Pretreatment arsenic removal process for high-arsenic wastewater in rare and precious workshop

Abstract

The invention discloses a pretreatment arsenic removal process for high-arsenic wastewater in rare and precious workshops. Comprising an SO3 < 2-> removal tank, a purification pump, a purification tower, an intermediate tank, a purified liquid pump, a first-stage vulcanization reaction tank, a first-stage vulcanization thickener, a first-stage filtrate tank, a first-stage filtrate pump, a second-stage vulcanization reaction tank, a second-stage vulcanization thickener, a pretreated liquid tank, a vulcanizing agent head tank, an absorption tower and a gas collection fan. The pretreatment arsenic removal efficiency is high, the operation is stable, the excess coefficient of H2S in the operation process is low, and the safety performance is high. According to the method, the problems of monomer sulfur blockage and on-site peculiar smell in the sulfur arsenic removal process of the SO3 < 2->-containing high-arsenic wastewater in rare and precious workshops can be particularly solved, and the on-site environment is good.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and more particularly to the field of arsenic-containing wastewater treatment technology in rare and precious workshops, specifically to a pretreatment process for arsenic removal from high-arsenic wastewater in rare and precious workshops. Background Technology

[0002] In the rare and precious metals extraction workshop, the complex extraction process generates a wide variety of wastewater with extremely complex compositions. SO3 is present in this wastewater. 2- The sulfidation process for arsenic removal can generate monomeric sulfur that clogs equipment and pipelines, and also produce large amounts of irritating and toxic gases, creating a harsh on-site environment. The complexity, high volatility, and discontinuity of rare and precious wastewater result in highly variable compositions, posing significant challenges to conventional water treatment methods. Similarly, the pH characteristics of some rare and precious wastewaters also contribute to incomplete sulfidation reactions and low arsenic removal rates during arsenic removal.

[0003] The above characteristics of rare and precious wastewater bring great difficulties and uncertainties to the traditional treatment of rare and precious workshop wastewater. Summary of the Invention

[0004] To solve the above-mentioned technical problems, this invention designs an arsenic removal process for the pretreatment of high-arsenic wastewater from rare and precious workshops.

[0005] The present invention adopts the following technical solution: A pretreatment process for arsenic removal from high-arsenic wastewater in rare and precious workshops, including SO3 2- Desorption tank, purification pump, purification tower, intermediate tank, purified liquid pump, primary vulcanization reaction tank, primary vulcanization thickener, primary filtrate tank, primary filtrate pump, secondary vulcanization reaction tank, secondary vulcanization thickener, pretreated liquid tank, high-level vulcanizing agent tank, absorption tower, and gas collecting fan. The high-arsenic wastewater generated in the rare and precious workshop is classified according to SO3 2- Content is divided into SO3 content 2- High-arsenic wastewater and SO3-free wastewater 2- High-arsenic wastewater, SO3-containing wastewater from rare and precious workshops 2- SO3 was added sequentially to high-arsenic wastewater, high-acid wastewater, and concentrated sulfuric acid. 2- SO3 removal tank 2- Removal reaction, removal of SO3 2- SO3 removal 2- The liquid is then pumped into a purification tower where SO3 is removed by air. 2- Impurity gases in the post-liquid, SO3 removal after degassing 2- The liquid then flows by gravity to the intermediate tank, where it mixes with the SO3-free solution in the rare and precious workshop. 2- High-arsenic wastewater is mixed to form mixed high-arsenic wastewater; The mixed high-arsenic wastewater in the intermediate tank is first pumped into the primary sulfidation reaction tank by the purified liquid pump. In the primary sulfidation reaction tank, the mixed high-arsenic wastewater and the sulfiding agent from the high-level sulfiding agent tank undergo a sulfidation arsenic removal reaction, removing most of the arsenic from the mixed high-arsenic wastewater. The primary sulfidation liquid from the outlet of the primary sulfidation reaction tank flows by gravity into the primary sulfidation thickener. In the thickener, it is concentrated and settled, and the sulfidation slag settles to the bottom of the primary sulfidation thickener. The supernatant flows by gravity to the primary filtrate tank. The primary sulfidation liquid in the primary filtrate tank is pumped into the secondary sulfidation reaction tank by the primary filtrate pump. In the secondary reaction tank, the primary sulfidation liquid and the sulfiding agent from the high-level sulfiding agent tank undergo another sulfidation arsenic removal reaction, removing most of the arsenic from the primary sulfidation liquid. The secondary sulfidation liquid from the outlet of the secondary sulfidation reaction tank flows by gravity into the secondary sulfidation thickener. In the thickener, it is concentrated and settled, and the sulfidation slag settles to the bottom of the secondary sulfidation thickener. The supernatant flows by gravity to the pre-treated liquid tank. The excess hydrogen sulfide gas generated during the two-stage sulfidation process of mixed high-arsenic wastewater is collected by a gas collecting fan through negative pressure pipelines from the top of the first-stage sulfidation reaction tank, the first-stage sulfidation thickener, the first-stage filtrate tank, the second-stage sulfidation reaction tank, and the second-stage sulfidation thickener. It is then transported to the absorption tower, where it is absorbed and treated with sodium hydroxide solution before being discharged in compliance with standards.

