A rare earth extraction high-sodium wastewater treatment system

Abstract

The present invention relates to the field of rare earth extraction wastewater treatment, and particularly to a high-sodium wastewater treatment system for rare earth extraction, which includes a settling tank. The outlet of the settling tank is successively connected in series with three groups of purification units through pipelines. The outlet of the last purification unit is successively connected in series with a flocculation unit, an evaporation unit, and a salt production unit through pipelines. The purification unit includes a first chemical addition part and a sedimentation part. The purification unit is used for removing extraction oil and heavy metals in the wastewater; the sedimentation part is used for removing precipitates in the wastewater after adding chemicals; the flocculation unit is used for the flocculation precipitation of substances such as colloids in the wastewater; the evaporation unit is used for the natural evaporation of the wastewater, so as to realize the concentration of the wastewater, and the salt production unit is used for the precipitation and post-treatment of product salts. The present invention deeply removes the characteristic pollutants, organic matters, and impurities contained in the high-sodium wastewater from rare earth extraction, and uses solar energy and wind energy for natural evaporation, ultimately realizing zero discharge of wastewater and the recycling of industrial salts.

Description

Technical Field

[0001] The present invention relates to the field of rare earth extraction wastewater treatment, and particularly to a high-sodium wastewater treatment system for rare earth extraction. Background Art

[0002] In the process of rare earth extraction and separation, due to the extensive use of acid-base substances such as hydrochloric acid, ammonia water, and liquid caustic soda, high-concentration saline wastewater will ultimately be generated. These wastewaters not only contain high concentrations of salts (such as sodium chloride), but may also contain harmful substances such as heavy metal ions and organic solvents. For every 1 ton of rare earth oxide separated, 30 - 60 tons of wastewater will be produced. If such a large amount of wastewater is directly discharged into the environment, it will have a serious negative impact on the soil, water source, and ecological environment.

[0003] Conventional methods for high-sodium wastewater in rare earth separation usually achieve zero discharge of wastewater through forced evaporation methods such as multi-effect evaporation or MVR evaporation, but this requires a large amount of thermal energy and electrical energy, and the energy consumption and carbon emissions per unit of wastewater are very high. At the same time, the by-product salt obtained through forced evaporation often has poor quality, generally contains more impurities, and there will be more heavy metal ions doped in the product, posing a risk of producing hazardous waste. Summary of the Invention

[0004] In order to solve the aforementioned technical problems, the present invention provides a high-sodium wastewater treatment system for rare earth extraction, which solves the high energy consumption problem of high-sodium wastewater in rare earth extraction through natural evaporation and concentration crystallization; removes impurities and heavy metal ions in the wastewater through methods such as static settlement, multiple purification, and flocculation air flotation, reducing the hazardous waste risk of by-product salt; specifically, it is achieved through the following technical solutions.

[0005] A high-sodium wastewater treatment system for rare earth extraction of the present invention includes a static settlement tank, and the static settlement tank is used for static settlement and stratification treatment of wastewater.

[0006] The outlet of the static settlement tank is successively connected in series with three groups of purification units through pipelines, and the water outlet of the last group of purification units is successively connected in series with a flocculation unit, an evaporation unit, and a salt output unit through pipelines.

[0007] The purification unit includes a first chemical addition part and a sedimentation part. The first chemical addition part includes a reflux bin and a bin cover sealedly installed thereon. A number of stirring fan blades are rotatably installed in the reflux bin, and the reflux bin is communicated with a chemical agent tank through a first chemical addition pump.

[0008] The sedimentation part includes a sedimentation cylinder and a spiral tube installed inside it. The spiral tube is communicated with the first chemical addition part, and an annular groove is opened on the inner side of the spiral tube.

[0009] The flocculation unit includes a flocculation cylinder. A second chemical addition part is installed on the side of the flocculation cylinder, a gas supply part is installed at the bottom of the flocculation cylinder, and a slag collection cylinder is installed inside the flocculation cylinder.

[0010] The evaporation unit includes a number of evaporation ponds, and the salt discharging unit includes a number of crystallization ponds and a salt discharging workshop.

[0011] Preferably, the first chemical adding part includes a first pipeline. The outlet of the static pond is communicated with the first pipeline through a pipeline installed with a pump body. The first pipeline is fixedly communicated with a conical pipe. The conical pipe is coaxially arranged in the reflux bin. The bottom side of the reflux bin is fixedly communicated with a second pipeline.

[0012] A first motor is installed on the bin cover. The output end of the first motor passes through the bin cover and is fixed to a number of stirring fan blades.

[0013] Preferably, the sedimentation part includes a third pipeline. The third pipeline is communicated with the first chemical adding part. The third pipeline is hermetically passed through a sedimentation cylinder and fixedly communicated with a volute pipe. The top of the sedimentation cylinder is fixedly communicated with a fourth pipeline.

[0014] A conical platform is arranged below the volute pipe. The conical platform is coaxially fixed to the bottom of the sedimentation cylinder. An annular channel is formed between the conical platform and the sedimentation cylinder. The bottom of the annular channel is fixedly communicated with a number of sewage discharge pipes. Control valves are installed on each of the sewage discharge pipes.

[0015] The inner top of the volute pipe is fixed to a sedimentation plate. The inner bottom of the volute pipe is fixed to a guide plate. The outer sides of the sedimentation plate and the guide plate are hermetically fixed through an annular plate. A number of mounting columns are fixed on the guide plate. The mounting columns are fixed to the conical platform.

