A system for efficiently recovering valuable components from low-iron sulfur-containing gold-silver flotation tailings

Abstract

The utility model relates to a kind of from low iron sulfur gold-bearing silver flotation tailings high-efficiency recovery valuable component's system, including hydraulic cyclone sorting machine A, hydraulic cyclone sorting machine A overflow and sand trap mouth are connected in thickener and ball mill feed inlet respectively, thickener underflow mouth is connected in flotation system A feed inlet, ball mill discharge port is connected in hydraulic cyclone sorting machine B feed inlet by 2# pump pool and 2# slurry pump;Flotation system A concentrate mouth and hydraulic cyclone sorting machine B overflow are connected in flotation system B feed inlet;Flotation system B tailings mouth is connected in pulse high gradient high-intensity magnetic separation system;Flotation system B concentrate mouth and pulse high gradient high-intensity magnetic separation system concentrate mouth are connected in fine particle roasting fluidized bed furnace feed inlet, fine particle roasting fluidized bed furnace discharge port is sequentially connected with carbon-in-pulp system and smelting system, and fine particle roasting fluidized bed furnace gas outlet is connected in acid-making system.The closed-loop process system realizes the comprehensive, efficient, green, tailless utilization of low iron sulfur gold-bearing silver flotation tailings.

Description

Technical Field

[0001] This invention belongs to the field of metallurgical and low-grade flotation tailings recovery technology, specifically relating to a system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings. Background Technology

[0002] Gold mineral resources are non-renewable. With the depletion of easily mined resources, the secondary utilization of tailings has become an essential path for the sustainable development of the mining industry. Gold tailings in my country generally contain Au 0.4–0.8 g / t, Ag 6–10 g / t, Fe 15–20%, and S 1–3%. Gold is mostly found as intercalated or encapsulated gold, while iron coexists with magnetite, limonite, and siderite. Sulfur is found in sulfide ores and sulfates, resulting in a "poor, fine, and complex" composition. Existing gold recovery methods mainly include gravity separation, flotation, amalgamation, cyanidation, and other leaching methods. Gravity separation is mainly used to recover coarse-grained gold, but for complexly embedded gold ores, the grade and recovery rate of the gold concentrate are low. Flotation can only recover individual fine-grained gold or gold along with intercalated carrier minerals. Amalgamation causes significant environmental pollution and has been phased out. Cyanidation and other leaching methods have high extraction costs and are difficult to recover gold that is encapsulated or affected by many interfering factors. Due to the limitations of the aforementioned recovery methods and the complexity of their application scenarios, any single recovery method has certain limitations. Therefore, how to recover valuable components from gold-bearing flotation tailings and maximize the extraction of valuable metals remains a challenging problem in the gold production field.

[0003] In response, those skilled in the art have conducted extensive research, and there are already reports on the research literature on the recovery of gold from flotation tailings, such as S1: Hu Shanyou et al. Experimental study and practice of flotation process of tailings of a gold mine [J]. Gold, 2004, 25(12): 42-44. This article records the use of sodium carbonate as pH adjuster and copper sulfate as activator to recover gold by single flotation method, and the gold recovery rate of the obtained gold concentrate is 69%. S2: Wang Gaichao et al. Production practice of recovering gold from flotation tailings [J]. Gold, 2004, 25(9): 41-42. This article records the use of sluice-shaking table for pre-enrichment, followed by grinding-mercuration treatment to further recover some gold, which causes serious environmental pollution. S3:CN104841565A describes a method for recovering gold from gold flotation tailings. This process involves grinding the gold flotation tailings, adding lime to adjust the pH, and then adding emulsifiers, flocculants, collectors, and frothers to adjust the slurry before flotation. The resulting gold concentrate has a gold recovery rate of 70%. However, this process requires fine grinding of all tailings and involves a large variety of reagents and high reagent consumption, leading to high production costs. Furthermore, the technical solutions described in the aforementioned literature only recover a single element and lack economic and environmental benefits for recovering gold and silver from flotation tailings with dispersed, complex, and frequently interfering deposits.

[0004] To overcome the shortcomings or defects of existing technologies, this invention provides a green process system for efficiently recovering valuable components such as gold, silver, iron, and sulfur from low-iron and sulfur-containing gold and silver flotation tailings and simultaneously preparing building materials. Utility Model Content

[0005] This invention provides a system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings. Based on the material characteristics, the system innovatively adopts a technical route of "classified tiered recovery and cross-coordination" to comprehensively and efficiently recover valuable components such as gold, silver, sulfur, and iron from low-iron, sulfur-containing gold and silver flotation tailings, ultimately obtaining gold ingots, silver ingots, sulfuric acid, high-quality iron concentrate, and tailings that can be directly used as building materials.

