Zinc-containing wastewater recycling device and use method

Abstract

The invention discloses a zinc-containing wastewater recycling device which comprises an oil-water mixed phase separation mechanism and an activated carbon adsorption separation mechanism, the device is used for performing oil-water separation on the zinc-containing wastewater in three stages: in the first-stage separation, a large amount of oil phase and solid impurities are removed under the action of an oil scraper and a settling slope, and in the second-stage separation, the oil phase mixed in the water phase rises to the liquid level along with bubbles to be separated under the action of a compressed air pipe; in the third-stage separation, activated carbon powder is used for adsorbing a residual oil phase in an overflow water phase, a filter press is used for filter pressing, zinc-containing waste water which is relatively clean in oil removal is obtained, oil-water separation of the zinc-containing waste liquid is achieved, and the zinc-containing waste water after oil removal is recycled to a production system. Compared with a chemical method and a high-temperature decomposition method, addition of impurity elements and energy consumption can be effectively avoided, the input amount of activated carbon can be effectively reduced in the carbon powder adsorption process, and the workload of a filter press is reduced, so that the production cost is effectively controlled, and the production efficiency is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal hydrometallurgy, and in particular relates to a device for recycling zinc-containing wastewater and a method for using the device. Background Art

[0002] The generation of zinc-containing wastewater is inevitable in the wet zinc smelting industry. Zinc-containing wastewater contains zinc and other valuable metals, oils, organic matter, solid impurities, etc. Direct discharge will cause environmental pollution and loss of valuable metals. In the past, zinc-containing wastewater was usually collected and directly recycled into the system. This method will cause oils and organic matter other than valuable metals to be brought into the system, which will cause serious harm to the zinc electrolysis process and seriously affect the quality of zinc sheets and the service life of the plates. Therefore, a large amount of activated carbon powder needs to be invested in adsorption and filtration after direct recycling to the system, which not only increases production costs, but also increases the workload of the filter press and reduces production efficiency.

[0003] The main sources of oil and organic matter in the hydrometallurgical zinc smelting industry are: equipment lubricating oil and engine oil leaking into the system, P used in comprehensive recovery, 204 and kerosene enters the system with the raffinate. The main effects are as follows: First, the presence of oils and organic matter can shift the electrode potential of the zinc cathode to the negative direction, hindering the discharge of zinc ions and making it difficult for zinc to precipitate, while hydrogen is relatively easy to precipitate, resulting in a back-dissolving burn plate, and causing a significant decrease in the efficiency of electrolytic deposition current and an increase in power consumption; second, fatty acids can cause manganese ions to precipitate outside the electrolytic cell. Unlike normal precipitation near the anode, which can gather in the anode mud and settle to the bottom of the tank, they are suspended in the solution, making the crystal growth of the chute, sump, and cooling tower faster, and increasing the frequency of crystal removal; third, the more types of oils and organic matter enter the system, the more there will be a superposition effect, which will reduce the concentration of the spirit world and the dangerous concentration, making it more likely to have a back-dissolving burn plate, and organic matter is likely to produce derivatives or derived chelates, which are more harmful and take longer to precipitate and dissolve. Summary of the invention

[0004] In view of the problems existing in the prior art, the present invention provides a device and method for recycling zinc-containing wastewater. The device and method can be used to separate oils and organic matter that are unfavorable to production in the zinc-containing wastewater, and then recycle the zinc-containing wastewater, thereby realizing the resource and green utilization of the zinc-containing wastewater, which is beneficial to improving the efficiency of the enterprise and meeting the requirements of the country for green development of the industry and energy conservation and emission reduction.

