] With the continuous development of gold resources, readily processable gold ore is becoming increasingly scarce, making the development and utilization of refractory gold ore increasingly important. Statistics show that refractory gold ore reserves account for approximately 60% of the world's total gold reserves, and this proportion is similar in my country. Currently, about one-third of the world's total gold production comes from refractory gold ore; in my country's proven gold reserves, refractory gold ore accounts for approximately 30%. Therefore, efficient processing technology for refractory gold ore has become one of the core issues in the gold extraction field.

[0003] Refractory gold ores, also known as refractory gold ore, refractory metallurgical ore, or stubborn gold ore, usually contain high levels of impurities such as sulfur, arsenic, carbon, lead, and zinc. Their direct cyanide leaching rate is generally low, typically only 10%–30%. The main reasons for their difficulty in processing include the following aspects: (1) Gold is encapsulated in carrier minerals, including physical-mechanical encapsulation, chemical solid solution, or surface chemical coating, which hinders the contact between cyanide and gold; (2) The ore contains cyanide-consuming and oxygen-consuming substances, such as sulfides and oxides of arsenic, lead, zinc, antimony, iron, manganese, nickel, and cobalt. These components have high solubility in cyanide solutions and significantly consume cyanide and dissolved oxygen in the solution; (3) The presence of gold-depleting substances, such as carbonaceous materials and clay minerals, can adsorb gold-cyanide complexes, causing gold loss; (4) The influence of conductive minerals. When gold forms compounds or comes into contact with minerals such as tellurium, bismuth, and antimony, the anodic dissolution process of gold is inhibited.

[0004] Oxidized lead-zinc-gold-silver concentrates are typical refractory gold concentrates, and conventional cyanide leaching processes are ineffective. Currently, pretreatment methods such as enhanced cyanidation, oxidative roasting-leaching, pressure oxidation-leaching, and bacterial oxidation-leaching are commonly used to significantly improve gold recovery rates. However, these processes generally suffer from the problem of inefficient and comprehensive recovery of associated valuable elements (such as zinc and lead), resulting in low resource utilization.

[0005] Therefore, achieving comprehensive recovery of valuable metals from this type of ore has become a key technological direction for improving the resource utilization efficiency and sustainable development capabilities of smelting enterprises. Summary of the Invention

[0006] In view of the above-mentioned technical problems in the prior art, the present invention provides a method for the comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates.

[0007] The technical solution of this invention to solve the above-mentioned technical problems is as follows: This invention provides a method for the comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates, comprising the following steps: (1) Cyanide desulfurization flotation: The lead-zinc-gold-silver concentrate is ground and then desulfurized under alkaline conditions and in the presence of sodium cyanide. Then flotation is carried out to obtain a mixed lead-zinc-gold-silver concentrate and flotation tailings. (2) Cyanide leaching of lead-zinc mixed concentrate: The lead-zinc mixed gold and silver concentrate obtained in step (1) is subjected to cyanide leaching treatment to separate the gold and silver-containing leachate and leachate residue; the leachate is used to recover gold and silver through a displacement smelting process, and the leachate residue is sent to a lead-zinc pyrometallurgical system to recover lead and zinc. (3) Enhanced cyanidation of flotation tailings: The flotation tailings obtained in step (1) are finely ground and cyanided under hydrogen peroxide enhanced conditions to obtain a gold and silver-containing leachate and leachate residue; the leachate is then used to recover gold and silver through a displacement smelting process. (4) Roasting and acid leaching for zinc extraction: The leaching residue obtained in step (3) is mixed with sulfur-containing gold concentrate in a certain proportion and then subjected to oxidative roasting. The roasted residue is then treated with dilute sulfuric acid to obtain acid leaching solution and acid leaching residue. The acid leaching solution is then treated with sulfidation to obtain zinc concentrate. (5) Secondary cyanidation of acid leaching residue: After fine grinding and alkaline adjustment of the acid leaching residue obtained in step (4), secondary cyanidation leaching is carried out; the resulting leaching solution is used to recover gold and silver, and the leaching tailings are used to recover iron concentrate.