[0006] Preferably, the SO3 2- The removal tank includes SO3 2- Remove one tank and SO3 2- Remove SO3 from the second tank 2- A component analyzer is installed in the second removal tank to remove SO3. 2- Remove SO3 from tank 1 2- Both removal tanks are enclosed tanks with agitators and covers. The upper part of the tank has a vent for air intake and an exhaust port for connecting to a gas delivery pipeline. A component analyzer is used to measure the composition of the liquid within the tanks. (SO3) 2- The addition of concentrated sulfuric acid and high-acid wastewater to the desulfurization tank is based on SO3. 2- The addition of SO3 is automatically controlled based on the analysis data from the component analyzer in the second tank. 2- When adding concentrated sulfuric acid and high-acid wastewater to the desulfurization tank, first adjust the amount of high-acid wastewater added to make a short-term addition (i.e., the amount of high-acid wastewater added is less than the theoretical required amount), then open the concentrated sulfuric acid addition valve and the SO3... 2- The component analysis data in the second tank is interlocked, and the amount of concentrated sulfuric acid added is automatically adjusted through the control system.

[0007] Preferably, the addition of concentrated sulfuric acid is controlled by a concentrated sulfuric acid addition valve.

[0008] As a preferred option, a Roots blower is used to direct SO3 2- Remove one tank and SO3 2- Air is blown into the second tank to remove SO3. 2-The waste gas generated during the process is blown off.

[0009] Preferably, the intermediate tank includes intermediate tank A and intermediate tank B, and the degassing process removes SO3. 2- The channels through which the downstream liquid flows by gravity to intermediate tank A and intermediate tank B are controlled by the inlet valves of intermediate tank A and intermediate tank B, respectively. SO3 is discharged from the bottom of the purification tower. 2- After removal, the liquid can be switched between intermediate tank A and intermediate tank B via the inlet valves of intermediate tank A and intermediate tank B, allowing it to enter either intermediate tank A or intermediate tank B alternately. Intermediate tank A and intermediate tank B are used alternately, and when one tank is in the discharge phase, all external liquid enters the other tank.

[0010] As a preferred option, SO3 2- Remove one tank and SO3 2- The waste gas generated and blown out by the second removal tank, as well as the desorption waste gas discharged from the top of the purification tower, are collected by pipelines and transported to the outside for treatment by the purification fan.

