A method for treating and recycling lead-zinc ore dressing wastewater

Abstract

This invention proposes a method for treating and reusing lead-zinc ore beneficiation wastewater. The method includes pretreatment of the raw ore to obtain a raw ore slurry, followed by a flotation process. The flotation process includes lead flotation of the raw ore slurry and zinc flotation of the lead flotation tailings. The resulting lead concentrate slurry, zinc concentrate slurry, and tailings slurry undergo solid-liquid separation using reagents and a thickener. Wastewater overflowing from the thickener is transported to a mixing tank for collection. The outlet of the mixing tank is connected to the inlet of an adsorption tower group, and the wastewater overflows into the adsorption tower group. After adsorption, the wastewater overflows into a pump tank, where sodium sulfide is added. The wastewater is then pumped to a high-level water tank and finally reused in the flotation process. This method avoids the investment in large-scale water treatment equipment, uses conventional water treatment reagents, is environmentally friendly and economical, requires small amounts, and is widely available, reducing water treatment operating costs and reagent consumption. The process specifically treats wastewater and has broad application prospects for achieving zero discharge of non-ferrous metal beneficiation wastewater.

Description

Technical Field

[0001] This invention relates to the field of mineral processing wastewater reuse, specifically to a method for treating and reusing lead-zinc mineral processing wastewater. Background Technology

[0002] Non-ferrous metal beneficiation wastewater mainly includes concentrate filtrate, beneficiation process wastewater, and total tailings water. This wastewater has a complex composition and varying pH values. Currently, domestic non-ferrous metal beneficiation wastewater treatment technologies largely rely on chemical oxidation or natural degradation, which suffers from problems such as high reagent consumption leading to resource waste, long treatment cycles resulting in low degradation efficiency, and incomplete removal of heavy metals from the treated wastewater.

[0003] The existing lead-zinc mine wastewater treatment and reuse process is as follows: Figure 1 As shown, the lead concentrate slurry, zinc concentrate slurry, and tailings slurry produced by flotation need to be separated into solid and liquid phases by thickeners, filters, and sedimentation tanks.

[0004] The overflow water obtained by separating lead concentrate slurry and zinc concentrate slurry through a thickener, and the filtered water obtained by passing the substrate of the thickener through a filter; these filtered water and overflow water are respectively precipitated and discharged as wastewater in the corresponding lead concentrate settling tank and zinc concentrate settling tank. The wastewater generated from flotation is settled in a sedimentation tank in a ditch and then overflows. The substrate of the tailings thickener is filtered through a filter press to remove wastewater. This wastewater eventually flows into a mixing tank. The flotation tailings contain a large amount of suspended particles, heavy metal ions, and reagents. Therefore, when the tailings undergo solid-liquid separation in a thickener, polyacrylamide (PAM) is added to the thickener for flocculation and sedimentation (to remove heavy metal ions such as lead, copper, arsenic, cadmium, thallium, and antimony as precipitates, and to oxidize and remove pollutants such as ammonia nitrogen and COD). Activated carbon is added to the mixing tank to adsorb the residual reagents in the wastewater. Finally, the wastewater in the mixing tank is pumped to a high-level tank and reused in the flotation process.

[0005] The current problem is that polyacrylamide in this process has a relatively significant effect on the flocculation of suspended solids, but its effect on the treatment of residual reagents in wastewater and its effect on heavy metal ions are minimal. Moreover, the large-scale use will result in the wastewater in the subsequent mixing tank containing a large amount of polyacrylamide and reagents used in flotation, as well as residual heavy metals from the dewatering of lead concentrate and zinc concentrate. Adding only a small amount of activated carbon is insufficient to adsorb the large amount of reagents and residual heavy metals, causing polyacrylamide and reagents used in flotation to mix into the recycled water. When the recycled water is reused in the original flotation environment, it will cause minerals to float without purpose, and the mixed collectors will have non-selective collection of mineral particles in the flotation system, which will have a secondary impact on the original flotation environment and seriously affect the flotation quality of the concentrate. Summary of the Invention

[0006] The purpose of this invention is to provide a method for treating and reusing lead-zinc ore beneficiation wastewater.