[0008] Furthermore, in step (1), the pulp concentration is adjusted to 50-60 wt%, the pH value is 9-10, the sodium cyanide dosage is 10-30 kg / t, and the grinding fineness is controlled to be -0.074 mm or more. The flotation operation adopts a primary roughing and secondary cleaning process, the collector is butyl xanthate with a dosage of 100-300 g / t, and the frother is No. 2 oil with a dosage of 10-20 g / t.

[0009] Furthermore, in step (2), the slurry concentration is controlled at 30-40 wt%, the pH value is 9-10, the sodium cyanide concentration is 1.00%-1.50%, and the leaching time is 30-40 hours.

[0010] Further, in step (2), the leaching residue is adjusted to a pulp concentration of 50-60 wt%, and 5.0-7.0 kg / t of sodium cyanide is added before it enters the grinding mill and is ground to a fineness of -0.037 mm accounting for 95%. Then, a second cyanide leaching is carried out, with the pulp concentration controlled at 20-30 wt%, the sodium cyanide concentration at 0.50%-0.70%, and the leaching time at 20-25 hours.

[0011] Furthermore, in step (3), the pulp concentration is controlled at 50-60 wt% during the grinding of flotation tailings, 1-2 kg / t of hydrogen peroxide is added, and the amount of sodium cyanide added is 5.0-7.0 kg / t. After grinding, the fineness reaches -0.037 mm, accounting for 95%. Then, the pulp concentration is adjusted to 20-30 wt%, the sodium cyanide concentration is 0.30%-0.50%, and the leaching time is 20-25 hours.

[0012] Furthermore, in step (4), the mass ratio of flotation tailings leaching residue to sulfur-containing gold concentrate is 1:0.8-1; the oxidative roasting temperature is 600-650℃ and the roasting time is 30-60 minutes; during acid leaching, the pulp concentration is controlled at 35-40wt%, the sulfuric acid concentration is 1%-3%, the temperature is 70-80℃, and the time is 120-240 minutes; the zinc content in the acid leaching solution is 3-10g / L, and sodium hydrosulfide 1-3g / L is added for sulfidation treatment.

[0013] Furthermore, in step (5), the pulp concentration is controlled at 50-60 wt% during grinding of the acid leaching residue, and the grinding fineness is -0.037 mm, accounting for 95%; after grinding, the pulp concentration is adjusted to 35-40 wt%, the pH is adjusted to 10-11 with sodium hydroxide, 1-3 kg / t of ammonium bicarbonate is added, and the sodium cyanide concentration is 0.30%-0.50%. Gold and silver are recovered by secondary leaching and secondary pressure filtration process; iron concentrate is recovered by high-temperature reduction roasting process of leaching tailings.

[0014] Furthermore, the gold and silver leaching solutions mentioned in steps (2), (3) and (5) all employ a zinc powder replacement-gold mud smelting process to recover gold and silver.

[0015] Furthermore, the sulfur content of the sulfur-containing gold concentrate mentioned in step (4) is 30% to 40%.

[0016] Furthermore, the final tailings in step (5) are recycled using a high-temperature reduction roasting process to recover iron concentrate.

[0017] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention uses a cyanide-based sulfur-suppressing flotation process to treat lead-zinc-gold-silver mixed concentrate, effectively realizing the recovery of associated lead-zinc minerals and solving the problem of low lead-zinc recovery rate caused by excessive grinding, mineral mudification and severe oxidation in traditional cyanide tailings.

[0018] 2. By cyanide leaching of lead-zinc mixed gold and silver concentrate, and by controlling the grinding fineness and sodium cyanide concentration during the process, combined with secondary pressure filtration and secondary leaching, the leaching efficiency and recovery rate of gold and silver were significantly improved.

[0019] 3. By integrating multiple stages of processes, including enhanced cyanidation of flotation tailings, acid leaching of zinc from roasted leaching residue, and secondary cyanidation leaching of acid leaching residue, the key technical problems of low silver recovery rate and easy secondary gold encapsulation during roasting cyanidation process, which lead to a decrease in gold and silver cyanidation recovery rate, are effectively solved. At the same time, the high-efficiency production of zinc concentrate is achieved through acid leaching and sulfidation recovery processes.

