Continuous separation device and method for oil residue-containing wastewater in rare earth production process

Abstract

The invention discloses a continuous separation device for oil residue-containing wastewater in a rare earth production process, the continuous separation device comprises a diversion pool, a Dohr clarifying barrel, a horizontal screw centrifuge and a disc centrifuge, the diversion pool comprises a diversion pool body and an oil residue scraper, the diversion pool body is of a box body structure with an opening at the top, a track is arranged at the top of the diversion pool body, and the oil residue scraper is mounted on the track; the shunting pool body is provided with an oil collecting groove, a shunting pool oil discharging opening, a shunting pool water discharging opening, a slag collecting groove and a shunting pool slag discharging opening; the shunting pool oil discharging opening and the shunting pool slag discharging opening are respectively provided with a conveying pump and a control valve; an oil discharge port of the shunting pool is connected with a material inlet of the disc centrifuge through a pipeline, and a slag discharge port of the shunting pool is connected with a material inlet of the Dole clarifying barrel through a pipeline. The invention further discloses a continuous separation method for the oil residue-containing wastewater in the rare earth production process. The continuous oil-water-slag separation of the sulfuric acid rare earth transformation wastewater can be realized, so that the pretreatment efficiency of the rare earth transformation wastewater is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of rare earth hydrometallurgy, and in particular relates to a continuous separation device and method for oily residue wastewater in a rare earth production process. Background Art

[0002] In the rare earth production process, different elements are separated at each stage. Especially in the process of separating impurity elements from rare earth elements, the wastewater produced in the extraction process contains oil, emulsions and residues due to entrainment, chemical reactions, etc. For example, the calcium salt and magnesium salt wastewater produced by the saponification system using a solid saponifier contains, in addition to organic matter, a large amount of calcium slag and magnesium slag wrapped with organic matter, causing organic losses and bringing difficulties to the next step of wastewater treatment. At present, the industry's transformation wastewater treatment basically adopts the process route of ordinary oil separators, aeration and washing sediments, and manual oil recovery. It is impossible to achieve continuous oil-water-slag separation. The multi-step separation process is complicated, the labor intensity is high, and the organic recovery rate is low, especially the organic loss entrained in the slag is large.

[0003] Publication No. CN106145443A discloses a method for treating wastewater produced by rare earth, comprising the following steps: (1) passing the wastewater produced by rare earth into a sedimentation tank, and passing the supernatant through an impurity filter to remove particulate impurities; (2) adding a mixture of sodium carbonate and sodium bicarbonate to the wastewater after the impurities are removed to precipitate rare earth elements, separate solid and liquid, and add hydrochloric acid to the solid phase to obtain rare earth chloride; (3) passing the liquid phase separated in step (2) into a sedimentation tank, adding alkali to the sedimentation tank, adjusting the pH value to 10-13, and introducing the wastewater into an intermediate water tank by overflow after standing, using a lifting pump to extract the wastewater in the intermediate water tank into an ammonia stripper, converting ammonia nitrogen in the ammonia stripper into ammonia gas, and using a vacuum pump to extract the ammonia gas into a gas-liquid separator; detecting the drainage treated by the ammonia stripper, and directly discharging the drainage through a drainage pipe if the ammonia nitrogen meets the standard. The application uses a sedimentation tank + filter to remove impurities, uses alkaline solution precipitation, and a stripping device to remove ammonia nitrogen, ultimately achieving industrial utilization of wastewater. The entire process operates intermittently and cannot be operated continuously and automatically.

[0004] Publication No. CN113998818A discloses a method and system for treating wastewater from rare earth production. The wastewater from rare earth production is initially purified by pretreatment, and then the organic components of the wastewater are degraded by a catalytic oxidation device. The wastewater enters an ultrafiltration device and an ion exchanger for final purification in sequence. After purification, the wastewater is separated and purified in a nanofiltration device, and the nanofiltration concentrated water is returned to a high-efficiency sedimentation tank for treatment. The nanofiltration produced water enters a bipolar membrane electrodialysis device to produce hydrochloric acid solution, sodium hydroxide solution and dilute liquid. The dilute liquid is concentrated by a reverse osmosis device, and the produced reverse osmosis concentrated water is merged into the nanofiltration produced water. Finally, the hydrochloric acid solution is concentrated and concentrated for extraction and separation in rare earth production. Part of the sodium hydroxide solution is used for saponification production, and the remaining part of the sodium hydroxide solution is used to make sodium carbonate solution. This application uses a catalytic oxidation device to degrade the organic components of the wastewater, and the wastewater enters an ultrafiltration device and an ion exchanger for final purification in sequence, thereby reducing the organic content in the wastewater. However, the organic recycling of the wastewater is not achieved, and valuable resources are decomposed. Summary of the invention

[0005] The purpose of the present invention is to provide a continuous separation device and method for oil-residue wastewater in the rare earth production process, which can realize the continuous oil-water-residue separation of rare earth sulfate transformation wastewater to improve the pretreatment efficiency of rare earth transformation wastewater.

