Calcium carbide process vinyl chloride mercury-containing wastewater treatment method and device

Abstract

The invention discloses a calcium carbide process vinyl chloride mercury-containing wastewater treatment method and device, and belongs to the field of wastewater treatment.The calcium carbide process vinyl chloride mercury-containing wastewater treatment device comprises a heating assembly, a separation assembly, a mixing assembly, a filtering assembly, a three-way valve and a product water tank, the heating assembly is communicated with the separation assembly through a pipeline, and the heating assembly is communicated with a mixing assembly for mixing a solution and wastewater through a pipeline; by arranging the mixing assembly, the heating assembly, the separating assembly, the filtering assembly and the three-way valve, sodium sulfide is adopted as a desulfurizing agent and is input into the static mixer after being mixed with liquid in the product water pipe, the material introduction amount is small, the safety of the device is improved, chemical reaction heat of all components is fully utilized during equipment operation, and the utilization of material heat energy is considered; the energy utilization rate is high, the traditional treatment mode is changed, an alkaline mercury removal process is directly adopted, and the operation risk caused by acid-base reaction is avoided, so that the safety during equipment operation and the overall working efficiency are improved.

Description

Technical Field

[0001] The invention belongs to the field of wastewater treatment, and specifically relates to a method and device for treating mercury-containing wastewater from vinyl chloride produced by a calcium carbide process. Background Art

[0002] Wastewater treatment is the use of physical, chemical and biological methods to treat wastewater, purify wastewater, reduce pollution, and even recycle and reuse wastewater to make full use of water resources. Now in the production process of calcium carbide polyvinyl chloride enterprises, mercury-containing catalysts will be carried out with the materials, eventually forming mercury-containing wastewater. This type of wastewater needs to be treated by specific equipment to screen and treat the mercury in the wastewater to reduce the impact of the wastewater on the surrounding environment.

[0003] Chinese invention patent CN104230085A discloses a method for treating mercury-containing wastewater in the production of polyvinyl chloride by the calcium carbide process; the method is carried out according to the following steps: the first step is to add the mercury-containing wastewater into a mercury treatment tank, add diatomaceous earth in an amount of 40 mg to 60 mg per liter of mercury-containing wastewater, add diatomaceous earth into the mercury treatment tank and mix evenly, add sodium hydrosulfide in an amount of 45 mol to 55 mol per 1 mol of mercury in the mercury-containing wastewater, add sodium hydrosulfide into the mercury treatment tank and mix evenly to obtain a mixed solution; The above design treats the mercury in the wastewater by adding diatomaceous earth and sodium hydrosulfide during the treatment of mercury-containing wastewater. This method has certain problems in actual use. Specifically, the mercury content in the solution is not fixed, and the amount of reagent added cannot be adjusted in time according to the mercury content in the wastewater, which can easily cause the mercury removal rate to be unstable, resulting in affected wastewater treatment efficiency. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In order to solve the problems raised in the above background technology, the present invention adopts the following technical solutions.

[0006] A method and device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process, comprising a heating component (1), a separation component (2), a mixing component (3), a filtering component (4), a three-way valve (5) and a product water tank (6), wherein the heating component (1) is connected to the separation component (2) via a pipeline, and the heating component (1) is connected to a mixing component (3) for mixing a mixed solution and wastewater via a pipeline, wherein a feeding pump body (34) for inputting sodium sulfide as a desulfurizing agent and a storage tank (35) are arranged in the mixing component (3), wherein the mercury in the wastewater inside the mixing component (3) is separated by using the sodium sulfide stored in the storage tank (35), and the wastewater in the mixing component (3) is input into a filtering component (4) with a filtering function via a pipeline, wherein a three-way valve (5) for controlling the opening and closing of the pipeline itself is installed on the external pipeline of the filtering component (4), and the three-way valve (5) is connected to a product water tank (6) for storing the filtered wastewater.