[0005] The zinc-containing wastewater recycling device of the present invention comprises an oil-water mixed phase separation mechanism and an activated carbon adsorption separation mechanism; wherein the oil-water mixed phase separation mechanism comprises a shell, and an inner cavity of the shell is divided into a primary oil-water separation tank, a secondary oil-water separation tank, and an oil storage tank by a partition, and the oil storage tank is located between the primary oil-water separation tank and the secondary oil-water separation tank; a liquid inlet pipe is arranged on the top of the primary oil-water separation tank, the bottom of the primary oil-water separation tank is a V-shaped sedimentation bottom, a slag discharge pipe is connected with the bottom of the primary oil-water separation tank, the primary oil-water separation tank and the secondary oil-water separation tank are connected by more than one connecting pipe, and an oil scraper I is arranged at the primary oil-water separation tank. Above the partition between the oil-water separation tank and the oil storage tank; an air distribution pipe is arranged at the bottom of the secondary oil-water separation tank, and the air distribution pipe is connected to the air source through a compressed air inlet pipe, an oil scraper II is arranged above the partition between the secondary oil-water separation tank and the oil storage tank, a water phase overflow pipe is arranged at one side of the secondary oil-water separation tank and its water inlet is located at the bottom of the secondary oil-water separation tank, and a vent pipe I is arranged at one side of the bottom of the secondary oil-water separation tank; an oil outlet is opened at one side of the upper part of the oil storage tank, a vent pipe II and a drain pipe are arranged at the bottom of the secondary oil-water separation tank, the drain pipe and the slag discharge pipe are connected to the delivery pump through a pipeline, and the oil outlet is connected to the oil receiving pan through an oil guide groove; The activated carbon adsorption and separation mechanism includes a stirring tank, a carbon powder bin, a stirrer, an overflow channel, a chute, an intermediate liquid storage tank, and a filter press. The carbon powder bin is arranged above the inlet of the stirring tank, the stirrer is arranged in the stirring tank, the overflow channel is arranged in the stirring tank and its outlet is connected with the intermediate liquid storage tank through an inclined chute, the intermediate liquid storage tank is connected with the filter press through a filter pressure delivery pump and a pipeline with a valve, and the water phase overflow pipe of the secondary oil-water separation tank is connected with the stirring tank through an overflow delivery pump and a pipeline.

[0006] The height of the partition between the primary oil-water separation tank and the oil storage tank is higher than the height of the partition between the secondary oil-water separation tank and the oil storage tank, and the height of the oil outlet on the shell is lower than the height of the partition between the secondary oil-water separation tank and the oil storage tank.

[0007] The oil scraper I or the oil scraper II comprises an arc-shaped scraper blade and a rotating shaft. The scraper blade is movably arranged on the housing through the rotating shaft. The rotating shaft is connected to the output shaft of the motor and is driven to rotate thereby.

[0008] Valves are arranged on the compressed air inlet pipe, vent pipe I, vent pipe II, drainage pipe, slag discharge pipe and air distribution pipe outlet.

[0009] The method of using the above device is as follows: (1) Zinc-containing wastewater enters the primary oil-water separation tank of the oil-water mixed phase separation mechanism through the liquid inlet pipe. In the primary oil-water separation tank, the zinc-containing wastewater is naturally separated by the difference in density between the oil and water phases. The upper oil phase overflows into the oil storage tank through the partition under the action of the oil scraper I, and the middle water phase flows into the secondary oil-water separation tank through the connecting pipe. The solid impurities settle at the bottom of the V-shaped sedimentation tank and are collected at the bottom of the primary oil-water separation tank and discharged through the slag discharge port. (2) Compressed air enters the air distribution pipe through the compressed air inlet pipe, and pneumatically stirs the wastewater in the secondary oil-water separation tank, so that the oil phase mixed in the water phase rises to the liquid surface together with the bubbles, and overflows into the oil storage tank through the partition under the action of the oil scraper II. The lower de-oiled water phase overflows through the water phase overflow pipe and enters the stirring tank of the activated carbon adsorption separation mechanism through the overflow delivery pump. The activated carbon powder is added into the stirring tank through the carbon powder bin, and the stirrer is turned on to stir and adsorb to remove oil. After adsorption, the liquid overflows into the chute through the overflow channel, and flows into the intermediate liquid storage tank through the chute. The liquid in the intermediate liquid storage tank enters the filter press under the action of the filter press delivery pump for filtration, and the filtrate is sent to the wet zinc smelting system for reuse; (3) The oil in the oil storage tank overflows through the oil outlet and is diverted to the oil receiving pan through the oil guide groove for collection; (4) The solid impurities discharged from the slag outlet, the bottom flow of the oil storage tank, the separated oil phase, and the activated carbon slag after filter pressing are all sent to the boiling roasting furnace for processing and recovery of valuable metals.