[0006] The technical solution is as follows:

[0007] The continuous separation device for oily residue wastewater in the rare earth production process includes: a diverter tank, a Doyle clarification barrel, a horizontal screw centrifuge, and a disc centrifuge. The diverter tank is used for sedimentation separation of transformation wastewater, including: a diverter tank body and an oily residue scraper. The diverter tank body is a box structure with an opening on the top. A track is arranged on the top of the diverter tank body, and an oily residue scraper is installed on the track; an oil collecting trough and a slag collecting ditch are arranged on the right side of the diverter tank body, and a diverter tank oil discharge port and a diverter tank drainage are arranged on the right side of the diverter tank body. The outlet of the diverter pool and the slag outlet of the diverter pool are respectively provided with a conveying pump and a control valve; the oil outlet of the diverter pool is connected to the material inlet of the disc centrifuge through a pipeline, and the slag outlet of the diverter pool is connected to the material inlet of the Doyle clarification barrel through a pipeline.

[0008] Furthermore, the diversion pool drain outlet is connected to the top opening of the diversion pool body through a pipeline, and the diversion pool drain outlet is provided with a delivery pump and a control valve.

[0009] Furthermore, the oil residue scraper includes: a fixed bracket, a traveling wheel, a first adjustment motor, a second adjustment motor, and a rotating bracket. The fixed bracket is connected to a plurality of traveling wheels, the traveling wheels are located on the track, and the traveling wheels are provided with a traveling motor; the first adjustment motor and the second adjustment motor are fixed to the upper part of the fixed bracket; the rotating bracket includes: a connecting frame, a long arm frame, a lower scraper, a long connecting arm, a short arm frame, an upper scraper, and a short connecting arm; the top of the connecting frame is connected to the bottom right side of the fixed bracket, the top of the long arm frame is hinged to the bottom of the connecting frame, and the lower The scraper is connected to the bottom end of the long arm frame; the lower part of the long connecting arm is hinged to the middle part of the long arm frame, and the long connecting arm is located on the left side of the long arm frame; one end of the pull rope is connected to the upper part of the long connecting arm, and the other end is connected to the rotating shaft of the first adjustment motor; the right side of the short arm frame is hinged to the upper part of the long arm frame, the upper scraper is connected to the left side of the short arm frame, and the short arm frame is located on the left side of the long arm frame; the bottom end of the short connecting arm is hinged to the middle part of the short arm frame, and the short connecting arm is located at the upper part of the short arm frame; one end of the pull rope is connected to the top of the short connecting arm, and the other end is connected to the rotating shaft of the second adjustment motor.

[0010] Furthermore, the connecting frame, the long arm frame, the lower scraper, the short arm frame and the fixed bracket are rectangular in shape.

[0011] Furthermore, the hinged positions of the short arm frame and the long arm frame are located above the hinged positions of the short arm frame and the long arm frame.

[0012] Furthermore, the Doyle clarifier includes: a clarifier body, a center barrel, and a mud rake. The clarifier body is a closed structure. The center barrel and the mud rake are located inside the clarifier body. The center barrel is located above the mud rake. The top of the center barrel is connected to the bottom of the top of the clarifier body. The material inlet arranged on the top of the Doyle clarifier is located on the inner side of the center barrel; an overflow trough is arranged above the inner wall of the clarifier body, and a clarified liquid outlet is arranged on the side wall of the clarifier body, and the clarified liquid outlet is connected to the overflow trough; a stirring motor is arranged above the top of the clarifier body, and both ends of the connecting shaft are respectively connected to the rotating shaft and the mud rake of the stirring motor; a clarifier slag discharge port is arranged at the bottom of the clarifier body, and the clarifier slag discharge port is connected to the material inlet of the horizontal screw centrifuge through a pipeline, and a conveying pump and a control valve are arranged at the clarifier slag discharge port.

