A device for recycling zinc-containing wastewater and a use method thereof

Abstract

The application 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 separates the zinc-containing wastewater into three stages through oil-water separation. In the first stage, a large amount of oil phase and solid impurities are removed under the action of an oil scraper and a sedimentation slope; in the second stage, the oil phase mixed in the water phase is separated from the bubbles and rises to the liquid surface under the action of a compressed air pipe; and in the third stage, the residual oil phase in the overflow water phase is adsorbed by using activated carbon powder, and pressure filtration is performed by using a filter press, so that the zinc-containing wastewater with relatively clean oil is obtained. The zinc-containing wastewater after oil removal is recycled to a production system. The device can realize resourceization and green recycling of the zinc-containing wastewater. Compared with a chemical method and a high-temperature decomposition method, the device can effectively avoid the addition of impurity elements and energy consumption, and can effectively reduce the amount of activated carbon in the carbon powder adsorption process and the working load of the filter press, so that the production cost is effectively controlled, and the production efficiency is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of non-ferrous hydrometallurgy, and particularly relates to a device for recycling zinc-containing wastewater and a use method. BACKGROUND

[0002] The generation of zinc-containing wastewater is inevitable in the zinc hydrometallurgy industry, and the zinc-containing wastewater contains zinc and other valuable metals, oils and organic matters, solid impurities and the like. Direct discharge will cause environmental pollution and valuable metal loss and the like. In the past, the zinc-containing wastewater was usually collected and directly recycled to the system. Such a method will cause oils and organic matters other than valuable metals to be brought into the system, which will seriously harm the zinc electrodeposition process and seriously affect the quality of zinc sheets and the service life of the electrode plate. Therefore, after being directly recycled to the system, a large amount of activated carbon powder needs to be added for adsorption and filtration, which not only increases the production cost, but also increases the working load of the filter press and reduces the production efficiency.

[0003] In the zinc hydrometallurgy industry, the main sources of oils and organic matters are: equipment lubricating oil and machine oil leakage into the system, P 204 and kerosene entering the system with raffinate. The main influences are as follows: 1. The existence of oils and organic matters can make the electrode potential of zinc cathode deviate to the negative direction, make zinc ion discharge blocked, and zinc is difficult to deposit, while hydrogen is relatively easy to deposit, thereby producing back-dissolution and burning plate, and causing the deposition current efficiency to decrease significantly and the power consumption to increase; 2. Fatty acids can make manganese ions deposit outside the electrolytic cell, which is different from the normal deposition near the anode, and can be deposited in the anode mud and settled to the bottom of the cell, but is suspended in the solution, so that the crystallization growth of the launder, liquid collecting tank and cooling tower is accelerated, and the frequency of crystallization removal is increased; 3. The more types of oils and organic matters entering the system, the more the additive effect exists, which reduces the critical concentration and the dangerous concentration, and makes it easier to occur back-dissolution and burning plate. The organic matters can possibly produce derivatives or chelates, which are more harmful and have a longer back-dissolution time. SUMMARY

[0004] In view of the problems in the prior art, the application provides a zinc-containing wastewater recycling device and method. The device and method can separate the oils and organic matters that are not conducive to production from the zinc-containing wastewater, and then recycle and utilize the zinc-containing wastewater, so as to realize the resourceization and green utilization of the zinc-containing wastewater, improve the enterprise benefit, and meet the requirements of the state for green development, energy saving and emission reduction of the industry.

[0005] The application discloses a zinc-containing wastewater recycling device, which comprises an oil-water mixed phase separation mechanism and an activated carbon adsorption separation mechanism.

[0006] The activated carbon adsorption separation mechanism comprises 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 the outlet of the overflow channel is communicated with the intermediate liquid storage tank through an inclined chute, the intermediate liquid storage tank is connected with the filter press through a filter press conveying pump and a pipeline provided with a valve, and the water phase overflow pipe of the secondary oil-water separation tank is communicated with the stirring tank through an overflow conveying pump and a pipeline.

