A separation device for recovering crystalline salt by step-by-step precipitation of heavy metals

Abstract

The invention discloses a separation device for recovering crystalline salt by step-by-step precipitation of heavy metals, and relates to the technical field of separation devices. The separation device comprises a liquid inlet buffering and dispensing mechanism, a complex reaction mechanism, a step-by-step precipitation mechanism, a sediment separation mechanism, a crystallized salt precipitation mechanism and a crystallized salt separation mechanism. The liquid inlet buffering and dispensing mechanism is connected to the complex reaction mechanism, the step-by-step precipitation mechanism is connected to the complex reaction mechanism, the sediment separation mechanism is connected to the step-by-step precipitation mechanism, the step-by-step precipitation mechanism is connected to the crystallized salt precipitation mechanism, and the crystallized salt separation mechanism is connected to the crystallized salt precipitation mechanism. The liquid inlet buffering and dispensing mechanism is used for preliminary buffering and dispensing of wastewater, the complex reaction mechanism is used for forming complexes to provide conditions for subsequent step-by-step precipitation, the step-by-step precipitation mechanism is used for step-by-step precipitation, the sediment separation mechanism is used for separation and recovery to avoid secondary pollution, and the crystallized salt precipitation mechanism promotes the crystallization and precipitation of salt in the solution.

Description

Technical Field

[0001] The invention relates to the technical field of separation devices, in particular to a separation device for recovering crystalline salt by step-by-step precipitation of heavy metals. Background Art

[0002] Heavy metal wastewater treatment technologies have developed rapidly in recent years, primarily focusing on methods such as chemical precipitation, ion exchange, membrane separation, and electrochemistry. Chemical precipitation is widely used due to its low cost and ease of operation, but traditional processes suffer from low precipitation efficiency and high reagent consumption. With increasingly stringent environmental protection requirements, efficient and low-consumption heavy metal separation and resource recovery technologies have become a research hotspot. In particular, integrated devices combining complex reactions, step-by-step precipitation, and crystallization for salt separation are expected to achieve simultaneous recovery of heavy metals and salts, improving resource utilization.

[0003] Current mainstream technologies rely on mechanical float valves or ultrasonic sensors for liquid level control, but the former lacks precision, while the latter is costly. Stirring devices often use fixed blades or static mixers, which limit mixing uniformity. Sediment separation often uses plate and frame filter presses or centrifuges, which consume a lot of energy and are prone to clogging. Furthermore, existing crystallization processes typically rely on single cooling or evaporation methods, limiting the purity of the crystallized salt due to temperature control accuracy and insufficient solution disturbance.

[0004] Existing technologies result in unstable heavy metal separation efficiency; liquid level fluctuations easily affect reaction conditions, and there is a lack of dynamic compensation mechanisms; and the liquid recovery rate after sediment separation is low, with a high risk of secondary contamination. Therefore, those skilled in the art have provided a separation device for recovering crystalline salts by step-by-step precipitation of heavy metals to address the aforementioned issues. Summary of the Invention

[0005] The object of the present invention is to provide a separation device for recovering crystalline salts by step-by-step precipitation of heavy metals, so as to solve the problems raised in the prior art.

[0006] To achieve the above object, the present invention provides the following technical solutions:

[0007] The separation device includes a liquid inlet buffering and adjusting mechanism, a complex reaction mechanism, a step-by-step precipitation mechanism, a sediment separation mechanism, a crystallization salt precipitation mechanism and a crystallization salt separation mechanism. The liquid inlet buffering and adjusting mechanism is connected to the complex reaction mechanism, the step-by-step precipitation mechanism is connected to the complex reaction mechanism, the sediment separation mechanism is connected to the step-by-step precipitation mechanism, the step-by-step precipitation mechanism is connected to the crystallization salt precipitation mechanism, and the crystallization salt separation mechanism is connected to the crystallization salt precipitation mechanism.

[0008] By adopting the above technical solution, the inlet buffering and preparation mechanism can preliminarily buffer and prepare the input heavy metal-containing wastewater to ensure the stability and efficiency of subsequent treatment. The complexing reaction mechanism forms a stable complex by adding a complexing agent to react with the heavy metal ions, providing conditions for subsequent step-by-step precipitation. The step-by-step precipitation mechanism adjusts the pH value of the solution and adds different complexing agents to gradually precipitate the heavy metal ions, thereby achieving effective separation of heavy metals. The sediment separation mechanism separates and recovers the precipitated heavy metal slag to avoid secondary pollution. The crystallization salt precipitation mechanism uses temperature differences and turbulence to promote the crystallization of salt in the solution, thereby improving the purity and recovery rate of the crystallized salt.

[0009] Furthermore, the liquid inlet buffer preparation mechanism includes a buffer tank, a liquid inlet pipe, a connecting pipe, a regulating pipe, a pH pump, a liquid inlet valve, a pH sensor, a connecting valve, a stirring assembly and a liquid level stabilization assembly. The buffer tank is connected to the liquid inlet pipe, the buffer tank is connected to the regulating pipe, the buffer tank is connected to the connecting pipe, the connecting pipe is connected to the connecting valve, the connecting valve is connected to the complexing reaction mechanism, the pH pump is connected to the regulating pipe, the liquid inlet pipe is connected to the liquid inlet valve, the stirring assembly is firmly connected to the buffer tank, the liquid level stabilization assembly is firmly connected to the buffer tank, the pH sensor is firmly connected to the buffer tank, the pH pump is used to initially adjust the pH value of the original liquid, the connecting valve is used to control the flow entering the complexing reaction mechanism, and the liquid inlet valve is used to control the flow of the original liquid entering the buffer tank.

[0010] By adopting the above technical solution, the pH sensor can monitor the pH value of the liquid in the buffer tank in real time, ensuring precise pH control. The stirring component stirs the liquid in the buffer tank to evenly mix it, improving the efficiency and stability of the complexation reaction. The liquid level stabilization component maintains the stability of the liquid level in the buffer tank, preventing fluctuations in the liquid level from affecting the complexation reaction. The design of the entire liquid inlet buffering mechanism ensures stable input of the stock solution and enables precise control of the stock solution, providing excellent conditions for the subsequent complexation reaction.