[0007] As a preferred technical solution of the present invention, the mixing assembly (3) comprises a static mixer (31), a solution feed pipe (32), a feeding pipe (33), a feeding pump body (34), a storage tank (35) and a discharge pipe (36), wherein the solution feed pipe (32) is connected to a side of the static mixer (31), the feeding pipe (33) is connected to a side of the static mixer (31) away from the solution feed pipe (32), the discharge pipe (36) is installed at the top of the static mixer (31), the discharge pipe (36) is connected to the filter assembly (4), the storage tank (35) is arranged on the side of the static mixer (31), the sodium sulfide in the storage tank (35) is input into the static mixer (31) through the feeding pump body (34) and the feeding pipe (33), and flow monitors are installed outside the static mixer (31) and the feeding pipe (33).

[0008] As a preferred technical solution of the present invention, the main component of the solution stored in the storage tank (35) is sodium sulfide, and the reaction equation is HgCl2+Na2S=HgS↓+2NaCl, and the water in the storage tank (35) comes from the filtered water source stored in the product water tank (6).

[0009] As a preferred technical solution of the present invention, the filter assembly (4) comprises a first bag filter (41), a second bag filter (42), an input pipe (43) and an output pipe (44); the first bag filter (41) and the second bag filter (42) are both connected to the static mixer (31) via a discharge pipe (36); the input pipe (43) is installed on the side of the first bag filter (41) and the second bag filter (42); the output pipe (44) is installed on the top of the first bag filter (41) and the second bag filter (42); and the output pipe (44) is connected to the three-way valve (5).

[0010] As a preferred technical solution of the present invention, the first bag filter (41) and the second bag filter (42) have the same structure, and PP filter bags are used inside the first bag filter (41) and the second bag filter (42).

[0011] As a preferred technical solution of the present invention, the heating assembly (1) comprises a first heater (11), a second heater (12), a wastewater feed pipe (13), a connecting pipe (14) and a hot water inlet pipe (15); the first heater (11) is provided with a wastewater feed pipe (13) for conveying mercury-containing detection; the connecting pipe (14) is provided on the side of the first heater (11); the second heater (12) is connected to a hot water inlet pipe (15) for inputting conversion hot water; the second heater (12) is connected to the separation assembly (2) via a pipeline; and the second heater (12) is connected to the first heater (11) via a pipeline.

[0012] As a preferred technical solution of the present invention, the temperature in the first heater (11) rises to 45-60°C, and heat is exchanged with the liquid from the separation component (2), and the mercury-containing alkali liquid after heat exchange is heat exchanged with the converted hot water to 80-90°C.

[0013] As a preferred technical solution of the present invention, the separation component (2) comprises a stripping tower (21), an exhaust pipe (22), a vacuum pump (23) and a matching pump body (24); the exhaust pipe (22) is installed at the top of the stripping tower (21); the vacuum pump (23) is installed at the end of the exhaust pipe (22); the matching pump body (24) is arranged on the side of the stripping tower (21); the matching pump body (24) is connected to the stripping tower (21) through a pipeline, and the matching pump body (24) is connected to the first heater (11).

[0014] As a preferred technical solution of the present invention, the three-way valve (5) is provided with three groups of connection ports, one end of which is connected to the filter assembly (4), one end of which is connected to the mixing assembly (3), and one end of which is connected to the product water tank (6), and a mercury content detector is installed on the pipeline connecting the three-way valve (5) and the filter assembly (4).