[0016] Preferably, one end of the flocculation cylinder is respectively fixedly communicated with a first solenoid valve and a second solenoid valve. Two groups of second chemical adding parts are sequentially installed on one side of the flocculation cylinder close to the first solenoid valve. An annular gap is formed between the slag collecting cylinder and the flocculation cylinder. A baffle is hermetically installed in the annular gap between the first solenoid valve and the second solenoid valve.

[0017] A number of mounting blocks are uniformly fixed on the inner wall of the flocculation cylinder. The mounting blocks are fixed to the slag collecting cylinder. A fifth pipeline is fixedly installed on the slag collecting cylinder. A sewage pump is installed on the fifth pipeline. One end of the fifth pipeline is arranged at the bottom of the slag collecting cylinder.

[0018] Preferably, the second chemical adding part includes a circulation bin. The circulation bin is fixed to the flocculation cylinder. A second motor is fixed on the circulation bin. The output end of the second motor passes through the side wall of the circulation bin and is fixed to a number of circulation fan blades. The circulation fan blades are arranged in the circulation bin and can rotate along its axis.

[0019] The top side of the circulation bin is fixedly communicated with a reflux pipe. The reflux pipe is fixedly communicated with a shunt bin. A number of shunt holes are opened on the shunt bin;

[0020] The bottom side of the circulation bin is fixedly communicated with the inlet pipe, and the inlet pipe is internally communicated with the flocculation cylinder.

[0021] The circulation bin is fixedly communicated with the outlet of the second chemical dosing pump, and the inlet of the second chemical dosing pump is communicated with the chemical agent tank.

[0022] Preferably, the air supply part includes a cylinder wall, the cylinder wall is fixed to the bottom of the flocculation cylinder, an air supply pipe is installed on the cylinder wall, the air supply pipe is communicated with a high-pressure air pipe, the air supply pipe is fixedly communicated with a gas distribution groove, the gas distribution groove is arranged inside the cylinder wall, and the gas distribution groove is hermetically fixed to the bottom of the flocculation cylinder.

[0023] The gas distribution groove is fixedly communicated with a plurality of gas distribution pipes, and a plurality of nozzles are fixed on each of the plurality of gas distribution pipes, and the nozzles are communicated with the bottom of the flocculation cylinder.

[0024] Preferably, the output end of the first motor passes through the bin cover and is coaxially fixed to the flow dividing block, the flow dividing block is coaxially arranged at one end of the conical pipe away from the first pipe, and the flow dividing block is in the shape of a bullet head.

[0025] Preferably, the chemical agent added by the first group of the second chemical dosing parts is PAC, and the chemical agent added by the second group of the second chemical dosing parts is PAM.

[0026] Preferably, the cushion structure of the evaporation pond is, from outside to inside, a compacted foundation, a first layer of non-woven filament geotextile, a first layer of HDPE high-density ethylene geomembrane, an on-line conductor detection layer, a second layer of non-woven filament geotextile, a second layer of HDPE high-density ethylene geomembrane, and a third layer of non-woven filament geotextile.

[0027] Preferably, the chemical agent added by the first group of the first chemical dosing parts is polyaluminum chloride, the chemical agent added by the second group of the first chemical dosing parts is liquid sodium hydroxide, and the chemical agent added by the third group of the first chemical dosing parts is ethylenediaminetetraacetic acid.

[0028] After adopting the above technical solution, the beneficial effects of the present invention are:

[0029] 1. The present invention realizes the addition of chemical agents through the first chemical dosing part in the purification unit, realizes the separation of precipitates through the sedimentation part in the purification unit, realizes the deep degreasing of rare earth extraction high-sodium wastewater and the removal of heavy metal ions through three groups of purification units connected in series in sequence, and through the combination of the first chemical dosing part and the sedimentation part, continuously reacts to remove the extraction oil and heavy metal ions that are difficult to remove in the wastewater, facilitating the efficient recovery of sodium salts in the wastewater.

[0030] 2. The present invention realizes the aggregation of suspended substances such as colloids in wastewater through the flocculation unit, and combines the air flotation principle to make the flocs float to the water surface, thereby realizing the further purification of wastewater. This method is fast and efficient. On the one hand, it realizes the continuous operation of wastewater flocculation, and on the other hand, it realizes the efficient removal of flocs through the air flotation method, greatly improving the work efficiency.

[0031] 3. By means of natural drying combined with wind evaporation, the energy consumption is reduced, thus realizing the green and environmental protection treatment of the high-sodium wastewater in rare earth extraction.

[0032] 4. The recycling of sodium salts in wastewater is realized through the way of concentration and crystallization. On the one hand, it reduces the discharge pollution of wastewater, and on the other hand, through the recycling of sodium salts, the wastewater treatment cost of enterprises can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0034] Figure 1 It is a schematic diagram of a high-sodium wastewater treatment system for rare earth extraction;

[0035] Figure 2 It is a front sectional view of the first chemical addition part;

[0036] Figure 3 It is a longitudinal sectional view of the sedimentation part;

[0037] Figure 4 It is a transverse sectional view of the sedimentation part;

[0038] Figure 5 It is a front sectional view of the flocculation unit;

[0039] Figure 6 It is a schematic diagram of the disassembly of parts of the flocculation unit;

[0040] Figure 7 It is a structural schematic diagram of the second chemical addition part;

[0041] Figure 8 For Figure 7 Partial sectional view;

[0042] Figure 9 It is a structural schematic diagram of the air supply part;

[0043] Figure 10 It is a structural schematic diagram of the cushion layer of the evaporation pond.