[0011] Furthermore, the liquid level stabilization component includes an upper limit liquid level probe, a lower limit liquid level probe, a first elastic member, a first electromagnetic block, a buffer cover, a float, a guide rod, a limit ring and a one-way micro-pressure breathing valve. The buffer cover and the buffer tank are tightly connected. The limit ring and the first electromagnetic block are provided in an even number, and each group of limit rings and first electromagnetic blocks is provided with two each. The limit ring and the first electromagnetic block are located at the upper and lower ends of the buffer tank, respectively. The upper limit liquid level probe and the limit ring are tightly connected, the lower limit liquid level probe and the limit ring are tightly connected, the guide rod and the buffer cover are tightly connected, the buffer cover and the buffer tank are tightly connected, and the buffer cover There is a micro-guide hole on it, which is used for the liquid to slowly enter and slow down the liquid level fluctuation. The limit ring and the guide rod are slidably connected. The limit ring is used to control the displacement range of the float to correspond to the upper and lower limit thresholds of the liquid level. The upper limit liquid level probe and the lower limit liquid level probe are upper and lower conductive electrodes. The float and the guide rod are slidably connected. The one-way micro-pressure breathing valve is connected to the buffer tank. The one-way micro-pressure breathing valve is located above the buffer tank. The first electromagnetic block and the buffer cover are tightly connected, the first elastic member and the first electromagnetic block are tightly connected, the first elastic member and the limit ring are tightly connected, and the first electromagnetic block and the limit ring are magnetically repelled.

[0012] By adopting the above technical solution, when the liquid level in the buffer tank rises, the float rises with it, driving the upper and lower level probes, to which it is securely connected, to move together. When the liquid level reaches the preset upper threshold, the upper level probe connects with the liquid surface, forming a conductive path, thereby triggering the corresponding control signal. Simultaneously, the rise of the float is also driven by the sliding connection between the guide rod and the limit ring, as well as the repulsive transmission of the magnetic poles between the first electromagnetic block and the limit ring, causing the limit ring to move due to the repulsive force. The first elastic member provides elastic force to reset the limit ring. When the liquid level drops, the float drops with it. Similarly, when the liquid level reaches the preset lower threshold, the lower level probe also contacts the corresponding liquid surface, forming a conductive path, triggering the corresponding control signal. The provision of a one-way micro-pressure breathing valve allows the gas in the buffer tank to be discharged unidirectionally when the pressure changes, thereby further stabilizing the liquid level. The design of the entire liquid level stabilization assembly not only ensures stable control of the liquid level, but also enables real-time monitoring and feedback of liquid level changes, providing reliable protection for subsequent complexation reactions.

[0013] Furthermore, the stirring assembly includes a stirring rod, a screw rod, a universal coupling, a hinge block, a stirring motor, a moving block, a transmission bevel gear, a second electromagnetic block, a third electromagnetic block and a second elastic member. The stirring motor and the buffer tank are fastened together, the stirring motor and the stirring rod are transmission-connected, the moving block and the third electromagnetic block are fastened together, the second elastic member and the second electromagnetic block are fastened together, the second elastic member and the moving block are fastened together, the second electromagnetic block and the moving block are magnetically attracted to each other for transmission, the third electromagnetic block and the moving block are magnetically attracted to each other for transmission, the moving block and the stirring rod are slidingly connected, the moving block and the transmission bevel gear are transmission-connected, the transmission bevel gear and the third electromagnetic block are slidingly connected, the transmission bevel gear and the stirring rod are slidingly connected, the transmission bevel gear and the universal coupling are transmission-connected, the universal coupling and the screw rod are hinged, and the screw rod and the hinge block are hinged.

[0014] By adopting the above technical solution, when the stirring motor starts, its power is transmitted to the stirring rod, causing the stirring rod to start rotating. At the same time, the second electromagnetic block and the third electromagnetic block generate an attractive force on the moving block through the attraction of the magnetic poles, causing the moving block to slide on the stirring rod. Due to the presence of the second elastic member, it provides a certain elastic support and reset function for the moving block. As the stirring rod rotates, the moving block transmits power to the screw rod through the sliding connection between the transmission bevel gear and the stirring rod, and the transmission connection between the transmission bevel gear and the universal coupling. Under the action of the universal coupling, the screw rod can rotate around the axis of the stirring rod and maintain a certain angle with the stirring rod through the hinge block, thereby achieving a stirring effect of rotation and revolution, which not only ensures the uniformity and efficiency of the stirring, but also realizes the flexible adjustment of the stirring amplitude through the cooperation of the electromagnetic block and the elastic member, thereby improving the adaptability and stability of the device.

[0015] Furthermore, the complexation reaction mechanism includes a complexation motor, a complexation tank, a first agitator, a liquid storage barrel, a metering pump, a circulation pump, a circulation pipe, a heating box, a cooling box and an oscillation component. The complexation motor and the complexation tank are tightly connected, the complexation motor and the first agitator are transmission connected, the liquid storage barrel and the metering pump are connected, the metering pump and the complexation tank are connected, the complexation tank and the connecting valve are connected, the circulation pipe and the cooling box are connected, the circulation pump and the heating box are connected, the heating box and the circulation pump are connected, the circulation pump and the cooling box are connected, the circulation pipe surrounds the complexation tank, and the oscillation component includes an eccentric wheel, an oscillation block and an oscillation frame. The oscillation block and the oscillation frame are slidingly connected, the eccentric wheel and the oscillation block are transmission connected, and the first agitator and the eccentric wheel are transmission connected.

[0016] By adopting the above technical solution, after the complexing motor is started, its power is transmitted to the first agitator, causing the first agitator to rotate in the complexing tank and stir the liquid in the complexing tank. At the same time, the metering pump quantitatively pumps the complexing agent in the liquid storage barrel into the complexing tank to react with the heavy metal ions. The circulation pump heats and cools the liquid in the circulation pipe through the cooperation of the heating box and the cooling box to control the temperature of the complexing reaction. The eccentric wheel of the oscillation component rotates under the drive of the first agitator, and the sliding connection between the oscillation block and the oscillation frame causes the oscillation frame to produce reciprocating oscillations, further improving the efficiency and uniformity of the complexing reaction. The design of the entire complexing reaction mechanism not only ensures the stable progress of the complexing reaction, but also realizes the precise control of the complexing reaction conditions, providing good conditions for the subsequent step-by-step precipitation.