[0007] The height of the partition plate between the primary oil-water separation tank and the oil storage tank is higher than the height of the partition plate 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 plate between the secondary oil-water separation tank and the oil storage tank.

[0008] The scraper I or the scraper II comprises an arc-shaped scraper and a rotating shaft, the scraper is movably arranged on the shell through the rotating shaft, and the rotating shaft is connected with the output shaft of a motor and is driven to rotate by the motor.

[0009] Valves are arranged on the compressed air inlet pipe, the emptying pipe I, the emptying pipe II, the water drainage pipe, the residue discharge pipe and the gas distribution pipe.

[0010] The use method of the device is as follows.

[0011] (1) the zinc-containing wastewater enters the first-stage oil-water separation tank of the oil-water mixed phase separation mechanism through the liquid inlet pipe, the zinc-containing wastewater is naturally stratified in the first-stage oil-water separation tank through the density difference between the oil-water phases, the upper oil phase flows into the oil storage tank through the overflow of the partition under the action of the oil scraper I, the middle water phase flows into the second-stage oil-water separation tank through the connecting pipe, and the solid impurities are collected at the bottom of the first-stage oil-water separation tank and discharged through the slag discharge port;

[0012] (2) compressed air enters the gas distribution pipe through the compressed air inlet pipe to aerate the wastewater in the second-stage oil-water separation tank, so that the oil phase mixed in the water phase rises to the liquid surface with the air bubbles, and the oil phase flows into the oil storage tank through the overflow of the partition under the action of the oil scraper II, and the lower oil-removed water phase flows out through the water phase overflow pipe and enters the stirring tank of the activated carbon adsorption separation mechanism through the overflow conveying pump, the activated carbon powder is added into the stirring tank through the carbon powder bin, the stirrer is started, and the oil is removed by stirring and adsorption, and the liquid after adsorption flows into the intermediate liquid storage tank through the overflow channel, and the liquid in the intermediate liquid storage tank flows into the filter press conveying pump to enter the filter press for pressure filtration, and the filtrate is sent to the zinc hydrometallurgy system for reuse;

[0013] (3) the oil phase in the oil storage tank flows out through the oil outlet and is guided to the oil collection disc through the oil guide groove;

[0014] (4) the solid impurities, the bottom flow of the oil storage tank, the separated oil phase and the activated carbon residue after pressure filtration are all sent to the fluidized roasting furnace for treatment and recovery of valuable metals.

[0015] Advantages and technical effects of the present application:

[0016] The device of the present application preliminarily separates the zinc-containing wastewater by using the oil-water mixed phase separation mechanism to remove most of the oil and organic matter, and then uses a small amount of activated carbon powder for adsorption and filtration to remove the oil and organic matter remaining in the water phase, and 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 pressure filtration are sent to the fluidized roasting furnace for roasting, which can improve the heat of the fluidized roasting and further recover the valuable metals mixed therein. This method removes the oil and organic matter in the zinc-containing wastewater by physical separation, which can effectively avoid the addition of impurity elements and energy consumption compared with chemical method and high-temperature decomposition method, and can effectively reduce the amount of activated carbon in the carbon powder adsorption process, reduce the working load of the filter press, and apply this zinc-containing wastewater recycling method to the zinc hydrometallurgy process, thereby effectively controlling the production cost and improving the production efficiency.

[0017] The present application realizes the resource utilization and green utilization of zinc-containing wastewater, which is beneficial to improve the enterprise efficiency and meet the requirements of national green development, energy saving and emission reduction. BRIEF DESCRIPTION OF DRAWINGS

[0018] Fig. 1 Structure diagram of oil-water mixed phase separation mechanism of the present application;

[0019] Fig. 2 Structure diagram of oil storage tank part;

[0020] Fig. 3 Structure diagram of activated carbon adsorption separation mechanism;