[0007] This invention is implemented by the following technical solution: A method for treating and reusing lead-zinc ore beneficiation wastewater includes pretreatment of the raw ore to obtain a raw ore slurry, followed by a flotation process. The flotation process includes lead flotation of the raw ore slurry and zinc flotation of the lead flotation tailings. The lead concentrate slurry, zinc concentrate slurry, and tailings slurry obtained from flotation are subjected to solid-liquid separation using reagents and a thickener. The wastewater separated by the thickener is transported to a mixing tank for collection. The outlet of the mixing tank and the inlet of the adsorption tower group are connected by a pipeline. The wastewater is sent into the adsorption tower group through overflow. After adsorption by the adsorption tower group, the wastewater is sent into the pump pool through overflow. Sodium sulfide is added to the pump pool to react the residual heavy metal ions in the wastewater to generate corresponding metal sulfides. The wastewater is then pumped to a high-level water tank and finally reused in the flotation process.

[0008] Preferably, the lead concentrate obtained from lead flotation enters the lead concentrate tank, the slurry from the lead concentrate tank enters the lead concentrate thickener, the overflow water from the lead concentrate thickener flows by gravity to the lead concentrate settling tank, the overflow water from the lead concentrate settling tank is transported to the mixing tank, and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve; the sediment at the bottom of the lead concentrate settling tank is transported back to the lead concentrate thickener for further flocculation and sedimentation, the underflow from the lead concentrate thickener is pumped to the lead concentrate filter for filtration, the filtrate produced by the lead concentrate filter is returned to the lead concentrate settling tank, and the filter cake produced by the lead concentrate filter is the final lead concentrate product.

[0009] Preferably, the zinc concentrate obtained from zinc flotation enters a zinc concentrate tank, the slurry from the zinc concentrate tank enters a zinc concentrate thickener, the overflow water from the zinc concentrate thickener flows by gravity to a zinc concentrate settling tank, the overflow water from the zinc concentrate settling tank is transported to a mixing tank, and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through a first L-type three-way ball valve; the sediment at the bottom of the zinc concentrate settling tank is transported back to the zinc concentrate thickener for further flocculation and sedimentation, the underflow from the zinc concentrate thickener is pumped to a zinc concentrate filter for filtration, the filtrate produced by the zinc concentrate filter is returned to the zinc concentrate settling tank, and the filter cake produced by the zinc concentrate filter is the final zinc concentrate product.

[0010] Preferably, the tailings from the zinc flotation enter the flotation tailings tank, the slurry from the flotation tailings tank flows by gravity to the tailings thickener, the overflow water from the tailings thickener flows by gravity to the slime thickener, the sediment at the bottom of the slime thickener is transported back into the tailings thickener for further flocculation and sedimentation, the overflow water from the slime thickener is transported to the mixing tank, and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve; the underflow from the tailings thickener is pumped to the tailings filter press for filtration, the filtrate produced by the tailings filter press is transported to the mixing tank, and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve, the filter cake produced by the tailings filter press is the final tailings product.

[0011] Preferably, lime is added to the flotation tailings tank to adjust the pH value of the slurry in the flotation tailings tank to 7-7.5; Add 30 g / m³ of polyaluminum sulfate to the inlet of the tailings thickener. 3 ; Add lime and 20 g / m³ of polyaluminum sulfate to the outlet of the tailings thickener. 3 Adjust the pH value of the overflow water from the tailings thickener to 7-7.5; Add 1 g / m³ of polyacrylamide to the inlet of the slurry thickener 3 ; Add 1 g / m³ of polyacrylamide to the inlet of the lead concentrate thickener 3 ; Add 1 g / m³ of polyacrylamide to the inlet of the zinc concentrate thickening tank. 3 ; Add 5-10 g / m of sodium sulfide to the inlet of the pump pool 3 .

[0012] Preferably, the adsorption tower group is provided with two groups, one for standby and one for use. The two adsorption tower groups are respectively connected to the mixing tank through overflow pipes, and a first L-shaped three-way ball valve is installed on the overflow pipe.

[0013] Preferably, the lime is supplied via a lime dispensing machine.

[0014] Preferably, the polyaluminum sulfate and polyacrylamide are supplied via an automatic drug delivery machine.