[0017] Furthermore, the step-by-step sedimentation mechanism includes a sedimentation tank, a pH probe, a medicine pump, an acidic agent barrel, an alkaline agent barrel, a discharge valve and an overflow pipe. The sedimentation tank is connected to the overflow pipe, and the overflow pipe is used to automatically overflow to the next sedimentation section after the liquid level reaches a set height. The medicine pump is connected to the sedimentation tank, and the acidic agent barrel and the alkaline agent barrel are both connected to the medicine pump. The sedimentation tank is connected to the discharge valve, and the discharge valve is located at the bottom of the sedimentation tank. The discharge valve is connected to the sediment separation mechanism.

[0018] By adopting the above technical solution, the pH value in the precipitation tank is monitored in real time by a pH probe to ensure precise control of the precipitation reaction. When the pH value needs to be adjusted, the drug pump pumps the agent in the acidic agent barrel or the alkaline agent barrel into the precipitation tank to react with the complex, causing the heavy metal ions to gradually precipitate. As the precipitation reaction proceeds, the liquid level gradually rises. When the liquid level reaches the set height, the overflow pipe automatically overflows the excess liquid to the next precipitation section, achieving the effect of segmented precipitation. When the precipitation is completed, the discharge valve is opened, and the precipitated heavy metal slag falls into the sediment separation mechanism under the action of gravity for further processing. The design of the entire step-by-step precipitation mechanism not only ensures the stable progress of the precipitation reaction, but also realizes precise control of the precipitation conditions, effectively improving the separation efficiency and purity of heavy metals.

[0019] Furthermore, the sediment separation mechanism includes a rotary drum filter, a reflux pipe, a scraping motor, a pressing elastic member, a scraper and a scraping shaft. The scraping motor is fastened to the rotary drum filter, the scraping motor is transmission-connected to the scraping shaft, the scraping shaft is fastened to the pressing elastic member, the pressing elastic member is fastened to the scraper, the scraping shaft is transmission-connected to the scraper, the reflux pipe is connected to the sedimentation tank, and the rotary drum filter is connected to the discharge valve.

[0020] With this technical solution, after the scraper motor starts, its power is transmitted to the scraper shaft, causing it to begin rotating. The compression spring provides a certain degree of elastic support for the scraper blade, ensuring a close fit between the scraper blade and the drum filter surface. As the scraper shaft rotates, the scraper blade slides across the drum filter surface, scraping off any heavy metal residue adhering to the drum filter. The scraped heavy metal residue passes through the drum filter and falls into the collection device below, while the unscraped liquid flows back into the sedimentation tank through the return pipe, effectively separating the sediment. The design of the entire sediment separation mechanism ensures thorough sediment separation while preventing secondary contamination of the liquid, providing excellent conditions for subsequent processing.

[0021] Furthermore, the crystallization salt precipitation mechanism includes a double-layer coil crystallization tank, a temperature probe and a spoiler. The spoiler is provided with a guide groove, in which a polytetrafluoroethylene ball is embedded. The temperature probe and the double-layer coil crystallization tank are tightly connected. The spoiler and the double-layer coil crystallization tank are tightly connected. The upper layer of the double-layer coil crystallization tank is used to transport high-temperature steam, and the lower layer of the upper layer of the double-layer coil crystallization tank is used to transport cooling water.

[0022] By adopting the above-mentioned technical solution, the design of the double-layer coil crystallization tank fully utilizes the effect of temperature differences on salt crystallization. High-temperature steam circulates in the upper layer of the double-layer coil crystallization tank, providing the necessary heat for the solution, promoting the dissolution of salt and the active movement of ions. The cooling water transported from the bottom layer quickly removes the heat, forming a significant temperature gradient. This temperature difference prompts the salt in the solution to crystallize and precipitate rapidly within the appropriate temperature range. The guide grooves and polytetrafluoroethylene ball design on the spoiler further enhance the turbulence effect of the solution during the crystallization process, allowing the salt in the solution to contact the cooling surface more evenly, thereby improving the crystallization efficiency and the purity of the salt. The design of the entire crystallization salt precipitation mechanism not only ensures the efficient crystallization of the salt, but also achieves a dual improvement in the purity and recovery rate of the crystallized salt through precise temperature control and turbulence.

[0023] Furthermore, the crystallization and salt separation mechanism includes a spiral filter press, a vibrating screen, a salt outlet hopper, a filtrate pipe and a salt separation box. The spiral filter press is connected to the double-layer coil crystallization tank, the spiral filter press is connected to the salt outlet hopper, the salt outlet hopper is connected to the vibrating screen, and the vibrating screen is connected to the salt separation box.

[0024] By adopting the above technical solution, the spiral filter press can perform preliminary squeezing and dehydration on the crystallized salt precipitated in the double-layer coil crystallization tank to remove excess water and impurities. The squeezed crystallized salt enters the salt outlet hopper through the outlet of the spiral filter press. The design of the salt outlet hopper ensures that the crystallized salt can flow smoothly into the subsequent vibrating screener. The vibrating screener further screens and grades the crystallized salt through vibration, removes fine particles and impurities, and obtains relatively pure crystallized salt. Finally, the screened crystallized salt enters the salt separation box through the outlet of the vibrating screener, realizing the effective separation and recovery of the crystallized salt.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] The liquid level stabilization component monitors and controls the buffer tank liquid level in real time through the repulsive transmission of the magnetic poles of the float, guide rod, limit ring, and electromagnetic block, combined with the conductive feedback of the upper and lower limit liquid level probes. The one-way micro-pressure breathing valve balances the air pressure in the tank, and cooperates with the micro-diversion holes of the buffer cover to slow down the fluctuation of the liquid level and ensure the stability of the liquid input before the complexation reaction. The stirring component adopts an articulated design of a screw rod and a universal coupling. The electromagnetic block drives the sliding of the moving block, which drives the transmission bevel gear to realize the rotation and revolution of the stirring rod, thereby improving the mixing uniformity. The step-by-step precipitation mechanism uses a pH probe to link the drug pump, accurately adding acidic / alkaline agents, and adjusting the pH value in stages to gradually precipitate heavy metal ions. The overflow pipe automatically overflows the liquid level in sections. Combined with the drum filter's compression elastic member, it ensures the scraper fits snugly. The scraper shaft rotates to remove sediment, which is then discharged through a discharge valve. The liquid is recycled through a reflux pipe to avoid secondary contamination. The double-coil crystallization tank utilizes the temperature difference between the upper and lower layers of high-temperature steam and cooling water to create a temperature gradient for salt precipitation. The polytetrafluoroethylene balls on the spoiler enhance solution turbulence and improve crystal purity. After the spiral filter press dehydrates the crystallized salt, the vibrating screen uses high-frequency vibration to separate salt particles of different sizes, which are ultimately collected in the salt separation tank for efficient salt recovery. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0028] Figure 2 This is a structural diagram of the liquid inlet buffering and dispensing mechanism of the present invention;