[0044] Description of the reference numerals in the drawings:

[0045] 101 - Static settling tank, 102 - Purification unit;

[0046] 200 - First chemical addition section, 201 - First pipeline, 202 - Conical pipe, 203 - Return flow bin, 204 - Bin cover, 205 - First motor, 206 - Shunt block, 207 - Stirring fan blades, 208 - First chemical addition pump, 209 - Second pipeline;

[0047] 300 - Sedimentation section, 301 - Third pipeline, 302 - Sedimentation cylinder, 303 - Spiral pipe, 304 - Conical platform, 305 - Drain pipe, 306 - Fourth pipeline, 307 - Annular groove, 308 - Sedimentation plate, 309 - Deflector plate, 310 - Annular plate, 311 - Mounting column;

[0048] 400 - Flocculation unit, 401 - Flocculation cylinder, 402 - Mounting block, 403 - Slag collection cylinder, 404 - Fifth pipeline, 405 - Drainage pump, 406 - Baffle, 407 - First solenoid valve, 408 - Second solenoid valve, 410 - Second chemical addition section, 411 - Circulation bin, 412 - Second motor, 413 - Circulation fan blades, 414 - Return pipe, 415 - Shunt bin, 416 - Shunt holes, 417 - Inflow pipe, 418 - Second chemical addition pump, 420 - Gas supply section, 421 - Cylinder wall, 422 - Gas supply pipe, 423 - Gas distribution groove, 424 - Gas distribution pipe, 425 - Nozzle;

[0049] 500 - Evaporation unit, 501 - Evaporation pond;

[0050] 600 - Salt output unit, 601 - Crystallization pond, 602 - Salt output workshop. Detailed implementation manners

[0051] The features and exemplary embodiments of various aspects of the present invention will be described in detail below. In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only configured to explain the present invention and are not configured to limit the present invention. For those skilled in the art, the present invention can be implemented without some of these specific details. The following description of the embodiments is only to provide a better understanding of the present invention by showing examples of the present invention.

[0052] The orientation terms used in the following description are all the directions shown in the figures, and do not limit the specific structure of the present invention. In the description of the present invention, it should also be noted that unless otherwise clearly specified and limited, the terms "installation, connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection or an integral connection; it can be directly connected or indirectly connected. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0053] An embodiment of the present invention provides a rare earth extraction high-sodium wastewater treatment system. Refer to Figure 1 , the system includes a settling tank 101, and the settling tank 101 is used for the static separation treatment of wastewater. Since a large amount of extractant is required in the rare earth extraction process, some organic solvents are contained in the wastewater. Due to the difference in density between the organic solvent and water, the wastewater is discharged into the settling tank 101 and left to stand for about 12 hours. During the standing period, the oil layer containing the extractant will gradually float to the water surface, causing obvious stratification of the wastewater in the settling tank 101. After the standing is over, the oil layer is removed by a skimmer, thereby effectively reducing the content of organic solvents in the wastewater, improving the efficiency of wastewater treatment on the one hand, and reducing the cost of subsequent wastewater treatment on the other hand.

[0054] Among them, since the effect of oil-water separation in the wastewater gradually deteriorates with the increase of the pH value of the wastewater, before standing, hydrochloric acid needs to be added to the wastewater to adjust the pH value of the wastewater to 2-3, thereby enhancing the stratification effect of the wastewater in the settling tank 101.

[0055] The outlet of the settling tank 101 is sequentially connected in series with three groups of purification units 102 through pipelines. The outlet of the last group of purification units 102 is sequentially connected in series with a flocculation unit 400, an evaporation unit 500 and a salt output unit 600 through pipelines. The first group of purification units 102 is used for further oil removal of the wastewater, the second group of purification units 102 is used for preliminary removal of heavy metal ions in the wastewater, and the third group of purification units 102 is used for deep removal of heavy metal ions in the wastewater.

[0056] The purification unit 102 includes a first chemical addition part 200 and a sedimentation part 300. Refer to Figure 2 , the first chemical addition part 200 includes a first pipeline 201. The outlet of the settling tank 101 is communicated with the first end of the first pipeline 201 through a pipeline equipped with a pump body. The second end of the first pipeline 201 is fixedly communicated with a conical pipe 202. The conical pipe 202 is coaxially arranged inside a reflux chamber 203. A chamber cover 204 is fixedly installed at the end of the reflux chamber 203 far from the first pipeline 201 in a sealed manner. The inner cavity formed by the reflux chamber 203 and the chamber cover 204 is used to complete the full mixing of the medicine and the wastewater.

[0057] One end of the bin cover 204 far from the reflux bin 203 is fixedly installed with a first motor 205. The output end of the first motor 205 passes through the bin cover 204 and is fixedly coaxial with the shunt block 206. The shunt block 206 is coaxially arranged at one end of the conical pipe 202 far from the first pipe 201. The shape of the shunt block 206 is similar to a bullet head and is used to evenly distribute the wastewater flowing into the reflux bin 203 from the conical pipe 202 in all directions. A number of stirring fan blades 207 are evenly fixed along the circumferential direction on the side surface of the shunt block 206 and are used to achieve sufficient mixing of the wastewater and the medicine.