[0021] In the figure: 1 - first-stage oil-water separation tank; 2 - second-stage oil-water separation tank; 3 - oil storage tank; 4 - oil scraper I; 5 - V-shaped settling bottom; 6 - slag discharge pipe; 7 - communication 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 - stirring tank; 21 - carbon powder bin; 22 - stirrer; 23 - overflow delivery pump; 24 - overflow passage; 25 - chute; 26 - intermediate liquid storage tank; 27 - filter press; 28 - filter press delivery pump. DETAILED DESCRIPTION

[0022] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application;

[0023] Example 1: as Figs. 1-3As shown, the zinc-containing wastewater recycling device comprises an oil-water mixed phase separation mechanism and an activated carbon adsorption separation mechanism. The oil-water mixed phase separation mechanism comprises a rectangular shell, and the inner cavity of the shell is divided into a first oil-water separation tank 1, a second oil-water separation tank 2 and an oil storage tank 3 by two partitions. The oil storage tank 3 is located between the first oil-water separation tank and the second oil-water separation tank, and the height of the partition between the first oil-water separation tank and the oil storage tank is 2 cm higher than that of the partition between the second oil-water separation tank and the oil storage tank. The top of the first oil-water separation tank is provided with a liquid inlet pipe 8, and the bottom of the first oil-water separation tank is a V-shaped sedimentation bottom 5 (inclination angle 30°). A residue discharge pipe 6 is in communication with the bottom of the first oil-water separation tank. The first oil-water separation tank 1 and the second oil-water separation tank 2 are connected by two communication pipes 7. An oil scraper I 4 is arranged above the partition between the first oil-water separation tank and the oil storage tank. The oil scraper I comprises an arc-shaped scraper and a rotating shaft. The scraper is movably arranged on the shell through the rotating shaft, and the rotating shaft is connected with the output shaft of a motor and driven to rotate by the motor. The bottom of the second oil-water separation tank is provided with a gas distribution pipe 9, which is connected with an air source through a compressed air inlet pipe 10. An oil scraper II 11 is arranged above the partition between the second oil-water separation tank and the oil storage tank. The oil scraper II comprises an arc-shaped scraper and a rotating shaft. The scraper is movably arranged on the shell through the rotating shaft, and the rotating shaft is connected with the output shaft of a motor and driven to rotate by the motor. A water phase overflow pipe 12 is arranged on one side of the second oil-water separation tank, and the water inlet of the water phase overflow pipe 12 is located at the bottom of the second oil-water separation tank. A vent pipe I 13 is arranged on one side of the bottom of the second oil-water separation tank. An oil outlet 14 is formed in one side of the upper part of the oil storage tank. The height of the oil outlet 14 is 2 cm lower than the height of the partition between the second oil-water separation tank and the oil storage tank. The whole device is a gradient. The bottom of the second oil-water separation tank is provided with a vent pipe II 15 and a drain pipe 16. The drain pipe 16 and the residue discharge pipe 6 are connected with a conveying pump 17 through pipes. The oil outlet 14 is connected with an oil receiving disc 19 through a oil guide groove 18. The activated carbon adsorption 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 the outlet of the overflow channel 24 is connected with the intermediate liquid storage tank 26 through an inclined chute 25. The intermediate liquid storage tank 26 is connected with the filter press 27 through a filter press conveying pump 28 and a pipe with a valve. The water phase overflow pipe 12 of the second oil-water separation tank is connected with the stirring tank 20 through an overflow conveying pump 23 and a pipe. Valves are arranged on the outlets of the compressed air inlet pipe 10, the vent pipe I 13, the vent pipe II 15, the drain pipe 16, the residue discharge pipe 6 and the gas distribution pipe 9.

