A process for bulk re-concentration of polymetallic mine tailings

Abstract

The present application belongs to the field of tailings re-election resource comprehensive utilization, and particularly relates to a multi-metal ore tailings centralized re-election process. The process comprises the following steps: step S10: treating various tailings; step S20: adding various efficient collector combinations and depressor combinations, and then pouring the ore slurry into a stirring barrel; step S30: a micro-bubble generating device is installed at the bottom of the stirring barrel, and a large number of micro-bubbles are formed after stirring and slurry mixing; step S40: the micro-bubbles float to the top of the stirring barrel to form a foam layer, a scraper is arranged at the top of the stirring barrel to scrape the foam layer, and first rough selection is performed to obtain rough selected ore one and tailings one; step S50: the tailings one is subjected to second rough selection to obtain tailings two and rough selected ore two, and the tailings two is subjected to fine selection to obtain tailings three and rough selected ore three; the obtained rough selected ore one, rough selected ore two and rough selected ore three are poured into a flotation machine for sweeping selection to obtain a concentrate. The present application solves the problem of recycling fine and difficult-to-recycle minerals.

Description

Technical Field

[0001] This invention belongs to the field of comprehensive utilization of tailings reprocessing resources, and specifically relates to a centralized reprocessing technology for polymetallic mine tailings. Background Technology

[0002] Polymetallic ores exhibit varying hardness among their minerals, resulting in fine and uneven particle size distribution. Fine grinding is essential to obtain high-grade concentrates, leading to complex beneficiation processes, often involving staged grinding and separation, and generating various tailings. Despite staged grinding, most component minerals in the metallic ore exhibit significant selective grinding. Due to past limitations in mining equipment and high beneficiation costs, a large amount of valuable metals in the tailings could not be recovered. With advancements in beneficiation technology, soaring metal prices, and increasingly depleted mineral resources, comprehensive tailings recycling has become urgent to avoid significant resource waste. Particle size analysis and testing of tailings indicate that valuable metal losses are primarily concentrated in ultrafine materials below -400 mesh. Therefore, a technologically advanced and cost-effective microbubble mineralization beneficiation technology has been developed to further recover refractory metallic minerals from these tailings. This is crucial for improving enterprise economic efficiency, increasing mineral resource utilization, and promoting the sustainable development of mineral resources.

[0003] Currently, a pre-enrichment method for gold in low-grade gold-bearing sulfide tailings, patent number CN109046745B, is available on the market. This method includes the following steps: (1) grinding the raw ore, followed by mixed flotation and tailings removal to obtain a mixed concentrate; (2) adding inhibitors to the mixed concentrate to inhibit the separation of arsenopyrite and flotation to obtain gold-bearing arsenopyrite; (3) further re-selecting the gold-bearing arsenopyrite using a combined flotation-gravity separation process to obtain a gold-arsenic concentrate, thus achieving pre-enrichment of gold and facilitating subsequent gold extraction. The raw material used in this invention is sulfide tailings from non-ferrous metal mines. The proposed method offers stable processing results and a simple process flow.

[0004] However, there is also a problem: most metallic minerals are brittle and easily broken. They are easily ground into mud when the grinding speed is fast, and over-ground minerals are difficult to recover in subsequent flotation processes and are lost with the tailings. Summary of the Invention

[0005] This solution provides a centralized reprocessing technology for polymetallic mine tailings to address the problem of recovering fine and difficult-to-recover minerals.

[0006] To achieve the above objectives, this solution provides a centralized reprocessing technology for polymetallic ore tailings, comprising the following steps:

[0007] Step S10: Collectively process various types of tailings;

[0008] Step S20: After adding various high-efficiency collector combinations and inhibitor combinations, pour the slurry into the mixing tank;

[0009] Step S30: A microbubble generator is installed at the bottom of the mixing tank, which generates a large number of microbubbles after stirring and slurry preparation;

[0010] Step S40: Microbubbles float to the top of the mixing tank to form a foam layer. A scraper is installed at the top of the mixing tank to scrape off the foam layer for the first roughing process, resulting in rougher ore one and tailings one.