[0058] A number of medicine inlet holes are opened on the side surface of the bin cover 204. The number of medicine inlet holes are respectively communicated with the medicine tank through the first medicine adding pump 208, so as to ensure that the medicine in the medicine tank can be transported into the reflux bin 203 and the inside of the bin cover 204 through the first medicine adding pump 208, and the mixing of the medicine and the wastewater is completed.

[0059] The bottom of the side surface of the reflux bin 203 is fixedly communicated with the second pipe 209 and is used to discharge the medicine and the wastewater mixed inside the reflux bin 203 and the bin cover 204 to the outside.

[0060] In the above structure, the wastewater enters the conical pipe 202 from the first pipe 201. Due to the configuration relationship between the conical pipe 202 and the shunt block 206, the wastewater entering the inside of the reflux bin 203 and the bin cover 204 is dispersed in all directions. At this time, a number of first medicine adding pumps 208 transport the medicine in the medicine tank into the inside of the reflux bin 203 and the bin cover 204, and through the stirring fan blades 207 driven by the first motor 205, sufficient mixing of the wastewater and the medicine is realized. After mixing, it flows downward through the gap between the conical pipe 202 and the side wall of the reflux bin 203 and is discharged to the outside through the second pipe 209.

[0061] In the above structure, the wastewater first flows upward and then downward, and flows from the middle to the surrounding directions. And during the flowing process, the stirring fan blades 207 are used to stir to realize flow disturbance, which strengthens the mixing effect of the medicine and the wastewater.

[0062] Among them, since the functions of the three groups of purification units 102 are different, the medicines added by the first medicine adding parts 200 in the three groups of purification units 102 are different. The medicine added by the first medicine adding part 200 in the first group is polyaluminum chloride. The aluminum ions of polyaluminum chloride form aluminum extraction compounds with low solubility with the extractant existing in the form of emulsified oil and dissolved oil. These aluminum extraction compounds will precipitate in-situ and be adsorbed and wrapped by the polymeric aluminum compounds (i.e., aluminum hydroxide, the reaction product of liquid alkali and liquid alkali), forming larger flocs or precipitates, so as to achieve the purpose of deep oil removal.

[0063] The medicine added by the first medicine adding part 200 in the second group is liquid sodium hydroxide. After adding liquid sodium hydroxide, the pH value of the wastewater is adjusted to 10 - 11.5. As the pH value increases, the heavy metal ions (such as Cu2+ , Pb 2+ , Zn 2+ , etc.) will combine with hydroxide ions to form corresponding hydroxides with low solubility, such as Cu(OH) 2 , Pb(OH) 2 , Zn(OH) 2 , etc., to achieve the purpose of removing heavy metal ions.

[0064] The reagent added by the first chemical addition part 200 of the third group is ethylenediaminetetraacetic acid. Ethylenediaminetetraacetic acid can undergo a chelation reaction with heavy metal ions. Ethylenediaminetetraacetic acid undergoes a coordination reaction with heavy metal ions through multiple coordination atoms (mainly nitrogen and oxygen) in its molecule to form a complex with a ring structure. These complexes have high stability, greatly reducing the activity of heavy metal ions and making them more difficult to dissolve in water. As the chelation reaction proceeds, heavy metal ions are gradually complexed by ethylenediaminetetraacetic acid to form water-insoluble precipitates.

[0065] As a further explanation of the above embodiments, see Figure 3 , Figure 4 , the sedimentation part 300 includes a third pipeline 301. The third pipeline 301 is communicated with the second pipeline 209 through a pipeline installed with a pump body. The third pipeline 301 is sealed through the side wall of the sedimentation cylinder 302 and fixedly communicated with the spiral pipe 303. The diameter of the spiral pipe 303 at the connection with the third pipeline 301 is 2 to 5 times the diameter of the third pipeline 301, and the track shape of the spiral pipe 303 is spiral.

[0066] A conical platform 304 is coaxially arranged directly below the spiral pipe 303. The top of the conical platform 304 is conical. The conical platform 304 is coaxially fixed to the bottom of the sedimentation cylinder 302. An annular channel is formed between the side wall of the conical platform 304 and the side wall of the sedimentation cylinder 302. This annular channel is used for the aggregation of sediments inside the sedimentation cylinder 302. The bottom of this annular channel is fixedly communicated with a plurality of sewage pipes 305. Control valves are installed on all the plurality of sewage pipes 305. The top of the side of the sedimentation cylinder 302 is fixedly communicated with a fourth pipeline 306. The fourth pipeline 306 is used to discharge the settled wastewater outward.

[0067] An annular groove 307 is annularly opened on the inner side of the spiral pipe 303. The annular groove 307 communicates the spiral pipe 303 with the sedimentation cylinder 302. The inner top of the spiral pipe 303 is fixed to the sedimentation plate 308, and the inner bottom of the spiral pipe 303 is fixed to the diversion plate 309. The sedimentation plate 308 and the diversion plate 309 are annular inclined plates with the same structure, and the inclination direction is from the inside to the outside and from top to bottom. The outer sides of the sedimentation plate 308 and the diversion plate 309 are fixedly sealed by an annular plate 310. A plurality of mounting columns 311 are uniformly fixed along the circumference at the bottom of the diversion plate 309. The mounting columns 311 are fixed to the conical platform 304.