[0006] The specific technical solution is as follows: A system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings includes a hydrocyclone separator A. The overflow port and sand outlet of the hydrocyclone separator A are respectively connected to the feed inlets of a thickener and a ball mill. The underflow port of the thickener is connected to the feed inlet of flotation system A. The discharge port of the ball mill is connected to the feed inlet of hydrocyclone separator B via a No. 2 pump tank and a No. 2 slurry pump. The concentrate outlet of flotation system A and the overflow port of hydrocyclone separator B are both connected to the feed inlet of flotation system B. The tailings outlet of flotation system B is connected to a pulsed high-gradient magnetic separation system. The concentrate outlet of flotation system B and the concentrate outlet of the pulsed high-gradient magnetic separation system are both connected to the feed inlet of a fine-particle roasting fluidized bed furnace. The discharge port of the fine-particle roasting fluidized bed furnace is sequentially connected to a carbon leaching system and a smelting system. The gas outlet of the fine-particle roasting fluidized bed furnace is connected to an acid production system.

[0007] Furthermore, preferably, the front end of the feed inlet of the hydrocyclone separator A is connected to a mixing tank via a No. 1 pump pool and a No. 1 slurry pump for adjusting the slurry of the material to be processed.

[0008] Furthermore, preferably, both flotation system A and flotation system B include a mixing tank, two scavenging machines, and two cleaning machines connected in sequence.

[0009] Furthermore, preferably, the pulse high gradient magnetic separation system includes two pulse high gradient magnetic separators connected in series.

[0010] Furthermore, preferably, the carbon immersion system includes a washing tank, a pump pool, a transfer pump, multiple carbon immersion tanks connected in series, and a filter machine.

[0011] Furthermore, preferably, the settling port of the hydrocyclone separator B is connected to the feed port of the ball mill to form a closed-loop grinding and classification system.

[0012] The beneficial effects of this utility model are as follows: This utility model achieves comprehensive and efficient recovery of gold, silver, iron, and sulfur from low-iron and sulfur-containing gold and silver flotation tailings and the reuse of tailings through a closed-loop process system of classification and sorting, acid activation flotation, mixed magnetic separation, mixed roasting, and water washing and carbon leaching. The gold recovery rate is ≥80%, silver ≥75%, iron concentrate grade ≥60% and recovery rate ≥75%, sulfur recovery rate ≥85%, and sulfur content in tailings ≤0.15%. It has a high comprehensive utilization rate of resources and significant economic and environmental benefits. It solves the pain points of traditional processes such as single recovery components, low recovery rate, high reagent consumption, and inability to reuse tailings. It has demonstration and promotion value for the green transformation of the gold industry.

[0013] (1) The material to be treated is first classified by a primary cyclone classification, which can effectively separate the fine-grained gold-silver-pyrite minerals and coarse-grained intergrown oxide minerals in the tailings. Then, combined with the corresponding "acid flotation system", the iron hydroxide colloid on the surface of the gold-silver-pyrite minerals is dissolved to fully expose them and improve the flotation recovery rate. For the coarse-grained intergrown oxide minerals, a secondary grinding classification is carried out to further separate them into individual minerals.

[0014] (2) The gold and silver sulfur concentrate obtained by acid flotation is mixed with the overflow of heavy sand classification and secondary flotation. This can make full use of the heterogeneous aggregation-collision-adhesion between coarse pyrite and fine gold, so that the fine particles can float with the help of coarse sulfur, thereby further improving the recovery rate. At the same time, water glass can disperse silicate mud, reduce flocculation, ensure foam cleanliness, improve product quality and reduce the amount of flotation reagents used.

[0015] (3) By using a pulsed high gradient magnetic separation system to perform two-stage mixed magnetic separation on the tailings of the secondary flotation, fine-grained limonite, siderite and associated gold and silver in iron oxides can be fully captured, thereby improving the recovery rate of iron and gold and silver.

[0016] (4) The intermediate products, gold-silver sulfur concentrate and gold-silver iron concentrate, are cleverly mixed and roasted in a reasonable ratio. The sulfur in the raw materials serves as a self-heating fuel, which can provide a heat source for roasting and be oxidized into SO2 in time for use by the acid production system. Moreover, this roasting process can convert limonite and siderite in the iron concentrate into Fe2O3 / Fe3O4, thereby improving the iron grade; and make the roasting slag form a honeycomb pore structure, which provides a larger specific surface area for subsequent gold leaching and promotes the improvement of the leaching rate. Attached Figure Description

[0017] Figure 1 This is a diagram illustrating the equipment for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings according to this utility model. In the diagram: 1-Agitator, 2-Pump pool #1, 3-Pulse pump #1, 4-Hydrocyclone separator A, 5-Thickener, 6-Flotation system A, 7-Ball mill, 8-Pump pool #2, 9-Pulse pump #2, 10-Hydrocyclone classifier B, 11-Flotation system B, 12-Pulse high gradient magnetic separation system, 13-Fine particle roasting fluidized bed furnace, 14-Carbon leaching system, 15-Smelting system, 16-Acid production system. Detailed Implementation

[0018] To make the technical problems and solutions solved by this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining the present utility model and are not intended to limit the present utility model.