[0011] Step S50: Tailings 1 is roughed again to obtain Tailings 2 and rougher ore 2. Tailings 2 is cleaned to obtain Tailings 3 and rougher ore 3. The obtained rougher ore 1, rougher ore 2 and rougher ore 3 are poured into a flotation machine for scavenging to obtain concentrate.

[0012] The principle of this scheme is as follows: First, the raw metal ore is crushed and then ground in a grinding mill until the fineness of the ore powder is less than 200 mesh and the content is 80.3%. In the roughing operation, the mineral is first added to a mixing tank. A microbubble generator is installed at the bottom of the mixing tank. Then, various combinations of high-efficiency collectors and inhibitors are added to the mixing tank. After stirring and adjusting the slurry, a large number of microbubbles are formed. The rougher ore and tailings 1 are obtained through a scraper. Tailings 1 undergoes further roughing to obtain tailings 2 and rougher ore 2. Tailings 2 undergoes further cleaning to obtain tailings 3 and rougher ore 3. The obtained rougher ore 1, rougher ore 2, and rougher ore 3 are then poured into a flotation machine for scavenging to obtain the concentrate.

[0013] The beneficial effects of this method are as follows: 1. Microbubbles have the following characteristics: small and dense bubble diameter, large carrying capacity, fast floating speed, and short movement distance, which can effectively cause fine mineral particles to adhere and float. In addition, the sufficient contact between the reagent and the mineral effectively shortens the mineralization time and improves the floatability differences among minerals. Forced mineralization slurry conditioning solves the problems of poor foaming effect and small floatability differences in concentrated tailings re-selection. 2. This method has good recovery effect on ultrafine materials with valuable metals below -400 mesh. 3. It concentrates and processes the tailings discarded from stage grinding and stage separation together, resulting in high efficiency.

[0014] Furthermore, the inhibitor combination in step S20 consists of cyanide and sulfonated lignin. The cyanide forms a hydrophilic film on the surface of the mineral particles, thereby achieving the purpose of inhibition.

[0015] Furthermore, the collector combination in step S20 consists of xanthate and a foaming agent. The foaming agent increases bubble generation and bubble strength. Xanthate can better separate hydrophilic and hydrophobic minerals, while the activator can enhance the hydrophobicity of the minerals.

[0016] Further, the microbubble generating device in step S10 includes a turbulence plate and a bubble generator. The turbulence plate is fixedly connected to the through pipe and is parallel to the flotation machine. The bubble generator includes an annular slide plate, a bottom plate, and an annular filter plate. The bottom plate is fixedly connected to the flotation machine, and the annular filter plate is fixedly connected to the bottom plate. The annular filter plate is coaxially arranged with the impeller and has filter holes and grooves. The annular slide plate is coaxially arranged with the annular filter plate and is slidably connected to the annular filter plate. The annular slide plate cooperates with the grooves. The operator pours the slurry into the inlet and starts the motor simultaneously. The motor drives the main shaft to rotate, which in turn drives the impeller to rotate. The impeller generates a rotational suction force that draws the slurry from the inlet pipe into the reaction tank. At the same time, air from the air inlet pipe is also drawn into the slurry in the reaction tank, generating bubbles of varying sizes. At this time, the rotation of the impeller will agitate the water flow, and the water flow will generate a centrifugal force that impacts the annular filter plate and the annular slide plate. Due to the L-shaped annular structure, the annular slide plate will be subjected to an upward force. The slide plate rises, the filter holes of the annular filter plate open, and the air bubbles pass through the filter holes, producing small air bubbles.

[0017] As the slurry passes through the filter plate, the impact force decreases, and the annular slide plate quickly falls, scraping away slag from the filter holes on the annular filter plate to prevent clogging. When the annular slide plate falls, the filter holes are blocked, and the centrifugal force of the water flow increases, causing the annular slide plate to rise again, repeating the cycle. Once a foam layer forms, it overflows from the reaction tank. The upper end of the reaction tank is connected to a foam overflow trough, and the foam layer flows into the foam overflow trough due to gravity and is then discharged from the discharge port. The tailings at the bottom are discharged from the tailings discharge port. This completes the flotation separation.