[0029] Figure 3 This is a schematic diagram of the structure of the liquid level stabilization component of the present invention;

[0030] Figure 4 This is a schematic structural diagram of the stirring assembly of the present invention;

[0031] Figure 5 Schematic diagram of the complex reaction mechanism structure of the present invention;

[0032] Figure 6This is a schematic diagram of the structure of the oscillation component of the present invention;

[0033] Figure 7 This is a schematic diagram of the structure of the step-by-step precipitation mechanism of the present invention;

[0034] Figure 8 This is a structural diagram of the sediment separation mechanism of the present invention;

[0035] Figure 9 Schematic diagram of the structure of the crystallization salt precipitation mechanism of the present invention;

[0036] Figure 10 It is a schematic structural diagram of the crystallization and salt separation mechanism of the present invention.

[0037] In the figure: 1. Liquid inlet buffering and dispensing mechanism; 11. Buffer tank; 12. Liquid inlet pipe; 13. Connecting pipe; 14. Regulating pipe; 15. pH pump; 16. Liquid inlet valve; 17. pH sensor; 18. Connecting valve; 19. Stirring assembly; 191. Stirring rod; 192. Screw rod; 193. Universal coupling; 194. Articulated block; 195. Stirring motor; 196. Moving block; 197. Transmission bevel gear; 198. Second electromagnetic block; 199 , third electromagnetic block; 1910, second elastic member; 110, liquid level stabilization assembly; 1101, upper limit liquid level probe; 1102, lower limit liquid level probe; 1103, first elastic member; 1104, first electromagnetic block; 1105, buffer cover; 11051, micro-flow hole; 1106, float; 1107, guide rod; 1108, limit ring; 1109, one-way micro-pressure breathing valve; 2, complexation reaction mechanism; 21, complexation motor; 22, complexation Combined tank; 23. First agitator; 24. Liquid storage tank; 25. Dosing pump; 26. Circulation pump; 27. Circulation pipe; 28. Heating tank; 29. Cooling tank; 210. Oscillating assembly; 2101. Eccentric wheel; 2102. Oscillating block; 2103. Oscillating rack; 3. Step-by-step sedimentation mechanism; 31. Sedimentation tank; 32. pH probe; 33. Drug pump; 34. Acidic agent tank; 35. Alkaline agent tank; 36. Discharge valve; 37. Overflow pipe; 4. Sediment separation mechanism; 41. Rotary drum filter; 42. Reflux pipe; 43. Slag scraping motor; 44. Compression elastic member; 45. Scraper; 46. Scraper shaft; 5. Crystallization salt precipitation mechanism; 51. Double-layer coil crystallization tank; 52. Temperature probe; 53. Spoiler; 531. Guide groove; 532. Polytetrafluoroethylene ball; 6. Crystallization salt separation mechanism; 61. Screw filter press; 62. Vibrating screen; 63. Salt outlet hopper; 64. Filtrate pipe; 65. Salt separation box. DETAILED DESCRIPTION

[0038] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] See also Figure 1 - Figure 10 As shown, the present invention provides a technical solution for a separation device for recovering crystalline salts by step-by-step precipitation of heavy metals:

[0040] The separation device includes a liquid inlet buffering and adjusting mechanism 1, a complexing reaction mechanism 2, a step-by-step sedimentation mechanism 3, a sediment separation mechanism 4, a crystallization salt precipitation mechanism 5 and a crystallization salt separation mechanism 6. The liquid inlet buffering and adjusting mechanism 1 is connected to the complexing reaction mechanism 2, the step-by-step sedimentation mechanism 3 is connected to the complexing reaction mechanism 2, the sediment separation mechanism 4 is connected to the step-by-step sedimentation mechanism 3, the step-by-step sedimentation mechanism 3 is connected to the crystallization salt precipitation mechanism 5, and the crystallization salt separation mechanism 6 is connected to the crystallization salt precipitation mechanism 5.

[0041] By adopting the above technical scheme, the liquid inlet buffering and preparation mechanism 1 can perform preliminary buffering and preparation on the input heavy metal-containing wastewater to ensure the stability and efficiency of subsequent treatment. The complexing reaction mechanism 2 forms a stable complex by adding a complexing agent to react with the heavy metal ions, providing conditions for subsequent step-by-step precipitation. The step-by-step precipitation mechanism 3 adjusts the pH value of the solution and adds different complexing agents to gradually precipitate the heavy metal ions, thereby achieving effective separation of heavy metals. The sediment separation mechanism 4 separates and recovers the precipitated heavy metal slag to avoid secondary pollution. The crystallization salt precipitation mechanism 5 utilizes temperature difference and turbulence to promote the crystallization of salt in the solution, thereby improving the purity and recovery rate of the crystallized salt.

[0042] Furthermore, the liquid inlet buffer preparation mechanism 1 includes a buffer tank 11, a liquid inlet pipe 12, a connecting pipe 13, a regulating pipe 14, a pH pump 15, a liquid inlet valve 16, a pH sensor 17, a connecting valve 18, a stirring assembly 19 and a liquid level stabilization assembly 110. The buffer tank 11 is connected to the liquid inlet pipe 12, the buffer tank 11 is connected to the regulating pipe 14, the buffer tank 11 is connected to the connecting pipe 13, the connecting pipe 13 is connected to the connecting valve 18, the connecting valve 18 is connected to the complexing reaction mechanism 2, the pH pump 15 is connected to the regulating pipe 14, the liquid inlet pipe 12 is connected to the liquid inlet valve 16, the stirring assembly 19 is firmly connected to the buffer tank 11, the liquid level stabilization assembly 110 is firmly connected to the buffer tank 11, the pH sensor 17 is firmly connected to the buffer tank 11, the pH pump 15 is used to initially adjust the pH value of the original liquid, the connecting valve 18 is used to control the flow entering the complexing reaction mechanism 2, and the liquid inlet valve 16 is used to control the flow of the original liquid entering the buffer tank 11.