[0010] Advantages and technical effects of the present invention: The device of the present invention uses an oil-water mixed phase separation mechanism to initially separate the zinc-containing wastewater from oil and water, remove most of the oil and organic matter, and then use a small amount of activated carbon powder for adsorption and filtration to remove the oil and organic matter remaining in the water phase. The zinc-containing wastewater after oil removal is recycled to the system, and the separated oil and organic matter and the activated carbon residue after filter pressing are sent to a fluidized bed roasting furnace for firing, which can increase the heat for fluidized bed roasting and further recover the valuable metals mixed therein. This method removes oil and organic matter from zinc-containing wastewater by physical separation. Compared with chemical methods and high-temperature decomposition methods, it can effectively avoid the addition of impurity elements and energy consumption, and can effectively reduce the input amount of activated carbon in the carbon powder adsorption process, reduce the workload of the filter press, and apply this zinc-containing wastewater recycling method to the wet zinc smelting process, thereby effectively controlling production costs and improving production efficiency.

[0011] The present invention realizes the resource and green utilization of zinc-containing wastewater, is beneficial to improving enterprise benefits, and meets the country's requirements for green industrial development, energy conservation and emission reduction. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 This is a schematic diagram of the structure of the oil-water mixed phase separation mechanism of the present invention; Figure 2 It is a schematic diagram of the partial structure of the oil storage tank; Figure 3 It is a schematic diagram of the structure of the activated carbon adsorption separation mechanism; In the figure: 1-primary oil-water separation tank; 2-secondary oil-water separation tank; 3-oil storage tank; 4-oil scraper I; 5-V-shaped sedimentation bottom; 6-slag discharge pipe; 7-connecting pipe; 8-liquid inlet pipe; 9-air distribution pipe; 10-compressed air inlet pipe; 11-oil scraper II; 12-water phase overflow pipe; 13-vent pipe I; 14-oil outlet; 15-vent pipe II; 16-drain pipe; 17-delivery pump; 18-oil guide groove; 19-oil receiving tray; 20-mixing tank; 21-carbon powder bin; 22-mixer; 23-overflow delivery pump; 24-overflow channel; 25-chute; 26-intermediate liquid storage tank; 27-filter press; 28-filter press delivery pump. DETAILED DESCRIPTION