[0013] The continuous separation method of oily residue wastewater in the rare earth production process comprises:

[0014] The transformation wastewater enters the diversion tank, where it flows under gravity to separate the oil phase, water phase, and sediment slag. The pipeline connected to the oil outlet of the diversion tank transports the separated oil phase to the disc centrifuge, and the pipeline connected to the slag outlet of the diversion tank transports the separated phase to the Doyle clarification tank.

[0015] The slag liquid containing sediment slag and transformation wastewater enters the Doyle clarification tank from the top for secondary water-slag separation. The water phase is discharged from the clarified liquid outlet, and the sediment slag is transported to the horizontal screw centrifuge through the pipeline;

[0016] The horizontal screw centrifuge rotates at high speed and uses centrifugal force to separate the solid and liquid of the sediment. The liquid phase mixed with the water phase and the oil phase is discharged into the disc centrifuge; the disc centrifuge separates the oil phase from the diversion tank and the liquid phase of the horizontal screw centrifuge and discharges them.

[0017] Preferably, the sedimentation and separation process of the transformation wastewater in the diversion tank includes:

[0018] After the transformation wastewater enters the diversion tank, the travel motor is started, and the travel wheel drives the oil residue scraper to move to the left side of the diversion tank. After the oil residue scraper reaches the set position, the travel motor stops;

[0019] Start the first adjustment motor, pull the long connecting arm through the pull rope, the long connecting arm pulls the long arm frame to rotate, and adjust the horizontal height of the lower scraper to the bottom of the diversion pool; start the second adjustment motor, pull the short connecting arm through the pull rope, the short connecting arm drives the short arm frame to rotate, and adjust the horizontal height of the upper scraper to the height of the oil phase floating on the upper part of the transformation wastewater;

[0020] Start the travel motor, and the travel wheel drives the oil residue scraper to move to the right. After the oil residue scraper reaches the set position, the travel motor stops. When the oil residue scraper moves to the right, the lower scraper pushes the sludge settled at the bottom of the diversion pool to the right, and the sludge enters the sludge collecting ditch; the upper scraper pushes the oil phase to the right, and the oil phase enters the oil collecting tank.

[0021] Preferably, in the Doyle clarification barrel, the stirring motor drives the mud rake to rotate, and the sludge settled to the bottom is thickened by the mud rake and collected at the slag discharge port of the clarification barrel at the bottom, and the sludge is output to the horizontal screw centrifuge through a pipeline.

[0022] Preferably, the pipeline connected to the drainage outlet of the diversion pool transports the separated water phase to the wastewater treatment process or to the diversion pool body for reuse.

[0023] The technical effects of the present invention include:

[0024] The present invention can realize the continuous oil-water-slag separation of the rare earth sulfate transformation wastewater, so as to improve the pretreatment efficiency of the rare earth transformation wastewater, reduce the labor intensity of workers, recycle organic matter, improve the impurity content of the waste residue, and improve the water quality of the wastewater after pretreatment to facilitate the next step of treatment.

[0025] The present invention realizes the separation of water-oil-residue, so that both the oil phase and the water phase can be reused in the production process, reducing the production cost. It not only recovers the valuable oil in the wastewater, but also recovers the valuable oil entrained in the waste residue, with a higher recovery rate, a lower water content in the discharged waste residue, and a lower entrained oil content, which is more friendly to transportation costs and the natural environment.

[0026] The present invention realizes continuous and automatic operation of the entire separation process by regulating the water inlet and outlet balance of the separation process through flow rate.

[0027] The economic benefits of the invention are remarkable after application.

[0028] The wastewater produced during the rare earth extraction and separation process enters the continuous separation system with a flow rate controlled at 4m 3 / h, the solid content in the raw water is 5%, the oil content is 1050mg / L, and the disc centrifuge processes 1m 3 / h, and the slag discharge of the horizontal screw centrifuge is 0.2t / h.

[0029] name Oil content Moisture content Remark After treatment, water phase 32ppm —— Mixed water phase of the effluent from the disc centrifuge and the effluent from the diversion tank Before treatment 5.35％ —— —— After treatment 3.34％ 34.2％ Horizontal screw centrifuge discharge port

[0030] Continuous operation for 30 days, total water treatment volume 2880m 3 The organic recycling volume is 95.6kg / day, the monthly recycling volume is 2868kg, the discounted volume is 717kg, the organic price is about 50,000 / ton, and the recycled organic value is 35,850 yuan. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural principle diagram of the continuous separation device of oil-water-slag of sulfuric acid rare earth transformation wastewater in the present invention.