[0043] By adopting the above technical solution, the pH sensor 17 can monitor the pH value of the liquid in the buffer tank 11 in real time, ensuring the precise control of the pH value. The stirring component 19 stirs the liquid in the buffer tank 11 to evenly mix it, thereby improving the efficiency and stability of the complexation reaction. The liquid level stabilizing component 110 can maintain the stability of the liquid level in the buffer tank 11, avoiding the influence of the complexation reaction on the effect of the liquid level fluctuation. The design of the entire liquid inlet buffering and dispensing mechanism 1 not only ensures the stable input of the stock solution, but also realizes the precise control of the stock solution, providing good conditions for the subsequent complexation reaction.

[0044] Furthermore, the liquid level stabilization component 110 includes an upper limit liquid level probe 1101, a lower limit liquid level probe 1102, a first elastic member 1103, a first electromagnetic block 1104, a buffer cover 1105, a float 1106, a guide rod 1107, a limiting ring 1108 and a one-way micro-pressure breathing valve 1109. The buffer cover 1105 is tightly connected to the buffer tank 11. There are an even number of limiting rings 1108 and the first electromagnetic block 1104, and each group of limiting rings 1108 and the first electromagnetic block 1104 is provided with two. The limiting rings 1108 and the first electromagnetic block 1104 are each provided with one at the upper and lower ends of the buffer tank 11. The upper limit liquid level probe 1101 is tightly connected to the limiting ring 1108, the lower limit liquid level probe 1102 is tightly connected to the limiting ring 1108, the guide rod 1107 is tightly connected to the buffer cover 1105, and the buffer cover 1105 is tightly connected to the buffer tank 11. The buffer cover 1105 is provided with a micro-guide hole 11051, which is used for the liquid to slowly enter and slow down the liquid level fluctuation. The limit ring 1108 and the guide rod 1107 are slidably connected. The limit ring 1108 is used to control the displacement range of the float 1106 so as to correspond to the upper and lower limit thresholds of the liquid level. The upper limit liquid level probe 1101 and the lower limit liquid level probe 1102 are upper and lower conductive electrodes. The float 1106 and the guide rod 1107 are slidably connected. The one-way micro-pressure breathing valve 1109 is connected to the buffer tank 11. The one-way micro-pressure breathing valve 1109 is located above the buffer tank 11. The first electromagnetic block 1104 and the buffer cover 1105 are fastened together. The first elastic member 1103 and the first electromagnetic block 1104 are fastened together. The first elastic member 1103 and the limit ring 1108 are fastened together. The first electromagnetic block 1104 and the limit ring 1108 are magnetically repelled.

[0045] By adopting the above technical solution, when the liquid level in the buffer tank 11 rises, the float 1106 rises accordingly, driving the upper limit liquid level probe 1101 and the lower limit liquid level probe 1102, which are tightly connected to it, to move together. When the liquid level reaches the preset upper limit threshold, the upper limit liquid level probe 1101 connects with the liquid surface, forming a conductive path, thereby triggering the corresponding control signal. At the same time, the rise of the float 1106 is also caused by the sliding connection between the guide rod 1107 and the limit ring 1108, as well as the repulsive transmission of the magnetic poles between the first electromagnetic block 1104 and the limit ring 1108, causing the limit ring 1108 to move due to the repulsive force. The first elastic member 1103 provides elastic force to reset the limit ring 1108. When the liquid level drops, the float 1106 also drops. Similarly, when the liquid level reaches the preset lower limit threshold, the lower limit liquid level probe 1102 also contacts the corresponding liquid surface, forming a conductive path, triggering the corresponding control signal. The one-way micro-pressure breathing valve 1109 allows the gas in the buffer tank 11 to be discharged in one direction when the pressure changes, thereby further stabilizing the liquid level. The design of the entire liquid level stabilization assembly 110 not only ensures stable control of the liquid level, but also enables real-time monitoring and feedback of liquid level changes, providing reliable protection for subsequent complexation reactions.

[0046] Furthermore, the stirring assembly 19 includes a stirring rod 191, a screw rod 192, a universal coupling 193, a hinge block 194, a stirring motor 195, a moving block 196, a transmission bevel gear 197, a second electromagnetic block 198, a third electromagnetic block 199 and a second elastic member 1910, the stirring motor 195 is fastened to the buffer tank 11, the stirring motor 195 is transmission-connected to the stirring rod 191, the moving block 196 is fastened to the third electromagnetic block 199, the second elastic member 1910 is fastened to the second electromagnetic block 198, and the second elastic member 1910 and the moving block 196 is fastened, the second electromagnetic block 198 and the moving block 196 are attracted to each other for transmission, the third electromagnetic block 199 and the moving block 196 are attracted to each other for transmission, the moving block 196 is slidingly connected to the stirring rod 191, the moving block 196 is transmission-connected to the transmission bevel gear 197, the transmission bevel gear 197 and the third electromagnetic block 199 are slidingly connected, the transmission bevel gear 197 and the stirring rod 191 are slidingly connected, the transmission bevel gear 197 and the universal coupling 193 are transmission-connected, the universal coupling 193 and the screw rod 192 are hinged, and the screw rod 192 and the hinge block 194 are hinged.

[0047] By adopting the above technical solution, when stirring motor 195 is started, its power is transmitted to stirring rod 191, causing stirring rod 191 to begin rotating. Simultaneously, second electromagnetic block 198 and third electromagnetic block 199, through the attraction of their magnetic poles, generate an attractive force on movable block 196, causing movable block 196 to slide on stirring rod 191. The presence of second elastic member 1910 provides a certain degree of elastic support and reset for movable block 196. As stirring rod 191 rotates, movable block 196 transmits power to screw rod 192 through the sliding connection between transmission bevel gear 197 and stirring rod 191, and the transmission connection between transmission bevel gear 197 and universal coupling 193. Under the action of the universal joint 193, the spiral rod 192 can rotate around the axis of the stirring rod 191, and maintain a certain angle with the stirring rod 191 through the hinge block 194, thereby achieving a stirring effect of rotation and revolution, which not only ensures the uniformity and efficiency of stirring, but also realizes flexible adjustment of the stirring amplitude through the cooperation of the electromagnetic block and the elastic part, thereby improving the adaptability and stability of the device.