[0013] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention; Example 1: Figure 1-3As shown, the zinc-containing wastewater recycling device includes an oil-water mixed phase separation mechanism and an activated carbon adsorption separation mechanism; wherein the oil-water mixed phase separation mechanism includes a rectangular shell, and the inner cavity of the shell is divided into a primary oil-water separation tank 1, a secondary oil-water separation tank 2, and an oil storage tank 3 by two partitions, and the oil storage tank 3 is located between the primary oil-water separation tank and the secondary oil-water separation tank, and the height of the partition between the primary oil-water separation tank and the oil storage tank is 2 cm higher than the height of the partition between the secondary oil-water separation tank and the oil storage tank; a liquid inlet pipe 8 is arranged on the top of the primary oil-water separation tank, and the bottom of the primary oil-water separation tank is a V-shaped sedimentation bottom 5 (with an inclination angle of 30°), and a slag discharge pipe 6 is connected to the primary oil-water separation tank. The bottom of the oil-water separation tank is connected, the primary oil-water separation tank 1 and the secondary oil-water separation tank 2 are connected through two connecting pipes 7, the oil scraper I 4 is arranged above the partition between the primary oil-water separation tank and the oil storage tank, the oil scraper I includes an arc-shaped scraper blade and a rotating shaft, the scraper blade is movably arranged on the shell through the rotating shaft, the rotating shaft is connected to the motor output shaft and driven to rotate; an air distribution pipe 9 is arranged at the bottom of the secondary oil-water separation tank, the air distribution pipe 9 is connected to the air source through the compressed air inlet pipe 10, the oil scraper II 11 is arranged above the partition between the secondary oil-water separation tank and the oil storage tank, the oil scraper II includes an arc-shaped scraper blade and a rotating shaft, the scraper blade is movably arranged on the shell through the rotating shaft, the rotating shaft is connected to the motor output shaft and driven to rotate; an air distribution pipe 9 is arranged at the bottom of the secondary oil-water separation tank, the air distribution pipe 9 is connected to the air source through the compressed air inlet pipe 10, and the oil scraper II 11 is arranged above the partition between the secondary oil-water separation tank and the oil storage tank. The output shaft of the machine is connected and driven to rotate; the water phase overflow pipe 12 is arranged on one side of the secondary oil-water separation tank and its water inlet is located at the bottom of the secondary oil-water separation tank, and the vent pipe I 13 is arranged on one side of the bottom of the secondary oil-water separation tank; an oil outlet 14 is opened on one side of the upper part of the oil storage tank, and the height of the oil outlet 14 is 2 cm lower than the height of the partition between the secondary oil-water separation tank and the oil storage tank, and the overall gradient is formed; the bottom of the secondary oil-water separation tank is provided with a vent pipe II 15 and a drain pipe 16, the drain pipe 16 and the slag discharge pipe 6 are connected to the delivery pump 17 through a pipeline, and the oil outlet 14 is connected to the oil receiving pan 19 through an oil guide groove 18; the activated carbon adsorption separation mechanism includes a stirring tank 20, a carbon powder bin 21 , agitator 22, overflow channel 24, chute 25, intermediate liquid storage tank 26, filter press 27, the carbon powder bin 21 is arranged above the entrance of the stirring tank 20, the agitator 22 is arranged in the stirring tank, the overflow channel 24 is arranged in the stirring tank and its outlet is connected with the intermediate liquid storage tank 26 through the inclined chute 25, the intermediate liquid storage tank 26 is connected with the filter press 27 through the filter press delivery pump 28 and the pipeline with a valve, the water phase overflow pipe 12 of the secondary oil-water separation tank is connected with the stirring tank 20 through the overflow delivery pump 23 and the pipeline; valves are arranged on the compressed air inlet pipe 10, the vent pipe I 13, the vent pipe II 15, the drain pipe 16, the slag discharge pipe 6, and the air distribution pipe 9 outlet; When the above device is used: 1. Zinc-containing wastewater mainly comes from the zinc-containing wastewater generated during the cleaning of zinc sheets and plates in the electrolysis process. It is collected in the ditch through the floor drain and the flow rate is controlled by the liquid inlet pipe 8. 3 / h enters the primary oil-water separation tank 1 of the oil-water mixed phase separation mechanism, and the liquid inlet pipe controls the inlet flow rate of zinc-containing wastewater (controlled according to the actual amount of zinc-containing wastewater generated and the processing capacity of the oil-water mixed phase separation mechanism). The zinc-containing wastewater will naturally stratify in the primary oil-water separation tank according to the density difference of the oil-water phase. The upper oil phase overflows into the oil storage tank 3 through the partition under the action of the oil scraper Ⅰ4 (the speed is 30r / min, and the scraper scraping depth is 0.5cm below the water phase), and the middle water phase flows into the secondary oil-water separation tank 2 through the connecting pipe 7. In this process, the pressure difference between the primary oil-water separation tank and the secondary oil-water separation tank is formed by the flow of wastewater, which provides potential energy for the water phase of the connecting pipe, and the zinc-containing wastewater naturally flows from the primary oil-water separation tank to the secondary oil-water separation tank; the solid impurities are settled through the V-shaped sedimentation bottom 5 and collected at the bottom of the primary oil-water separation tank, separated from the water phase, and the solid impurities are discharged through the slag discharge port 6; 2. Compressed air enters the U-shaped air distribution pipe 9 (pore diameter 3mm, spacing 5cm) through the compressed air inlet pipe 10, and pneumatically stirs the wastewater in the secondary oil-water separation tank, so that the bubbles evenly penetrate the entire liquid phase, so that the oil phase mixed in the water phase rises to the liquid surface together with the bubbles, and overflows into the oil storage tank 3 through the partition under the action of the oil scraper II 11. The speed of the oil scraper II is 30r / min, and the scraping depth of the scraper is 0.5cm below the water phase; the lower deoiled water phase overflows through the water phase overflow pipe 12, the water phase overflow pipe 12 is an inverted U-shaped pipe, and the inner bend of the water phase overflow pipe is the water phase overflow baseline The overflow baseline of the water phase is 2-3 cm lower than the partition between the secondary oil-water separation tank and the oil storage tank, so that the water phase can be discharged in time without taking out the oil phase; the overflowed liquid enters the stirring tank 20 of the activated carbon adsorption separation mechanism through the overflow delivery pump 23, and the activated carbon powder is added into the stirring tank through the carbon powder bin 21, and the stirrer 22 is turned on. The stirring and adsorption are carried out for 1 hour to remove the oil. After adsorption, the liquid overflows into the inclined chute 25 through the overflow channel 24, and flows into the intermediate liquid storage tank 26 through the chute. The liquid in the intermediate liquid storage tank enters the filter press 27 for filtration under the action of the filter pressure delivery pump 28, and the filtrate is sent to the wet zinc smelting for reuse; 3. The oil phase from the primary oil-water separation tank 1 and the secondary oil-water separation tank 2 contains a small amount of water phase, which can be naturally separated after standing in the oil storage tank 3. The upper oil phase overflows through the oil outlet 14 and is guided to the oil receiving pan 19 through the oil guide groove 18 for collection; the lower water phase is discharged through the drain pipe 16 and recovered together with the solid impurities discharged from the slag discharge pipe 6; 4. The solid impurities discharged from the slag discharge port, the bottom flow of the oil storage tank, the separated oil phase, and the activated carbon slag after filter pressing are all sent to the boiling roasting furnace for processing and recovery of valuable metals.