[0020] 4. This invention provides a comprehensive recovery method for oxidized lead-zinc-gold-silver concentrates. The overall process is simple and smooth with high integration, realizing the comprehensive recovery of valuable elements such as gold, silver, zinc, and iron and the efficient utilization of resources, significantly improving the economic benefits of enterprises. Detailed Implementation

[0021] The principles and features of the present invention are described below. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0022] Example 1: A method for the comprehensive recovery of valuable elements from oxide-type lead-zinc-gold-silver concentrates includes the following steps: (1) Primary cyanide-sulfur-suppressing flotation of lead-zinc-gold mixed concentrate: The main components of the lead-zinc-gold-silver concentrate are: Au 10g / t, Ag 100g / t, Pb 1.0%, Zn 1.0%, sulfur 1.0%, As 0.50%; the concentration of the lead-zinc-gold-silver concentrate slurry was adjusted to 50wt%, 3kg / t of soda ash was added during grinding, the pH value was adjusted to 9, 10kg / t of sodium cyanide was added, and the grinding time was 15min; the grinding fineness of -0.074mm accounted for 90%, and the grinding... The ore is then fed into a leaching tank with a stirring speed of 50 r / min and a leaching time of 120 min. Then, 100 g / t of butyl xanthate collector and 10 g / t of frother No. 2 oil are added. A flotation process with one roughing and two cleaning stages is adopted to obtain a lead-zinc mixed gold and silver concentrate containing 20.0% lead, 20% zinc, 1200 g / t silver and 50 g / t gold, and a mixed tailings containing 0.30% lead, 0.80% zinc, 60 g / t silver and 4 g / t gold. (2) Cyanide leaching of gold and silver from secondary lead-zinc mixed gold and silver concentrate: The slurry concentration of the lead-zinc mixed gold and silver concentrate was adjusted to 30wt%, the pH value of the slurry was controlled to 10, the sodium cyanide concentration was controlled to 1.00%, and the leaching time was 36h. After leaching, the gold and silver-containing leachate was obtained by pressure filtration and entered the zinc powder replacement gold and silver and gold mud smelting to produce gold ingots and silver ingots. The filter cake was adjusted to a slurry concentration of 50wt%, the amount of soda ash added was 1.0kg / t, the amount of sodium cyanide added was 5.0kg / t, and it was put into the grinding mill. The grinding time was 20min, and the fineness after grinding was -0.037mm, accounting for 95%. After grinding, the slurry concentration was adjusted to 20wt%, the sodium cyanide concentration was controlled to 0.50%, and the leaching time was 24h. The leaching residue of the lead-zinc mixed gold and silver concentrate contained 4g / t of gold, 100g / t of silver, 20% of lead, and 20% of zinc. It was put into the lead-zinc pyrometallurgical smelting system for comprehensive recovery.

[0023] (3) Enhanced cyanide leaching of gold and silver from three-stage mixed flotation tailings: The mixed flotation tailings are slurry adjusted to a ore concentration of 50%, hydrogen peroxide 1 kg / t, soda ash 1.0 kg / t, sodium cyanide 5.0 kg / t are added, and the mixture is fed into a grinding mill. The grinding time is 20 min, and the fineness after grinding is -0.037 mm, accounting for 95%. After grinding, the slurry concentration is adjusted to 20 wt%, the sodium cyanide concentration is controlled at 0.30%, and the leaching time is 24 h. The gold and silver leaching solution is used to replace gold and silver with zinc powder and smelt gold mud to produce gold and silver ingots. The leaching residue of the mixed flotation tailings contains 3 g / t of gold, 30 g / t of silver, 0.30% of lead, and 0.80% of zinc, and is then fed into the next process.