[0024] When the above device is used:

[0025] 1. The zinc-containing wastewater mainly comes from the zinc-containing wastewater generated during the cleaning of zinc sheets and polar plates in the electrolysis process. The wastewater is collected by a floor drain and flows into a trench at a flow rate of 2 m 3The zinc-containing wastewater enters the first-stage oil-water separation tank 1 of the oil-water mixed phase separation mechanism through the inlet pipe, and the flow of the zinc-containing wastewater is controlled by the inlet pipe (controlled according to the actual amount of zinc-containing wastewater and the processing capacity of the oil-water mixed phase separation mechanism). The zinc-containing wastewater is naturally stratified in the first-stage oil-water separation tank according to the density difference between the oil and water phases. The upper oil phase is overflowed to the oil storage tank 3 through the baffle under the action of the oil scraper I 4 (the rotating speed is 30 r / min, and the scraping depth of the scraper is 0.5 cm below the water phase), and the middle water phase flows to the second-stage oil-water separation tank 2 through the connecting pipe 7. The process is driven by the pressure difference between the first-stage oil-water separation tank and the second-stage oil-water separation tank formed by the wastewater flow, which provides potential energy for the water phase of the connecting pipe. The zinc-containing wastewater naturally flows from the first-stage oil-water separation tank to the second-stage oil-water separation tank. The solid impurities are collected at the bottom of the first-stage oil-water separation tank through the V-shaped sedimentation bottom 5 and are separated from the water phase. The solid impurities are discharged through the slag discharge port 6.

[0026] 2. The compressed air enters the U-shaped air distribution pipe 9 through the compressed air inlet pipe 10 (the air hole diameter is 3 mm, and the spacing is 5 cm), and the wastewater in the second-stage oil-water separation tank is aerated and stirred, so that the gas bubbles uniformly penetrate the entire liquid phase, and the oil phase mixed in the water phase rises to the liquid surface with the gas bubbles. Under the action of the oil scraper II 11, the oil phase is overflowed to the oil storage tank 3 through the baffle. The rotating speed of the oil scraper II is 30 r / min, and the scraping depth of the scraper is 0.5 cm below the water phase. The lower oil-removed water phase is overflowed through the water phase overflow pipe 12. The water phase overflow pipe 12 is a reverse U-shaped pipe, the inner bend of the water phase overflow pipe is the water phase overflow baseline, and the water phase overflow baseline is lower than the baffle between the second-stage oil-water separation tank and the oil storage tank by 2-3 cm, so that the water phase can be discharged in time without bringing out the oil phase. The overflowed liquid enters the stirring tank 20 of the activated carbon adsorption separation mechanism through the overflow conveying pump 23. The activated carbon powder is added into the stirring tank through the carbon powder bin 21. The stirrer 22 is started, the oil is removed by adsorption for 1 h, and the adsorbed liquid is overflowed to the inclined chute 25 through the overflow channel 24. The liquid flows into the intermediate liquid storage tank 26 through the chute. The liquid in the intermediate liquid storage tank is subjected to pressure filtration under the action of the pressure filtration conveying pump 28 and enters the pressure filter 27 for pressure filtration. The filtrate is sent to the zinc hydrometallurgy for reuse.

[0027] 3. The oil phase from the first-stage oil-water separation tank 1 and the second-stage oil-water separation tank 2 contains a small amount of water phase. After standing in the oil storage tank 3, the oil phase and the water phase can be naturally stratified. The upper oil phase is overflowed through the oil outlet 14 and is guided to the oil collection disc 19 through the oil guide tank 18. The lower water phase is discharged through the drain pipe 16 and is recovered together with the solid impurities discharged through the slag discharge pipe 6.

[0028] 4. The solid impurities discharged through the slag discharge port, the bottom flow of the oil storage tank, the separated oil phase, and the activated carbon residue after pressure filtration are all sent to the fluidized roasting furnace for treatment and recovery of valuable metals.

[0029] According to the zinc-containing wastewater recycling method, the oil and organic matter in the zinc-containing wastewater can be effectively removed by the oil-water mixed phase separation equipment and activated carbon adsorption and filtration, the activated carbon input amount is reduced, the production cost is reduced, the filter press load is reduced, and the zinc and other valuable metals in the zinc-containing wastewater are effectively recovered. Therefore, the method realizes the resource utilization and green utilization of the zinc-containing wastewater, is beneficial to improving the enterprise benefits, and meets the advantages of meeting the requirements of the state on the green development, energy saving and emission reduction of the industry.