[0015] A method for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process, using the above-mentioned treatment device, comprises the following steps: S1. The mercury-containing alkali solution is input into the heating component, and the wastewater is heated by the heating component to a temperature of 45-60°C, and heat is exchanged with the liquid from the separation component. The mercury-containing alkali solution and the converted hot water are input into the second heater for heat exchange to 80-90°C, and then the heated mixed solution is input into the separation component; S2. The gas entering the top of the stripping tower is recovered through the cooperation of the vacuum pump and the exhaust pipe, and the gas is input into the vinyl chloride for recycling. After that, steam is input into one side of the stripping tower to perform countercurrent heat exchange with the alkali solution input through the second heater. A remote level gauge is provided at the bottom of the stripping tower, and cooperates with the pump body to extract the solution at the bottom of the stripping tower. After heat exchange with the mercury-containing alkali solution in the first heater, the solution is input into the mixing component after passing through the flow monitor; S3, through the cooperation of the feeding pump body and the feeding pipe, the sodium sulfide solution stored in the storage tank is input into the static mixer through the flow monitor, and is fully mixed and reacted with the liquid in the static mixer; S4. The fully mixed liquid is input into the first bag filter or the second bag filter through the discharge pipe, and the impurities in the liquid are filtered by the first bag filter or the second bag filter. The filtered solution enters the product water tank through the three-way valve; S5. A mercury content detector is set on the side of the three-way valve to transport the liquid in a targeted manner according to the mercury content in the liquid. When the mercury content is lower than the set value, the three-way valve opens, and the water from the filter component enters the product water tank. When the mercury content is higher than the set value, the three-way valve opens, and the water from the filter component returns through the pipeline, mixes with the mercury-containing alkali solution, and enters the mixing component again for mixing.

[0016] Compared with the prior art, the present invention has the following beneficial effects: In the present invention, a mixing component, a heating component, a separation component, a filtering component and a three-way valve are provided, sodium sulfide is used as a desulfurizing agent, and is mixed with the liquid in the product water pipe and then input into a static mixer, so that less material is introduced, the safety of the device is improved, the chemical reaction heat of each component is fully utilized during the operation of the equipment, the utilization of the thermal energy of the material is considered, the energy utilization rate is high, the traditional treatment method is changed, the alkaline mercury removal process is directly adopted, and the operational risks caused by the acid-base reaction are eliminated, thereby improving the safety of the equipment during operation and the overall work efficiency.

[0017] In the present invention, multiple groups of flow monitors and mercury content detectors are set up, and an automatic control method of cascade regulation is adopted in conjunction with a static mixer to improve mixing efficiency, accelerate reaction, avoid the use of a buffer sedimentation tank, shorten the process flow, and when the equipment is in operation, it can achieve accurate input of a corresponding total amount of desulfurizer when treating wastewater, reduce unnecessary pollution, and improve the working quality of the equipment itself. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a three-dimensional diagram of the overall structure of the present invention.

[0019] Figure 2 It is a plan view of the wastewater treatment process structure of the present invention.

[0020] Figure 3 It is a three-dimensional diagram of the mixing assembly structure of the present invention.

[0021] Figure 4 It is a schematic diagram of the structure of the filter assembly in the present invention.

[0022] Figure 5 It is a schematic diagram of the structure of the heating component and the separation component in the present invention.

[0023] Figure 6 It is a schematic diagram of the liquid flow direction when the device of the present invention is running.

[0024] Figure 7 It is a process flow chart of the overall equipment in the present invention.

[0025] The corresponding relationship between the illustrations and component names in the figure is as follows: 1. Heating assembly; 11. First heater; 12. Second heater; 13. Wastewater feed pipe; 14. Connecting pipe; 15. Hot water inlet pipe; 2. Separation assembly; 21. Stripping tower; 22. Exhaust pipe; 23. Vacuum pump; 24. Matching pump body; 3. Mixing assembly; 31. Static mixer; 32. Solution feed pipe; 33. Feed pipe; 34. Feed pump body; 35. Storage tank; 36. Discharge pipe; 4. Filter assembly; 41. First bag filter; 42. Second bag filter; 43. Input pipe; 44. Output pipe; 5. Three-way valve; 6. Product water tank. DETAILED DESCRIPTION

[0026] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings.

[0027] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0028] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments. The present invention provides the following embodiments.

[0029] Depend on Figure 1 and Figure 2As shown, it is a structural schematic diagram of the mercury-containing wastewater treatment device in this embodiment, including a heating component 1, a separation component 2, a mixing component 3, a filtering component 4, a three-way valve 5 and a product water tank 6. The heating component 1 is connected to the separation component 2 through a pipeline, and the heating component 1 is connected to the mixing component 3 of the mixed solution and wastewater through a pipeline. A feeding pump body 34 and a storage tank 35 for inputting sodium sulfide as a desulfurizing agent are provided in the mixing component 3. The sodium sulfide stored in the storage tank 35 is used to separate mercury in the wastewater inside the mixing component 3. The wastewater in the mixing component 3 is input into the filtering component 4 with a filtering function through a pipeline. The external pipeline of the filtering component 4 is equipped with a three-way valve 5 for controlling the opening and closing of the pipeline itself, and the three-way valve 5 is connected to the product water tank 6 for storing the filtered wastewater.