[0024] (4) Fourth-stage roasting and acid leaching for zinc extraction: The leaching residue from the mixed flotation tailings is mixed with gold concentrate containing 10-30 g / t of gold, 30 g / t of silver, 2% of zinc, and 30% of sulfur at a ratio of 1:0.8. The mixture is then roasted in a fluidized bed furnace at a temperature of 600℃ and an air volume of 8000 m³ / h. 3 The roasting time is 30 minutes. The roasting residue is adjusted with dilute sulfuric acid to a pulp concentration of 35 wt% and a sulfuric acid concentration of 1%. The acid leaching temperature is 70℃ and the acid leaching time is 120 minutes. After acid leaching, the residue is filtered, washed and dehydrated. The acid leaching solution contains 3 g / L of zinc. 1 g / L of sodium hydrosulfide is added to produce zinc concentrate containing 50% zinc. The acid leaching residue contains 15 g / t of gold and 60 g / t of silver, and proceeds to the next process.

[0025] (5) Five-stage acid leaching residue cyanidation leaching of gold and silver: The acid leaching residue is adjusted to a pulp concentration of 50wt% and fed into a ball mill. The grinding fineness is controlled to 0.037mm, accounting for 95%. The pulp concentration after grinding is controlled to 35wt%. Sodium hydroxide is added to adjust the pH value to 10. 1kg / t of ammonium bicarbonate is added. The sodium cyanide concentration is controlled to 0.30%. The cyanidation time is 24+12 hours. The leaching is carried out twice and then filtered twice. The leaching solution is treated with zinc powder replacement-smelting process to recover gold and silver. The leaching tailings are treated with high-temperature reduction roasting to recover iron concentrate.

[0026] Example 2: A method for the comprehensive recovery of valuable elements from oxide-type lead-zinc-gold-silver concentrates includes the following steps: (1) Primary cyanide-sulfur-suppressing flotation of lead-zinc-gold mixed concentrate: The main components of the lead-zinc-gold-silver concentrate are: Au 20g / t, Ag 200g / t, Pb 2.5%, Zn 2.5%, sulfur 2.5%, As 0.70%; the concentration of the lead-zinc-gold-silver concentrate slurry was adjusted to 55wt%, 4kg / t of soda ash was added during grinding, the pH value was adjusted to 9.5, 20kg / t of sodium cyanide was added, and the grinding time was 20min; the grinding fineness of -0.074mm accounted for 90%, and the grinding time was 20min. The ore was then introduced into two leaching tanks with a stirring speed of 75 r / min and a leaching time of 180 min. Then, 200 g / t of butyl xanthate collector and 15 g / t of frother No. 2 oil were added. A flotation process with one roughing and two cleaning stages was adopted to obtain a lead-zinc mixed gold and silver concentrate containing 22.5% lead, 22.5% zinc, 1500 g / t silver and 100 g / t gold, and a mixed tailings containing 0.35% lead, 1.0% zinc, 80 g / t silver and 5.0 g / t gold. (2) Cyanide leaching of gold and silver from secondary lead-zinc mixed gold and silver concentrate: The slurry concentration of the lead-zinc mixed gold and silver concentrate was adjusted to 35%, the pH value of the slurry was controlled to 10, the sodium cyanide concentration was controlled to 1.25%, and the leaching time was 36h. After leaching, the gold and silver-containing leachate was obtained by pressure filtration and entered the zinc powder replacement gold and silver and gold mud smelting to produce gold ingots and silver ingots. The filter cake was adjusted to a slurry concentration of 55wt%, the amount of soda ash added was 2.0kg / t, the amount of sodium cyanide added was 6.0kg / t, and it was put into the grinding mill. The grinding time was 25min, and the fineness after grinding was -0.037mm, accounting for 95%. After grinding, the slurry concentration was adjusted to 25wt%, the sodium cyanide concentration was controlled to 0.60%, and the leaching time was 24h. The leaching residue of the lead-zinc mixed gold and silver concentrate contained 5g / t of gold, 125g / t of silver, 22.5% of lead, and 22.5% of zinc. It was put into the lead-zinc pyrometallurgical smelting system for comprehensive recovery.