[0011] Preferably, the primary vulcanizing reaction tank is equipped with a #1 vulcanizing agent addition valve at the inlet and a primary oxidation-reduction potential meter at the outlet. The secondary vulcanizing reaction tank is equipped with a #2 vulcanizing agent addition valve at the inlet and a secondary oxidation-reduction potential meter at the outlet. The amount of vulcanizing agent added to the primary vulcanizing reaction tank is controlled by interlocking the #1 vulcanizing agent addition valve with the primary oxidation-reduction potential value of the liquid at the outlet of the primary vulcanizing reaction tank. The amount of vulcanizing agent added to the secondary vulcanizing reaction tank is controlled by interlocking the #2 vulcanizing agent addition valve with the secondary oxidation-reduction potential value of the liquid at the outlet of the secondary vulcanizing reaction tank. The vulcanizing agent can be sodium sulfide or sodium hydrosulfide solution, preferably sodium hydrosulfide solution. During operation, the reaction is run with a slight under-addition of vulcanizing agent to the primary vulcanizing reaction tank to ensure that the vulcanizing agent in the primary vulcanizing reaction tank is not excessive; the reaction is run with a slight over-addition of vulcanizing agent to the secondary vulcanizing reaction tank to ensure thorough arsenic removal during the vulcanization pretreatment and control of excess H2S gas generation.

[0012] The installation of negative pressure collection pipes at the top of the primary vulcanization reaction tank, primary vulcanization thickener, primary filtrate tank, secondary vulcanization reaction tank, and secondary vulcanization thickener ensures that all equipment operates under slight negative pressure, preventing the leakage of toxic gases generated during the reaction.

[0013] Preferably, the bottom of the absorption tower is connected to a NaOH tank. After NaOH is added to the NaOH tank, it is transported to the spray layer inside the absorption tower by an absorption pump for recycling. When the Na2S in the NaOH tank reaches a certain concentration, a portion of the solution is opened and sent to the sulfiding agent preparation tank.

[0014] The H2S-containing waste gas collected under negative pressure at the top of the primary vulcanization reaction tank, primary vulcanization thickener, primary filtrate tank, secondary vulcanization reaction tank, and secondary vulcanization thickener is transported to the absorption tower by a gas collecting fan, where it is absorbed and removed by sodium hydroxide solution. The absorbed liquid generated during the circulation absorption of the H2S-containing waste gas in the NaOH tank is periodically partially diverted to the vulcanizing agent preparation tank based on changes in the composition of the circulating sodium hydroxide solution.

[0015] Preferably, after adding the vulcanizing agent into the vulcanizing agent preparation tank, it is transported to the vulcanizing agent high-level tank by the vulcanizing agent delivery pump.

[0016] Preferably, the purification tower is a packed tower, SO3 2- After removal, the liquid is sprayed into the purification tower from the top, and SO3 is removed from the purification tower. 2- After removal, the liquid flows from top to bottom and comes into contact with the air flowing from bottom to top. The air then acts as a stripping agent to further remove SO3. 2- Remove the dissolved gas components from the liquid.

