Yellow phosphorus production sewage circulation purification system

Abstract

The utility model relates to the technical field of environment-friendly treatment of industrial sewage, in particular to a yellow phosphorus production sewage circulating purification system, which is provided with a yellow phosphorus sewage tank, a multi-stage sedimentation mechanism, a concentration filtering mechanism and a clear liquid collecting tank which are sequentially arranged along a sewage treatment flow, the yellow phosphorus sewage tank is used for collecting yellow phosphorus production sewage; the multi-stage sedimentation mechanism is provided with a plurality of deep cone sedimentation machines which are arranged in series and are used for carrying out sedimentation separation on the conveyed yellow phosphorus sewage; the concentrating and filtering mechanism is used for concentrating and separating the conveyed settling floating liquid; and the clear liquid collecting tank is used for collecting the clear liquid separated by the concentrating and filtering mechanism and conveying the clear liquid to the phosphorus collecting tower through a water conveying pipe. Aiming at the special characteristics of yellow phosphorus production sewage purification treatment, the utility model constructs a closed circulation purification system, has the technical characteristics of greatly reducing the occupied area, being low in construction and operation cost and excellent in separation and purification effect, and has remarkable technical effect and economic benefit.

Description

Technical Field

[0001] This utility model relates to the field of environmental protection treatment technology for industrial wastewater, specifically a wastewater recycling and purification system for yellow phosphorus production. Background Technology

[0002] Yellow phosphorus is an important basic industrial raw material, mainly used in chemical, pesticide, and other fields. Yellow phosphorus is usually produced by the electric furnace process, which generates a large amount of phosphorus-containing wastewater – the yellow phosphorus production wastewater. To recover yellow phosphorus from this wastewater and protect the environment, it is necessary to purify and treat it.

[0003] For a long time, the purification and treatment of wastewater from yellow phosphorus production has mainly been achieved through sedimentation separation.

[0004] The traditional approach involves constructing multiple large sedimentation tanks (troughs) on the ground. These tanks are connected via corresponding equipment / pipelines according to a predetermined sedimentation separation sequence. Examples include Chinese patent documents such as "A Wastewater Treatment System for Yellow Phosphorus Production Enterprises" (publication number CN 205473189 U, publication date August 17, 2016), "A New Process for Yellow Phosphorus Industrial Wastewater Treatment" (publication number CN 1699206 A, publication date November 23, 2005), and "A Treatment Process for Yellow Phosphorus Wastewater" (publication number CN107285555 A, publication date October 24, 2017). Clearly, this purification process involving multiple large sedimentation tanks on the ground presents the following technical problems:

[0005] 1. Purification facilities require a large area, have high construction costs, and face significant technical challenges in closed-loop systems;

[0006] 2. There is a high risk of groundwater pollution;

[0007] 3. The purification efficiency of the sedimentation separation process in the sedimentation tank alone is relatively low. In order to meet the requirements of the industry, more sedimentation tanks need to be built to support the process.

[0008] 4. The cleaning of each sedimentation tank requires manual labor, which is labor-intensive and costly for workers;

[0009] 5. The concentration of impurities in the final clear liquid obtained by sedimentation separation of yellow phosphorus production wastewater is usually above 100 mg / L, which is difficult to achieve the ideal technical requirement of ≤40 mg / L. The purification effect of sedimentation separation is not good.

[0010] In light of this, in recent years, the industry has attempted to research purification technologies that reduce the need for ground-based sedimentation tanks and construct closed-loop systems. Examples include a Chinese patent document titled "Closed-Loop Treatment and Recycling System for Yellow Phosphorus Production Wastewater," publication number CN 222411260 U, published on January 28, 2025. This type of technology replaces traditional sedimentation tanks with sedimentation equipment and delivers the purified cooling water to the yellow phosphorus production equipment, forming a closed loop of yellow phosphorus production wastewater – purification treatment – ​​yellow phosphorus production. This technology offers significant advantages over traditional methods.

[0011] However, the technology disclosed in CN 222411260 U describes the following purification process for wastewater from yellow phosphorus production: The supernatant is separated by sedimentation equipment and sent to a cooling water tank; the intermediate mixture is then separated by sedimentation equipment and sent to a coagulation and flocculation tank for chemical separation; the supernatant separated by the flocculation tank is sent to the cooling water tank; the flocculated mixture separated by the flocculation tank is sent to a flotation tank; the clear liquid separated by the flotation tank is sent to the cooling water tank; the mixture separated by the flotation tank is sent to a filter; and the clear liquid separated by the filter is sent to the cooling water tank. It is evident that the water entering the cooling water tank is separated by different purification and separation devices within the purification system, at least four separate streams. The purification levels of each stream are difficult to be consistent, making it difficult for the impurity concentration in the cooling water to reach the ideal technical requirement of ≤40mg / L. This results in poor separation and purification effects, which in turn negatively impact the downstream yellow phosphorus production equipment and processes in the closed-loop system. The most direct impact is the potential for blockage in the water supply pipes and a reduction in yellow phosphorus collection efficiency. Utility Model Content

[0012] The technical objective of this utility model is to provide a yellow phosphorus production wastewater recycling and purification system that reduces land occupation, has low construction and operating costs, excellent separation and purification effects, and forms a closed loop, addressing the specific characteristics of yellow phosphorus production wastewater purification and treatment and the shortcomings of existing technologies.

[0013] The technical objective of this utility model is achieved through the following technical solution: a wastewater recycling and purification system for yellow phosphorus production, wherein the recycling and purification system comprises yellow phosphorus wastewater tanks arranged sequentially along the wastewater treatment process.

[0014] Multi-stage sedimentation mechanism, concentration and filtration mechanism, and clear liquid collection tank;

[0015] The yellow phosphorus wastewater tank is used to collect wastewater from yellow phosphorus production, and the yellow phosphorus wastewater tank is connected to the inlet of the multi-stage sedimentation mechanism through a yellow phosphorus wastewater feeding pipe.

[0016] The multi-stage sedimentation mechanism has multiple deep cone sedimentation machines arranged in series. The discharge port of the multi-stage sedimentation mechanism is connected to the inlet of the concentration and filtration mechanism through a sedimentation and flotation feed pipe. The discharge port of at least one deep cone sedimentation machine upstream of the multi-stage sedimentation mechanism is connected to a yellow phosphorus slurry collection tank through a sedimentation slurry collection pipe. The discharge ports of the remaining deep cone sedimentation machines are connected to mud and phosphorus collection tanks through sedimentation slurry collection pipes.