[0068] Among them, the functions of the spiral tube 303 are reflected in the following two aspects. First, the liquid in the third pipeline 301 does not directly flow into the sedimentation cylinder 302, avoiding the too fast flow rate at the outlet position of the third pipeline 301 from affecting the sedimentation effect in the sedimentation cylinder 302. Second, through the guiding action of the spiral tube 303, the liquid flowing into the sedimentation cylinder 302 flows along the tangential direction of the circumference, causing the liquid to flow circumferentially in the sedimentation cylinder 302, avoiding the flow between the liquids at different horizontal heights and preventing poor sedimentation effects caused by turbulence.

[0069] Through the above structure in this embodiment, the sedimentation of solid substances in the wastewater can be quickly achieved, and solid-liquid separation can be completed. First, the wastewater after adding medicine through the first medicine adding part 200 is transported through the pipeline to the third pipeline 301. After entering the sedimentation cylinder 302, due to the change in pipe diameter, the flow rate of the wastewater slows down. After the wastewater passes through the annular groove 307 and enters the sedimentation cylinder 302 from the spiral tube 303, the flow rate further slows down. Therefore, in the slow flow rate, the solid substances mixed in the wastewater will settle downward, slide along the upper surface of the conical platform 304 to the bottom of the sedimentation cylinder 302. The solid substances that have not been completely sedimented in the wastewater move upward after passing through the annular groove 307 to the upper middle part of the sedimentation cylinder 302, and the flow rate further slows down. At this time, the solid substances settle downward under the action of gravity on the upper surface of the sedimentation plate 308. Since the sedimentation plate 308 is inclined, the solid substances settling on the upper surface of the sedimentation plate 308 will continue to slide downward to the bottom of the sedimentation cylinder 302. When the solid substances at the bottom of the sedimentation cylinder 302 are deposited to a certain thickness, the control valve on the sewage discharge pipe 305 is opened to discharge the sediment at the bottom of the sedimentation cylinder 302 outward.

[0070] Through the successive slowdown of the wastewater flow rate in the above structure, the solid substances mixed in the wastewater are sedimented in layers and finally deposited at the bottom of the sedimentation cylinder 302. This structure avoids the problem of reduced production efficiency caused by the static sedimentation method.

[0071] As a further explanation of the above embodiment, see Figure 1 、 Figure 5 、 Figure 6 , the fourth pipeline 306 in the third sedimentation part 300 is connected to the inlet of the flocculation unit 400 through a pipeline installed with a pump body. The flocculation unit 400 includes a flocculation cylinder 401. The cross-sectional shape of the flocculation cylinder 401 is a runway shape. One end of the flocculation cylinder 401 is fixedly connected to a first solenoid valve 407 and a second solenoid valve 408 respectively. The first solenoid valve 407 is connected to the fourth pipeline 306 of the third sedimentation part 300, and the second solenoid valve 408 is connected to the inlet of the evaporation unit 500.

[0072] On one side of the side wall of the flocculation cylinder 401 close to the first solenoid valve 407, two groups of second chemical dosing parts 410 are successively installed, which are used to add chemicals into the flocculation cylinder 401 to achieve the aggregation of colloids in the wastewater in the flocculation cylinder 401. At the bottom of the flocculation cylinder 401, an air supply part 420 is installed, which is used to uniformly ventilate the inside of the flocculation cylinder 401. By combining the bubbles with the aggregates in the wastewater, the aggregates are floated to the water surface.

[0073] A number of mounting blocks 402 are uniformly fixed on the inner wall of the flocculation cylinder 401. The lower ends of the mounting blocks 402 are arranged with chamfers. A number of mounting blocks 402 are fixed to the outer surface of the slag collection cylinder 403, so that a runway-shaped gap is formed between the slag collection cylinder 403 and the flocculation cylinder 401. The cross-section of the slag collection cylinder 403 gradually narrows from top to bottom. A fifth pipeline 404 is fixedly installed on the side of the slag collection cylinder 403. A sewage pump 405 is installed on the fifth pipeline 404. One end of the fifth pipeline 404 is arranged at the bottom of the slag collection cylinder 403.

[0074] A baffle 406 is vertically installed at one end of the outer side of the slag collection cylinder 403 close to the first solenoid valve 407. The baffle 406 is arranged in the gap between the slag collection cylinder 403 and the flocculation cylinder 401 and is distributed between the first solenoid valve 407 and the second solenoid valve 408, so as to completely separate the first solenoid valve 407 and the second solenoid valve 408. The wastewater entering the flocculation cylinder 401 through the first solenoid valve 407 can only flow along the gap between the slag collection cylinder 403 and the flocculation cylinder 401 for one week and then be discharged from the second solenoid valve 408.

[0075] The above process increases the travel of the wastewater in the flocculation cylinder 401, so that during the flow of the wastewater in the flocculation cylinder 401, it is fully mixed with the chemicals added into the flocculation cylinder 401 through the second chemical dosing part 410 to achieve the aggregation of colloids in the wastewater. The bubbles introduced into the flocculation cylinder 401 through the air supply part 420 float the aggregated flocs to the water surface, thereby completing the removal of impurities such as colloids in the wastewater.