[0014] According to the zinc-containing wastewater recycling method of the present invention, the zinc-containing wastewater is subjected to oil-water mixed phase separation equipment and activated carbon adsorption and filtration, which can effectively remove oil and organic matter in the zinc-containing wastewater, reduce the input of activated carbon, reduce production costs, reduce the load of the filter press, and effectively recover zinc and other valuable metals in the zinc-containing wastewater. Therefore, the method realizes the resource and green utilization of zinc-containing wastewater, has the advantages of improving corporate benefits and meeting the national requirements for green development of the industry and energy conservation and emission reduction.

Claims

1. A zinc-containing wastewater recycling device, characterized in that: It comprises an oil-water mixed phase separation mechanism and an activated carbon adsorption separation mechanism; wherein the oil-water mixed phase separation mechanism comprises a shell, wherein the inner cavity of the shell is divided into a primary oil-water separation tank (1), a secondary oil-water separation tank (2), and an oil storage tank (3) by a partition, and the oil storage tank (3) is located between the primary oil-water separation tank and the secondary oil-water separation tank; a liquid inlet pipe (8) is arranged at the top of the primary oil-water separation tank, the bottom of the primary oil-water separation tank is a V-shaped sedimentation bottom (5), a slag discharge pipe (6) is connected to the bottom of the primary oil-water separation tank, the primary oil-water separation tank (1) and the secondary oil-water separation tank (2) are connected via one or more connecting pipes (7), and an oil scraper I (4) is arranged above the partition between the primary oil-water separation tank and the oil storage tank; An air distribution pipe (9) is arranged at the bottom of the secondary oil-water separation tank, and the air distribution pipe (9) is connected to an air source through a compressed air inlet pipe (10). An oil scraper II (11) is arranged above a partition between the secondary oil-water separation tank and the oil storage tank. A water phase overflow pipe (12) is arranged at one side of the secondary oil-water separation tank and its water inlet is located at the bottom of the secondary oil-water separation tank. A vent pipe I (13) is arranged at one side of the bottom of the secondary oil-water separation tank. An oil outlet (14) is opened at one side of the upper part of the oil storage tank. A vent pipe II (15) and a drain pipe (16) are arranged at the bottom of the secondary oil-water separation tank. The drain pipe (16) and the slag discharge pipe (6) are connected to a delivery pump (17) through a pipeline. The oil outlet (14) is connected to an oil receiving pan (19) through an oil guide groove (18). The activated carbon adsorption and separation mechanism comprises a stirring tank (20), a carbon powder bin (21), a stirrer (22), an overflow channel (24), a chute (25), an intermediate liquid storage tank (26), and a filter press (27). The carbon powder bin (21) is arranged above the inlet of the stirring tank (20), the stirrer (22) is arranged in the stirring tank, the overflow channel (24) is arranged in the stirring tank and its outlet is connected to the intermediate liquid storage tank (26) through the inclined chute (25), the intermediate liquid storage tank (26) is connected to the filter press (27) through a filter press delivery pump (28) and a pipeline with a valve, and the water phase overflow pipe (12) of the secondary oil-water separation tank is connected to the stirring tank (20) through an overflow delivery pump (23) and a pipeline.