[0032] Figure 2 It is a structural principle diagram of the oil residue scraper in the present invention. DETAILED DESCRIPTION

[0033] The following description sufficiently illustrates specific embodiments of the invention to enable those skilled in the art to practice and reproduce the invention.

[0034] like Figure 1 The figure shows the structural principle diagram of the continuous separation device of oil-water-slag of sulfuric acid rare earth transformation wastewater in the present invention.

[0035] The continuous separation device of oil-water slag of sulfuric acid rare earth transformation wastewater comprises: a diversion tank 1, a Doyle clarification barrel 2, a horizontal screw centrifuge 3, and a disc centrifuge 4.

[0036] Diverter pool 1 performs preliminary oil, water and slag sedimentation and separation of rare earth sulfate transformation wastewater. The transformation wastewater is pumped to diverter pool 1. Diverter pool 1 utilizes the different densities of oil, slag and water to achieve preliminary separation of oil, water and slag, separates high-oil content wastewater and high-solid content wastewater, and greatly reduces the water intake of secondary separation. Diverter pool 1 also serves as a buffer and transfer for transformation wastewater.

[0037] The diverter pool 1 utilizes gravity sedimentation to separate solid particles and liquids, and its structure includes: a diverter pool body 11 and an oil residue scraper 12. The diverter pool body 11 is a box structure with an open top, a track 111 is provided on the top of the diverter pool body 11, and the oil residue scraper 12 is installed on the track 111 on the top of the diverter pool body 11.

[0038] An oil collecting trough 112 and a slag collecting ditch 115 are arranged on the right side inside the diverter pool body 11, and a diverter pool oil discharge port 113, a diverter pool water outlet 114 and a diverter pool slag discharge port 116 are arranged on the right side. The oil collecting trough 112, the diverter pool oil discharge port 113, the diverter pool water outlet 114, the slag collecting ditch 115 and the diverter pool slag discharge port 116 are located on the same side, the oil collecting trough 112 is located above the diverter pool water outlet 114, the bottom and both ends of the oil collecting trough 112 are respectively connected to the inner wall of the diverter pool body 11, the slag collecting ditch 115 is located at the bottom of the diverter pool body 11, and the diverter pool oil discharge port 113 is located above the bottom of the oil collecting trough 112.

[0039] The oil outlet 113 of the diverter pool is connected to the material inlet of the disc centrifuge 4 through a pipeline to transport the liquid phase (oil-water mixed phase) to the disc centrifuge 4; the water outlet 114 of the diverter pool transports the water phase to the wastewater treatment process or to the diverter pool body 11 for reuse through a pipeline; the slag outlet 116 of the diverter pool is connected to the material inlet of the Doyle clarification tank 2 through a pipeline to transport the precipitated slag to the Doyle clarification tank 2. The oil outlet 113 of the diverter pool, the water outlet 114 of the diverter pool, and the slag outlet 116 of the diverter pool are respectively provided with a delivery pump and a control valve. The slag collecting ditch 115 is located below the water outlet 114.

[0040] like Figure 2 FIG. 1 is a schematic diagram showing the structure of the oil residue scraper 12 of the present invention.

[0041] The oil residue scraper 12 includes: a fixed bracket 1201 , a traveling wheel 1202 , a first adjustment motor 1203 , a second adjustment motor 1204 , and a rotating bracket 1205 .

[0042] The rotating shafts of the two traveling wheels 1202 are connected to the fixed bracket 1201 . The traveling wheels 1202 are located on the track 111 . The traveling wheels 1202 are provided with traveling motors. The first adjustment motor 1203 and the second adjustment motor 1204 are fixed on the upper part of the fixed bracket 1201 .

[0043] The rotating bracket 1205 includes: a connecting frame 1206, a long arm frame 1207, a lower scraper 1208, a long connecting arm 1209, a short arm frame 1210, an upper scraper 1211, and a short connecting arm 1212; the top of the connecting frame 1206 is connected to the bottom right side of the fixed bracket 1201, the top of the long arm frame 1207 is hinged to the bottom of the connecting frame 1206, the lower scraper 1208 is connected to the bottom end of the long arm frame 1207, and the lower scraper 1208 is located on the left side of the long arm frame 1207; the lower part of the long connecting arm 1209 is hinged to the middle part of the long arm frame 1207, and the long connecting arm 120 9 is located on the left side of the long arm frame 1207; one end of the pull rope is connected to the upper part of the long connecting arm 1209, and the other end is connected to the rotating shaft of the first adjustment motor 1203; the right side of the short arm frame 1210 is hinged at the upper part of the long arm frame 1207, the upper scraper 1211 is connected to the left side of the short arm frame 1210, and the short arm frame 1210 is located on the left side of the long arm frame 1207; the bottom end of the short connecting arm 1212 is hinged at the middle part of the short arm frame 1210, and the short connecting arm 1212 is located at the upper part of the short arm frame 1210; one end of the pull rope is connected to the top of the short connecting arm 1212, and the other end is connected to the rotating shaft of the second adjustment motor 1204.