[0018] The bubble generator continuously produces qualified and stable bubbles, and the filter holes are repeatedly scraped by the annular slide plate, preventing clogging. Furthermore, compared to using a filter screen to generate small bubbles, this method utilizes the centrifugal force of the water flow to throw large bubbles to the surrounding areas, and then the bubble generator produces multiple small bubbles. This ensures that the small bubbles are not only generated in the center of the reaction tank but are distributed throughout the tank, thus enhancing the flotation effect.

[0019] Furthermore, the annular filter plate and the annular slider are provided with limiting blocks. The limiting blocks can prevent the annular slider from sliding out of the groove.

[0020] Furthermore, the annular slide plate is provided with a flow passage hole at its upper end. The flow passage hole is located at the upper end of the annular slide plate. When the annular slide plate is in the groove, the flow passage hole is blocked by the annular filter plate. When the annular slide plate floats up, the flow passage hole is not blocked. The flow passage hole allows water to flow through the annular slide plate, causing the floating annular slide plate to fall back down.

[0021] Furthermore, the turbulence plate is provided with holes. The holes in the turbulence plate help the bubble generator produce more small bubbles.

[0022] Furthermore, the flotation machine includes a reaction tank surrounded by an insulation chamber. The insulation chamber has an air inlet and an air outlet. The air inlet is connected to a pump, and the air outlet is connected to the reaction tank of the flotation machine. It also includes a one-way valve fixed at the connection between the air outlet and the reaction tank, connecting the insulation chamber to the reaction tank. When the pump starts, it introduces gas into the insulation chamber, which keeps the gas warm. The gas then enters the reaction tank through the air outlet. The one-way valve closes the channel between the reaction tank and the insulation chamber, preventing liquid in the reaction tank from flowing into the insulation chamber. This design uses continuous hot air to keep the liquid in the reaction tank warm, preventing freezing in low temperatures during winter and improving screening efficiency. Simultaneously, the one-way valve injects high-speed microbubbles into the reaction tank at certain pressures, effectively increasing the number of microbubbles and also blowing up the annular slide plate, accelerating its up-and-down movement and increasing bubble production. Attached Figure Description

[0023] Figure 1 This is a flow chart of a flotation process involving two roughing, one cleaning, and one scavenging flotation using the method of this invention.

[0024] Figure 2 This is a flow chart of a flotation process consisting of one roughing, one cleaning, and one scavenging stage using the method of this invention.

[0025] Figure 3 This is a frontal cross-sectional view of the microbubble generator inside the mixing tank.

[0026] Figure 4 This is a structural diagram of the microbubble generator's annular sliding plate falling.

[0027] Figure 5 This is a structural diagram of the rising annular sliding plate of a microbubble generator. Detailed Implementation

[0028] The markings in the accompanying drawings of the instruction manual include: 1. Motor; 2. Foam overflow tank; 3. Reaction tank; 4. Discharge port; 5. Main shaft; 6. Tailings discharge port; 7. Bottom plate; 8. Through pipe; 9. Air inlet pipe; 10. Liquid inlet pipe; 11. Turbulence plate; 12. Impeller; 13. Annular slide plate; 14. Filter hole; 15. Annular filter plate; 16. Flow hole; 17. Insulation cavity; 18. Check valve; 19. Air inlet.

[0029] The basic implementation examples are as follows: Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 As shown:

[0030] This solution provides a centralized reprocessing technology for polymetallic ore tailings. Workers collect and process various types of tailings, then add combinations of high-efficiency collectors and inhibitors, stir and adjust the slurry, and feed it into a mixing tank equipped with a microbubble generator at the bottom. After slurry adjustment, a large number of microbubbles are formed. These microbubbles have the following characteristics: small and dense bubble diameter, large carrying capacity, fast floating speed, and short travel distance, effectively adhering to and floating fine-grained minerals. Furthermore, the sufficient contact between the reagents and minerals effectively shortens the mineralization time and improves the difference in floatability among various minerals. Forced mineralization slurry adjustment solves the problems of poor foaming effect and small floatability differences in centralized tailings reprocessing. This method features a short process flow, simple equipment requirements, simple operation, low mineral processing cost, and a simple reagent system.