[0015] Preferably, the adsorption tower group consists of three adsorption towers arranged in a stepped manner from high to low. Each adsorption tower structure includes a tower body, a mesh basket, and activated carbon. The mesh basket is fixedly installed inside the tower body and is filled with activated carbon. The inlet at the top of the first adsorption tower is connected to the outlet at the bottom of the mixing tank via an overflow pipe, and adjacent adsorption towers are connected via overflow pipes. That is, the outlet at the bottom of the previous adsorption tower is connected to the inlet at the top of the next adsorption tower via an overflow pipe, and the outlet at the bottom of the last adsorption tower is connected to the inlet at the top of the pump tank via an overflow pipe.

[0016] Preferably, a hot water inlet pipe is provided above the inlet of the first adsorption tower in each adsorption tower group, and a valve is installed on the hot water inlet pipe. A second L-shaped three-way ball valve is installed on the overflow pipe connecting the adsorption tower group to the pump pool. The second L-shaped three-way ball valve is connected to one end of the guide pipe, and the other end of the guide pipe is connected to the inlet of the tailings compressor.

[0017] The advantages of this invention are as follows: The combined use of PAS and PAM, along with a slime thickener, separates the slime and flocculated sediment from the recycled wastewater, preventing it from flowing back into the flotation environment. This also reduces the amount of PAM used, lowering reagent costs and facilitating further treatment of the recycled wastewater. Furthermore, the use of a stepped adsorption tower group further adsorbs residual reagents from the previous step, reducing reagent levels in the recycled wastewater. Then, sodium sulfide is added to the pump tank to react residual heavy metal ions in the wastewater to form corresponding metal sulfides, thus avoiding secondary impacts of heavy metal ions on the flotation environment.

[0018] In practical use, the overall solution avoids the need for dedicated investment in large-scale water treatment equipment. The water treatment agents used are all conventional agents, which are environmentally friendly, economical, and available in small quantities and wide range of sources, thus reducing water treatment operating costs and agent consumption. The entire process aims to reduce the impact of reuse on flotation and has broad application prospects for achieving zero discharge of non-ferrous metal beneficiation wastewater. Attached Figure Description

[0019] Figure 1 This is a flowchart of the existing technology for treating and reusing lead-zinc mine wastewater; Figure 2 This is a process flow diagram of wastewater treatment and reuse according to the present invention; Figure 3 This is a partial structural schematic diagram of the present invention; Figure 4 yes Figure 3 A partial structural diagram viewed from above.

[0020] In the diagram: 1. Mixing tank, 2. First L-type three-way ball valve, 3. Tower body, 4. Mesh basket, 5. Activated carbon, 6. Overflow pipe, 7. Second L-type three-way ball valve, 8. Pump tank, 9. Water pump, 10. Hot water inlet pipe, 11. Valve. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] like Figures 2 to 4 As shown, a method for treating and reusing lead-zinc ore beneficiation wastewater includes pretreatment of the raw ore to obtain raw ore slurry, followed by a flotation process. The flotation process includes lead flotation of the raw ore slurry and zinc flotation of the lead flotation tailings. The lead concentrate slurry, zinc concentrate slurry, and tailings slurry obtained from flotation are subjected to solid-liquid separation using reagents and a thickener. The wastewater separated by the thickener is transported to a mixing tank for collection. The outlet of the mixing tank and the inlet of the adsorption tower group are connected by a pipeline. The wastewater is sent into the adsorption tower group through overflow. After adsorption by the adsorption tower group, the wastewater is sent into the pump pool through overflow. Sodium sulfide is added to the pump pool to react the residual heavy metal ions in the wastewater to generate corresponding metal sulfides. The wastewater is then pumped to a high-level water tank and finally reused in the flotation process.

[0023] Lead concentrate obtained from lead flotation enters the lead concentrate trough. The slurry from the lead concentrate trough enters the lead concentrate thickener. The overflow water from the lead concentrate thickener flows by gravity to the lead concentrate settling tank. The overflow water from the lead concentrate settling tank is transported to the mixing tank, and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve. The underflow from the lead concentrate thickener is pumped to the lead concentrate filter for filtration. The filtrate produced by the lead concentrate filter is returned to the lead concentrate settling tank. Since the underflow from the lead concentrate thickener is lead concentrate product, a small amount of fine lead concentrate product overflows into the lead concentrate settling tank during the filtration process. The sediment at the bottom of the lead concentrate settling tank is pumped back into the lead concentrate thickener for further flocculation and sedimentation to avoid the loss of this part of the lead concentrate. The filter cake produced by the lead concentrate filter is the final lead concentrate product.