[0030] In use, the mercury-containing alkali solution is input into the heating component 1, and the mercury-containing alkali solution is heated by the operation and heating of the heating component 1. During the heating process, the mercury-containing alkali solution is heat-exchanged with the liquid in the separation component 2. Then, the heated solution is input into the separation component 2. With the cooperation of the separation component 2 itself, the gas in the input material is recovered to complete the screening of some impurities. Then, the solution is re-input into the heating component 1 by cooperating with the pump body 24, and is input into the mixing component 3 using the internal components of the heating component 1. The mixing component 3 uses sodium sulfide as a reactant to treat the mercury in the solution. After the material in the mixing component 3 is fully reacted, the liquid is filtered through the filtering component 4. Finally, the mercury content in the filtered solution is detected by the three-way valve 5. After passing the test, the liquid is directly input into the product water tank 6 to complete the wastewater treatment. The solution in the product water tank 6 is directly input into the salt tank for subsequent processing and treatment.

[0031] By the attached Figure 3 As shown, it is a schematic diagram of the structure of the mixing component 3 in this embodiment, the mixing component 3 includes a static mixer 31, a solution feed pipe 32, a feeding pipe 33, a feeding pump body 34, a storage tank 35 and a discharge pipe 36, the solution feed pipe 32 is connected to the side of the static mixer 31, the feeding pipe 33 is connected to the side of the static mixer 31 away from the solution feed pipe 32, the discharge pipe 36 is installed at the top of the static mixer 31, the discharge pipe 36 is connected to the filter component 4, the storage tank 35 is arranged on the side of the static mixer 31, the sodium sulfide in the storage tank 35 is input into the static mixer 31 through the feeding pump body 34 and the feeding pipe 33, and the static mixer 31 and the feeding pipe 33 are both equipped with flow monitors.

[0032] During use, the liquid obtained by mixing sodium sulfide and the water stored in the product water tank 6 is input into the static mixer 31 through the feeding pump body 34, and is mixed and reacted with the liquid output from the heating component 1. In the process of the feeding pump body 34 conveying the liquid, the flow monitor of the feeding pipe 33 is used to monitor the total amount of the input liquid. The static mixer 31 is also equipped with a flow monitor on the outside, which can monitor the solution input into the heating component 1, so as to reasonably adjust the total amount of the solution and sodium sulfide entering the static mixer 31, so that the liquid in the mixing component 3 can be mixed more fully, and then the liquid in the static mixer 31 is output to the filter component 4 with the cooperation of the discharge pipe 36 for subsequent filtration.

[0033] By the attached Figure 3 As shown, the solution stored in the storage tank 35 is mainly composed of sodium sulfide, and the reaction equation is HgCl2+Na2S=HgS↓+2NaCl, and the water in the storage tank 35 comes from the filtered water source stored in the product water tank 6. Sodium sulfide is used as a desulfurizing agent, and the product water is sent to the salt tank as a raw material for sodium hydroxide. In the production process of sodium hydroxide, sodium sulfide is used as a reducing agent to reduce the content of free chlorine in the brine without bringing in other materials.

[0034] By the attached Figure 4 As shown, it is a schematic diagram of the structure of the filter assembly 4 in this embodiment, the filter assembly 4 includes a first bag filter 41, a second bag filter 42, an input pipe 43 and an output pipe 44, the first bag filter 41 and the second bag filter 42 are both connected to the static mixer 31 through the discharge pipe 36, the input pipe 43 is installed on the side of the first bag filter 41 and the second bag filter 42, the output pipe 44 is installed on the top of the first bag filter 41 and the second bag filter 42, and the output pipe 44 is connected to the three-way valve 5.