[0017] The discharge port of the concentration and filtration mechanism is connected to the clear liquid collection tank through a concentrated clear liquid collection pipe, and the slurry discharge port of the concentration and filtration mechanism is connected to the mud and phosphorus collection tank through a concentrated slurry collection pipe.

[0018] The clear liquid collection tank is connected to the phosphorus collection tower via a water supply pipe.

[0019] The aforementioned technical measures address the specific needs of yellow phosphorus production wastewater purification. They sequentially arrange multi-stage sedimentation and thickening / filtration mechanisms within the yellow phosphorus wastewater treatment process. This allows the yellow phosphorus wastewater in the wastewater tank to be separated through these mechanisms. The high-phosphorus slurry enters the yellow phosphorus collection tank, the low-phosphorus slurry enters the sludge collection tank, and the clear liquid enters the clear liquid collection tank. From there, the system is circulated through a closed loop to the phosphorus collection tower. Therefore, this closed-loop purification system requires minimal land use. The multi-stage sedimentation and thickening / filtration mechanisms, which can be supported on the ground, replace traditional large-scale ground-mounted sedimentation tanks, significantly reducing land consumption. Furthermore, the multi-stage sedimentation and thickening / filtration mechanisms are easy to automate, resulting in low construction and operating costs for the circulating purification system. Furthermore, the purification system described above ensures that the yellow phosphorus wastewater in the yellow phosphorus wastewater tank is separated sequentially by multi-stage sedimentation and concentration filtration mechanisms. The separated clear liquid then enters a clear liquid collection tank, eliminating the problem of clear liquid confluence caused by multiple separation and purification processes. This results in a relatively constant degree of purification in the clear liquid entering the collection tank, leading to excellent separation and purification effects. The system ensures that the impurity concentration in the clear liquid entering the collection tank reaches the ideal technical requirement of ≤40 mg / L. Therefore, the closed-loop purification system constructed using the above-mentioned technical measures has the technical advantages of significantly reducing land occupation, low construction and operating costs, and excellent separation and purification effects.

[0020] As one of the preferred technical solutions, the clear liquid collection tank is divided into a relatively independent first clear liquid collection tank and a second clear liquid collection tank. The first clear liquid collection tank and the second clear liquid collection tank are connected to the concentration and filtration mechanism through corresponding concentrated clear liquid collection pipes.

[0021] The first collection tank of clear liquid is connected to the high-temperature phosphorus collection tower through the water supply pipe of the high-temperature phosphorus collection tower, and is used to supply the high-temperature phosphorus collection tower with operating water; the second steam heating coil is arranged in the first collection tank of clear liquid, and the second steam heating coil is used to heat the clear liquid in the first collection tank of clear liquid to the temperature corresponding to the operation of the high-temperature phosphorus collection tower.

[0022] The second collection tank for the clear liquid is connected to a closed cooling tower via a cooling water supply pipe. The closed cooling tower is used to cool the clear liquid in the second collection tank to a temperature corresponding to the operation of the low-temperature phosphorus collection tower, and is connected to the low-temperature phosphorus collection tower via a low-temperature phosphorus collection tower water supply pipe to supply operating water to the low-temperature phosphorus collection tower.

[0023] The above-mentioned technical measures, based on a closed-loop system, specifically address the unique characteristics of the relatively high-temperature and relatively low-temperature phosphorus collection towers in the yellow phosphorus production process. A closed-loop clear liquid collection tank is specifically configured, and the clear liquid collected in the first and second collection tanks is heated by corresponding steam coils and a closed-loop cooling tower to obtain water at the corresponding process temperature. This water, meeting the required process temperature, is then delivered to the relatively high-temperature and relatively low-temperature phosphorus collection towers via corresponding water supply pipes. Therefore, the closed-loop purification system constructed by these technical measures is more suitable for the yellow phosphorus production process and helps ensure its reliable and efficient implementation.

[0024] Furthermore, the second collection tank for the clear liquid has a relatively independent closed cooling tower makeup water tank and a cooling water tank;

[0025] The closed cooling tower water supply tank is connected to the drain pipe and / or cooling water tank of the closed cooling tower, and is connected to the closed cooling tower through the closed cooling tower water supply pipe, and is used to supply heat exchange cooling water to the closed cooling tower.

[0026] The cooling water tank is connected to the drain pipe of the closed cooling tower, and is also connected to the low-temperature phosphorus collection tower via the water supply pipe of the low-temperature phosphorus collection tower.

[0027] The above-mentioned technical measures are designed to address the unique characteristics of heat exchange water in closed-loop cooling towers, enabling the water replenishment of closed-loop cooling towers to form a self-sufficient closed-loop system with better closed-loop performance.

[0028] As one of the preferred technical solutions, the multiple deep cone sedimentation machines of the multi-stage sedimentation mechanism are arranged in series with a structure in which the upstream deep cone sedimentation machine overflows sequentially to the downstream deep cone sedimentation machine;

[0029] Each deep cone settling machine has a guide plate at its feed inlet that extends downwards to at least the middle of the corresponding settling chamber. The guide plate is arranged with inclined tube packing in the settling chamber in the height direction.

[0030] The yellow phosphorus wastewater entering the multi-stage sedimentation mechanism flows in a bypass path from top to bottom and from bottom to top;

[0031] Furthermore, the feed inlet of the first deep cone sedimentation machine in the multi-stage sedimentation mechanism has a baffle plate with a toothed upper edge. The yellow phosphorus wastewater flows into the guide channel formed by the guide plate of the first deep cone sedimentation machine after the baffle plate is flipped up.

[0032] The multi-stage sedimentation mechanism described above consists of multiple deep cone sedimentation machines arranged in series, creating a flow path for the yellow phosphorus wastewater entering the multi-stage sedimentation mechanism that is both vertically and horizontally deflected, thereby reliably improving the sedimentation and separation effect. Simultaneously, the structure at the inlet of the first deep cone sedimentation machine ensures a relatively uniform distribution of the incoming yellow phosphorus wastewater and also provides a certain mixing effect on the chemicals contained in the wastewater, further enhancing the sedimentation and separation efficiency.