[0017] The beneficial effects of this invention are: (1) The high-arsenic wastewater generated in the rare and precious workshop is treated according to SO3 2- Content is divided into SO3 content 2- High-arsenic wastewater and SO3-free wastewater 2- High-arsenic wastewater is beneficial for the classification and treatment of high-arsenic wastewater in rare and precious workshops; (2) SO3-containing materials generated in the rare and precious workshop 2- High arsenic wastewater in SO3 2- Remove one tank and SO3 2- The second desulfurization tank reacts with added high-acid wastewater or concentrated sulfuric acid to remove SO3. 2- This can effectively solve the problem of blockage caused by monomeric sulfur; (3) SO3 is discharged through a Roots blower 2- Remove one tank and SO3 2- Air is blown into the second tank to remove SO3. 2- The waste gas generated during the process is stripped, which can effectively reduce SO3 in the reaction liquid. 2- The content; (4) By using SO3 2- Remove one tank and SO3 2- SO3 removal in the second tank 2- The subsequent "de-SO3" 2- The "post-liquid" is pumped into the purification tower for air removal, further reducing SO3 removal costs. 2- The dissolved content of impurity gases in the post-liquid ensures the removal of SO3 after desorption. 2- Minimize the content of dissolved impurity gases in the "post-liquid"; (5) By analyzing SO3 2- Remove SO3 from tank 1 2- The waste gas generated and blown out from the second removal tank, as well as the desorption waste gas discharged from the top of the purification tower, are collected using negative pressure pipelines and transported to external treatment by a purification fan, thus avoiding SO3 emissions. 2- Waste gas overflows during the removal process; (6) By setting up two intermediate tanks (intermediate tank A and intermediate tank B) and using them alternately (when one tank supplies liquid to the outside, the other tank acts as the receiving tank, at which time SO3 is removed) 2- The downstream liquid and other high-arsenic wastewater all enter the receiving tank (the two tanks alternately serve as external supply tanks or receiving tanks), allowing the liquid in the intermediate tank sufficient time for uniform mixing. This ensures the relative stability of the high-arsenic wastewater composition in the single intermediate tank, effectively avoiding inaccuracies in control caused by fluctuations in the composition of the mixed high-arsenic wastewater during the sulfidation reaction. This stabilizes the effluent quality and reduces the excessive generation of hydrogen sulfide gas. (7) The mixed high-arsenic wastewater collected in intermediate tanks A and B is successively pumped by a purified liquid pump and a primary filtrate pump to the primary sulfidation reaction tank and the secondary sulfidation reaction tank for two sulfidation arsenic removal reactions. During operation, the primary sulfidation reaction tank is operated with a slight under-load reaction (to ensure that the sulfiding agent is not excessive and that no excessive H2S gas is generated), and the secondary sulfidation reaction tank is operated with a slight over-load reaction (to ensure that the sulfiding agent is slightly excessive). With this operation, the H2S gas excess coefficient is the lowest and the on-site environment is the best. (8) By setting up a primary filtrate tank after the primary vulcanizing thickener, the vulcanized liquid after the primary vulcanization is pumped to the secondary vulcanizing reaction tank by the primary filtrate pump. Compared with the method of gravity flow from the primary vulcanizing thickener to the secondary vulcanizing reaction tank, the height of the primary vulcanizing reaction tank, the primary vulcanizing thickener, and the vulcanizing equipment platform are effectively reduced; (9) By supplying the vulcanizing agent from the high-level vulcanizing agent tank to the primary vulcanizing reaction tank and the secondary vulcanizing reaction tank by gravity, it is beneficial to maintain the relative stability of the supply capacity to the primary vulcanizing reaction tank and the secondary vulcanizing reaction tank. (10) By intermittently discharging the sodium hydroxide liquid after absorption by the absorption tower to the sulfurizing agent preparation tank, the sodium sulfide liquid generated after sodium hydroxide absorbs hydrogen sulfide is recycled, which saves costs and reduces external pollution. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 1 Chinese: 1. SO3 2- Remove one tank, 2, SO3 2-1. Desulfurization tank 2; 3. Purification pump; 4. Purification tower; 5. Intermediate tank A; 6. Intermediate tank B; 7. Purified liquid pump; 8. Inlet valve of intermediate tank A; 9. Inlet valve of intermediate tank B; 10. Purification blower; 11. Roots blower; 12. Concentrated sulfuric acid addition valve; 13. Primary sulfuric acid reaction tank; 14. Primary sulfuric acid thickener; 15. Primary filtrate tank; 16. Primary filtrate pump; 17. Secondary sulfuric acid reaction tank; 18. Secondary sulfuric acid... 19. Thickener, 20. Pre-treated liquid tank, 21. Vulcanizing agent preparation tank, 22. Vulcanizing agent delivery pump, 23. High-level vulcanizing agent tank, 24. No. 1 vulcanizing agent addition valve, 25. No. 2 vulcanizing agent addition valve, 26. Absorption tower, 27. NaOH tank, 28. Absorption pump, 29. Gas collecting fan, 30. Open valve, 31. Component analyzer, 32. Primary oxidation-reduction potentiometer, 33. Secondary oxidation-reduction potentiometer. Detailed Implementation