[0024] The zinc concentrate obtained from zinc flotation enters the zinc concentrate trough. The slurry from the zinc concentrate trough enters the zinc concentrate thickener. The overflow water from the zinc concentrate thickener flows by gravity to the zinc concentrate settling tank. The overflow water from the zinc concentrate settling tank is transported to the mixing tank, and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve. The underflow from the zinc concentrate thickener is pumped to the zinc concentrate filter for filtration. The filtrate produced by the zinc concentrate filter is returned to the zinc concentrate settling tank. Since the underflow from the zinc concentrate thickener is the zinc concentrate product, a small amount of fine zinc concentrate product overflows into the lead concentrate settling tank during the filtration process. The sediment at the bottom of the zinc concentrate settling tank is transported back to the zinc concentrate thickener for further flocculation and sedimentation, also to avoid the loss of this part of the zinc concentrate. The filter cake produced by the zinc concentrate filter is the final zinc concentrate product.

[0025] The tailings from zinc flotation enter the flotation tailings tank. The slurry from the flotation tailings tank flows by gravity to the tailings thickener. The overflow water from the tailings thickener flows by gravity to the slime thickener. The sediment at the bottom of the slime thickener is transported back into the tailings thickener for further flocculation and sedimentation. The overflow water from the slime thickener is transported to the mixing tank and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve. The underflow from the tailings thickener is pumped to the tailings filter press for filtration. The filtrate produced by the tailings filter press is transported to the mixing tank and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve. The filter cake produced by the tailings filter press is the final tailings product.

[0026] Water from leaks, spills, and septic tanks generated during the mineral processing and from sanitation work enters the sedimentation tank. The overflow from the sedimentation tank is then transported to the mixing tank, and from there flows through the first L-type three-way ball valve into adsorption tower group a or adsorption tower group b.

[0027] The flotation process described above is the same as that in existing technologies and remains unchanged. The difference lies in the addition of a slime thickener after the tailings thickener. This ensures that the flocculated sediment and tailings impurities undergo further solid-liquid separation via the slime thickener. The separated substrate is then filtered through a tailings filter press for solid waste disposal. Furthermore, adjustments have been made to the reagent addition process and the subsequent treatment of wastewater collected in the mixing tank. Specific details are as follows: Add lime to the flotation tailings tank to adjust the pH value of the slurry in the flotation tailings tank to 7-7.5; Add 30 g / m³ of polyaluminum sulfate (PAS) to the inlet of the tailings thickener. 3 Add lime and 20g / m³ of polyaluminum sulfate to the outlet of the tailings thickener. 3Adjust the pH of the overflow water from the tailings thickener to 7-7.5. PAS primarily coagulates impurities in the wastewater, making them easier to settle and filter, thus separating them from the water. This allows tailings and sediments to be more easily discharged from the bottom of the tailings thickener and sent to the tailings filter press for filtration, thereby reducing the amount of tailings and flocculated sediments in the wastewater. However, since the wastewater overflowing from the tailings thickener still contains fine sludge, sediments, and heavy metal ions, 1 g / m³ of polyacrylamide (PAM) is added to the inlet of the sludge thickener. 3 This process further coagulates impurities in the wastewater (removing heavy metal ions such as lead, copper, arsenic, cadmium, thallium, and antimony from the wastewater as precipitates, and oxidizing and removing pollutants such as ammonia nitrogen and COD). The coagulated precipitate is discharged from the bottom of the slime thickener and sent to the tailings filter press for filtration, thereby further reducing the amount of tailings and flocculated precipitates in the wastewater and thus reducing the impact on the subsequent flotation environment.