[0033] As one of the preferred technical solutions, each deep cone sedimentation machine in the multi-stage sedimentation mechanism has a steam heating coil arranged at its bottom. This technical measure addresses the special characteristic of yellow phosphorus being prone to crystallization in low-temperature environments (≤45℃). By using steam heating coils, the temperature of the sedimentation slurry is maintained, preventing crystallization and blockage caused by excessively low temperatures, thus ensuring the stable and long-term operation of the multi-stage sedimentation mechanism.

[0034] Furthermore, the discharge port of each deep cone settling machine in the multi-stage settling mechanism is a siphon bend structure connected to the bottom of the corresponding settling chamber. This technical measure can generate adsorption characteristics at the bottom of the corresponding settling chamber, thereby effectively adsorbing and discharging the slurry that has settled to the bottom of the corresponding settling chamber, and the slurry discharge effect is significantly better than that of a direct discharge structure.

[0035] As one of the preferred technical solutions, each deep cone sedimentation unit in the multi-stage sedimentation mechanism has a temperature-regulating steam pipe that can be connected to a steam pipe to introduce steam into the corresponding sedimentation chamber. This technical measure regulates the temperature of the yellow phosphorus wastewater in the corresponding sedimentation chamber by introducing steam, ensuring that the yellow phosphorus wastewater in the multi-stage sedimentation mechanism tends to be at a constant temperature. This is beneficial for ensuring the sedimentation and separation effect, ensuring the stable flow of yellow phosphorus wastewater in each sedimentation chamber of the multi-stage sedimentation mechanism, and also helps to improve the tar coagulation phenomenon in yellow phosphorus wastewater. This is especially prominent when combined with reagents, effectively solving the long-standing problem of scaling caused by tar coagulation in yellow phosphorus wastewater.

[0036] As one of the preferred technical solutions, the top of the deep cone settling machine at the tail of the multi-stage settling mechanism is connected to a settling liquid overflow pipe that is higher than the drain outlet.

[0037] The sedimentation overflow pipe is connected to the yellow phosphorus wastewater tank.

[0038] The above-mentioned technical measures, through the design of the overflow structure, can ensure the stable operation of the entire purification system, especially the multi-stage sedimentation mechanism, without affecting the purification effect of the final discharged liquid.

[0039] As one of the preferred technical solutions, the concentration and filtration mechanism is a parallel arrangement of two concentration machines;

[0040] At the top of each concentrator, there is a concentrated clear liquid overflow pipe that is higher than the drain port;

[0041] The concentrated clear liquid overflow pipe is connected to the yellow phosphorus wastewater tank.

[0042] The concentration and filtration mechanism described above can effectively handle the feeding flow of the multi-stage sedimentation mechanism, and can also make the two thickeners redundant to ensure continuous filtration operation, thereby ensuring the stable operation of the entire purification system. This is especially evident in the overflow structure design.

[0043] As one of the preferred technical solutions, a mixer is connected to the yellow phosphorus wastewater feeding pipe;

[0044] The mixer is connected to a PAC dosing device and / or a PAM dosing device, which is used to inject the corresponding agents into the yellow phosphorus wastewater transported to the multi-stage sedimentation mechanism.

[0045] The mixer has at least one set of turbulence-dispersing blades arranged inside, and at least one set of turbulence-dispersing blades is located downstream of the dosing port.

[0046] The above-mentioned technical measures enable the yellow phosphorus wastewater entering the multi-stage sedimentation mechanism to carry flocculants, thereby reliably improving the separation and purification effect of the multi-stage sedimentation mechanism and the concentration and filtration mechanism, especially the multi-stage sedimentation mechanism. On the other hand, the design structure of the mixer ensures that the added agents are automatically and uniformly mixed during the transportation of yellow phosphorus wastewater.

[0047] The beneficial technical effects of this utility model are as follows: The above-mentioned technical measures address the specific needs of yellow phosphorus production wastewater purification and treatment. By sequentially arranging multi-stage sedimentation and thickening / filtration mechanisms within the yellow phosphorus wastewater treatment process, the yellow phosphorus wastewater in the wastewater tank is separated through these mechanisms. The separated high-phosphorus slurry enters a recyclable yellow phosphorus collection tank, the separated low-phosphorus slurry enters a reusable sludge-phosphorus collection tank, and the separated clear liquid enters a clear liquid collection tank and is then circulated through a water supply pipe to the phosphorus collection tower in a closed loop. Therefore, the closed-loop purification system constructed by the above-mentioned technical measures does not require excessive land use. The multi-stage sedimentation and thickening / filtration mechanisms, which can be supported on the ground, replace the traditional multiple large ground-based sedimentation tanks, significantly reducing land use. Furthermore, the multi-stage sedimentation and thickening / filtration mechanisms are easy to clean automatically, resulting in low construction and operating costs for the above-mentioned circulating purification system. Moreover, the purification system of the above-mentioned technical measures ensures that the yellow phosphorus wastewater in the yellow phosphorus wastewater tank is separated by a multi-stage sedimentation mechanism and a concentration filtration mechanism. The separated clear liquid enters the clear liquid collection tank. The source of the clear liquid collected in the clear liquid collection tank is relatively unique, and there is no problem of clear liquid confluence under multi-channel separation and purification technology. This makes the purification degree of the clear liquid entering the clear liquid collection tank relatively constant, resulting in excellent separation and purification effect. It can make the impurity concentration in the clear liquid entering the clear liquid collection tank significantly lower than the ideal technical requirement of ≤40mg / L, and can reach ≤10mg / L. According to tests, it is usually 3 to 10mg / L.

[0048] In summary, compared with the traditional purification and separation technologies disclosed in CN 205473189 U, CN 1699206 A, and CN 107285555 A, the above-mentioned technical measures have the following technical advantages:

[0049] 1. The purification facilities have a small footprint, are easy to construct, and have low construction costs, and can effectively form a closed loop;

[0050] 2. It poses a low risk of groundwater pollution and is highly environmentally friendly and safe;

[0051] 3. The combination of multi-stage sedimentation and concentration filtration mechanisms results in high purification efficiency and enables continuous purification production;

[0052] 4. The multi-stage sedimentation and concentration filtration mechanisms can be automatically cleaned, requiring virtually no manual cleaning, resulting in low operating and management costs;

[0053] 5. The combination of multi-stage sedimentation and concentration filtration mechanisms results in excellent purification, with the concentration of impurities in the final separated liquid being far below the ideal technical requirement of ≤40mg / L, typically ≤10mg / L.