[0019] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings: Example: Figure 1 As shown, a pretreatment process for arsenic removal from high-arsenic wastewater in a rare and precious workshop includes SO3. 2- Remove SO3 from tank 1 2- 2. Desulfurization tank 2, purification pump 3, purification tower 4, intermediate tank A 5, intermediate tank B 6, purified liquid pump 7, intermediate tank A inlet valve 8, intermediate tank B inlet valve 9, purification fan 10, Roots blower 11, concentrated sulfuric acid addition valve 12, primary sulfidation reaction tank 13, primary sulfidation thickener 14, primary filtrate tank 15, primary filtrate pump 16, secondary sulfidation reaction tank 17, secondary sulfidation thickener 18, pretreated liquid tank 19, sulfiding agent preparation tank 20, sulfiding agent delivery pump 21, sulfiding agent high-level tank 22, #1 sulfiding agent addition valve 23, #2 sulfiding agent addition valve 24, absorption tower 25, NaOH tank 26, absorption pump 27, gas collecting fan 28, open valve 29, component analyzer 30, primary oxidation-reduction potentiometer 31, secondary oxidation-reduction potentiometer 32.

[0020] First, based on the composition and generation process of various wastewaters from the rare and precious materials workshop, the high-arsenic wastewater generated in the rare and precious materials workshop is classified according to SO3... 2- Content is divided into SO3 content 2- High-arsenic wastewater and SO3-free wastewater 2- High-arsenic wastewater.

[0021] Then the rare and precious workshop containing SO3 2- Adding SO3 to high-arsenic wastewater 2- Remove one tank of SO3. 2- Removal of SO3 and SO2 in tank 1 2- Remove SO3 from tank 2. 2- High-arsenic wastewater reacts with high-acid wastewater and concentrated sulfuric acid to form SO32- The removal reaction. To reduce the removal of SO3. 2- The content of impurity gases in the liquid after the Roots blower 11 is reduced to SO3. 2- Removal of SO3 and SO2 in tank 1 2- Air is blown into tank 2 to remove SO3 from the liquid in both tanks. 2- SO3 removal after 2- The liquid is then pumped into purification tower 4 by purification pump 3, where SO3 is removed. 2- The "post-liquid" comes into contact with the counter-flowing air, further removing "SO3". 2- Impurity gases in the "post-liquid". SO3 removal after degassing. 2- The liquid then flows by gravity to intermediate tank A5 or intermediate tank B6, and mixes with other SO3-free components in the rare and precious materials workshop. 2- The high-arsenic wastewater is mixed to form mixed high-arsenic wastewater. Intermediate tanks A5 and B6 are used alternately; when one tank supplies liquid externally, the other tank acts as a receiving tank, during which SO3 removal... 2- The wastewater and other high-arsenic wastewater all enter this receiving tank. The two tanks alternately serve as either supply or receiving tanks.

[0022] The mixed high-arsenic wastewater from intermediate tanks A5 and B6 is first pumped into the primary sulfidation reaction tank 13 by the purified liquid pump 7. In the primary sulfidation reaction tank 13, the mixed high-arsenic wastewater undergoes a sulfidation and arsenic removal reaction with the sulfiding agent from the high-level sulfiding agent tank 22, removing most of the arsenic from the mixed high-arsenic wastewater. To avoid the excessive generation of hydrogen sulfide in the primary sulfidation reaction tank 13, the amount of sulfiding agent added to the primary sulfidation reaction tank 13 is controlled by interlocking the No. 1 sulfiding agent addition valve 23 with the primary oxidation-reduction potential value of the liquid at the outlet of the primary sulfidation reaction tank 13, ensuring a slight under-addition of sulfiding agent. The primary sulfidated liquid at the outlet of the primary sulfidation reaction tank 13 flows by gravity into the primary sulfidation thickener 14, where it is concentrated and settled. The sulfidation slag settles to the bottom of the primary sulfidation thickener 14, and the supernatant flows by gravity to the primary filtrate tank 15.