[0028] The lead concentrate and zinc concentrate cells contain reagents and heavy metal ions added during flotation. Polyacrylamide (PAM) at 1 g / m³ is added at the inlet of the lead concentrate thickener. 3 Add 1 g / m³ of polyacrylamide (PAM) to the inlet of the zinc concentrate thickening tank. 3 This process further coagulates impurities in the wastewater (removing heavy metal ions such as lead, copper, arsenic, cadmium, thallium, and antimony from the wastewater as precipitates, and oxidizing and removing pollutants such as ammonia nitrogen and COD). The coagulated precipitate is discharged from the thickener substrate and sent to the filter for filtration. At the same time, the overflowing wastewater is sent back to the filter for filtration after passing through the sedimentation tank precipitate, thereby further reducing the amount of flocculated precipitate in the wastewater and thus reducing the impact on the subsequent flotation environment.

[0029] After the above preliminary wastewater treatment, the amount of sludge, flocculated sediment, and a large amount of heavy metal ions in the wastewater will be reduced, while the amount of polyacrylamide (PAM) used will be significantly reduced, thereby lowering costs. However, a small amount of heavy metal ions and reagents will still be present in the wastewater. Therefore, two sets of adsorption towers (one for standby) are added after the mixing tank 1. The two adsorption towers are connected to the mixing tank 1 through overflow pipes. The overflow pipes are equipped with a first L-type three-way ball valve 2 to facilitate switching the flow direction of the wastewater, so that while one set of adsorption towers is in normal use, the other set of adsorption towers can be maintained and kept on standby.

[0030] To facilitate the adsorption of residual reagents in wastewater and ensure that the adsorption towers can be recycled and reused, the adsorption tower assembly was designed.

[0031] This adsorption tower group consists of three adsorption towers arranged in a stepped manner from high to low, thereby performing multiple adsorption treatments on residual reagents in the wastewater, making the residual reagents in the reused wastewater negligible. Each adsorption tower structure includes a tower body 3, a mesh basket 4, and activated carbon 5. The mesh basket 4 is filled with activated carbon 5, which is made of 20-mesh porous coconut shell carbon, wrapped in a nylon bag with good porosity, and the entire bag is placed in the mesh basket 4. The mesh basket 4 is then suspended and fixed inside the tower body 3. There are 3 bags per tower, 1 ton per bag. The distance from the bottom of the mesh basket 4 to the bottom of the tower body 3 is 0.5 meters to enhance the permeability of wastewater, strengthen the adsorption effect, and facilitate the regeneration and reuse of activated carbon. The top inlet of the first adsorption tower is connected to the bottom outlet of the mixing tank 1 via an overflow pipe 6. Adjacent adsorption towers are connected via an overflow pipe 6, meaning the bottom outlet of the previous adsorption tower is connected to the top inlet of the next adsorption tower via an overflow pipe 6. The bottom outlet of the last adsorption tower is connected to the top inlet of the pump tank 8 via an overflow pipe 6. All liquids are transported by overflow.

[0032] To enable the adsorption tower group to be recycled, a hot water inlet pipe 10 is installed above the inlet of the first adsorption tower in each adsorption tower group. A valve 11 is installed on the hot water inlet pipe 10. A second L-shaped three-way ball valve 7 is installed on the overflow pipe 6 connecting the adsorption tower group to the pump pool 8. One end of the second L-shaped three-way ball valve 7 is connected to the guide pipe, and the other end of the guide pipe is connected to the inlet of the tailings compressor. When one adsorption tower group is not in use, the valve 11 on the hot water inlet pipe 10 is opened, and the second L-shaped three-way ball valve 7 is switched to connect the overflow pipe 6 to the guide pipe. Hot water flows into the adsorption tower group through the hot water inlet pipe 10 to desorb the activated carbon 5. The hot water enhances the molecular thermal motion by increasing the temperature, reducing the binding force between the adsorbent and the adsorbate, causing the reagent to detach from the surface of the activated carbon. The detached reagent flows into the tailings filter press with the hot water for recycling, thereby enabling the activated carbon to be regenerated through desorption and improving the service life of the adsorption tower.