[0076] Among them, the operator can control the flow rates of the first solenoid valve 407 and the second solenoid valve 408, so that the liquid level height in the flocculation cylinder 401 is 3 cm to 5 cm higher than the upper surface of the slag collection cylinder 403, so as to ensure that after the sewage pump 405 pumps the flocs in the slag collection cylinder 403 away through the fifth pipeline 404, the suspended matters floating on the water surface can smoothly flow into the slag collection cylinder 403, which is convenient for the centralized treatment of the flocs floating on the water surface.

[0077] As a further explanation of the above embodiment, see Figure 7 、 Figure 8, the second chemical addition part 410 includes a circulation bin 411. The circulation bin 411 is fixed to the side wall of the flocculation cylinder 401. A second motor 412 is fixedly installed on the side of the circulation bin 411 away from the flocculation cylinder 401. The output end of the second motor 412 passes through the side wall of the circulation bin 411 and is fixed to a number of circulation fan blades 413. The circulation fan blades 413 are arranged inside the circulation bin 411 and can rotate along its axis.

[0078] The top side of the circulation bin 411 is fixedly communicated with the first end of a return pipe 414. The second end of the return pipe 414 passes through the side wall of the flocculation cylinder 401 and is fixedly communicated with a distribution bin 415. A number of distribution holes 416 are evenly formed in the height direction on the side of the distribution bin 415 away from the return pipe 414. The distribution holes 416 communicate the distribution bin 415 with the inside of the flocculation cylinder 401.

[0079] The bottom side of the circulation bin 411 is fixedly communicated with the first end of an inlet pipe 417. The second end of the inlet pipe 417 passes through the side wall of the flocculation cylinder 401 and is communicated with the inside of the flocculation cylinder 401. The inlet pipe 417 is located directly below the return pipe 414. The return pipe 414 and the inlet pipe 417 are horizontally arranged. The return pipe 414 and the inlet pipe 417 are located on the first side of the vertical plane where the axis of the circulation bin 411 is located.

[0080] The bottom side of the circulation bin 411 is fixedly communicated with the outlet of a second chemical addition pump 418. The second chemical addition pump 418 is located on the second side of the vertical plane where the axis of the circulation bin 411 is located. The inlet of the second chemical addition pump 418 is communicated with a chemical agent tank.

[0081] Among them, the chemical agent added by the first group of the second chemical addition parts 410 is PAC (polyaluminum chloride), and the chemical agent added by the second group of the second chemical addition parts 410 is PAM (polyacrylamide). As a coagulant, PAC can neutralize the surface charge of colloidal particles in the wastewater and make them coagulate with each other into larger flocs. As a coagulant aid, PAM can further enhance the stability of the flocs.

[0082] With the above structure, the present invention performs chemical agent addition treatment on the wastewater inside the flocculation cylinder 401. After the wastewater enters the flocculation cylinder 401 through the first solenoid valve 407, it first flows through the side where the second chemical addition part 410 is located, thereby completing the chemical agent addition process for the wastewater. The second motor 412 drives the circulation fan blades 413 to rotate, sucking the wastewater in the flocculation cylinder 401 into the inside of the circulation bin 411 through the inlet pipe 417. At the same time, the second chemical addition pump 418 pumps the chemical agent in the chemical agent tank into the inside of the circulation bin 411, realizing the uniform mixing of the chemical agent and the wastewater inside the circulation bin 411. After the two are mixed, they are transported to the inside of the distribution bin 415 through the return pipe 414 and are evenly dispersed in the wastewater inside the flocculation cylinder 401 through the distribution holes 416.

[0083] By the above method, the medicament is evenly added to the wastewater in the flocculation cylinder 401. During the process of the wastewater flowing circularly in the flocculation cylinder 401, the aggregation of substances such as colloids in the wastewater is gradually achieved, thereby forming flocs. The flocs are combined with the bubbles input into the wastewater through the air supply part 420, and then float to the water surface position of the flocculation cylinder 401.

[0084] For a further explanation of the above embodiment, see Figure 9 , the air supply part 420 includes a cylinder wall 421, the cylinder wall 421 is fixed to the bottom of the flocculation cylinder 401, one side of the cylinder wall 421 is provided with an air supply pipe 422, the first end of the air supply pipe 422 is communicated with a high-pressure air pipe, the second end of the air supply pipe 422 is fixedly communicated with a gas distribution groove 423, the gas distribution groove 423 is arranged inside the cylinder wall 421, and the gas distribution groove 423 is fixedly sealed to the bottom of the flocculation cylinder 401.

[0085] A plurality of branch air pipes 424 are uniformly and fixedly communicated with the outer surface of the gas distribution groove 423. A plurality of nozzles 425 are fixedly installed on the branch air pipes 424. The nozzles 425 pass through the bottom of the flocculation cylinder 401 and are fixedly communicated with the bottom of the flocculation cylinder 401.

[0086] Wherein, a check valve is installed inside the branch air pipe 424 to prevent the wastewater in the flocculation cylinder 401 from flowing back to the inside of the gas distribution groove 423 through the nozzles 425 and the branch air pipes 424.