[0035] The first bag filter 41 and the second bag filter 42 have the same structure and can flexibly filter the liquid output by the discharge pipe 36 to separate the sediment or impurities in the liquid. Then, the liquid is transported to the three-way valve 5 through the output pipe 44 to facilitate the detection of the components on the side of the three-way valve 5.

[0036] By the attached Figure 4 As shown, the first bag filter 41 and the second bag filter 42 have the same structure, and PP filter bags are used inside the first bag filter 41 and the second bag filter 42. When in use, an open-close operation mode is adopted, which is convenient for operation and maintenance. The PP filter bag has a long service life and can be reused.

[0037] By the attached Figure 5As shown, it is a schematic diagram of the structure of the heating component 1 in this embodiment, the heating component 1 includes a first heater 11, a second heater 12, a wastewater feed pipe 13, a connecting pipe 14 and a hot water inlet pipe 15, the first heater 11 is provided with a wastewater feed pipe 13 for conveying mercury detection on the side, the connecting pipe 14 is provided on the side of the first heater 11, the second heater 12 is connected to the side of the hot water inlet pipe 15 for inputting conversion hot water, the second heater 12 is connected to the separation component 2 through a pipeline, and the second heater 12 is connected to the first heater 11 through a pipeline.

[0038] During use, the first heater 11 is used to preliminarily heat the input mercury-containing alkali liquid, and then the heated alkali liquid is input into the second heater 12. The second heater 12 cooperates with the hot water converted in the separation component 2 to further heat the alkali liquid, and then the alkali liquid is input into the separation component 2 to facilitate the separation component 2 to process the alkali liquid. The connecting pipe 14 is used to directly input the liquid discharged from the separation component 2 into the mixing component 3.

[0039] By the attached Figure 5 As shown, the temperature in the first heater 11 rises to 45-60°C, and heat is exchanged with the liquid from the separation component 2. The mercury-containing alkali liquid after heat exchange is heat exchanged with the converted hot water to 80-90°C.

[0040] By the attached Figure 5 As shown, it is a schematic diagram of the structure of the separation component 2 in this embodiment, the separation component 2 includes a stripping tower 21, an exhaust pipe 22, a vacuum pump 23 and a matching pump body 24. The stripping tower 21 is equipped with an exhaust pipe 22 at the top, the vacuum pump 23 is installed at the end of the exhaust pipe 22, and the matching pump body 24 is arranged on the side of the stripping tower 21. The matching pump body 24 is connected to the stripping tower 21 through a pipeline, and the matching pump body 24 is connected to the first heater 11. During use, the vacuum pump 23 is used to recover the incoming gas, and the gas is directly discharged from the stripping tower 21 through the exhaust pipe 22 and transported to the vinyl chloride for recycling. After the recovery is completed, the matching pump body 24 is used to re-input the liquid inside the stripping tower 21 into the first heater 11, so as to facilitate the full transportation of the heating component 1.

[0041] By the attached Figure 6 As shown, it is a schematic diagram of the structure of the three-way valve 5 in this embodiment. The three-way valve 5 is provided with three groups of connection ports, one end of which is connected to the filter component 4, one end of which is connected to the mixing component 3, and one end of which is connected to the product water tank 6. A mercury content detector is installed on the pipeline connecting the three-way valve 5 and the filter component 4. During use, the mercury content of the filtered liquid can be detected, and the liquid can be transported according to the mercury content in the liquid.