[0019] In the description of this utility model, it should be understood that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0020] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," and "connect" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0021] like Figure 1As shown in the figure, this embodiment provides a system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings. The system includes a mixing tank 1 for preparing the material to be processed into a slurry. The outlet of the mixing tank 1 is connected to the inlet of a hydrocyclone separator A4 via a No. 1 pump tank 2 and a No. 1 slurry pump 3. The overflow and underflow outlets of the hydrocyclone separator A4 are connected to the inlets of a thickener 5 and a ball mill 7, respectively. The underflow outlet of the thickener 5 is connected to the inlet of the flotation system A6. The outlet of the ball mill 7 is connected to the flotation system A6 via a No. 2 pump tank 8 and a No. 2 slurry pump 9. The feed inlet of hydrocyclone separator B10; the concentrate outlet of flotation system A6 and the overflow outlet of hydrocyclone separator B10 are both connected to the feed inlet of flotation system B11; the tailings outlet of flotation system B11 is connected to pulse high gradient strong magnetic separation system 12; the concentrate outlet of flotation system B11 and the concentrate outlet of pulse high gradient strong magnetic separation system 12 are both connected to the feed inlet of fine particle roasting fluidized bed furnace 13; the discharge outlet of fine particle roasting fluidized bed furnace 13 is sequentially connected to carbon leaching system 14 and smelting system 15; the gas outlet of fine particle roasting fluidized bed furnace 13 is connected to acid production system 16.

[0022] The aforementioned flotation system A6 and flotation system B11 each include a slurry conditioning tank, two scavengers and two cleaners connected in sequence, used for slurry conditioning and scavenging and cleaning of flotation feed, respectively; the aforementioned pulse high gradient magnetic separation system 12 includes two pulse high gradient magnetic separators connected in series, used for scavenging and cleaning, respectively; the carbon leaching system 14 includes a washing tank, a pump pool, a transfer pump, multiple carbon leaching tanks connected in series and a filter, used for washing, filtering, cyanide leaching and gold-loaded carbon slurry filtration of roasted slag, respectively.

[0023] In addition, the sand settling port of the aforementioned hydrocyclone separator B10 is connected to the feed port of the ball mill 7. The ball mill 7, the No. 2 pump tank 8, the No. 2 slurry pump 9, and the hydrocyclone separator B10 together constitute a closed-loop grinding and classification system for continuous grinding and classification of heavy sand.

[0024] It should be noted that the above-mentioned equipment is all existing equipment, and the equipment is generally connected by pipes or belts, which is a conventional method in this field and will not be elaborated on here.

[0025] The specific working principle of the above system for recovering gold and silver flotation tailings containing low iron and sulfur is as follows: (1) Selective separation of materials to be processed: The materials to be processed are transported to the mixing tank 1, and the slurry is adjusted to a concentration of 40%~45%. Then, it is transported to the hydrocyclone separator A4 through the No. 1 pump tank 2 and the No. 1 slurry pump 3 for separation. The feed pressure is controlled at 0.035~0.15MPa to obtain light overflow and heavy sand with -0.037mm accounting for 70%~80%. The light overflow flow rate is controlled to be 40%~60% of the total feed.

[0026] (2) Light overflow acid activation and flotation, as detailed below: A1: The light overflow obtained in step (1) is sent to thickener 5 and concentrated into a concentrated slurry of 60%~65%; A2: Transfer the concentrated slurry to the mixing tank of flotation system A6, add sulfuric acid, adjust the pH to 2-3, stir for 5-10 minutes, then add dilution water to adjust the slurry concentration to 25%-30% and the pH to 6-6.5; A3: Transfer the slurry from step A2 into flotation system A6 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate I and tailings I; (3) Heavy sand grinding and classification: The heavy sand from step (1) is transported to ball mill 7, and after grinding, it is transported to hydrocyclone separator B10 via pump pool 8 and slurry pump 9 for classification, to obtain a classification overflow with -0.043mm accounting for 80%~85% and concentration of 30%~35%; (4) Carrier mixing flotation: The overflow from step (3) and the gold-silver-sulfur concentrate I from step A3 are both transferred to flotation system B11 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate II and tailings II. (5) Strong / weak magnetite mixed magnetic separation: The tailings II from step (4) are transferred to a pulse high gradient magnetic separation system for one roughing and one cleaning to obtain gold-silver-iron concentrate (including magnetite, limonite and siderite) and tailings III; tailings III and tailings I from step (2) are combined into total tailings, which can be directly used as building materials. (6) Mixed roasting: The gold and silver sulfur concentrate II from step (4) and the gold and silver iron concentrate from step (5) are transported to the fine-grained roasting fluidized bed furnace 13 for roasting to obtain gold and silver roasting slag and sulfur dioxide, wherein the sulfur dioxide is transferred to the acid production system 16 to produce sulfuric acid. (7) Roasting slag water washing-carbon leaching: The gold and silver-containing roasting slag from step (6) is sequentially transferred to the washing tank and pump pool of the carbon leaching system 14. After water washing and filtration, the rinsed slag is transferred to the carbon leaching tank by the conveying pump for multiple leachings. The gold and silver are adsorbed by the activated carbon, and the iron concentrate remains in the leaching tank. (8) Gold and silver refining and casting: The gold and silver loaded activated carbon from step (7) is filtered by a filter and then transferred to the metallurgical system, where it undergoes conventional desorption-electrowinning-smelting-gold and silver separation-casting in sequence to obtain gold and silver ingots.