[0031] The first roughing process yields rougher ore 1 and tailings 1. Tailings 1 undergoes a second roughing process to yield tailings 2 and rougher ore 2. Tailings 2 is then further refined to yield tailings 3 and rougher ore 3. The resulting rougher ore 1, rougher ore 2, and rougher ore 3 are then fed into a flotation machine for scavenging to obtain concentrate.

[0032] This project innovatively installs a microbubble generator at the bottom of the mixing tank, including a motor 1, a foam overflow tank 2, a reaction tank 3, a discharge port 4, a main shaft 5, a tailings discharge port 6, a bottom plate 7, a connecting pipe 8, an air inlet pipe 9, a liquid inlet pipe 10, a turbulence plate 11, and an impeller 12. The motor 1 drives the main shaft 5 to rotate. The motor 1 and the main shaft 5 are fixedly connected via a coupling. The main shaft 5 is also fixedly connected to the impeller 12. The main shaft 5 is located inside the connecting pipe 8, which is connected to the air inlet pipe 9 and the liquid inlet pipe 10. A turbulence plate 11 is fixedly connected to the end of the connecting pipe 8. The turbulence plate 11 has holes for generating small bubbles and is parallel to the bottom plate 7. The air inlet pipe 9 allows external air to enter, and the liquid inlet pipe 10 allows slurry to enter. The connecting pipe 8 is connected to the reaction tank 3 to deliver gas and slurry into the reaction tank 3. The foam overflow tank 2 is fixedly connected to the reaction tank 3. The foam overflowing from the reaction tank 3 will flow into the foam overflow tank 2 due to gravity, and then flow out from the discharge port 4. The impeller 12 is used to stir the slurry and at the same time generate suction to draw air and slurry into the reaction tank 3 from the air inlet pipe 9 and the liquid inlet pipe 10.

[0033] The annular filter plate 15 is circular in shape, with a circular groove on the ring. The annular filter plate 15 has equidistantly distributed filter holes 14, which penetrate the annular filter plate 15. The upper end of the annular filter plate 15 does not have filter holes 14. The annular filter plate 15 is fixedly connected to the base plate 7. The annular slide plate 13 is generally circular in shape, but its upper end curves inward to form an arc. The annular slide plate 13 is slidably connected to the annular filter plate 15, and the annular slide plate 13 and the annular filter plate 15 are coaxially arranged. The size of the annular slide plate 13 is just right to be inserted into the groove of the annular filter hole 14, blocking the filter hole 14. The upper end of the annular slide plate 13 has a flow hole 16 for water flow. The flow hole 16 ensures that when the annular slide plate 13 floats due to water impact, the water flow can pass through the flow plate, causing the annular slide plate 13 to fall. The flow holes 16 of the annular slide plate 13 are blocked by the annular filter plate 15 when the annular slide plate 13 falls, and can only be exposed when it floats.

[0034] The operator pours the slurry into the inlet and simultaneously starts motor 1. Motor 1 drives the main shaft 5 to rotate, which in turn drives the impeller 12. The impeller 12 generates a rotational suction force that draws the slurry from the inlet pipe 10 into the reaction tank 3. At the same time, air from the air inlet pipe 9 is also drawn into the slurry in the reaction tank 3, generating bubbles of varying sizes. The rotation of the impeller 12 agitates the water flow, which generates a centrifugal force that impacts the annular filter plate 15 and the annular slide plate 13. Due to its L-shaped annular structure, the annular slide plate 13 experiences an upward force, causing it to rise. This opens the filter holes 14 of the annular filter plate 15, allowing the bubbles to pass through and forming small bubbles.