[0054] Compared to the technology disclosed in CN 222411260 U, the above-mentioned technical measures have a unique purification path under the upstream and downstream cooperation of the multi-stage sedimentation mechanism and the concentration and filtration mechanism. That is, the clear liquid entering the clear liquid collection tank comes solely from the concentration and filtration mechanism. There is no problem of clear liquid confluence under multi-path separation and purification technology, which makes the purification degree of the clear liquid entering the clear liquid collection tank relatively constant. This results in excellent separation and purification effect, and the concentration of impurities in the clear liquid entering the clear liquid collection tank is far lower than the ideal technical requirement of ≤40mg / L, usually ≤10mg / L. Moreover, the entire purification system has a simpler and more compact structure.

[0055] Therefore, the closed-loop purification system constructed by the above-mentioned technical measures has the technical characteristics of significantly reducing land occupation, low construction and operation costs, and excellent separation and purification effect, with significant technical effects and economic benefits. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of one structure of the present utility model.

[0057] Figure 2 for Figure 1 A magnified view of a section of the yellow phosphorus wastewater tank.

[0058] Figure 3 for Figure 1 A magnified view of a section of the multi-stage settlement mechanism.

[0059] Figure 4 for Figure 3 Enlarged view of the bottom structure of a medium-deep cone settling machine.

[0060] Figure 5 for Figure 3 Enlarged view of the upper and middle structure of the medium-deep cone settling machine.

[0061] Figure 6 for Figure 1 A magnified view of a portion of the intermediate cleaning solution collection tank.

[0062] Meaning of the codes in the image:

[0063] 1—Yellow phosphorus wastewater tank; 11—Yellow phosphorus wastewater collection pipe; 12—Yellow phosphorus wastewater feeding pipe; 13—Mixer; 14—PAC dosing device; 15—PAM dosing device;

[0064] 2—Multi-stage settling mechanism; 21—Deep cone settling machine; 22—Sediment collection pipe; 23—Steam heating coil one; 24—Temperature regulating steam connection; 25—Settling liquid feeding pipe; 26—Settling liquid overflow pipe; 27—Guide plate; 28—Break plate;

[0065] 3—Concentration and filtration mechanism; 31—Concentrator; 32—Concentrated slurry collection pipe; 33—Concentrated clear liquid collection pipe; 34—Concentrated clear liquid overflow pipe;

[0066] 4—Yellow phosphorus slurry collection tank;

[0067] 5—Mud and phosphorus collection tank; 51—Mud and phosphorus circulation pipe;

[0068] 6—Clear liquid collection tank; 61—First clear liquid collection tank; 62—Steam heating coil two; 63—High-temperature phosphorus collection tower water supply pipe; 64—Second clear liquid collection tank; 65—Cooling water supply pipe; 66—Closed-loop cooling tower; 67—Closed-loop cooling tower makeup water tank; 68—Cooling water tank; 69—Low-temperature phosphorus collection tower water supply pipe; 610—Closed-loop cooling tower makeup water pipe;

[0069] 7—High-temperature phosphorus collection tower;

[0070] 8—Low-temperature phosphorus collection tower;

[0071] 9—Air compressor supply mechanism. Detailed Implementation

[0072] This utility model relates to the field of environmental protection treatment technology for industrial wastewater, specifically a wastewater recycling and purification system for yellow phosphorus production. The main technical solution of this utility model will be described in detail below with reference to several embodiments. Embodiment 1 is illustrated in conjunction with the accompanying drawings. Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6 The technical solution of this utility model is clearly and thoroughly explained; although other embodiments are not shown in separate drawings, their main structures can still be referred to the drawings of Embodiment 1.

[0073] It should be noted that the accompanying drawings of this utility model are schematic, and unnecessary details have been simplified to clarify the technical purpose of this utility model, so as to avoid obscuring the technical solution contributed by this utility model to the prior art. In addition, the expressions such as "about" and "basically" regarding quantity or fit relationship in the following text mean that reasonable assembly errors and processing errors are allowed in the industry, and do not literally describe absolute quantity or fit relationship.

[0074] Example 1

[0075] See Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 and Figure 6As shown, this utility model is a closed-loop purification system for wastewater from yellow phosphorus production. It includes a yellow phosphorus wastewater tank 1, a multi-stage sedimentation mechanism 2, a concentration and filtration mechanism 3, and a clear liquid collection tank 6 arranged sequentially along the wastewater treatment process. Yellow phosphorus wastewater from the yellow phosphorus production line enters the yellow phosphorus wastewater tank 1. The yellow phosphorus wastewater in the yellow phosphorus wastewater tank 1 undergoes sedimentation and separation through the multi-stage sedimentation mechanism 2 and concentration and filtration through the concentration and filtration mechanism 3. The resulting clear liquid enters the clear liquid collection tank 6 and is then transported to the phosphorus collection tower, forming a closed-loop purification process.

[0076] Specifically, such as Figure 1 and Figure 2 As shown, the yellow phosphorus wastewater tank 1 is a pit-type structure used to collect the yellow phosphorus wastewater generated throughout the entire yellow phosphorus production line. A cover plate is installed at the opening of the yellow phosphorus wastewater tank 1, and the cover plate is equipped with necessary manholes, exhaust vents, etc.

[0077] like Figure 1 and Figure 2 As shown, the yellow phosphorus wastewater tank 1 is connected to the inlet of the multi-stage sedimentation mechanism 2 via a yellow phosphorus wastewater feed pipe 12. A submersible pump is connected to the end of the yellow phosphorus wastewater feed pipe 12 that extends into the yellow phosphorus wastewater tank 1 to pump the yellow phosphorus wastewater in the tank 1 to the multi-stage sedimentation mechanism 2 via the feed pipe 12. A valve controlling its on / off state is connected to the yellow phosphorus wastewater feed pipe 12; for automated operation, this valve is preferably an electromagnetically controlled valve; this valve is located upstream of the mixer 13 described below.