[0044] The first adjustment motor 1203 rotates, the pull rope is retracted, and the long connecting arm 1209 pulls the long arm frame 1207 to rotate, so that the horizontal height of the lower scraper 1208 moves up, and vice versa, the horizontal height of the lower scraper 1208 moves down; the second adjustment motor 1204 rotates, the pull rope is retracted, the short connecting arm 1212 drives the short arm frame 1210 to rotate, so that the horizontal height of the upper scraper 1211 moves up, and vice versa, the horizontal height of the upper scraper 1211 moves down.

[0045] The traveling wheel 1202 drives the oil residue scraper 12 to move horizontally on the track 111, thereby realizing the overall movement of the oil residue scraper 12 and moving the precipitated slag and oil phase. The precipitated slag precipitated at the bottom of the diversion tank body 11 is collected by the lower scraper 1208 to the slag collecting ditch 115, and discharged by a delivery pump through the slag discharge port 116; the oil phase floating on the upper part of the wastewater is collected by the upper scraper 1211 to the oil collecting tank 112, and discharged by a delivery pump. The middle-layer effluent is reused according to the process requirements or enters the next treatment process.

[0046] The connecting frame 1206, the long arm frame 1207, the lower scraper 1208, the short arm frame 1210, and the fixed bracket 1201 are rectangular in shape. The hinge position of the short arm frame 1210 and the long arm frame 1207 is located above the hinge position of the short arm frame 1210 and the long arm frame 1207.

[0047] The connecting frame 1206, the long arm frame 1207, the lower scraper 1208, the long connecting arm 1209, the short arm frame 1210, the upper scraper 1211 and the short connecting arm 1212 are treated with anti-corrosion to avoid corrosion by the wastewater of rare earth sulfate transformation.

[0048] The Doyle clarification barrel 2 comprises: a clarification barrel body 21, a central barrel 22, and a mud rake 23. The clarification barrel body 21 is a closed structure. The central barrel 22 and the mud rake 23 are located inside the clarification barrel body 21. The central barrel 22 is located above the mud rake 23. The top of the central barrel 22 is connected to the bottom of the top of the clarification barrel body 21. An overflow trough 24 is arranged above the inner wall of the clarification barrel body 21. A clarified liquid outlet 25 is arranged on the side wall of the clarification barrel body 21. The clarified liquid outlet 25 is connected to the overflow trough 24. A stirring motor 27 is arranged above the top of the clarification barrel body 21. The two ends of the connecting shaft 26 are respectively connected to the rotating shaft of the stirring motor 27 and the mud rake 23. A clarification barrel slag discharge port 28 is arranged at the bottom of the clarification barrel body 21. The clarification barrel slag discharge port 28 is connected to the material inlet of the horizontal screw centrifuge 3 through a pipeline. The clarification barrel slag discharge port 28 is provided with a conveying pump and a control valve. The material inlet of the Doyle clarification barrel 2 is located inside the central barrel 22. The Doyle clarification tank 2 receives the precipitated slag with high solid content from the diversion tank 1, and separates the slag from the wastewater by the principle of gravity sedimentation. The separated water phase is transported to the wastewater treatment process or to the diversion tank body 11 for reuse through a pipeline, and the precipitated slag is transported to the horizontal screw centrifuge 3 through a pipeline.