[0048] Furthermore, the complexation reaction mechanism 2 includes a complexation motor 21, a complexation tank 22, a first agitator 23, a liquid storage barrel 24, a metering pump 25, a circulation pump 26, a circulation pipe 27, a heating box 28, a cooling box 29 and an oscillation component 210. The complexation motor 21 and the complexation tank 22 are fastened together, the complexation motor 21 and the first agitator 23 are in transmission connection, the liquid storage barrel 24 is in communication with the metering pump 25, the metering pump 25 and the complexation tank 22 are in communication, the complexation tank 22 is in communication with the connecting valve 18, and the circulation pipe 27 is in communication with the connecting valve 18. 27 is connected to the cooling box 29, the circulating pump 26 is connected to the heating box 28, the heating box 28 is connected to the circulating pump 26, the circulating pump 26 is connected to the cooling box 29, the circulating pipe 27 surrounds the complexing tank 22, the oscillation component 210 includes an eccentric wheel 2101, an oscillation block 2102 and an oscillation frame 2103, the oscillation block 2102 and the oscillation frame 2103 are slidingly connected, the eccentric wheel 2101 and the oscillation block 2102 are transmission connected, and the first agitator 23 and the eccentric wheel 2101 are transmission connected.

[0049] By adopting the above-mentioned technical scheme, after the complexing motor 21 starts, its power is transmitted to the first agitator 23, so that the first agitator 23 is rotated in the complexing tank 22, and the liquid in the complexing tank 22 is stirred.Simultaneously, the quantitative pump 25 pumps the complexing agent quantitative pump 25 in the liquid storage barrel 24 into the complexing tank 22, and reacts with heavy metal ions.The circulating pump 26 heats and cools the liquid in the circulation pipe 27 by the cooperation of the heating box 28 and the cooling box 29, to control the temperature of the complexing reaction.The eccentric wheel 2101 of the oscillation assembly 210 rotates under the drive of the first agitator 23, and is connected by the sliding of the oscillation block 2102 and the oscillation frame 2103, so that the oscillation frame 2103 is produced to and fro, further improving the efficiency and uniformity of the complexing reaction.The design of whole complexing reaction mechanism 2 has not only guaranteed the stable carrying out of complexing reaction, but also realized the accurate control to the complexing reaction condition, for follow-up step-by-step precipitation provides good conditions.

[0050] Furthermore, the step-by-step sedimentation mechanism 3 includes a sedimentation tank 31, a pH probe 32, a drug pump 33, an acidic agent barrel 34, an alkaline agent barrel 35, a discharge valve 36 and an overflow pipe 37. The sedimentation tank 31 is connected to the overflow pipe 37. The overflow pipe 37 is used to automatically overflow to the next sedimentation section after the liquid level reaches a set height. The drug pump 33 is connected to the sedimentation tank 31, and the acidic agent barrel 34 and the alkaline agent barrel 35 are both connected to the drug pump 33. The sedimentation tank 31 is connected to the discharge valve 36, and the discharge valve 36 is located at the bottom of the sedimentation tank 31. The discharge valve 36 is connected to the sediment separation mechanism 4.

[0051] By adopting the above technical solution, the pH value in the precipitation tank 31 is monitored in real time by the pH probe 32 to ensure precise control of the precipitation reaction. When the pH value needs to be adjusted, the drug pump 33 pumps the agent in the acidic agent barrel 34 or the alkaline agent barrel 35 into the precipitation tank 31 to react with the complex, causing the heavy metal ions to gradually precipitate. As the precipitation reaction proceeds, the liquid level gradually rises. When the liquid level reaches the set height, the overflow pipe 37 automatically overflows the excess liquid to the next precipitation section, achieving the effect of segmented precipitation. When the precipitation is completed, the discharge valve 36 is opened, and the precipitated heavy metal slag falls into the sediment separation mechanism 4 under the action of gravity for further processing. The design of the entire step-by-step precipitation mechanism 3 not only ensures the stable progress of the precipitation reaction, but also realizes precise control of the precipitation conditions, effectively improving the separation efficiency and purity of heavy metals.

[0052] Furthermore, the sediment separation mechanism 4 includes a rotary drum filter 41, a return pipe 42, a scraping motor 43, a pressing elastic member 44, a scraper 45 and a scraping shaft 46. The scraping motor 43 is fastened to the rotary drum filter 41, the scraping motor 43 is transmission-connected to the scraping shaft 46, the scraping shaft 46 is fastened to the pressing elastic member 44, the pressing elastic member 44 is fastened to the scraper 45, the scraping shaft 46 is transmission-connected to the scraper 45, the return pipe 42 is connected to the sedimentation tank 31, and the rotary drum filter 41 is connected to the discharge valve 36.

[0053] By adopting the above technical solution, after the scraping motor 43 is started, its power is transmitted to the scraping shaft 46, causing the scraping shaft 46 to start rotating. The compression elastic member 44 provides a certain elastic support for the scraper 45, ensuring that the scraper 45 is in close contact with the surface of the drum filter 41. As the scraping shaft 46 rotates, the scraper 45 slides on the surface of the drum filter 41, scraping off the heavy metal slag attached to the drum filter 41. The scraped heavy metal slag falls into the collection device below through the drum filter 41, while the liquid that is not scraped off flows back into the sedimentation tank 31 through the return pipe 42, achieving effective separation of the sediment. The design of the entire sediment separation mechanism 4 not only ensures the thorough separation of the sediment, but also avoids secondary contamination of the liquid, providing good conditions for subsequent processing.

[0054] Furthermore, the crystallization salt precipitation mechanism 5 includes a double-layer coil crystallization tank 51, a temperature probe 52 and a spoiler 53. The spoiler 53 is provided with a guide groove 531, and a polytetrafluoroethylene ball 532 is embedded in the guide groove 531. The temperature probe 52 and the double-layer coil crystallization tank 51 are tightly connected. The spoiler 53 and the double-layer coil crystallization tank 51 are tightly connected. The upper layer of the double-layer coil crystallization tank 51 is used to transport high-temperature steam, and the upper and lower layers of the double-layer coil crystallization tank 51 are used to transport cooling water.

[0055] By adopting the above technical solution, the design of the double-layer coil crystallization tank 51 fully utilizes the effect of temperature difference on salt crystallization. High-temperature steam circulates in the upper layer of the double-layer coil crystallization tank 51, providing the necessary heat for the solution, promoting the dissolution of salt and the active movement of ions. The cooling water transported from the bottom layer quickly takes away the heat, forming a significant temperature gradient. This temperature difference prompts the salt in the solution to crystallize and precipitate rapidly within a suitable temperature range. The guide groove 531 and polytetrafluoroethylene ball 532 design on the spoiler 53 further enhance the turbulence effect of the solution during the crystallization process, allowing the salt in the solution to contact the cooling surface more evenly, thereby improving the crystallization efficiency and the purity of the salt. The design of the entire crystallization salt precipitation mechanism 5 not only ensures the efficient crystallization of salt, but also achieves a dual improvement in the purity and recovery rate of the crystallized salt through precise temperature control and turbulence.