[0035] As the slurry passes through the filter plate, the impact force decreases, and the flow holes 16 of the annular slide plate 13 allow water to pass through. The annular slide plate 13 quickly falls down, scraping away slag from the filter holes 14 on the annular filter plate 15 to prevent clogging. When the annular slide plate 13 falls, the filter holes 14 are blocked, and the centrifugal force of the water flow increases again, causing the annular slide plate 13 to rise again, repeating the cycle. In this way, the bubble generator can continuously produce qualified and stable bubbles, and the filter holes 14 are repeatedly scraped by the annular slide plate 13, preventing them from becoming clogged.

[0036] The turbulence plate 11 has holes, which allows it to generate small bubbles when bubbles rise directly from the top. At the same time, the turbulence plate 11 prevents the upper foam layer from splashing.

[0037] Once the foam layer forms, it overflows from reaction tank 3. The upper end of reaction tank 3 is connected to foam overflow tank 2. The foam layer flows into foam overflow tank 2 due to gravity and is then discharged from discharge port 4. The bottom tailings are discharged from tailings discharge port 6. Flotation separation is completed.

[0038] A one-way valve closes the channel from the reaction tank 3 to the insulation chamber 17, preventing the liquid in the reaction tank 3 from flowing into the insulation chamber 17. A one-way valve 18 is located at the bottom of the reaction tank 3. The impeller 12 generates a rotating suction force that draws the slurry from the inlet pipe 10 into the reaction tank 3. Simultaneously, air from the air inlet pipe 9 is also drawn into the slurry in the reaction tank 3, generating bubbles of varying sizes. At this time, the rotation of the impeller 12 agitates the water flow, and the water flow generates a centrifugal force that impacts the annular filter plate 15 and the annular slide plate 13. Due to its L-shaped annular structure, the annular slide plate 13 experiences an upward force, causing it to rise. This opens the filter holes 14 of the annular filter plate 15, allowing the bubbles to pass through the filter holes 14, producing individual small bubbles.

[0039] This scheme uses a continuous flow of hot air to keep the liquid in the reaction tank 3 warm, preventing it from freezing in low winter temperatures and improving screening efficiency. Simultaneously, the one-way valve 18 injects high-speed microbubbles into the reaction tank at certain pressures, effectively increasing the number of microbubbles and also blowing up the annular slide plate 13, accelerating its up-and-down movement and increasing bubble production.

[0040] The circular sliding plate 13 is L-shaped. The drawing is for reference only. In practice, the size can be adjusted as needed to ensure that it can move up and down under the action of rotational force.

[0041] Numerous tiny bubbles, under the action of the stirring tank, come into full contact with the ore, altering the interaction between the reagents and the mineral surface and improving the floatability of valuable minerals. This method is highly effective in recovering ultrafine materials with valuable metals below -400 mesh. Simultaneously, the concentrate produced by the system is returned to the mixed flotation process section of the ore processing system for further recovery. Furthermore, tailings discarded from stage grinding and stage beneficiation are collected and processed together.

[0042] As attached Figure 1 , Figure 2 As shown:

[0043] This case study involves a large pyrite-type copper and zinc metal mine. The main metallic minerals in the ore are pyrite, chalcopyrite, sphalerite, arsenopyrite, and minor amounts of galena, chalcocite, and trace amounts of molybdenite, bornite, and argentite. The main gangue minerals are quartz and sericite, followed by calcite, barite, chlorite, and dolomite. The metallic minerals are finely grained. The main tailings include mixed tailings and zinc tailings. The overall tailings have a copper grade of 0.26%, a zinc grade of 0.17%, a gold grade of 0.24 g / t, and a silver grade of 10.34 g / t.

[0044] (1) One-time dosing of chemicals to adjust the slurry: Polymetallic tailings need to be continuously adjusted twice when fed into the mixing tank. For the first adjustment, based on the dry weight of each ton of tailings, add the following adjuster to the tailings: 4-5 kg / t of lime to adjust the pH value to 11.30-11.45; then add the high-efficiency and strong collector: Y89 at a dosage of 18-22 g / t.