[0027] Application Example 1

[0028] Raw material #1: A low-iron, sulfur-containing gold and silver flotation tailings. The main valuable elements are Au, Ag, Fe, and S, with grades of 0.64 g / t, 7.8 g / t, 18.56%, and 1.98%, respectively. Gold in the tailings mainly exists in the form of intercalated and encapsulated gold, accounting for 89.68%. Iron mainly exists in the form of magnetite and limonite, accounting for 88.78%, followed by siderite. Gangue minerals are mainly quartz sand and silicates.

[0029] like Figure 1 As shown, the specific steps for recovering raw ore #1 using the system described in this utility model are as follows: (1) Selective separation of materials to be processed: The materials to be processed are transported to the mixing tank 1, and the slurry is adjusted to a concentration of 40%~45%. Then, it is transported to the hydrocyclone separator A4 through the No. 1 pump tank 2 and the No. 1 slurry pump 3 for separation. The feed pressure is controlled at 0.035~0.15MPa to obtain light overflow and heavy sand with -0.037mm accounting for 70%~80%. The light overflow flow rate is controlled to be 40%~60% of the total feed.

[0030] (2) Recovery of gold, silver and sulfur from light overflow, as detailed below: A1: The light overflow obtained in step (1) is sent to thickener 5 and concentrated into a concentrated slurry of 60%~65%; A2: Transfer the concentrated slurry to the mixing tank of flotation system A6, add sulfuric acid, adjust the pH to 2-3, stir for 5-10 minutes, then add dilution water to adjust the slurry concentration to 25%-30% and the pH to 6-6.5; A3: Transfer the slurry from step A2 into flotation system A6 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate I and tailings I; wherein, 40g / t butyl xanthate and 25g / t pine oil are added to roughing process I, and 35g / t butyl xanthate and 10g / t pine oil are added to roughing process II.

[0031] (3) Heavy sand grinding and classification: The heavy sand from step (1) is fed to ball mill 7, and after grinding, it is fed to hydrocyclone separator B10 via pump pool 8 and slurry pump 9 for classification, to obtain a classification overflow with -0.043mm accounting for 80%~85% and a concentration of 30%~35%; wherein, the classification adopts φ250 hydrocyclone separator B10, and the classification concentration is 50%~55%; (4) Carrier mixing flotation: The overflow from step (3) and the gold-silver-sulfur concentrate I from step A3 are both transferred to flotation system B11 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate II and tailings II; wherein, 30 g / t of butyl xanthate and 10 g / t of pine oil are added to roughing process I, 15 g / t of butyl xanthate and 10 g / t of pine oil are added to roughing process II, and 350 g / t of water glass is added to cleaning process I. (5) Strong / weak magnetite mixed magnetic separation: The tailings II from step (4) are transferred to a pulse high gradient magnetic separation system for one roughing and one cleaning to obtain gold, silver and iron concentrate and tailings III; tailings III and tailings I from step (2) are combined into total tailings, which can be directly used as building materials; the operating parameters of the pulse high gradient magnetic separator are: background magnetic field strength 750~900mT, magnetic medium diameter and working gap 2~4mm, pulse intensity 100~120 times / minute, stroke 15~20cm; (6) Mixed roasting: The gold and silver sulfur concentrate II from step (4) and the gold and silver iron concentrate from step (5) are mixed according to the theoretical sulfur content of 28%~35% for roasting feed. After mixing, the mixture is sent to the fine-particle roasting fluidized bed furnace 13 for roasting. The roasting temperature is controlled at 600~650℃. After roasting, gold and silver roasting slag and sulfur dioxide are obtained. The sulfur dioxide is transferred to the acid production system 16 to produce sulfuric acid. (7) Roasting slag water washing-carbon leaching: The gold and silver-containing roasting slag from step (6) is sequentially transferred to the washing tank and pump pool of the carbon leaching system 14. After water washing and filtration, the rinsed slag is transferred to the carbon leaching tank by the conveying pump for multiple leachings. The gold and silver are adsorbed by the activated carbon, and the iron concentrate remains in the leaching tank. The total liquid-solid ratio in the water washing section is 3:1. In the carbon leaching section, the pH is controlled by lime at 10.5~11.5, the sodium cyanide concentration is controlled at 0.5‰~0.7‰, and the leaching concentration is 35%~45%.