[0087] With the above structure in this embodiment, the high-pressure gas input by the air supply pipe 422 is evenly distributed to the bottom of the flocculation cylinder 401 through the gas distribution groove 423, the branch air pipes 424 and the nozzles 425 to form fine bubbles, which facilitates the combination of the bubbles with the flocs in the wastewater of the flocculation cylinder 401, enables the flocs to quickly float to the water surface position of the flocculation cylinder 401, and realizes the removal of the flocs in the wastewater.

[0088] For a further explanation of the embodiment of the present invention, see Figure 1 , the outlet of the flocculation unit 400 is communicated with the inlet of the evaporation unit 500 through a pipeline equipped with a pump body. The evaporation unit 500 includes an evaporation pond 501. The inlet of the evaporation unit 500 is successively connected in series with a plurality of evaporation ponds 501 through a pipeline and a pump body. The evaporation pond 501 is used for the natural evaporation and concentration of wastewater. The outlet of the evaporation unit 500 is communicated with the salt output unit 600 through a pipeline equipped with a pump body and the inlet of the salt output unit 600. The salt output unit 600 includes a crystallization pond 601 and a salt output workshop 602. The inlet of the salt output unit 600 is connected in parallel with the inlets of a plurality of crystallization ponds 601 through a pipeline. The crystallization pond 601 is used for precipitating salt crystals. The outlets of the plurality of crystallization ponds 601 are connected in parallel through a pipeline and are transported to the inlet of the evaporation unit 500 through a pipeline equipped with a pump body.

[0089] The wastewater is conveyed to the crystallization pond 601 to complete the precipitation of crystal salts, and the crystal salts are collected by a collector in the salt output workshop 602 for further treatment. The remaining wastewater is conveyed to the evaporation unit 500 for re-evaporation and concentration.

[0090] Among them, the salt output workshop 602 is located in the middle of several crystallization ponds 601, which is convenient for the crystal salts precipitated in the crystallization ponds 601 to be collected and transported to the salt output workshop 602.

[0091] As a further explanation of the present invention, see Figure 10 , the cushion structure of the evaporation pond 501 from the outside to the inside is a compacted foundation, the first layer of filament non-woven geotextile, the first layer of HDPE high-density ethylene geomembrane, the on-line conductor detection layer, the second layer of filament non-woven geotextile, the second layer of HDPE high-density ethylene geomembrane, and the third layer of filament non-woven geotextile.

[0092] The above structure is distributed on the bottom and inner wall of the evaporation pond 501, aiming to prevent the wastewater in the evaporation pond 501 from penetrating into the soil and groundwater, thereby protecting the environment and groundwater resources from pollution.

[0093] Among them, the filament non-woven geotextile plays a role of connecting the upper and lower parts, connecting and enhancing. The HDPE high-density ethylene geomembrane enhances the anti-seepage performance and at the same time improves the strength and durability of the overall structure.

[0094] Among them, the on-line conductor detection layer is a layered structure integrating conductive elements (such as metal meshes, conductive fibers, etc.). These conductive elements form a monitoring network, which can sense and transmit the state information of the anti-seepage lining layer in real time. When the leaked liquid submerges the conductive elements, the resistance or current between them will change. By detecting the change of resistance or current between the conductive elements, any breakage or leakage point in the anti-seepage lining layer can be found in time, and the specific leakage position can be quickly located, thus greatly shortening the repair time and cost.

[0095] Among them, the setting method and usage method of the on-line conductor detection layer are prior arts and will not be elaborated additionally here.

[0096] According to the embodiments of the present invention as described above, these embodiments do not describe all the details in detail, nor do they limit the present invention to only the specific embodiments. Obviously, according to the above description, many modifications and changes can be made. This specification selects and specifically describes these embodiments in order to better explain the principle and practical application of the present invention, so that those skilled in the relevant technical field can make good use of the present invention and its modified use based on the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A rare earth extraction high sodium wastewater treatment system, characterized in that: It comprises a static tank (101), wherein the static tank (101) is used for static stratification treatment of wastewater; The outlet of the static pool (101) is connected in series with three groups of purification units (102) via pipelines, and the water outlet of the last group of purification units (102) is connected in series with a flocculation unit (400), an evaporation unit (500) and a salt outlet unit (600) via pipelines; The purification unit (102) comprises a first dosing section (200) and a sedimentation section (300); the first dosing section (200) comprises a reflux bin (203) and a bin cover (204) sealed therewith; a plurality of stirring blades (207) are rotatably mounted in the reflux bin (203); and the reflux bin (203) is connected to a medicine box via a first dosing pump (208); The sedimentation part (300) comprises a sedimentation cylinder (302) and a volute (303) installed inside the sedimentation cylinder, the volute (303) is in communication with the first dosing part (200), and an annular groove (307) is formed on the inner side of the volute (303); The flocculation unit (400) comprises a flocculation cylinder (401), a second dosing portion (410) is installed on the side of the flocculation cylinder (401), an air supply portion (420) is installed at the bottom of the flocculation cylinder (401), and a slag collecting cylinder (403) is installed inside the flocculation cylinder (401); The evaporation unit (500) includes a plurality of evaporation pools (501), and the salt output unit (600) includes a plurality of crystallization pools (601) and a salt output workshop (602); The first dosing unit (200) comprises a first pipeline (201), the outlet of the static pool (101) is connected to the first pipeline (201) via a pipeline equipped with a pump body, the first pipeline (201) is fixedly connected to a conical tube (202), the conical tube (202) is coaxially arranged in a reflux bin (203), and the bottom of the side of the reflux bin (203) is fixedly connected to a second pipeline (209); A first motor (205) is mounted on the bin cover (204), and an output end of the first motor (205) passes through the bin cover (204) and is fixed to a plurality of stirring blades (207); The sedimentation part (300) comprises a third pipe (301), the third pipe (301) is in communication with the first dosing part (200), the third pipe (301) is sealed and passes through the sedimentation cylinder (302) and is fixedly connected with the volute (303), and the top of the sedimentation cylinder (302) is fixedly connected with the fourth pipe (306); A conical platform (304) is provided below the volute (303), the conical platform (304) is coaxially fixed with the bottom of the settling cylinder (302), an annular channel is formed between the conical platform (304) and the settling cylinder (302), the bottom of the annular channel is fixedly connected to a plurality of sewage pipes (305), and a control valve is installed on each of the sewage pipes (305); The inner top of the volute (303) is fixed to a settling plate (308), the inner bottom of the volute (303) is fixed to a guide plate (309), the outer sides of the settling plate (308) and the guide plate (309) are sealed and fixed via an annular plate (310), a plurality of mounting columns (311) are fixed to the guide plate (309), and the mounting columns (311) are fixed to the conical platform (304).