[0049] The horizontal screw centrifuge 3 is a horizontal spiral unloading and continuously operated sedimentation equipment, with a drum and a feeding spiral inner cylinder arranged inside, and a slag discharge port 31, a liquid discharge port 32, and a material inlet arranged on the outer wall. The liquid discharge port 32 is connected to the material inlet of the disc centrifuge 4 through a pipeline. The material inlet of the horizontal screw centrifuge 3 is connected to the internal feeding spiral inner cylinder. The working principle is: the drum and the spiral rotate at a high speed in the same direction with a certain differential speed, and the material is continuously introduced into the feeding spiral inner cylinder by the feed pipe, and enters the drum after acceleration. Under the action of the centrifugal force field, the heavier solid phase is deposited on the drum wall to form a sediment layer. The feeding spiral inner cylinder continuously pushes the deposited solid phase to the drum cone end, and discharges it outside the machine through the slag discharge port 31. The lighter liquid phase forms an inner layer liquid ring, which continuously overflows the drum from the overflow port at the large end of the drum, is discharged through the liquid discharge port 32 and transported to the disc centrifuge 4. The horizontal screw centrifuge 3 can continuously feed, separate, wash and discharge at full speed. The horizontal screw centrifuge 3 receives the mud from the Doyle clarification barrel 2, and separates the water and oil in the mud through the high-speed rotating drum and the feeding spiral inner cylinder, thereby obtaining slag with low water content and oil content.

[0050] The disc centrifuge 4 is a type of vertical centrifuge. The drum is mounted on the upper end of the vertical shaft and is driven by an electric motor to rotate at high speed through a transmission device. A group of discs are stacked together in the drum. The disc centrifuge 4 receives the liquid phase from the diverter tank 1 and the horizontal screw centrifuge 3, and uses centrifugal force to achieve liquid-liquid separation. The separated oil phase is reused in the extraction process, and the separated water phase is transported to the wastewater treatment process or to the diverter tank body 11 for reuse through a pipeline.

[0051] Through the combination of the above equipment, efficient, continuous, purely physical and chemical, and fully automated oil and slag removal operations can be carried out on solid and oily wastewater, realizing the recovery of organic matter entrained in the water and slag, optimizing wastewater quality, and reducing wastewater pretreatment costs.

[0052] The continuous separation method of oil-water residue from rare earth sulfate transformation wastewater has the following steps:

[0053] Step 1: The transformed wastewater enters the diversion pool 1, and moves under the action of gravity to separate the oil phase, water phase, and sediment slag. The pipeline connected to the diversion pool oil outlet 113 transports the separated oil phase to the disc centrifuge 4, the pipeline connected to the diversion pool drain outlet 114 transports the separated water phase to the wastewater treatment process or to the diversion pool body 11 for reuse, and the pipeline connected to the diversion pool slag outlet 116 transports the separated phase to the Doyle clarification tank 2;

[0054] Open the control valves of the diversion pool oil outlet 113, the diversion pool water outlet 114, and the diversion pool slag outlet 116, and start the delivery pump to deliver the oil phase, the water phase, and the precipitated slag.

[0055] Step 11: After the transformed wastewater enters the diversion tank 1, the traveling motor is started, and the traveling wheel 1202 drives the oil residue scraper 12 to move to the left side of the diversion tank 1. After the oil residue scraper 12 reaches the set position, the traveling motor stops;

[0056] Step 12: Start the first adjustment motor 1203, pull the long connecting arm 1209 through the pull rope, the long connecting arm 1209 pulls the long arm frame 1207 to rotate, and adjusts the horizontal height of the lower scraper 1208 to the bottom of the diversion pool 1; start the second adjustment motor 1204, pull the short connecting arm 1212 through the pull rope, the short connecting arm 1212 drives the short arm frame 1210 to rotate, and adjusts the horizontal height of the upper scraper 1211 to the height of the oil phase floating on the upper part of the transformation wastewater;

[0057] Step 13: Start the travel motor, and the travel wheel 1202 drives the oil residue scraper 12 to move to the right. After the oil residue scraper 12 reaches the set position, the travel motor stops. During the movement of the oil residue scraper 12 to the right, the lower scraper 1208 pushes the precipitated residue at the bottom of the diversion pool 1 to the right, and the precipitated residue enters the residue collecting ditch 115; the upper scraper 1211 pushes the oil phase to the right, and the oil phase enters the oil collecting tank 112.

[0058] Step 2: The slag liquid containing precipitated slag and transformation wastewater from the diversion tank 1 enters the Doyle clarification tank 2 from the top for secondary water-slag separation, the water phase is discharged from the clarified liquid outlet 25, and the precipitated slag is transported to the horizontal screw centrifuge 3 through a pipeline;

[0059] In the Doyle clarification barrel 2, the stirring motor 27 drives the mud rake 23 to rotate, and the precipitated slag settled to the bottom is thickened by the mud rake 23 and collected at the clarification barrel slag discharge port 28 at the bottom, and the precipitated slag is output to the horizontal screw centrifuge 3 through the pipeline.