[0032] (8) Gold and silver refining and casting: The gold and silver loaded activated carbon from step (7) is filtered by a filter and then transferred to the metallurgical system, where it undergoes conventional desorption-electrowinning-smelting-gold and silver separation-casting in sequence to obtain gold and silver ingots.

[0033] The test results were as follows: gold recovery rate was 81.35%; silver recovery rate was 78.73%; iron grade of iron concentrate was 61.59% and iron recovery rate was 76.19%; sulfur recovery rate was 85.52%; and the tailings contained 0.14% sulfur, making it suitable as a high-quality building material.

[0034] Application Example 2

[0035] Raw material #2: A low-iron, sulfur-containing gold and silver flotation tailings. The main valuable elements are Au, Ag, Fe, and S, with grades of 0.53 g / t, 8.55 g / t, 17.62%, and 2.15%, respectively. Gold in the tailings mainly exists in the form of intercalated and encapsulated gold, accounting for 88.58%. Iron mainly exists in the form of magnetite and limonite, accounting for 89.95%, followed by siderite. Gangue minerals are mainly quartz sand and silicates.

[0036] like Figure 1 As shown, the specific steps for recovering raw ore #2 using the system described in this utility model are as follows: (1) Selective separation of materials to be processed: The materials to be processed are transported to the mixing tank 1, and the slurry is adjusted to a concentration of 40%~45%. Then, it is transported to the hydrocyclone separator A4 through the No. 1 pump tank 2 and the No. 1 slurry pump 3 for separation. The feed pressure is controlled at 0.035~0.15MPa to obtain light overflow and heavy sand with -0.037mm accounting for 70%~80%. The light overflow flow rate is controlled to be 40%~60% of the total feed.

[0037] (2) Recovery of gold, silver and sulfur from light overflow, as detailed below: A1: The light overflow obtained in step (1) is sent to thickener 5 and concentrated into a concentrated slurry of 60%~65%; A2: Transfer the concentrated slurry to the mixing tank of flotation system A6, add sulfuric acid, adjust the pH to 2-3, stir for 5-10 minutes, then add dilution water to adjust the slurry concentration to 25%-30% and the pH to 6-6.5; A3: Transfer the slurry from step A2 into flotation system A6 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate I and tailings I; wherein, 55g / t butyl xanthate and 20g / t pine oil are added to roughing process I, and 30g / t butyl xanthate and 10g / t pine oil are added to roughing process II.

[0038] (3) Heavy sand grinding and classification: The heavy sand from step (1) is fed to ball mill 7, and after grinding, it is fed to hydrocyclone separator B10 via pump pool 8 and slurry pump 9 for classification, to obtain a classification overflow with -0.043mm accounting for 80%~85% and a concentration of 30%~35%; wherein, the classification adopts φ250 hydrocyclone separator B10, and the classification concentration is 50%~55%; (4) Carrier mixing flotation: The overflow from step (3) and the gold-silver-sulfur concentrate I from step A3 are both transferred to flotation system B11 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate II and tailings II; wherein, 40 g / t of butyl xanthate and 10 g / t of pine oil are added to roughing process I, 10 g / t of butyl xanthate and 10 g / t of pine oil are added to roughing process II, and 400 g / t of water glass is added to cleaning process I; (5) Strong / weak magnetite mixed magnetic separation: The tailings II from step (4) are transferred to a pulse high gradient magnetic separation system for one roughing and one cleaning to obtain gold, silver and iron concentrate and tailings III; tailings III and tailings I from step (2) are combined into total tailings, which can be directly used as building materials; the operating parameters of the pulse high gradient magnetic separator are: background magnetic field strength 750~900mT, magnetic medium diameter and working gap 2~4mm, pulse intensity 130~170 times / minute, stroke 15~20cm; (6) Mixed roasting: The gold and silver sulfur concentrate II from step (4) and the gold and silver iron concentrate from step (5) are mixed according to the theoretical sulfur content of 28%~35% for roasting feed. After mixing, the mixture is sent to the fine-particle roasting fluidized bed furnace 13 for roasting. The roasting temperature is controlled at 600~650℃. After roasting, gold and silver roasting slag and sulfur dioxide are obtained. The sulfur dioxide is transferred to the acid production system 16 to produce sulfuric acid. (7) Roasting slag water washing-carbon leaching: The gold and silver-containing roasting slag from step (6) is sequentially transferred to the washing tank and pump pool of the carbon leaching system 14. After water washing and filtration, the rinsed slag is transferred to the carbon leaching tank by the conveying pump for multiple leachings. The gold and silver are adsorbed by the activated carbon, and the iron concentrate remains in the leaching tank. The total liquid-solid ratio in the water washing section is 3:1. In the carbon leaching section, the pH is controlled by lime at 10.5~11.5, the sodium cyanide concentration is controlled at 0.5‰~0.7‰, and the leaching concentration is 35%~45%.