Claims

1. A device for recycling zinc-containing wastewater, characterized in that: It 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 shell, the inner cavity of which is divided by a partition into a primary oil-water separation tank (1), a secondary oil-water separation tank (2), and an oil storage tank (3), and the oil storage tank (3) is located between the primary oil-water separation tank and the secondary oil-water separation tank; the top of the primary oil-water separation tank is provided with an inlet pipe (8), the bottom of the primary oil-water separation tank is a V-shaped settling bottom (5), the 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 by one or more connecting pipes (7), and the oil scraper I (4) is set above the partition between the primary oil-water separation tank and the oil storage tank; A gas distribution pipe (9) is installed at the bottom of the secondary oil-water separator. The gas distribution pipe (9) is connected to the air source through the compressed air inlet pipe (10). The oil scraper II (11) is installed above the partition between the secondary oil-water separator and the oil storage tank. The water phase overflow pipe (12) is installed on one side of the secondary oil-water separator and its inlet is located at the bottom of the secondary oil-water separator. The vent pipe I (13) is installed on one side of the bottom of the secondary oil-water separator. An oil outlet (14) is opened on one side of the upper part of the oil storage tank. The vent pipe II (15) and the drain pipe (16) are installed at the bottom of the secondary oil-water separator. The drain pipe (16) and the slag discharge pipe (6) are connected to the delivery pump (17) through the pipeline. The oil outlet (14) is connected to the oil receiving tray (19) through the oil guide groove (18). The activated carbon adsorption separation mechanism includes a stirring tank (20), a carbon powder bin (21), a mixer (22), an overflow channel (24), a chute (25), an intermediate storage tank (26), and a filter press (27). The carbon powder bin (21) is located above the inlet of the stirring tank (20), the mixer (22) is located inside the stirring tank, the overflow channel (24) is located inside the stirring tank and its outlet is connected to the intermediate storage tank (26) through an inclined chute (25), the intermediate storage tank (26) is connected to the filter press (27) through a filter press delivery pump (28) and a pipe 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 pipe. The height of the partition between the primary oil-water separator and the oil storage tank is higher than the height of the partition between the secondary oil-water separator 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 separator and the oil storage tank. Oil scraper I or oil scraper II includes an arc-shaped scraper blade and a rotating shaft. The scraper blade is movably mounted on the housing via the rotating shaft, and the rotating shaft is connected to the output shaft of the motor and driven to rotate by it. The method of using the above device is as follows: (1) Zinc-containing wastewater enters the first-stage oil-water separation tank of the oil-water mixed phase separation mechanism through the inlet pipe. In the first-stage oil-water separation tank, the zinc-containing wastewater naturally separates into layers due to the density difference between the oil and water phases. The upper oil phase overflows into the oil storage tank through the baffle plate under the action of the oil scraper I. The middle water phase flows into the second-stage oil-water separation tank through the connecting pipe. Solid impurities settle at the bottom of the first-stage oil-water separation tank through the V-shaped sedimentation bottom and are 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 with the air bubbles. Under the action of the oil scraper II, it overflows into the oil storage tank through the baffle. The lower layer of 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 conveying pump. Activated carbon powder is added into the stirring tank through the carbon powder bin. The stirrer is turned on to stir and adsorb. After adsorption, the liquid overflows into the chute through the overflow channel and flows into the intermediate storage tank through the chute. The liquid in the intermediate storage tank enters the filter press for filtration under the action of the filter press conveying pump. The filtrate is sent to the wet zinc smelting system for reuse. (3) The oil phase in the oil storage tank overflows through the oil outlet and is guided to the oil receiving pan for collection through the oil guide groove; (4) 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 pressure filtration are all sent to the fluidized bed roasting furnace for processing and recovery of valuable metals.

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

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