[0027] (3) Enhanced cyanide leaching of gold and silver from three-stage mixed flotation tailings: The mixed flotation tailings are slurry adjusted to a ore concentration of 55%, hydrogen peroxide 1.5 kg / t, soda ash 2.0 kg / t, sodium cyanide 6.0 kg / t are added, and the mixture is fed into a grinding mill. The grinding time is 25 min, and the fineness after grinding is -0.037 mm 95%. After grinding, the slurry concentration is adjusted to 25 wt%, the sodium cyanide concentration is controlled at 0.40%, and the leaching time is 24 h. The gold and silver leaching solution is used to replace gold and silver with zinc powder and smelt gold mud to produce gold and silver ingots. The leaching residue of the mixed flotation tailings contains 3.5 g / t of gold, 40 g / t of silver, 0.35% of lead, and 1.00% of zinc, and is then fed into the next process.

[0028] (4) Fourth-stage roasting and acid leaching for zinc extraction: The leaching residue from the mixed flotation tailings is mixed with a gold concentrate containing 20 g / t of gold, 40 g / t of silver, 2.5% of zinc, and 35% of sulfur at a ratio of 1:0.9. The mixture is then roasted in a fluidized bed furnace at a temperature of 625°C and an air volume of 10,000 m³ / h. 3 The roasting time was 45 minutes. The roasting residue was adjusted with dilute sulfuric acid to a pulp concentration of 37.5 wt% and a sulfuric acid concentration of 2%. The acid leaching temperature was 75℃ and the acid leaching time was 180 minutes. After acid leaching, the residue was filtered, washed, and dehydrated. The acid leaching solution contained 6.5 g / L of zinc. 2 g / L of sodium hydrosulfide was added to produce a zinc concentrate containing 57.5% zinc. The acid leaching residue contained 30 g / t of gold and 70 g / t of silver, and proceeded to the next process.

[0029] (5) Cyanide leaching of gold and silver from grade 5 acid leaching residue: The acid leaching residue is adjusted to a slurry concentration of 55wt% and fed into a ball mill. The grinding fineness is controlled to 0.037mm, accounting for 95%. The slurry concentration after grinding is controlled to 37.5wt%. Sodium hydroxide is added to adjust the pH value to 10.5. 2kg / t of ammonium bicarbonate is added. The sodium cyanide concentration is controlled to 0.40%. The cyanidation time is 24+12 hours. The leaching is carried out twice and then filtered twice. The leaching solution is treated with zinc powder replacement-smelting process to recover gold and silver. The leaching tailings are treated with high-temperature reduction roasting to recover iron concentrate.

[0030] Example 3: A method for the comprehensive recovery of valuable elements from oxide-type lead-zinc-gold-silver concentrates includes the following steps: (1) Primary cyanide-sulfur-suppressing flotation of lead-zinc-gold mixed concentrate: The main components of the lead-zinc-gold-silver concentrate are: Au 30g / t, Ag 300g / t, Pb 4.0%, Zn 4.0%, sulfur 4.0%, As 0.90%; the concentration of the lead-zinc-gold-silver concentrate slurry was adjusted to 60wt%, 3kg / t of soda ash was added during grinding, the pH value was adjusted to 10, 30kg / t of sodium cyanide was added, and the grinding time was 25min; the grinding fineness of -0.074mm accounted for 90%, and after grinding The ore is introduced into 1-3 leaching tanks, stirred at 100 r / min, and leached for 240 min. Then, 300 g / t of butyl xanthate collector and 20 g / t of frother No. 2 oil are added. A flotation process with one roughing and two cleaning stages is adopted to obtain a lead-zinc mixed gold and silver concentrate containing 25% lead, 25% zinc, 1800 g / t silver, and 150 g / t gold, and a mixed tailings containing 0.40% lead, 1.20% zinc, 100 g / t silver, and 6.0 g / t gold. (2) Cyanide leaching of gold and silver from secondary lead-zinc mixed gold and silver concentrate: The slurry concentration of the lead-zinc mixed gold and silver concentrate was adjusted to 40wt%, the pH value of the slurry was controlled to 10, the sodium cyanide concentration was controlled to 1.50%, and the leaching time was 36h. After leaching, the gold and silver-containing leachate was obtained by pressure filtration and entered the zinc powder replacement gold and silver and gold mud smelting to produce gold ingots and silver ingots. The filter cake was adjusted to a slurry concentration of 60wt%, the amount of soda ash added was 3.0kg / t, the amount of sodium cyanide added was 7.0kg / t, and it was put into the grinding mill. The grinding time was 30min, and the fineness after grinding was -0.037mm, accounting for 95%. After grinding, the slurry concentration was adjusted to 30wt%, the sodium cyanide concentration was controlled to 0.70%, and the leaching time was 24h. The leaching residue of the lead-zinc mixed gold and silver concentrate contained 6g / t of gold, 150g / t of silver, 25% of lead, and 25% of zinc. It was put into the lead-zinc pyrometallurgical smelting system for comprehensive recovery.