[0056] Furthermore, the crystallization and salt separation mechanism 6 includes a spiral filter press 61, a vibrating screen 62, a salt outlet hopper 63, a filtrate pipe 64 and a salt separation box 65. The spiral filter press 61 is connected to the double-layer coil crystallization tank 51, the spiral filter press 61 is connected to the salt outlet hopper 63, the salt outlet hopper 63 is connected to the vibrating screen 62, and the vibrating screen 62 is connected to the salt separation box 65.

[0057] By adopting the above technical solution, the spiral filter press 61 can perform preliminary squeezing and dehydration on the crystallized salt precipitated in the double-layer coil crystallization tank 51 to remove excess water and impurities. The squeezed crystallized salt enters the salt outlet 63 through the outlet of the spiral filter press 61. The design of the salt outlet 63 ensures that the crystallized salt can flow smoothly into the subsequent vibrating screener 62. The vibrating screener 62 further screens and grades the crystallized salt through vibration, removes fine particles and impurities therein, and obtains relatively pure crystallized salt. Finally, the screened crystallized salt enters the salt separation box 65 through the outlet of the vibrating screener 62, thereby achieving effective separation and recovery of the crystallized salt.

[0058] Working principle of the present invention:

[0059] The liquid level stabilization component 110 monitors and controls the liquid level of the buffer tank 11 in real time through the repulsive transmission of the magnetic poles of the float 1106, guide rod 1107, limit ring 1108 and electromagnetic block, combined with the conductive feedback of the upper and lower limit liquid level probes 1102. The one-way micro-pressure breathing valve 1109 balances the air pressure in the tank, and cooperates with the micro-flow holes 11051 of the buffer cover 1105 to slow down the fluctuation of the liquid level, ensuring the stability of the liquid input before the complexation reaction. The stirring component 19 adopts an articulated design of a screw rod 192 and a universal coupling 193. The electromagnetic block drives the moving block 196 to slide, driving the transmission bevel gear 197 to realize the rotation and revolution of the stirring rod 191, thereby improving the mixing uniformity; the step-by-step precipitation mechanism 3 is linked to the drug pump 33 through the pH probe 32, accurately adding acidic / alkaline agents, and adjusting the pH value in stages to gradually precipitate heavy metal ions. Overflow pipe 37 automatically overflows the liquid level in stages. Combining the elastic compression member 44 of the rotary drum filter 41 ensures the scraper 45 is in close contact, while the scraper shaft 46 rotates to remove sediment. The separated residue is discharged through the discharge valve 36, and the liquid is recycled through the return pipe 42 to avoid secondary contamination. The double-coil crystallization tank 51 utilizes the temperature difference between the upper and lower layers of high-temperature steam and cooling water to create a temperature gradient for salt precipitation. The polytetrafluoroethylene balls 532 of the spoiler 53 enhance solution turbulence and improve crystal purity. After the spiral filter press 61 squeezes and dehydrates the crystallized salt, the vibrating screen 62 uses high-frequency vibration to separate salt particles of different sizes, which are ultimately collected in the salt separation tank 65, achieving efficient salt recovery.

[0060] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A separation device for recovering crystalline salts by stepwise precipitation of heavy metals, characterized by: The separation device comprises a liquid inlet buffering and dispensing mechanism (1), a complexing reaction mechanism (2), a step-by-step precipitation mechanism (3), a sediment separation mechanism (4), a crystallized salt precipitation mechanism (5) and a crystallized salt separation mechanism (6); the liquid inlet buffering and dispensing mechanism (1) is connected to the complexing reaction mechanism (2), the step-by-step precipitation mechanism (3) is connected to the complexing reaction mechanism (2), the sediment separation mechanism (4) is connected to the step-by-step precipitation mechanism (3), the step-by-step precipitation mechanism (3) is connected to the crystallized salt precipitation mechanism (5), and the crystallized salt separation mechanism (6) is connected to the crystallized salt precipitation mechanism (5); The liquid inlet buffering and dispensing mechanism (1) comprises a buffer tank (11), a liquid inlet pipe (12), a connecting pipe (13), a regulating pipe (14), a pH pump (15), a liquid inlet valve (16), a pH sensor (17), a connecting valve (18), a stirring assembly (19) and a liquid level stabilizing assembly (110), wherein the buffer tank (11) is connected to the liquid inlet pipe (12), the buffer tank (11) is connected to the regulating pipe (14), the buffer tank (11) is connected to the connecting pipe (13), the connecting pipe (13) is connected to the connecting valve (18), and the connecting valve (18) is connected to the complexing reaction. The mechanism (2) is connected, the pH pump (15) is connected to the regulating pipe (14), the liquid inlet pipe (12) is connected to the liquid inlet valve (16), the stirring assembly (19) is tightly connected to the buffer tank (11), the liquid level stabilizing assembly (110) is tightly connected to the buffer tank (11), the pH sensor (17) is tightly connected to the buffer tank (11), the pH pump (15) is used to initially adjust the pH value of the raw liquid, the connecting valve (18) is used to control the flow rate entering the complex reaction mechanism (2), and the liquid inlet valve (16) is used to control the flow rate of the raw liquid entering the buffer tank (11); The liquid level stabilization assembly (110) comprises an upper limit liquid level probe (1101), a lower limit liquid level probe (1102), a first elastic member (1103), a first electromagnetic block (1104), a buffer cover (1105), a float (1106), a guide rod (1107), a limit ring (1108) and a one-way micro-pressure breathing valve (1109). The buffer cover (1105) and the buffer tank (11) are fastened together. The limit ring (1108) and the first electromagnetic block (1104) are provided in an even number. Two limiting rings (1108) and two first electromagnetic blocks (1104) are provided, and one limiting ring (1108) and one first electromagnetic block (1104) are provided at the upper and lower ends of the buffer tank (11), respectively. The upper limit liquid level probe (1101) and the limiting ring (1108) are fastened together, the lower limit liquid level probe (1102) and the limiting ring (1108) are fastened together, the guide rod (1107) and the buffer cover (1105) are fastened together, and the buffer cover (1105) and the buffer tank (11) are fastened together. The buffer cover (1105) is provided with a micro-guide hole (11051), and the micro-guide hole (11051) is used for liquid to slowly enter and slow down the fluctuation of the liquid level. The limit ring (1108) and the guide rod (1107) are slidably connected. The limit ring (1108) is used to control the displacement range of the float (1106) so as to correspond to the upper and lower limit thresholds of the liquid level. The upper limit liquid level probe (1101) and the lower limit liquid level probe (1102) are upper and lower conductive electrodes. The float (1106) and the guide rod (1107) The one-way micro-pressure breathing valve (1109) is connected to the buffer tank (11) by sliding connection, and the one-way micro-pressure breathing valve (1109) is located above the buffer tank (11). The first electromagnetic block (1104) and the buffer cover (1105) are fastened together, the first elastic member (1103) and the first electromagnetic block (1104) are fastened together, the first elastic member (1103) and the limiting ring (1108) are fastened together, and the first electromagnetic block (1104) and the limiting ring (1108) are driven by magnetic pole repulsion.