[0078] like Figure 1 and Figure 2As shown, to flocculate the yellow phosphorus wastewater entering the multi-stage sedimentation mechanism 2 and improve the sedimentation and separation effect, a mixer 13 is connected to the yellow phosphorus wastewater feeding pipe 12. This mixer 13 is connected to a PAC dosing device 14 and a PAM dosing device 15. The PAC dosing device 14 and PAM dosing device 15 add corresponding agents to the yellow phosphorus wastewater feeding pipe 12 through the mixer 13, so that the corresponding agents are mixed in the yellow phosphorus wastewater transported by the yellow phosphorus wastewater feeding pipe 12. To improve the mixing effect, three sets of baffles are arranged along the flow direction in the mixer 13, each set of baffles forming a grid-type flow channel. The first set of baffles is located upstream of the first dosing port, used to obstruct and turbulent the transported yellow phosphorus wastewater, causing the yellow phosphorus wastewater to collide and flow downstream, dispersing the yellow phosphorus wastewater so that the agent is incorporated relatively evenly. The second set of baffles is located downstream of the first dosing port and upstream of the second dosing port (i.e., the area between the two dosing ports). Its purpose is to obstruct and turbulent the incoming yellow phosphorus wastewater and its contained chemicals, causing them to collide and flow downstream, thus mixing the added chemicals and dispersing the yellow phosphorus wastewater to ensure relatively uniform addition of chemicals to the next dosing port. The third set of baffles is located downstream of the second dosing port, again obstructing and turbulent the incoming yellow phosphorus wastewater and its contained chemicals, causing them to collide and flow downstream, thus mixing the added chemicals.

[0079] The PAC dosing unit 14 and PAM dosing unit 15 described above have the same molding structure and are supported on the ground by a frame. They mainly consist of a chemical tank, a submersible pump, and corresponding pipelines. The chemical tank has a stirring structure, and the corresponding pipelines are connected to valves that control their on / off states. To achieve automated operation, these valves are preferably electromagnetically controlled valves.

[0080] like Figure 1 , Figure 3 , Figure 4 and Figure 5 As shown, the multi-stage settling mechanism 2 is supported on the ground by a frame. The multi-stage settling mechanism 2 is a series structure of multiple deep cone settling machines 21. These deep cone settling machines 21 are arranged in series with an upstream-to-downstream overflow structure. That is, the yellow phosphorus wastewater entering the first deep cone settling machine overflows to the second deep cone settling machine after filling its settling chamber, and overflows to the third deep cone settling machine after filling its settling chamber, and so on. To achieve a unified structure and ease of arrangement, multiple deep cone settling machines 21 are arranged within the same housing. Adjacent deep cone settling machines 21 are separated by partitions, forming relatively independent settling chambers. The top of the partitions forms an overflow channel between adjacent deep cone settling machines 21. Each deep cone settling machine 21 has a relatively independent conical bottom that connects to the corresponding settling chamber, and each deep cone settling machine 21 has a discharge port at its conical bottom.

[0081] To ensure the yellow phosphorus wastewater entering the corresponding deep cone sedimentation unit 21 is settled as thoroughly as possible and to improve the sedimentation and separation effect, each deep cone sedimentation unit 21 has a guide plate 27 extending downwards to the lower part of the corresponding sedimentation chamber at its inlet. This guide plate 27 separates the feed channel and the sedimentation chamber, guiding the continuous feed to the lower part of the corresponding sedimentation chamber before filling and overflowing. Within the sedimentation chamber in the height direction, the guide plate 27 is equipped with inclined tube packing to block and filter heavy substances in the yellow phosphorus wastewater, such as yellow phosphorus and phosphorus mud. Based on the aforementioned structure of the deep cone sedimentation unit 21 and the series connection of multiple deep cone sedimentation units 21, the yellow phosphorus wastewater entering the multi-stage sedimentation mechanism 2 flows along a top-down and bottom-up bypass path. In addition, to improve the distribution of yellow phosphorus wastewater entering the first deep cone settling machine 21 and to further mix the reagents contained in the yellow phosphorus wastewater, L-shaped vertical baffles 28 are arranged at the feed inlet of the first deep cone settling machine 21 (e.g., Figure 5 As shown), the upper edge of the baffle 28 has a toothed structure. The yellow phosphorus wastewater flows in and first overflows laterally in the groove formed by the baffle 28, and then flows into the guide channel formed by the guide plate 27 of the first deep cone sedimentation machine 21 through the toothed structure of the upper edge of the baffle 28.

[0082] Because yellow phosphorus and mud phosphorus impurities in yellow phosphorus wastewater are prone to scaling at low temperatures, in order to reduce scaling and clogging of the settling chamber during sedimentation and separation, temperature-controlled steam pipes 24 are arranged at the bottom of each deep cone setter 21. These pipes can be connected to steam pipes to introduce steam into the corresponding settling chamber. Figure 4 As shown in the figure, the yellow phosphorus wastewater in the corresponding settling chamber is heated by the introduced steam, so that the yellow phosphorus wastewater tends to a constant temperature state for settling and separation, reducing scaling.

[0083] As described above, in the multi-stage sedimentation mechanism 2, the separated yellow phosphorus slurry and mud phosphorus slurry are discharged into corresponding collection tanks through the discharge ports at the bottom of each deep cone sedimentation machine 21, while the separated flotation liquid is transported to the concentration and filtration mechanism 3 through the discharge port of the tail deep cone sedimentation machine 21. Therefore, based on the characteristic that yellow phosphorus easily crystallizes at low temperatures (usually ≤45℃), steam heating coils 23 are arranged at the bottom of each deep cone sedimentation machine 21 (e.g., Figure 4 As shown, the steam heating coil 23 is used to heat the sedimented slurry (yellow phosphorus slurry, mud phosphorus slurry) above its crystallization point (generally, the heating temperature is 65°C). The heating through the steam heating coil 23 is only a tubular heat exchange and does not involve the direct introduction of steam into the slurry. This is because it is difficult to directly introduce steam into the sedimented slurry for heating. Therefore, the structure of the steam heating coil 23 is basically independent of the temperature control structure that directly introduces steam.