[0060] Step 3: The horizontal screw centrifuge 3 rotates at high speed, and uses centrifugal force to separate the solid and liquid of the precipitated slag, and the liquid phase mixed with the water phase and the oil phase is discharged into the disc centrifuge 4;

[0061] The horizontal screw centrifuge 3 uses the centrifugal force of high-speed rotation to achieve solid-liquid separation. The slag is automatically collected and discharged with the help of the spiral pushing component. In this process, the oil phase wrapped in the precipitated slag enters the water phase, and the liquid phase mixed with the water phase and the oil phase is discharged to the disc centrifuge 4 for secondary separation.

[0062] Step 4: The disc centrifuge 4 separates the oil phase from the diversion tank 1 and the liquid phase from the horizontal screw centrifuge 3 into water and oil, and discharges them.

[0063] The oil-water mixed phase (liquid phase) from the upper layer of the diversion pool 1 and the liquid phase of the horizontal screw centrifuge 3 enter the disc centrifuge 4 together. The water-oil mixed phase flows through the gap between the discs to achieve rapid water-oil stratification. The oil phase and the water phase are discharged from their respective outlets. The oil phase is reused in the production process, and the water phase is reused or enters the next treatment process according to the process requirements.

[0064] The terms used in the present invention are illustrative and exemplary, rather than restrictive. Since the present invention can be implemented in various forms without departing from the spirit or essence of the technical solution, it should be understood that the above embodiments are not limited to any of the aforementioned details, but should be widely interpreted within the spirit and scope defined by the attached claims, so all changes and modifications falling within the scope of the claims or their equivalents should be covered by the attached claims.

Claims

1. A continuous separation device for oily residue wastewater in a rare earth production process, characterized in that: include: Diverter tank, Doyle clarification barrel, horizontal screw centrifuge, disc centrifuge. The diverter tank is used for sedimentation separation and transformation of wastewater, including: a diverter tank body and an oil residue scraper. The diverter tank body is a box structure with an opening on the top. A track is arranged on the top of the diverter tank body, and an oil residue scraper is installed on the track; an oil collecting trough and a slag collecting ditch are arranged on the right side of the inside of the diverter tank body, and a diverter tank oil discharge port, a diverter tank water outlet and a diverter tank slag discharge port are arranged on the right side of the diverter tank body. The oil collecting trough is located above the diverter tank water outlet, and the bottom and both ends of the oil collecting trough are respectively connected to the inner wall of the diverter tank body, the slag collecting ditch is located at the bottom of the diverter tank body, and the diverter tank oil discharge port is located above the bottom of the oil collecting trough. The diverter tank oil discharge port and the diverter tank slag discharge port are respectively provided with a conveying pump and a control valve; the diverter tank oil discharge port of the diverter tank is connected to the material inlet of the disc centrifuge through a pipeline, and the diverter tank slag discharge port of the diverter tank is connected to the material inlet of the Doyle clarification barrel through a pipeline.

2. The continuous separation device for oily residue wastewater in the rare earth production process according to claim 1, characterized in that: The drainage outlet of the diversion pool is connected to the top opening of the diversion pool body through a pipeline, and the drainage outlet of the diversion pool is provided with a delivery pump and a control valve.

3. The continuous separation device for oily residue wastewater in the rare earth production process according to claim 1, characterized in that: The oil residue scraper includes: a fixed bracket, a traveling wheel, a first adjustment motor, a second adjustment motor, and a rotating bracket. The fixed bracket is connected to a plurality of traveling wheels, the traveling wheels are located on the track, and the traveling wheels are provided with a traveling motor; the first adjustment motor and the second adjustment motor are fixed on the upper part of the fixed bracket; the rotating bracket includes: a connecting frame, a long arm frame, a lower scraper, a long connecting arm, a short arm frame, an upper scraper, and a short connecting arm; the top of the connecting frame is connected to the bottom right side of the fixed bracket, the top of the long arm frame is hinged to the bottom of the connecting frame, and the lower scraper It is connected to the bottom end of the long arm frame; the lower part of the long connecting arm is hinged to the middle part of the long arm frame, and the long connecting arm is located on the left side of the long arm frame; one end of the pull rope is connected to the upper part of the long connecting arm, and the other end is connected to the rotating shaft of the first adjustment motor; the right side of the short arm frame is hinged to the upper part of the long arm frame, the upper scraper is connected to the left side of the short arm frame, and the short arm frame is located on the left side of the long arm frame; the bottom end of the short connecting arm is hinged to the middle part of the short arm frame, and the short connecting arm is located on the upper part of the short arm frame; one end of the pull rope is connected to the top of the short connecting arm, and the other end is connected to the rotating shaft of the second adjustment motor.