[0039] (8) Gold and silver refining and casting: The gold and silver loaded activated carbon from step (7) is filtered by a filter and then transferred to the metallurgical system, where it undergoes conventional desorption-electrowinning-smelting-gold and silver separation-casting in sequence to obtain gold and silver ingots.

[0040] The experimental results obtained are as follows: gold recovery rate is 80.07%; silver recovery rate is 79.62%; iron grade of iron concentrate is 61.17% and iron recovery rate is 77.84%; sulfur recovery rate is 86.13%; and the tailings contain 0.15% sulfur, which can be used as high-quality building material.

[0041] Application Example 3

[0042] Raw material #3: A low-iron, sulfur-containing gold and silver flotation tailings. The main valuable elements are Au, Ag, Fe, and S, with grades of 0.72 g / t, 6.94 g / t, 17.85%, and 1.59%, respectively. Gold in the tailings mainly exists in the form of intercalated and encapsulated gold, accounting for 88.43%. Iron mainly exists in the form of magnetite and limonite, accounting for 88.15%, followed by siderite. Gangue minerals are mainly quartz sand and silicates.

[0043] like Figure 1 As shown, the specific steps for recovering raw ore #3 using the system described in this utility model are as follows: (1) Selective separation of materials to be processed: The materials to be processed are transported to the mixing tank 1, and the slurry is adjusted to a concentration of 40%~45%. Then, it is transported to the hydrocyclone separator A4 through the No. 1 pump tank 2 and the No. 1 slurry pump 3 for separation. The feed pressure is controlled at 0.035~0.15MPa to obtain light overflow and heavy sand with -0.037mm accounting for 70%~80%. The light overflow flow rate is controlled to be 40%~60% of the total feed.

[0044] (2) Recovery of gold, silver and sulfur from light overflow, as detailed below: A1: The light overflow obtained in step (1) is sent to thickener 5 and concentrated into a concentrated slurry of 60%~65%; A2: Transfer the concentrated slurry to the mixing tank of flotation system A6, add sulfuric acid, adjust the pH to 2-3, stir for 5-10 minutes, then add dilution water to adjust the slurry concentration to 25%-30% and the pH to 6-6.5; A3: Transfer the slurry from step A2 into flotation system A6 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate I and tailings I; wherein, 80g / t butyl xanthate and 20g / t pine oil are added to roughing process I, and 20g / t butyl xanthate and 10g / t pine oil are added to roughing process II.

[0045] (3) Heavy sand grinding and classification: The heavy sand from step (1) is fed to ball mill 7, and after grinding, it is fed to hydrocyclone separator B10 via pump pool 8 and slurry pump 9 for classification, to obtain a classification overflow with -0.043mm accounting for 80%~85% and a concentration of 30%~35%; wherein, the classification adopts φ250 hydrocyclone separator B10, and the classification concentration is 50%~55%; (4) Carrier mixing flotation: The overflow from step (3) and the gold-silver-sulfur concentrate I from step A3 are both transferred to flotation system B11 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate II and tailings II; wherein, butyl xanthate 25g / t and pine oil 15g / t are added in roughing process I, butyl xanthate 20g / t and pine oil 10g / t are added in roughing process II, and water glass 300g / t is added in cleaning process I; (5) Strong / weak magnetite mixed magnetic separation: The tailings II from step (4) are transferred to a pulse high gradient magnetic separation system for one roughing and one cleaning to obtain gold, silver and iron concentrate and tailings III; tailings III and tailings I from step (2) are combined into total tailings, which can be directly used as building materials; the operating parameters of the pulse high gradient magnetic separator are: background magnetic field strength 750~900mT, magnetic medium diameter and working gap 2~4mm, pulse intensity 180~200 times / minute, stroke 15~20cm; (6) Mixed roasting: The gold and silver sulfur concentrate II from step (4) and the gold and silver iron concentrate from step (5) are mixed according to the theoretical sulfur content of 28%~35% for roasting feed. After mixing, the mixture is sent to the fine-particle roasting fluidized bed furnace 13 for roasting. The roasting temperature is controlled at 600~650℃. After roasting, gold and silver roasting slag and sulfur dioxide are obtained. The sulfur dioxide is transferred to the acid production system 16 to produce sulfuric acid. (7) Roasting slag water washing-carbon leaching: The gold and silver-containing roasting slag from step (6) is sequentially transferred to the washing tank and pump pool of the carbon leaching system 14. After water washing and filtration, the rinsed slag is transferred to the carbon leaching tank by the conveying pump for multiple leachings. The gold and silver are adsorbed by the activated carbon, and the iron concentrate remains in the leaching tank. The total liquid-solid ratio in the water washing section is 3:1. In the carbon leaching section, the pH is controlled by lime at 10.5~11.5, the sodium cyanide concentration is controlled at 0.5‰~0.7‰, and the leaching concentration is 35%~45%.