[0084] As described above, sedimentation slurry will form at the bottom of the sedimentation chamber of each deep cone sedimentation machine 21 in the multi-stage sedimentation mechanism 2. Therefore, each deep cone sedimentation machine 21 needs to have an independent slurry discharge port at its bottom, which is connected to a corresponding sedimentation slurry collection pipe 22. In order to improve the discharge effect of the slurry at the bottom of the sedimentation chamber and reduce clogging, the part of the sedimentation slurry collection pipe 22 that extends into the corresponding deep cone sedimentation machine 21 is a siphon bend structure connected to the bottom of the corresponding sedimentation chamber (e.g., Figure 4 (As shown). Each sediment collection pipe 22 is connected to a valve to control its on / off state. To achieve automated operation, the valve is preferably an electromagnetically controlled valve; the valve is located outside the corresponding deep cone settling machine 21.

[0085] The structure and working characteristics of the aforementioned multi-stage sedimentation mechanism 2 result in a significantly higher concentration of yellow phosphorus in the slurry separated by the upstream deep cone sedimentation machines 21 compared to the downstream deep cone sedimentation machines 21. To achieve effective yellow phosphorus recovery and reduce the technical difficulty of processing the collected yellow phosphorus, the slurry with a higher yellow phosphorus concentration is collected separately for recovery, while the slurry with a lower yellow phosphorus concentration is collected separately for environmental treatment. Therefore, the discharge ports of the first and second deep cone sedimentation machines upstream of the aforementioned multi-stage sedimentation mechanism 2 are connected to yellow phosphorus slurry collection tanks 4 via corresponding sedimentation slurry collection pipes 22, respectively. The discharge ports of the remaining downstream deep cone sedimentation machines are connected to mud-phosphorus collection tanks 5 via corresponding sedimentation slurry collection pipes 22 (e.g.,...). Figure 1 and Figure 3 (As shown).

[0086] The yellow phosphorus slurry collection tank 4 is a pit-type structure used to collect the sedimentation and separation slurry—i.e., yellow phosphorus slurry—discharged from the upstream deep cone settling machine 21 of the multi-stage settling mechanism 2. A cover plate with necessary manholes is installed at the opening of the yellow phosphorus slurry collection tank 4. A mud pump is installed inside the yellow phosphorus slurry collection tank 4 to facilitate the external discharge and recycling of the yellow phosphorus slurry.

[0087] The mud-phosphorus collection tank 5 is a pit-type structure used to collect the sedimentation and separation slurry discharged from the downstream deep cone sedimentation machine 21 of the multi-stage sedimentation mechanism 2—that is, mud-phosphorus slurry. A cover plate with necessary manholes is installed at the opening of the mud-phosphorus collection tank 5. To facilitate the discharge of the mud-phosphorus slurry from the mud-phosphorus collection tank 5 for environmental treatment (e.g., brick firing), a mud pump is installed inside the mud-phosphorus collection tank 5. Furthermore, to further improve the purification effect and recover as much yellow phosphorus as possible from the mud-phosphorus slurry, the mud-phosphorus collection tank 5 is connected to a mud-phosphorus circulation pipe 51. The end of the circulation pipe 51 extending into the mud-phosphorus collection tank 5 is connected to the mud pump, and the other end of the circulation pipe 51 is connected to the inlet of the first deep cone sedimentation machine 21 of the multi-stage sedimentation mechanism 2, so as to circulate and purify the mud-phosphorus collected in the mud-phosphorus collection tank 5.

[0088] The discharge port of the multi-stage sedimentation mechanism 2, i.e., the discharge port of the tail deep cone sedimentation machine 21, is connected to the inlet of the concentration and filtration mechanism 3 through the sedimentation and flotation feed pipe 25. At the same time, in order to ensure the stable operation of the multi-stage sedimentation mechanism 2, an overflow port higher than the discharge port is opened at the top of the tail deep cone sedimentation machine 21 in the multi-stage sedimentation mechanism 2. The overflow port is connected to a sedimentation and flotation overflow pipe 26 higher than the discharge port. The sedimentation and flotation overflow pipe 26 is connected to the yellow phosphorus wastewater tank 1, so as to return the yellow phosphorus wastewater that fails to be discharged into the concentration and filtration mechanism 3 and is higher than the normal purification flow path to the yellow phosphorus wastewater tank 1, so as to achieve circulation purification under the stable operation of the system.

[0089] like Figure 1 and Figure 6 As shown, the concentration and filtration mechanism 3 is supported on the ground by a frame. The concentration and filtration mechanism 3 consists of two thickeners 31 arranged in parallel. Each thickener's inlet is connected to the sedimentation feed pipe 25 of the multi-stage sedimentation mechanism 2, and the sedimented and separated flocculant is fed to the two thickeners 31 through the corresponding sedimentation feed pipe 25. Depending on the operating conditions, the two thickeners 31 of the concentration and filtration mechanism 3 can operate synchronously or in redundant standby mode, typically in redundant standby mode. Therefore, a valve controlling the on / off state is connected to the sedimentation feed pipe 25 at the inlet of each thickener 31. To achieve automated operation, this valve is preferably an electromagnetically controlled valve.

[0090] The discharge ports of the two thickeners 31 in the thickening and filtration mechanism 3 are connected to the clear liquid collection tank 6 via their respective concentrated clear liquid collection pipes 33. Each concentrated clear liquid collection pipe 33 is connected to a negative pressure pump and a valve to control the on / off state of the pipe. For automated operation, the valve is preferably an electromagnetically controlled valve. The discharge ports of the two thickeners 31 in the thickening and filtration mechanism 3 are connected to the aforementioned mud and phosphorus collection tank 5 via their respective concentrated slurry collection pipes 32. Each concentrated slurry collection pipe 32 is connected to a valve to control its on / off state. For automated operation, the valve is preferably an electromagnetically controlled valve.

[0091] Each of the above-mentioned thickeners 31 in the thickening and filtration mechanism 3 is a conventional high-efficiency thickener. Multiple hollow filter plates are arranged in its filter chamber. Each filter plate has a filter structure and filter cloth on the outside. The top of each filter plate is connected to a filtrate manifold. The tail end of the filtrate manifold is connected to the concentrated clear liquid collection pipe 33, thereby filtering and separating the slurry entering the filter chamber.

[0092] To ensure the stable operation of each thickener 31 in the concentration and filtration mechanism 3, an overflow port higher than the drain port is provided at the top of each thickener 31. A concentrated clear liquid overflow pipe 34 higher than the drain port is connected to the overflow port. The concentrated clear liquid overflow pipe 34 is connected to the yellow phosphorus wastewater tank 1, so as to return the yellow phosphorus wastewater that has not been concentrated and filtered to the yellow phosphorus wastewater tank 1, so as to realize the circulation and purification under the stable operation of the system.