[0033] Because trace amounts of heavy metal ions remain in the recycled wastewater after adsorption and accumulate in pump tank 8, sodium sulfide (5-10 g / m³) is added at the pump tank inlet to avoid the impact of heavy metal ions on the subsequent flotation environment. 3The process involves precipitating heavy metal ions from the recycled wastewater. These precipitated heavy metal ions react with sodium sulfide to form corresponding metal sulfides, primarily lead sulfide, zinc sulfide, and copper sulfide. These metal sulfides are also the concentrates required for flotation, and sodium sulfide is added during the pretreatment stage. The purpose of this process is to react these heavy metal ions to form metal sulfides. If they do not react, these ions will simultaneously activate the lead, zinc, and copper minerals, causing them to float to the surface at the same time. Although they can be separated, they will all float together, making them difficult to separate. Therefore, these ions cannot be present when selecting lead. Thus, the recycled wastewater in the pump pool is pumped to a high-level water tank via pump 9 and finally reused in the flotation process, thereby reducing the secondary impact on the flotation environment.

[0034] As mentioned above, lime is supplied through a lime dispensing machine, while polyaluminum sulfate and polyacrylamide are supplied through an automatic dispensing machine.

[0035] Comparative example: Combined with appendix Figure 1 As shown, the comparative example and the mineral processing used in this application are from the same location, and the original implementation process for wastewater treatment differs in that: only 15~25g / m³ of polyacrylamide (PAM) is added at the inlet of the tailings thickener. 3 The pH value of its flotation tailings trough is 6.5-7.5.

[0036] The original water treatment and recycling system is adopted. The pH value fluctuates within the range of 6.5 to 7.5 depending on the reagents used in the non-ferrous metal beneficiation process. The content of solid suspended particles is also greatly affected by various factors, resulting in large fluctuations in the amount of flocculant used. There are a lot of residual reagents in the recycled water, which frequently affects the control of the non-ferrous metal beneficiation process and causes large fluctuations in production indicators.

[0037] Table 1: Analytical data of preferred embodiments and comparative examples

[0038] In comparison, the effluent treated using this invention showed that the pH value stabilized at 7-7.5, the anionic surfactant content decreased from 10.6 mg / L to 5.2 mg / L, the copper ion content decreased from 0.014 mg / L to 0.005 mg / L, the suspended solids decreased from 12 mg / L to 10 mg / L, and the COD value decreased from 218 mg / L to 152 mg / L. All the effluent was returned to the mineral processing flow.

[0039] This solution can be combined with monitoring equipment according to actual conditions to facilitate online monitoring of pH, flow rate, concentration, and water quality. Through online pH monitoring and network information transmission, it can achieve automatic dosing of lime and chemicals and precise pH control. Combined with the control of chemical dosage parameters, it can achieve precise dosing of each chemical and strictly control the quality of the effluent.

[0040] 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 treating and reusing lead-zinc ore beneficiation wastewater, comprising pre-treating the raw ore to obtain a raw ore slurry, and then carrying out a flotation process, wherein the flotation process includes lead flotation of the raw ore slurry and zinc flotation of the lead flotation tailings; Its features are: The lead concentrate slurry, zinc concentrate slurry, and tailings slurry obtained from flotation are separated into solid and liquid phases by reagents and a thickener. The wastewater separated by the thickener is transported to a mixing tank for collection. The outlet of the mixing tank and the inlet of the adsorption tower group are connected by a pipeline. The wastewater is sent into the adsorption tower group through overflow. After adsorption by the adsorption tower group, the wastewater is sent into the pump pool through overflow. Sodium sulfide is added to the pump pool to react the residual heavy metal ions in the wastewater to generate corresponding metal sulfides. The wastewater is then pumped to a high-level water tank and finally reused in the flotation process. The tailings from the zinc flotation enter the flotation tailings tank, the slurry from the flotation tailings tank flows by gravity to the tailings thickener, the overflow water from the tailings thickener flows by gravity to the slime thickener, the sediment at the bottom of the slime thickener is transported back into the tailings thickener for further flocculation and sedimentation, and the overflow water from the slime thickener is transported to the mixing tank. Add lime to the flotation tailings tank to adjust the pH value of the slurry in the flotation tailings tank to 7-7.5; Polyaluminium sulphate 30 g / m3was added at the inlet of the tailings thickener 3 ; At the outlet of the tailings thickener, lime and polyaluminum sulfate 20 g / m 3 , adjust the overflow water pH of the tailings thickener to 7-7.5; Polyacrylamide 1 g / m3was added at the inlet of the slime thickener 3 ; Add 1 g / m³ of polyacrylamide at the inlet of the lead concentrate thickener. 3 ; Add 1 g / m³ of polyacrylamide at the inlet of the zinc concentrate thickener. 3 ; Add 5-10 g / m of sodium sulfide to the pump inlet. 3 .