2. The rare earth extraction high sodium wastewater treatment system according to claim 1, characterized in that: One end of the flocculation cylinder (401) is fixedly connected to a first solenoid valve (407) and a second solenoid valve (408), two groups of second dosing parts (410) are sequentially installed on one side of the flocculation cylinder (401) close to the first solenoid valve (407), an annular gap is formed between the slag collecting cylinder (403) and the flocculation cylinder (401), and a baffle (406) is sealed between the first solenoid valve (407) and the second solenoid valve (408); A plurality of mounting blocks (402) are evenly fixed on the inner wall of the flocculation cylinder (401); the plurality of mounting blocks (402) are fixed to a slag collecting cylinder (403); a fifth pipe (404) is fixedly mounted on the slag collecting cylinder (403); a sewage pump (405) is mounted on the fifth pipe (404); and one end of the fifth pipe (404) is arranged at the bottom of the slag collecting cylinder (403).

3. The rare earth extraction high sodium wastewater treatment system according to claim 1, characterized in that: The second dosing section (410) comprises a circulation chamber (411), the circulation chamber (411) being fixed to the flocculation cylinder (401), a second motor (412) being fixed to the circulation chamber (411), an output end of the second motor (412) passing through a side wall of the circulation chamber (411) and being fixed to a plurality of circulation blades (413), the circulation blades (413) being arranged in the circulation chamber (411) and being able to rotate along their axis; The top side of the circulating chamber (411) is fixedly connected to the return pipe (414), the return pipe (414) is fixedly connected to the diversion chamber (415), and the diversion chamber (415) is provided with a plurality of diversion holes (416); The bottom side of the circulating chamber (411) is fixedly connected to the inlet pipe (417), and the inlet pipe (417) is connected to the inside of the flocculation cylinder (401); The circulating chamber (411) is fixedly connected to the outlet of the second dosing pump (418), and the inlet of the second dosing pump (418) is connected to the medicine box.

4. The rare earth extraction high sodium wastewater treatment system according to claim 1, characterized in that: The air supply portion (420) comprises a cylinder wall (421), the cylinder wall (421) is fixed to the bottom of the flocculation cylinder (401), an air supply pipe (422) is installed on the cylinder wall (421), the air supply pipe (422) is connected to the high-pressure air pipe, the air supply pipe (422) is fixedly connected to the air separation groove (423), the air separation groove (423) is arranged inside the cylinder wall (421), and the air separation groove (423) is sealed and fixed to the bottom of the flocculation cylinder (401); The gas distribution groove (423) is fixedly connected to a plurality of gas distribution pipes (424), a plurality of nozzles (425) are fixed on the plurality of gas distribution pipes (424), and the nozzles (425) are connected to the bottom of the flocculation cylinder (401).

5. The rare earth extraction high sodium wastewater treatment system according to claim 1, characterized in that: The output end of the first motor (205) passes through the compartment cover (204) and is coaxially fixed to a diverter block (206); the diverter block (206) is coaxially arranged at one end of the conical tube (202) away from the first pipeline (201); and the diverter block (206) is in the shape of a bullet head.

6. The rare earth extraction high sodium wastewater treatment system according to claim 2, characterized in that: The drug added by the second drug adding section (410) of the first group is PAC, and the drug added by the second drug adding section (410) of the second group is PAM.

7. The rare earth extraction high sodium wastewater treatment system according to claim 1, characterized in that: The cushion structure of the evaporation pond (501) is, from outside to inside, a compacted foundation, a first layer of filament non-blocking geotextile, a first layer of HDPE high-density polyethylene geomembrane, an online conductor detection layer, a second layer of filament non-blocking geotextile, a second layer of HDPE high-density polyethylene geomembrane, and a third layer of filament non-blocking geotextile.

8. The rare earth extraction high sodium wastewater treatment system according to claim 1, characterized in that: The reagent added by the first dosing section (200) of the first group is polyaluminium chloride, the reagent added by the first dosing section (200) of the second group is liquid sodium hydroxide, and the reagent added by the first dosing section (200) of the third group is ethylenediaminetetraacetic acid.

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