[0093] like Figure 1 and Figure 6 As shown, the clear liquid collection tank 6 is divided into a relatively independent first clear liquid collection tank 61 and a second clear liquid collection tank 64, and the second clear liquid collection tank 64 further has a relatively independent closed-loop cooling tower makeup water tank 67 and a cooling water tank 68. The first clear liquid collection tank 61, the second clear liquid collection tank 64, the closed-loop cooling tower makeup water tank 67, and the cooling water tank 68 are all relatively independent pit structures, each with a cover plate.

[0094] The first collection tank 61 and the second collection tank 64 of the clear liquid are respectively connected to the concentration and filtration mechanism 3 through the corresponding concentrated clear liquid collection pipe 33.

[0095] The first collection tank 61 of the clarified liquid is connected to the high-temperature phosphorus collection tower 7 via a water supply pipe 63. A submersible pump is connected to the end of the water supply pipe 63 that extends into the first collection tank 61. Under the pumping action of the submersible pump, the water supply pipe 63 is used to supply operating water to the high-temperature phosphorus collection tower 7. A valve is connected to the water supply pipe 63 to control its on / off state; for automated operation, this valve is preferably an electromagnetically controlled valve. A second steam heating coil 62 is arranged inside the first collection tank 61. The second steam heating coil 62 is used to heat the clarified liquid in the first collection tank 61 to the temperature corresponding to the operation of the high-temperature phosphorus collection tower 7 (generally 70-80°C).

[0096] The second collection tank 64 for the clear liquid is connected to the closed-loop cooling tower 66 via a cooling water supply pipe 65. A submersible pump is connected to the end of the cooling water supply pipe 65 that extends into the second collection tank 64. Under the pumping action of the submersible pump, the cooling water supply pipe 65 delivers cooling water to the closed-loop cooling tower 66. The closed-loop cooling tower 66 is installed above ground and is used to cool the clear liquid in the second collection tank 64 to a temperature corresponding to the operation of the low-temperature phosphorus collection tower 8 (generally 20–30°C). The drain pipe of the closed-loop cooling tower 66 is connected to a cooling water tank 68, delivering the cooled water to the cooling water tank 68.

[0097] Cooling water tank 68 is connected to low-temperature phosphorus collection tower 8 via low-temperature phosphorus collection tower water supply pipe 69. A submersible pump is connected to the end of the low-temperature phosphorus collection tower water supply pipe 69 that extends into the cooling water tank 68. Under the pumping action of the submersible pump, the low-temperature phosphorus collection tower water supply pipe 69 is used to supply operating water to the low-temperature phosphorus collection tower 8. A valve is connected to the low-temperature phosphorus collection tower water supply pipe 69 to control its on / off state. For automated operation, this valve is preferably an electromagnetically controlled valve.

[0098] The closed-loop cooling tower makeup water tank 67 is used to replenish the working water of the closed-loop cooling tower 66. The cooling water in the closed-loop cooling tower makeup water tank 67 can be external water (preferably), or it can be the drainage from the closed-loop cooling tower 66 or the cooling water tank 68 after further cooling. Based on heat exchange requirements, the temperature of the cooling water in the closed-loop cooling tower makeup water tank 67 should be significantly lower than the temperature of the clear liquid in the second clear liquid collection tank 64. The closed-loop cooling tower makeup water tank 67 is connected to the closed-loop cooling tower 66 through the closed-loop cooling tower makeup water pipe 610. The end of the closed-loop cooling tower makeup water pipe 610 that extends into the closed-loop cooling tower makeup water tank 67 is connected to a submersible pump. Under the pumping action of the submersible pump, the closed-loop cooling tower makeup water pipe 610 is used to deliver working water to the closed-loop cooling tower 66.

[0099] Of course, in order to adjust and control the entire purification system, the high-temperature phosphorus collection tower water supply pipe 63 and the low-temperature phosphorus collection tower water supply pipe 69 are respectively led out with other independently controllable branch pipes, such as branch pipes for electric furnace water, branch pipes for slag pot water replenishment, and branch pipes for refining rinsing water replenishment, etc.

[0100] To ensure the normal operation of the above-mentioned concentration and filtration mechanism 3 and to backflush and clean the filter cloth, the above-mentioned purification system also has an air supply mechanism 9, which is connected to each concentrator 31 of the concentration and filtration mechanism 3 through an air supply pipeline that can be controlled to be turned on or off.

[0101] Example 2

[0102] The rest of the content of this embodiment is the same as that of embodiment 1, except that:

[0103] The dosing equipment in the purification system is only a single PAC dosing device or PAM dosing device;

[0104] Correspondingly, the turbulence-inducing blades inside the mixer are arranged in two sets with a spacing between the front and rear of the dosing port.

[0105] Example 3

[0106] The rest of the content of this embodiment is the same as that of embodiment 1, except that:

[0107] Eliminate the mud-phosphorus circulation pipe between the mud-phosphorus collection tank and the multi-stage sedimentation mechanism.

[0108] Of course, the corresponding function will be removed.

[0109] Example 4

[0110] The rest of the content of this embodiment is the same as that of embodiment 1, except that:

[0111] The baffle plate at the feed inlet of the first deep cone settling machine in the multi-stage settling mechanism was removed.

[0112] Of course, the corresponding function will be removed.

[0113] Example 5

[0114] The rest of the content of this embodiment is the same as that of embodiment 1, except that:

[0115] The discharge port at the bottom of each deep cone settling machine in the multi-stage settling mechanism is a straight pipe structure.

[0116] Of course, the corresponding siphon function is eliminated.

[0117] The above embodiments are only used to illustrate the present invention and are not intended to limit it.

[0118] Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications can still be made to the above embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the present invention.