[0045] (2) Secondary slurry conditioning and high-pressure microbubble mineralization: After the slurry conditioning in step (1) is prepared by adding chemicals, the slurry is fed into the mixing tank. High-pressure air at the bottom of the mixing tank is fed in through the microbubble generator to carry out secondary mineralization of the slurry.

[0046] (3) Roughing I: The flotation concentration is controlled between 35% and 40%. Add 8 to 10 g of frother BK201 per ton of dry tailings. The foam enters the cleaning flotation cell, and the tailings are fed into roughing II.

[0047] (4) Roughing II: Add a combination of collectors: 10-12 g / t of butyl xanthate, 5-8 g / t of Y89 and 3-5 g / t of frother BK201, and carry out a second roughing.

[0048] (5) Scavenging: Add Y89 at a dosage of 5-8 g / t for scavenging. The final process tailings are discharged to the tailings dam or used for underground backfilling.

[0049] (6) Fine selection: This is a blank fine selection. The foam product is returned separately to the ore raw ore processing system for mixed selection, and the tailings product is returned to rough selection I for processing.

[0050]

[0051] After using this technology, the proportions of copper and zinc metals in the -400 mesh particle size of the tailings decreased from 50.95% and 51.94% to 11.60% and 9.55%, respectively. This verifies that the microbubble forced mineralization slurry conditioning technology has good technical applicability for the recovery of refractory minerals from tailings.

[0052] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A centralized reprocessing technology for polymetallic ore tailings, characterized in that, Includes the following steps: Step S10: Process the tailings in a centralized grinding mill; Step S20: After adding the collector combination and the inhibitor combination, pour the slurry into the mixing tank; Step S30: A microbubble generator is installed at the bottom of the mixing tank, which generates a large number of microbubbles after stirring and slurry preparation; Step S40: Microbubbles float to the top of the mixing tank to form a foam layer. A scraper is installed at the top of the mixing tank to scrape off the foam layer for the first roughing process, resulting in rougher ore one and tailings one. Step S50: Tailings 1 is roughed again to obtain Tailings 2 and rougher ore 2. Tailings 2 is cleaned to obtain Tailings 3 and rougher ore 3. The obtained rougher ore 1, rougher ore 2 and rougher ore 3 are poured into a flotation machine to obtain concentrate. The microbubble generating device in step S10 includes a turbulence plate and a bubble generator. The turbulence plate is fixedly connected to a through pipe and is parallel to the flotation machine. The bubble generator includes an annular slide plate, a bottom plate, and an annular filter plate. The bottom plate is fixedly connected to the flotation machine, and the annular filter plate is fixedly connected to the bottom plate. The annular filter plate is coaxially arranged with the impeller and has filter holes and grooves. The annular slide plate is coaxially arranged with the annular filter plate and is slidably connected to the annular filter plate. The annular slide plate cooperates with the grooves. The annular slide plate has a flow hole at its upper end.

2. The centralized reprocessing technology for metal ore tailings according to claim 1, characterized in that, The inhibitor combination in step S20 is cyanide and sulfonated lignin.

3. The centralized reprocessing technology for metal ore tailings according to claim 1, characterized in that, The collector combination in step S20 is xanthate and foaming agent.

4. The centralized reprocessing technology for metal ore tailings according to claim 1, characterized in that, The annular filter plate and the annular slider are equipped with limiting blocks.

5. The centralized reprocessing technology for metal ore tailings according to claim 1, characterized in that, The turbulence plate has holes.

6. The centralized reprocessing technology for metal ore tailings according to claim 1, characterized in that, The flotation machine includes a reaction tank, which is surrounded by an insulation cavity. The insulation cavity is provided with an air inlet and an air outlet. The air inlet is connected to a pump, and the air outlet is connected to the reaction tank of the flotation machine. It also includes a one-way valve, which is fixed at the connection between the air outlet and the reaction tank. The one-way valve connects the insulation cavity to the reaction tank.

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