2. The zinc-containing wastewater recycling device according to claim 1, characterized in that: The height of the partition between the primary oil-water separation tank and the oil storage tank is higher than the height of the partition between the secondary oil-water separation tank and the oil storage tank, and the height of the oil outlet on the shell is lower than the height of the partition between the secondary oil-water separation tank and the oil storage tank.

3. The zinc-containing wastewater recycling device according to claim 1, characterized in that: The oil scraper I or the oil scraper II comprises an arc-shaped scraper blade and a rotating shaft. The scraper blade is movably arranged on the housing through the rotating shaft. The rotating shaft is connected to the output shaft of the motor and is driven to rotate thereby.

4. The zinc-containing wastewater recycling device according to claim 1, characterized in that: Valves are provided on the compressed air inlet pipe (10), the vent pipe I (13), the vent pipe II (15), the drainage pipe (16), the slag discharge pipe (6), and the air distribution pipe (9) at their outlets.

5. A method for treating zinc-containing wastewater using the zinc-containing wastewater recycling device according to claim 1, characterized in that: Here are the steps: (1) Zinc-containing wastewater enters the primary oil-water separation tank of the oil-water mixed phase separation mechanism through the liquid inlet pipe. In the primary oil-water separation tank, the zinc-containing wastewater is naturally separated by the difference in density between the oil and water phases. The upper oil phase overflows into the oil storage tank through the partition under the action of the oil scraper I, and the middle water phase flows into the secondary oil-water separation tank through the connecting pipe. The solid impurities settle at the bottom of the V-shaped sedimentation tank and are collected at the bottom of the primary oil-water separation tank and discharged through the slag discharge port. (2) Compressed air enters the air distribution pipe through the compressed air inlet pipe, and pneumatically stirs the wastewater in the secondary oil-water separation tank, so that the oil phase mixed in the water phase rises to the liquid surface together with the bubbles, and overflows into the oil storage tank through the partition under the action of the oil scraper II. The lower de-oiled water phase overflows through the water phase overflow pipe and enters the stirring tank of the activated carbon adsorption separation mechanism through the overflow delivery pump. The activated carbon powder is added into the stirring tank through the carbon powder bin, and the stirrer is turned on for stirring and adsorption. After adsorption, the liquid overflows into the chute through the overflow channel, and flows into the intermediate liquid storage tank through the chute. The liquid in the intermediate liquid storage tank enters the filter press under the action of the filter press delivery pump for filtration, and the filtrate is sent to the wet zinc smelting system for reuse; (3) The oil in the oil storage tank overflows through the oil outlet and is diverted to the oil receiving pan through the oil guide groove for collection; (4) The solid impurities discharged from the slag outlet, the bottom flow of the oil storage tank, the separated oil phase, and the activated carbon slag after filter pressing are all sent to the boiling roasting furnace for processing and recovery of valuable metals.

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