Claims

1. A yellow phosphorus production wastewater recycling purification system, characterized in that: the recycling purification system has a yellow phosphorus wastewater tank (1), a multi-stage settling mechanism (2), a concentration filtering mechanism (3) and a clear liquid collecting tank (6) arranged in sequence along a wastewater treatment flow; the yellow phosphorus wastewater tank (1) is used for collecting yellow phosphorus production wastewater, and the yellow phosphorus wastewater tank (1) is connected with the feed inlet of the multi-stage settling mechanism (2) through a yellow phosphorus wastewater feeding pipe (12); the multi-stage settling mechanism (2) has a plurality of deep-cone settlers (21) arranged in series, the liquid discharge port of the multi-stage settling mechanism (2) is connected with the feed inlet of the concentration filtering mechanism (3) through a settling liquid feeding pipe (25), and the slurry discharge port of at least one deep-cone settler (21) at the upstream position of the multi-stage settling mechanism (2) is connected with a yellow phosphorus slurry collecting tank (4) through a slurry collecting pipe (22), and the slurry discharge ports of the remaining deep-cone settlers (21) are connected with a mud phosphorus collecting tank (5) through the slurry collecting pipes (22); the liquid discharge port of the concentration filtering mechanism (3) is connected with the clear liquid collecting tank (6) through a concentrated clear liquid collecting pipe (33), and the slurry discharge port of the concentration filtering mechanism (3) is connected with the mud phosphorus collecting tank (5) through a concentrated slurry collecting pipe (32); and the clear liquid collecting tank (6) is connected with a phosphorus collecting tower through a water feeding pipe.

2. The yellow phosphorus production wastewater recycling purification system according to claim 1, characterized in that: the clear liquid collecting tank (6) is divided into a clear liquid first collecting tank (61) and a clear liquid second collecting tank (64) which are relatively independent, the clear liquid first collecting tank (61) and the clear liquid second collecting tank (64) are connected with the concentration filtering mechanism (3) through corresponding concentrated clear liquid collecting pipes (33); the clear liquid first collecting tank (61) is connected with a high-temperature phosphorus collecting tower (7) through a high-temperature phosphorus collecting tower water feeding pipe (63) and is used for feeding working water to the high-temperature phosphorus collecting tower (7); a steam heating coil two (62) is arranged in the clear liquid first collecting tank (61) and is used for heating the clear liquid in the clear liquid first collecting tank (61) to a temperature corresponding to the working temperature of the high-temperature phosphorus collecting tower (7); the clear liquid second collecting tank (64) is connected with a closed cooling tower (66) through a cooling water feeding pipe (65), the closed cooling tower (66) is used for cooling the clear liquid in the clear liquid second collecting tank (64) to a temperature corresponding to the working temperature of a low-temperature phosphorus collecting tower (8), and is connected with the low-temperature phosphorus collecting tower (8) through a low-temperature phosphorus collecting tower water feeding pipe (69) and is used for feeding working water to the low-temperature phosphorus collecting tower (8).

3. The yellow phosphorus production wastewater recycling purification system according to claim 2, characterized in that: the clear liquid second collecting tank (64) has a closed cooling tower water supplement tank (67) and a cooling water tank (68) which are relatively independent. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ The closed cooling tower water supplement groove (67) is connected with the drain pipe and / or cooling water groove (68) of the closed cooling tower (66), and is connected with the closed cooling tower (66) through a closed cooling tower water supplement pipe (610) to serve as a heat exchange cooling water delivery device for the closed cooling tower (66); The cooling water groove (68) is connected with the drain pipe of the closed cooling tower (66) and is connected with the low-temperature phosphorus recovery tower (8) through a low-temperature phosphorus recovery tower water delivery pipe (69).

4. The yellow phosphorus production wastewater recycling and purifying system according to claim 1, characterized in that: The multiple deep-cone sedimentation machines (21) in the multiple-stage sedimentation mechanism (2) are arranged in series in a structure in which the upstream deep-cone sedimentation machine sequentially overflows into the downstream deep-cone sedimentation machine; Each deep-cone sedimentation machine (21) is provided with a flow guide plate (27) extending downward to the middle part of the corresponding sedimentation chamber; The yellow phosphorus wastewater entering the multiple-stage sedimentation mechanism (2) flows in a circumfluent path from top to bottom and from bottom to top; The first deep-cone sedimentation machine (21) in the multiple-stage sedimentation mechanism (2) is provided with a turbulence plate (28) with a tooth-shaped upper edge at the inlet thereof, and the yellow phosphorus wastewater flows into the flow guide passage formed by the flow guide plate (27) of the first deep-cone sedimentation machine (21) by turning upward the turbulence plate (28).

5. The yellow phosphorus production wastewater recycling and purifying system according to claim 1 or 4, characterized in that: Each deep-cone sedimentation machine (21) in the multiple-stage sedimentation mechanism (2) is provided with a steam heating coil (23) at the bottom thereof.

6. The yellow phosphorus production wastewater recycling and purifying system according to claim 5, characterized in that: The discharge port of each deep-cone sedimentation machine (21) in the multiple-stage sedimentation mechanism (2) is provided with a siphon bend structure connected to the bottom of the corresponding sedimentation chamber.

7. The yellow phosphorus production wastewater recycling and purifying system according to claim 1 or 4, characterized in that: Each deep-cone sedimentation machine (21) in the multiple-stage sedimentation mechanism (2) is provided with a temperature-adjusting steam connection pipe (24) connected to a steam pipe to introduce steam into the corresponding sedimentation chamber.

8. The yellow phosphorus production wastewater recycling and purifying system according to claim 1 or 4, characterized in that: The top of the last deep-cone sedimentation machine (21) in the multiple-stage sedimentation mechanism (2) is connected with a sedimentation supernatant overflow pipe (26) higher than the liquid discharge port; The sedimentation supernatant overflow pipe (26) is connected with the yellow phosphorus wastewater tank (1).

9. The yellow phosphorus production wastewater recycling and purifying system according to claim 1, characterized in that: The concentration and filtration mechanism (3) is provided with a parallel arrangement structure of two concentration machines (31); The top of each concentration machine (31) is connected with a concentration clear liquid overflow pipe (34) higher than the liquid discharge port; The concentration clear liquid overflow pipe (34) is connected with the yellow phosphorus wastewater tank (1).

10. The yellow phosphorus production wastewater recycling and purifying system according to claim 1, characterized in that: The yellow phosphorus wastewater feeding pipe (12) is connected with a mixer (13). The mixer (13) is connected with a PAC dosing device (14) and / or a PAM dosing device (15) for adding corresponding medicaments to the yellow phosphorus sewage delivered into the multi-stage settling mechanism (2); At least one group of turbulence vanes is arranged in the mixer (13), and at least one group of turbulence vanes is located downstream of the dosing port.

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