[0042] By the attached Figures 1 to 7A method for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process, using the above-mentioned treatment device, and the steps are as follows: S1, inputting mercury-containing alkali liquid into the heating component 1, heating the wastewater by using the heating component 1, the temperature rises to 45-60°C, and heat exchanges with the liquid from the separation component 2, and the mercury-containing alkali liquid and the converted hot water after heat exchange are input into the second heater 12 for heat exchange to 80-90°C, and then the heated mixed liquid is input into the separation component 2; S2, through the cooperation of the vacuum pump 23 and the exhaust pipe 22, the gas entering the top of the stripping tower 21 is recovered, and the gas is input into the vinyl chloride for recycling, and then steam is input into one side of the stripping tower 21, and countercurrent heat exchange is performed with the alkali solution input through the second heater 12. A remote level gauge is provided at the bottom of the stripping tower 21, and the solution at the bottom of the stripping tower 21 is extracted in cooperation with the pump body 24, and after heat exchange with the mercury-containing alkali solution in the first heater 11, it is input into the mixing component 3 after passing through the flow monitor; S3, through the cooperation of the feeding pump body 34 and the feeding pipe 33, the sodium sulfide solution stored in the storage tank 35 is input into the static mixer 31 through the flow monitor, and is fully mixed and reacted with the liquid inside the static mixer 31; S4, the fully mixed liquid is input into the first bag filter 41 or the second bag filter 42 through the discharge pipe 36, and the impurities in the liquid are filtered by the first bag filter 41 or the second bag filter 42, and the filtered solution enters the product water tank 6 through the three-way valve 5; S5. A mercury content detector is arranged on the side of the three-way valve 5, and the liquid is transported in a targeted manner according to the mercury content in the liquid. When the mercury content is lower than the set value, the three-way valve 5 is opened, and the water coming out of the filter component 4 enters the product water tank 6. When the mercury content is higher than the set value, the three-way valve 5 is opened, and the water coming out of the filter component 4 returns through the pipeline, mixes with the mercury-containing alkali solution, and enters the mixing component 3 again for mixing.

[0043] The above content is a further detailed description of the present invention in combination with specific implementation methods. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, several simple deductions or substitutions can be made without departing from the concept of the present invention, which should be regarded as belonging to the scope of protection determined by the claims submitted for the present invention.

Claims

1. A device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process, characterized in that: The invention comprises a heating component (1), a separation component (2), a mixing component (3), a filtering component (4), a three-way valve (5) and a product water tank (6), wherein the heating component (1) is connected to the separation component (2) through a pipeline, and the heating component (1) is connected to a mixing component (3) for mixing a mixed solution and wastewater through a pipeline, and the mixing component (3) is provided with a feeding pump body (34) for inputting sodium sulfide as a desulfurizing agent and a storage tank (35), and the sodium sulfide stored in the storage tank (35) is used to separate mercury in the wastewater inside the mixing component (3), and the wastewater in the mixing component (3) is input into the filtering component (4) with a filtering function through a pipeline, and the external pipeline of the filtering component (4) is equipped with a three-way valve (5) for controlling the opening and closing of the pipeline itself, and the three-way valve (5) is connected to a product water tank (6) for storing the filtered wastewater.

2. The device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process according to claim 1, characterized in that: The mixing assembly (3) comprises a static mixer (31), a solution feed pipe (32), a feeding pipe (33), a feeding pump body (34), a storage tank (35) and a discharge pipe (36). The solution feed pipe (32) is connected to a side of the static mixer (31), the feeding pipe (33) is connected to a side of the static mixer (31) away from the solution feed pipe (32), the discharge pipe (36) is installed at the top of the static mixer (31), the discharge pipe (36) is connected to the filter assembly (4), the storage tank (35) is arranged on the side of the static mixer (31), the sodium sulfide in the storage tank (35) is input into the static mixer (31) through the feeding pump body (34) and the feeding pipe (33), and flow monitors are installed outside the static mixer (31) and the feeding pipe (33).

3. The device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process according to claim 1, characterized in that: The solution stored in the storage tank (35) mainly contains sodium sulfide, and the reaction equation is HgCl2+Na2S=HgS↓+2NaCl, and the water in the storage tank (35) comes from the filtered water source stored in the product water tank (6).

4. The device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process according to claim 1, characterized in that: The filter assembly (4) comprises a first bag filter (41), a second bag filter (42), an input pipe (43) and an output pipe (44); the first bag filter (41) and the second bag filter (42) are both connected to the static mixer (31) via a discharge pipe (36); the input pipe (43) is installed on the side of the first bag filter (41) and the second bag filter (42); the output pipe (44) is installed on the top of the first bag filter (41) and the second bag filter (42); and the output pipe (44) is connected to the three-way valve (5).