4. The continuous separation device for oily residue wastewater in the rare earth production process according to claim 3, characterized in that: The connecting frame, the long arm frame, the lower scraper, the short arm frame and the fixed bracket are rectangular in shape.

5. The continuous separation device for oily residue wastewater in the rare earth production process according to claim 3, characterized in that: The hinged positions of the short arm frame and the long arm frame are located above the hinged positions of the short arm frame and the long arm frame.

6. The continuous separation device for oily residue wastewater in the rare earth production process according to claim 1, characterized in that: The Doyle clarifier includes: a clarifier body, a center barrel, and a mud rake. The clarifier body is a closed structure. The center barrel and the mud rake are located inside the clarifier body. The center barrel is located on the upper part of the mud rake. The top of the center barrel is connected to the bottom of the top of the clarifier body. The material inlet arranged on the top of the Doyle clarifier is located on the inner side of the center barrel; an overflow trough is arranged above the inner wall of the clarifier body, and a clarified liquid outlet is arranged on the side wall of the clarifier body, and the clarified liquid outlet is connected to the overflow trough; a stirring motor is arranged above the top of the clarifier body, and the two ends of the connecting shaft are respectively connected to the rotating shaft and the mud rake of the stirring motor; a clarifier slag discharge port is arranged at the bottom of the clarifier body, and the clarifier slag discharge port is connected to the material inlet of the horizontal screw centrifuge through a pipeline, and a conveying pump and a control valve are arranged at the clarifier slag discharge port.

7. A method for continuously separating oily residue wastewater in a rare earth production process using a continuous separation device as claimed in any one of claims 1 to 6, characterized in that: include: The transformation wastewater enters the diversion tank, where it flows under gravity to separate the oil phase, water phase, and sediment slag. The pipeline connected to the oil outlet of the diversion tank transports the separated oil phase to the disc centrifuge, and the pipeline connected to the slag outlet of the diversion tank transports the separated phase to the Doyle clarification tank. The slag liquid containing sediment slag and transformation wastewater enters the Doyle clarification tank from the top for secondary water-slag separation. The water phase is discharged from the clarified liquid outlet, and the sediment slag is transported to the horizontal screw centrifuge through the pipeline; The horizontal screw centrifuge rotates at high speed and uses centrifugal force to separate the solid and liquid of the sediment. The liquid phase mixed with the water phase and the oil phase is discharged into the disc centrifuge; the disc centrifuge separates the oil phase from the diversion tank and the liquid phase of the horizontal screw centrifuge and discharges them.

8. The method for continuous separation of oily residue wastewater in the rare earth production process according to claim 7, characterized in that: The sedimentation and separation process of transformation wastewater in the diversion tank includes: After the transformation wastewater enters the diversion tank, the travel motor is started, and the travel wheel drives the oil residue scraper to move to the left side of the diversion tank. After the oil residue scraper reaches the set position, the travel motor stops; Start the first adjustment motor, pull the long connecting arm through the pull rope, the long connecting arm pulls the long arm frame to rotate, and adjust the horizontal height of the lower scraper to the bottom of the diversion pool; start the second adjustment motor, pull the short connecting arm through the pull rope, the short connecting arm drives the short arm frame to rotate, and adjust the horizontal height of the upper scraper to the height of the oil phase floating on the upper part of the transformation wastewater; Start the travel motor, and the travel wheel drives the oil residue scraper to move to the right. After the oil residue scraper reaches the set position, the travel motor stops. When the oil residue scraper moves to the right, the lower scraper pushes the sludge settled at the bottom of the diversion pool to the right, and the sludge enters the sludge collecting ditch; the upper scraper pushes the oil phase to the right, and the oil phase enters the oil collecting tank.

9. The method for continuous separation of oily residue wastewater in the rare earth production process according to claim 7, characterized in that: In the Doyle clarification barrel, the stirring motor drives the mud rake to rotate, and the sludge that settles to the bottom is thickened by the mud rake and gathered at the slag discharge port of the clarification barrel at the bottom. The sludge is output to the horizontal screw centrifuge through the pipeline.

10. The method for continuous separation of oily residue wastewater in the rare earth production process according to claim 7, characterized in that: The pipeline connected to the drainage outlet of the diversion pool transports the separated water phase to the wastewater treatment process or to the diversion pool body for reuse.

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