2. The separation device for recovering crystalline salts by stepwise precipitation of heavy metals according to claim 1, characterized in that: The stirring assembly (19) comprises a stirring rod (191), a screw rod (192), a universal coupling (193), a hinge block (194), a stirring motor (195), a moving block (196), a transmission bevel gear (197), a second electromagnetic block (198), a third electromagnetic block (199) and a second elastic member (1910). The stirring motor (195) is fastened to the buffer tank (11). The stirring motor (195) is transmission-connected to the stirring rod (191). The moving block (196) is fastened to the third electromagnetic block (199). The second elastic member (1910) is fastened to the second electromagnetic block (198). The second elastic member (1910) is fastened to the moving block (196). ) are fastened together, the second electromagnetic block (198) and the moving block (196) are attracted to each other by magnetic poles, the third electromagnetic block (199) and the moving block (196) are attracted to each other by magnetic poles, the moving block (196) and the stirring rod (191) are slidably connected, the moving block (196) and the transmission bevel gear (197) are transmission-connected, the transmission bevel gear (197) and the third electromagnetic block (199) are slidably connected, the transmission bevel gear (197) and the stirring rod (191) are slidably connected, the transmission bevel gear (197) and the universal coupling (193) are transmission-connected, the universal coupling (193) and the screw rod (192) are hinged, and the screw rod (192) and the articulated block (194) are hinged.

3. The separation device for recovering crystalline salts by stepwise precipitation of heavy metals according to claim 2, characterized in that: The complexation reaction mechanism (2) includes a complexation motor (21), a complexation tank (22), a first agitator (23), a liquid storage barrel (24), a metering pump (25), a circulation pump (26), a circulation pipe (27), a heating box (28), a cooling box (29) and an oscillation component (210), wherein the complexation motor (21) and the complexation tank (22) are fastened together, the complexation motor (21) and the first agitator (23) are transmission-connected, the liquid storage barrel (24) and the metering pump (25) are in communication, the metering pump (25) and the complexation tank (22) are in communication, the complexation tank (22) and the connecting valve (18) are in communication, and the circulation pipe (27) is in communication. ) is connected to the cooling box (29), the circulating pump (26) is connected to the heating box (28), the heating box (28) is connected to the circulating pump (26), the circulating pump (26) is connected to the cooling box (29), the circulating pipe (27) surrounds the complexing tank (22), the oscillation component (210) includes an eccentric wheel (2101), an oscillation block (2102) and an oscillation frame (2103), the oscillation block (2102) and the oscillation frame (2103) are slidably connected, the eccentric wheel (2101) and the oscillation block (2102) are transmission-connected, and the first agitator (23) and the eccentric wheel (2101) are transmission-connected.

4. The separation device for recovering crystalline salts by stepwise precipitation of heavy metals according to claim 3, characterized in that: The step-by-step sedimentation mechanism (3) comprises a sedimentation tank (31), a pH probe (32), a drug pump (33), an acidic agent barrel (34), an alkaline agent barrel (35), a discharge valve (36) and an overflow pipe (37). The sedimentation tank (31) is connected to the overflow pipe (37). The overflow pipe (37) is used to automatically overflow to the next sedimentation section after the liquid level reaches a set height. The drug pump (33) is connected to the sedimentation tank (31). The acidic agent barrel (34) and the alkaline agent barrel (35) are both connected to the drug pump (33). The sedimentation tank (31) is connected to the discharge valve (36). The discharge valve (36) is located at the bottom of the sedimentation tank (31). The discharge valve (36) is connected to the sediment separation mechanism (4).

5. The separation device for recovering crystalline salts by stepwise precipitation of heavy metals according to claim 4, characterized in that: The sediment separation mechanism (4) comprises a drum filter (41), a return pipe (42), a scraping motor (43), a pressing elastic member (44), a scraper (45) and a scraping shaft (46); the scraping motor (43) and the drum filter (41) are fastened together; the scraping motor (43) and the scraping shaft (46) are transmission-connected; the scraping shaft (46) and the pressing elastic member (44) are fastened together; the pressing elastic member (44) and the scraper (45) are fastened together; the scraping shaft (46) and the scraper (45) are transmission-connected; the return pipe (42) and the sedimentation tank (31) are in communication; and the drum filter (41) and the discharge valve (36) are in communication.

6. The separation device for recovering crystalline salts by stepwise precipitation of heavy metals according to claim 5, characterized in that: The crystallization salt precipitation mechanism (5) comprises a double-layer coil crystallization tank (51), a temperature probe (52) and a spoiler (53), wherein the spoiler (53) is provided with a guide groove (531), wherein a polytetrafluoroethylene ball (532) is embedded in the guide groove (531), the temperature probe (52) and the double-layer coil crystallization tank (51) are tightly connected, and the spoiler (53) and the double-layer coil crystallization tank (51) are tightly connected, the upper layer of the double-layer coil crystallization tank (51) is used to transport high-temperature steam, and the upper and lower layers of the double-layer coil crystallization tank (51) are used to transport cooling water.

7. The separation device for recovering crystalline salts by stepwise precipitation of heavy metals according to claim 6, characterized in that: The crystallization and salt separation mechanism (6) includes a spiral filter press (61), a vibrating screen (62), a salt outlet hopper (63), a filtrate pipe (64) and a salt separation box (65), wherein the spiral filter press (61) is connected to the double-layer coil crystallization tank (51), the spiral filter press (61) is connected to the salt outlet hopper (63), the salt outlet hopper (63) is connected to the vibrating screen (62), and the vibrating screen (62) is connected to the salt separation box (65).

Images