[0046] (8) Gold and silver refining and casting: The gold and silver loaded activated carbon from step (7) is filtered by a filter and then transferred to the metallurgical system, where it undergoes conventional desorption-electrowinning-smelting-gold and silver separation-casting in sequence to obtain gold and silver ingots.

[0047] The test results obtained are as follows: gold recovery rate is 82.16%; silver recovery rate is 77.06%; iron grade of iron concentrate is 60.84% ​​and iron recovery rate is 78.51%; sulfur recovery rate is 87.47%; and the tailings contain 0.13% sulfur, which can be used as high-quality building material.

[0048] Application Example 4

[0049] Raw material #4: A low-iron, sulfur-containing gold and silver flotation tailings. The main valuable elements are Au, Ag, Fe, and S, with grades of 0.49 g / t, 8.06 g / t, 16.47%, and 1.83%, respectively. Gold in the tailings mainly exists in the form of intercalated and encapsulated gold, accounting for 89.11%. Iron mainly exists in the form of magnetite and limonite, accounting for 89.55%, followed by siderite. Gangue minerals are mainly quartz sand and silicates.

[0050] like Figure 1 As shown, the system described in this utility model is used to recover raw ore #4. The specific steps are as follows: (1) Selective separation of materials to be processed: The materials to be processed are transported to the mixing tank 1, and the slurry is adjusted to a concentration of 40%~45%. Then, it is transported to the hydrocyclone separator A4 through the No. 1 pump tank 2 and the No. 1 slurry pump 3 for separation. The feed pressure is controlled at 0.035~0.15MPa to obtain light overflow and heavy sand with -0.037mm accounting for 70%~80%. The light overflow flow rate is controlled to be 40%~60% of the total feed.

[0051] (2) Recovery of gold, silver and sulfur from light overflow, as detailed below: A1: The light overflow obtained in step (1) is sent to thickener 5 and concentrated into a concentrated slurry of 60%~65%; A2: Transfer the concentrated slurry to the mixing tank of flotation system A6, add sulfuric acid, adjust the pH to 2-3, stir for 5-10 minutes, then add dilution water to adjust the slurry concentration to 25%-30% and the pH to 6-6.5; A3: Transfer the slurry from step A2 into flotation system A6 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate I and tailings I; wherein, 65g / t butyl xanthate and 30g / t pine oil are added to roughing process I, and 40g / t butyl xanthate and 10g / t pine oil are added to roughing process II.

[0052] (3) Heavy sand grinding and classification: The heavy sand from step (1) is fed to ball mill 7, and after grinding, it is fed to hydrocyclone separator B10 via pump pool 8 and slurry pump 9 for classification, to obtain a classification overflow with -0.043mm accounting for 80%~85% and a concentration of 30%~35%; wherein, the classification adopts φ250 hydrocyclone separator B10, and the classification concentration is 50%~55%; (4) Carrier mixing flotation: The overflow from step (3) and the gold-silver-sulfur concentrate I from step A3 are both transferred to flotation system B11 for two roughing and two cleaning processes to obtain gold-silver-sulfur concentrate II and tailings II; wherein, butyl xanthate 20g / t and pine oil 20g / t are added in roughing process I, butyl xanthate 30g / t and pine oil 10g / t are added in roughing process II, and water glass 500g / t is added in cleaning process I; (5) Strong / weak magnetite mixed magnetic separation: The tailings II from step (4) are transferred to a pulse high gradient magnetic separation system for one roughing and one cleaning to obtain gold, silver and iron concentrate and tailings III; tailings III and tailings I from step (2) are combined into total tailings, which can be directly used as building materials; the operating parameters of the pulse high gradient magnetic separator are: background magnetic field strength 750~900mT, magnetic medium diameter and working gap 2~4mm, pulse intensity 150~180 times / minute, stroke 15~20cm; (6) Mixed roasting: The gold and silver sulfur concentrate II from step (4) and the gold and silver iron concentrate from step (5) are mixed according to the theoretical sulfur content of 28%~35% for roasting feed. After mixing, the mixture is sent to the fine-particle roasting fluidized bed furnace 13 for roasting. The roasting temperature is controlled at 600~650℃. After roasting, gold and silver roasting slag and sulfur dioxide are obtained. The sulfur dioxide is transferred to the acid production system 16 to produce sulfuric acid. (7) Roasting slag water washing-carbon leaching: The gold and silver-containing roasting slag from step (6) is sequentially transferred to the washing tank and pump pool of the carbon leaching system 14. After water washing and filtration, the rinsed slag is transferred to the carbon leaching tank by the conveying pump for multiple leachings. The gold and silver are adsorbed by the activated carbon, and the iron concentrate remains in the leaching tank. The total liquid-solid ratio in the water washing section is 3:1. In the carbon leaching section, the pH is controlled by lime at 10.5~11.5, the sodium cyanide concentration is controlled at 0.5‰~0.7‰, and the leaching concentration is 35%~45%.