[0031] (3) Enhanced cyanide leaching of gold and silver from three-stage mixed flotation tailings: The mixed flotation tailings are slurry adjusted to a ore concentration of 60%, hydrogen peroxide 2kg / t, soda ash 3.0kg / t, sodium cyanide 7.0kg / t are added, and the mixture is fed into a grinding mill. The grinding time is 30min, and the fineness after grinding is -0.037mm 95%. After grinding, the slurry concentration is adjusted to 30wt%, the sodium cyanide concentration is controlled at 0.50%, and the leaching time is 24h. The gold and silver leaching solution is used to replace gold and silver with zinc powder and smelt gold mud to produce gold and silver ingots. The leaching residue of the mixed flotation tailings contains 4g / t of gold, 50g / t of silver, 0.40% of lead, and 1.20% of zinc, and is then fed into the next process.

[0032] (4) Fourth-stage roasting and acid leaching for zinc extraction: The leaching residue from the mixed flotation tailings is mixed with gold concentrate containing 30 g / t of gold, 50 g / t of silver, 3% of zinc, and 40% of sulfur in a 1:1 ratio, and then roasted in a fluidized bed furnace at a roasting temperature of 650℃ and an air volume of 12000 m³ / h. 3 The roasting time is 60 min, and the slurry concentration of the roasted residue is adjusted to 40 wt% with dilute sulfuric acid. The sulfuric acid concentration is 3%, the acid leaching temperature is 80℃, and the acid leaching time is 240 min. After acid leaching, the residue is filtered, washed, and dehydrated. The acid leaching solution contains 10 g / L of zinc, and 3 g / L of sodium hydrosulfide is added to produce zinc concentrate with 65% zinc content. The acid leaching residue contains 45 g / t of gold and 80 g / t of silver, and proceeds to the next process.

[0033] (5) Five-stage acid leaching residue cyanidation leaching of gold and silver: The acid leaching residue is adjusted to a pulp concentration of 60wt% and fed into a ball mill. The grinding fineness is controlled to 0.037mm, accounting for 95%. After grinding, the pulp concentration is controlled to 40wt%. Sodium hydroxide is added to adjust the pH value to 11. 3kg / t of ammonium bicarbonate is added. The sodium cyanide concentration is controlled to 0.50%. The cyanidation time is 24+12 hours. Secondary leaching and secondary pressure filtration are performed. The leaching solution is treated with zinc powder replacement-smelting process to recover gold and silver. The leaching tailings are treated with high-temperature reduction roasting to recover iron concentrate.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates, characterized in that, Includes the following steps: (1) Cyanide desulfurization flotation: The lead-zinc-gold-silver concentrate is ground and desulfurized under alkaline conditions and in the presence of sodium cyanide, and then floated to obtain a mixed lead-zinc-gold-silver concentrate and flotation tailings. (2) Cyanide leaching of lead-zinc mixed concentrate: The lead-zinc mixed gold and silver concentrate obtained in step (1) is subjected to cyanide leaching to separate the gold and silver leaching solution and leaching residue. The leaching solution is smelted by displacement to recover gold and silver, and the leaching residue is sent to the lead-zinc pyrometallurgical system to recover lead and zinc. (3) Enhanced cyanidation of flotation tailings: The flotation tailings obtained in step (1) are finely ground and cyanided under hydrogen peroxide enhancement to obtain gold and silver leaching solution and leaching residue. The leaching solution is then smelted by displacement to recover gold and silver. (4) Roasting and acid leaching for zinc extraction: The leaching residue obtained in step (3) is mixed with sulfur-containing gold concentrate and then oxidized and roasted. The roasted residue is leached with dilute sulfuric acid to obtain acid leaching solution and acid leaching residue. The acid leaching solution is then treated with sulfidation to obtain zinc concentrate. (5) Secondary cyanidation of acid leaching residue: After fine grinding and alkalinity adjustment of the acid leaching residue obtained in step (4), secondary cyanidation leaching is carried out. Gold and silver are recovered from the leaching solution, and iron concentrate is recovered from the leaching tailings.

2. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to claim 1, characterized in that, In step (1), the pulp concentration of the lead-zinc-gold-silver concentrate is adjusted to 50-60 wt%, the pH value is adjusted to 9-10, the sodium cyanide dosage is 10-30 kg / t, and the grinding fineness is -0.074 mm or more. The flotation adopts a one-stage roughing and two-stage cleaning process. The collector added is butyl xanthate, the dosage of which is 100-300 g / t. The frother is No. 2 oil, the dosage of which is 10-20 g / t.

3. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to claim 1, characterized in that, In step (2), during the cyanide leaching, the slurry concentration of the lead-zinc mixed gold and silver concentrate is 30-40 wt%, the pH value is adjusted to 9-10, the sodium cyanide concentration is 1.00%-1.50%, and the leaching time is 30-40 hours.

4. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to claim 3, characterized in that, In step (2), the leaching residue is adjusted to a pulp concentration of 50-60 wt%, and the sodium cyanide is added at a rate of 5.0-7.0 kg / t. The residue is then fed into a grinding mill and refmilled until -0.037 mm accounts for 95%. A second cyanide leaching is then performed, with the pulp concentration adjusted to 20-30 wt% and the sodium cyanide concentration to 0.50%-0.70%. The leaching time is 20-25 hours.

5. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to claim 1, characterized in that, In step (3), during the grinding of the flotation tailings, the pulp concentration is adjusted to 50-60 wt%, hydrogen peroxide is added at 1-2 kg / t, sodium cyanide is added at 5.0-7.0 kg / t, the fineness after grinding is -0.037 mm accounting for 95%, the pulp concentration is adjusted to 20-30 wt%, the sodium cyanide concentration is 0.30%-0.50%, and the leaching time is 20-25 hours.

6. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to claim 1, characterized in that, In step (4), the mass ratio of the flotation tailings leaching residue to the sulfur-containing gold concentrate is 1:0.8-1; the oxidative roasting temperature is 600-650℃, and the roasting time is 30-60 minutes; the acid leaching pulp concentration is 35-40wt%, the sulfuric acid concentration is 1%-3%, the temperature is 70-80℃, and the time is 120-240 minutes; the acid leaching solution contains 3-10g / L of zinc and 1-3g / L of sodium hydrosulfide is added.

7. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to claim 1, characterized in that, In step (5), during the grinding of the acid leaching residue, the slurry concentration is adjusted to 50-60 wt%, the fineness is -0.037 mm accounting for 95%, and after grinding, the slurry concentration is adjusted to 35-40 wt%. The pH is adjusted to 10-11 with sodium hydroxide, 1-3 kg / t of ammonium bicarbonate is added, and the sodium cyanide concentration is 0.30%-0.50%. Gold and silver are recovered by secondary leaching and secondary pressure filtration. The leaching tailings are recovered by high-temperature reduction roasting.

8. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to any one of claims 1-7, characterized in that, In steps (2), (3) and (5), the gold and silver leaching solutions contain gold and silver, and the zinc powder replacement-gold mud smelting process is used to recover gold and silver.

9. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to any one of claims 1-7, characterized in that, The sulfur-containing gold concentrate described in step (4) contains 30% to 40% sulfur.

10. The method for comprehensive recovery of valuable elements from lead-zinc-gold-silver concentrates according to any one of claims 1-7, characterized in that, In step (5), the final tailings are processed using a high-temperature reduction roasting process to recover iron concentrate.