5. The device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process according to claim 4, characterized in that: The first bag filter (41) and the second bag filter (42) have the same structure, and PP filter bags are used inside the first bag filter (41) and the second bag filter (42).

6. The device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process according to claim 1, characterized in that: The heating assembly (1) comprises a first heater (11), a second heater (12), a wastewater feed pipe (13), a connecting pipe (14) and a hot water inlet pipe (15); the first heater (11) is provided with a wastewater feed pipe (13) for conveying wastewater for mercury detection; the connecting pipe (14) is provided on the side of the first heater (11); the second heater (12) is connected to a hot water inlet pipe (15) for inputting conversion hot water; the second heater (12) is connected to the separation assembly (2) via a pipeline; and the second heater (12) is connected to the first heater (11) via a pipeline.

7. The device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process according to claim 6, characterized in that: The temperature in the first heater (11) rises to 45-60°C, and heat is exchanged with the liquid from the separation component (2). The mercury-containing alkali liquid after heat exchange is heat exchanged with the converted hot water to 80-90°C.

8. The device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process according to claim 1, characterized in that: The separation component (2) comprises a stripping tower (21), an exhaust pipe (22), a vacuum pump (23) and a matching pump body (24); the exhaust pipe (22) is installed at the top of the stripping tower (21); the vacuum pump (23) is installed at the end of the exhaust pipe (22); the matching pump body (24) is arranged on the side of the stripping tower (21); the matching pump body (24) is connected to the stripping tower (21) through a pipeline, and the matching pump body (24) is connected to the first heater (11).

9. The device for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process according to claim 6, characterized in that: The three-way valve (5) is provided with three groups of connection ports, one end of which is connected to the filter assembly (4), one end of which is connected to the mixing assembly (3), and one end of which is connected to the product water tank (6), and a mercury content detector is installed on the pipeline connecting the three-way valve (5) and the filter assembly (4).

10. A method for treating mercury-containing wastewater from vinyl chloride produced by the calcium carbide process, using the treatment device described in any one of claims 1 to 9, characterized in that: The steps are as follows: S1, inputting mercury-containing alkali liquid into the interior of the heating component (1), heating the wastewater by using the heating component (1), raising the temperature to 45-60°C, exchanging heat with the liquid from the separation component (2), inputting the mercury-containing alkali liquid and the converted hot water into the second heater (12) for heat exchange to 80-90°C, and then inputting the heated mixed liquid into the interior of the separation component (2); S2, through the cooperation of the vacuum pump (23) and the exhaust pipe (22), the gas entering the top of the stripping tower (21) is recovered, and the gas is input into the vinyl chloride for recycling, and then steam is input into one side of the stripping tower (21) to perform countercurrent heat exchange with the alkali solution input through the second heater (12), and a remote liquid level meter is provided at the bottom of the stripping tower (21), and cooperates with the pump body (24) to extract the solution at the bottom of the stripping tower (21), and after heat exchange with the mercury-containing alkali solution in the first heater (11), it is input into the mixing component (3) after passing through the flow monitor; S3, by means of the cooperation of the feeding pump body (34) and the feeding pipe (33), the sodium sulfide solution stored in the storage tank (35) is input into the static mixer (31) through the flow monitor, and is fully mixed and reacted with the liquid in the static mixer (31); S4, the fully mixed liquid is input into the first bag filter (41) or the second bag filter (42) through the discharge pipe (36), and the impurities in the liquid are filtered by the first bag filter (41) or the second bag filter (42), and the filtered solution enters the product water tank (6) through the three-way valve (5); S5. A mercury content detector is provided on the side of the three-way valve (5). The liquid is transported in a targeted manner according to the mercury content in the liquid. When the mercury content is lower than a set value, the three-way valve (5) is opened, and the water from the filter component (4) enters the product water tank (6). When the mercury content is higher than the set value, the three-way valve (5) is opened, and the water from the filter component (4) returns through the pipeline, mixes with the mercury-containing alkali solution, and enters the mixing component (3) again for mixing.

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