[0053] (8) Gold and silver refining and casting: The gold and silver loaded activated carbon from step (7) is filtered by a filter and then transferred to the metallurgical system, where it undergoes conventional desorption-electrowinning-smelting-gold and silver separation-casting in sequence to obtain gold and silver ingots.

[0054] The experimental results obtained are as follows: gold recovery rate is 80.45%; silver recovery rate is 76.81%; iron grade of iron concentrate is 60.19% and iron recovery rate is 75.93%; sulfur recovery rate is 85.83%; and the tailings contain 0.15% sulfur and can be used as high-quality building materials.

[0055] In summary, the method described in this invention for treating this type of low-iron, sulfur-containing gold and silver flotation tailings can achieve a gold recovery rate of over 80%; a silver recovery rate of over 75%; an iron grade of over 60% and an iron recovery rate of over 75% in the iron concentrate; a sulfur recovery rate of over 85%; and a sulfur content of less than 0.15% in the tailings, meeting the standards for building sand and allowing for direct use as building materials, thus achieving zero tailings discharge.

[0056] The recycling effects of the system described in this utility model and the three solutions (S1, S2, S3) in the background technology are compared as follows:

[0057] It is evident that the system described in this utility model not only significantly outperforms other existing technologies in terms of gold recovery rate, but also simultaneously achieves comprehensive recovery of silver, iron, and sulfur, resulting in remarkable comprehensive resource utilization.

[0058] The present invention has been described in detail above through specific and preferred embodiments. However, those skilled in the art should understand that the present invention is not limited to the embodiments described above. Any modifications or equivalent substitutions made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings, characterized in that: The system includes a hydrocyclone separator A (4), whose overflow port and sand outlet are connected to the feed inlets of a thickener (5) and a ball mill (7), respectively. The underflow port of the thickener (5) is connected to the feed inlet of flotation system A (6). The discharge port of the ball mill (7) is connected to the feed inlet of hydrocyclone separator B (10) via a No. 2 pump tank (8) and a No. 2 slurry pump (9). The concentrate outlet of flotation system A (6) and the overflow port of hydrocyclone separator B (10) are both connected to... The feed inlet of flotation system B (11) is connected to the tailings outlet of flotation system B (11) and to pulse high gradient strong magnetic separation system (12). The concentrate outlet of flotation system B (11) and the concentrate outlet of pulse high gradient strong magnetic separation system (12) are both connected to the feed inlet of fine particle roasting fluidized bed furnace (13). The discharge outlet of fine particle roasting fluidized bed furnace (13) is connected to carbon leaching system (14) and smelting system (15) in sequence. The gas outlet of fine particle roasting fluidized bed furnace (13) is connected to acid production system (16).

2. The system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings according to claim 1, characterized in that: The front end of the feed inlet of the hydrocyclone separator A (4) is connected to a mixing tank (1) via a No. 1 pump tank (2) and a No. 1 slurry pump (3) for adjusting the slurry of the material to be processed.

3. A system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings according to claim 1 or 2, characterized in that: Both flotation system A (6) and flotation system B (11) include a mixing tank, two scavengers and two cleaners connected in sequence.

4. The system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings according to claim 3, characterized in that: The pulse high gradient magnetic separation system (12) includes two pulse high gradient magnetic separators connected in series.

5. A system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings according to claim 1 or 4, characterized in that: The carbon immersion system (14) includes a washing tank, a pump pool, a transfer pump, multiple carbon immersion tanks connected in series, and a filter machine.

6. The system for efficiently recovering valuable components from low-iron, sulfur-containing gold and silver flotation tailings according to claim 1, characterized in that: The settling port of the hydrocyclone separator B (10) is connected to the feed port of the ball mill (7) to form a closed-loop grinding and classification system.

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