2. The method for treating and reusing lead-zinc ore beneficiation wastewater according to claim 1, characterized in that, The lead concentrate obtained from lead flotation enters the lead concentrate tank, and the slurry from the lead concentrate tank enters the lead concentrate thickener. The overflow water from the lead concentrate thickener flows by gravity to the lead concentrate settling tank, and the overflow water from the lead concentrate settling tank is transported to the mixing tank. It then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve. The sediment at the bottom of the lead concentrate settling tank is transported back to the lead concentrate thickener for further flocculation and sedimentation. The underflow from the lead concentrate thickener is pumped to the lead concentrate filter for filtration. The filtrate produced by the lead concentrate filter is returned to the lead concentrate settling tank, and the filter cake produced by the lead concentrate filter is the final lead concentrate product.

3. The method for treating and reusing lead-zinc ore beneficiation wastewater according to claim 1, characterized in that, The zinc concentrate obtained from zinc flotation enters the zinc concentrate tank, and the slurry from the zinc concentrate tank enters the zinc concentrate thickener. The overflow water from the zinc concentrate thickener flows by gravity to the zinc concentrate settling tank, and the overflow water from the zinc concentrate settling tank is transported to the mixing tank. It then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve. The sediment at the bottom of the zinc concentrate settling tank is transported back to the zinc concentrate thickener for further flocculation and sedimentation. The underflow from the zinc concentrate thickener is pumped to the zinc concentrate filter for filtration. The filtrate produced by the zinc concentrate filter is returned to the zinc concentrate settling tank, and the filter cake produced by the zinc concentrate filter is the final zinc concentrate product.

4. The method for treating and reusing lead-zinc ore beneficiation wastewater according to claim 1, characterized in that, The tailings flow from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve; the underflow from the tailings thickener is pumped to the tailings filter press for filtration, and the filtrate produced by the tailings filter press is transported to the mixing tank, and then flows from the mixing tank into adsorption tower group a or adsorption tower group b through the first L-type three-way ball valve. The filter cake produced by the tailings filter press is the final tailings product.

5. The method for treating and reusing lead-zinc ore beneficiation wastewater according to claim 1, characterized in that, The adsorption tower group is provided with two groups, one for standby and one for use. The two adsorption tower groups are respectively connected to the mixing tank through overflow pipes, and the overflow pipes are equipped with the first L-shaped three-way ball valve.

6. The method for treating and reusing lead-zinc ore beneficiation wastewater according to claim 1, characterized in that, The lime is supplied via a lime dispensing machine.

7. A method for treating and reusing lead-zinc ore beneficiation wastewater according to claim 1, characterized in that, The polyaluminum sulfate and polyacrylamide are supplied via an automatic dispensing machine.

8. A method for treating and reusing lead-zinc ore beneficiation wastewater according to claim 1, characterized in that, The adsorption tower group consists of three adsorption towers arranged in a stepped manner from high to low. Each adsorption tower structure includes a tower body, a mesh basket, and activated carbon. The mesh basket is fixedly installed inside the tower body and is filled with activated carbon. The inlet at the top of the first adsorption tower is connected to the outlet at the bottom of the mixing tank via an overflow pipe, and adjacent adsorption towers are connected via overflow pipes. That is, the outlet at the bottom of the previous adsorption tower is connected to the inlet at the top of the next adsorption tower via an overflow pipe, and the outlet at the bottom of the last adsorption tower is connected to the inlet at the top of the pump tank via an overflow pipe.

9. A method for treating and reusing lead-zinc ore beneficiation wastewater according to claim 8, characterized in that, A hot water inlet pipe is provided above the inlet of the first adsorption tower in each adsorption tower group. A valve is installed on the hot water inlet pipe. A second L-type three-way ball valve is installed on the overflow pipe connecting the adsorption tower group to the pump pool. The second L-type three-way ball valve is connected to one end of the guide pipe, and the other end of the guide pipe is connected to the inlet of the tailings filter press.

Images