[0023] The primary sulfided liquid in the primary filtrate tank 15 is pumped into the secondary sulfidation reaction tank 17 by the primary filtrate pump 16. In the secondary sulfidation reaction tank 17, the primary sulfided liquid reacts again with the sulfiding agent from the high-level sulfiding agent tank 22 to undergo a sulfidation and arsenic removal reaction, removing most of the arsenic from the primary sulfided liquid. To ensure the arsenic removal efficiency in the secondary sulfidation reaction tank 17 and to minimize the excessive generation of hydrogen sulfide, the amount of sulfiding agent added to the secondary sulfidation reaction tank 17 is controlled by interlocking the 2# sulfiding agent addition valve 24 with the secondary redox potential value of the liquid at the outlet of the secondary sulfidation reaction tank 17, ensuring a slight excess of sulfiding agent is added. The secondary sulfided liquid at the outlet of the secondary sulfidation reaction tank 17 flows by gravity into the secondary sulfidation thickener 18. In the thickener, the sulfided slag settles to the bottom of the secondary sulfidation thickener 18, and the supernatant flows by gravity to the pretreated liquid tank 19.

[0024] Excess hydrogen sulfide gas generated during the two-stage sulfidation process of mixed high-arsenic wastewater is collected by a gas collecting fan 28 through negative pressure pipelines from the top of the primary sulfidation reaction tank 13, primary sulfidation thickener 14, primary filtrate tank 15, secondary sulfidation reaction tank 17, and secondary sulfidation thickener 18. It is then transported to the absorption tower 25, where it is absorbed and treated with sodium hydroxide solution before being discharged in compliance with standards. The absorbed liquid generated during the circulation absorption of H2S-containing waste gas in the NaOH tank 26 is periodically partially opened to the sulfiding agent preparation tank 20 for use, based on changes in the composition of the circulating sodium hydroxide liquid.

[0025] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Other variations and modifications are possible without departing from the technical solutions described in the claims.

Claims

1. A pretreatment process for arsenic removal from high-arsenic wastewater in rare and precious workshops, characterized in that, It includes SO3 2- Desorption tank, purification pump, purification tower, intermediate tank, purified liquid pump, primary vulcanization reaction tank, primary vulcanization thickener, primary filtrate tank, primary filtrate pump, secondary vulcanization reaction tank, secondary vulcanization thickener, pretreated liquid tank, high-level vulcanizing agent tank, absorption tower, and gas collecting fan. The high-arsenic wastewater generated in the rare and precious workshop is classified according to SO3 2- Content is divided into SO3 content 2- High-arsenic wastewater and SO3-free wastewater 2- High-arsenic wastewater, SO3-containing wastewater from rare and precious workshops 2- SO3 was added sequentially to high-arsenic wastewater, high-acid wastewater, and concentrated sulfuric acid. 2- SO3 removal tank 2- Removal reaction, removal of SO3 2- SO3 removal 2- The liquid is then pumped into a purification tower where SO3 is removed by air. 2- Impurity gases in the post-liquid, SO3 removal after degassing 2- The liquid then flows by gravity to the intermediate tank, where it mixes with the SO3-free solution in the rare and precious workshop. 2- High-arsenic wastewater is mixed to form mixed high-arsenic wastewater; The mixed high-arsenic wastewater in the intermediate tank is first pumped into the primary sulfidation reaction tank by the purified liquid pump. In the primary sulfidation reaction tank, the mixed high-arsenic wastewater and the sulfiding agent from the high-level sulfiding agent tank undergo a sulfidation arsenic removal reaction, removing most of the arsenic from the mixed high-arsenic wastewater. The primary sulfidation liquid from the outlet of the primary sulfidation reaction tank flows by gravity into the primary sulfidation thickener. In the thickener, it is concentrated and settled, and the sulfidation slag settles to the bottom of the primary sulfidation thickener. The supernatant flows by gravity to the primary filtrate tank. The primary sulfidation liquid in the primary filtrate tank is pumped into the secondary sulfidation reaction tank by the primary filtrate pump. In the secondary reaction tank, the primary sulfidation liquid and the sulfiding agent from the high-level sulfiding agent tank undergo another sulfidation arsenic removal reaction, removing most of the arsenic from the primary sulfidation liquid. The secondary sulfidation liquid from the outlet of the secondary sulfidation reaction tank flows by gravity into the secondary sulfidation thickener. In the thickener, it is concentrated and settled, and the sulfidation slag settles to the bottom of the secondary sulfidation thickener. The supernatant flows by gravity to the pre-treated liquid tank. The excess hydrogen sulfide gas generated during the two-stage sulfidation process of mixed high-arsenic wastewater is collected by a gas collecting fan through negative pressure pipelines from the top of the first-stage sulfidation reaction tank, the first-stage sulfidation thickener, the first-stage filtrate tank, the second-stage sulfidation reaction tank, and the second-stage sulfidation thickener. It is then transported to the absorption tower, where it is absorbed and treated with sodium hydroxide solution before being discharged in compliance with standards.

2. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 1, characterized in that, the... SO3 2- The removal tank includes SO3 2- Remove one tank and SO3 2- Remove SO3 from the second tank 2- A component analyzer is installed in the second removal tank to remove SO3. 2- Remove SO3 from tank 1 2- Both tanks are closed tanks with agitators and tank covers. The upper part of the tank has a vent for drawing in air and an exhaust port for connecting to a gas delivery pipeline.

3. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 1, characterized in that, The addition of concentrated sulfuric acid is controlled by a concentrated sulfuric acid addition valve.

4. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 2, characterized in that, Using Roots blowers to direct SO3 2- Remove one tank and SO3 2- Air is blown into the second tank to remove SO3. 2- The waste gas generated during the process is blown off.

5. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 1, characterized in that, The intermediate tank includes intermediate tank A and intermediate tank B, and the SO3 removal process after degassing... 2- The channels through which the liquid flows by gravity to intermediate tank A and intermediate tank B are controlled by the inlet valves of intermediate tank A and intermediate tank B, respectively.

6. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 4, characterized in that, for SO3 2- Remove one tank and SO3 2- The waste gas generated and blown out by the second removal tank, as well as the desorption waste gas discharged from the top of the purification tower, are collected by pipelines and transported to the outside for treatment by the purification fan.

7. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 1, characterized in that, The primary vulcanizing reaction tank is equipped with a #1 vulcanizing agent addition valve at the inlet and a primary oxidation-reduction potential meter at the outlet. The secondary vulcanizing reaction tank is equipped with a #2 vulcanizing agent addition valve at the inlet and a secondary oxidation-reduction potential meter at the outlet. The amount of vulcanizing agent added in the primary vulcanizing reaction tank is controlled by interlocking the #1 vulcanizing agent addition valve with the primary oxidation-reduction potential value of the liquid at the outlet of the primary vulcanizing reaction tank. The amount of vulcanizing agent added in the secondary vulcanizing reaction tank is controlled by interlocking the #2 vulcanizing agent addition valve with the secondary oxidation-reduction potential value of the liquid at the outlet of the secondary vulcanizing reaction tank.

8. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 1, characterized in that, The bottom of the absorption tower is connected to a NaOH tank. After NaOH is added to the NaOH tank, it is transported to the spray layer inside the absorption tower by an absorption pump for recycling. When the Na2S in the NaOH tank reaches a certain concentration, a portion of the solution is opened and sent to the sulfurizing agent preparation tank.

9. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 1, characterized in that, After the vulcanizing agent is added to the vulcanizing agent preparation tank, it is transported to the high-level vulcanizing agent tank by the vulcanizing agent delivery pump.

10. The arsenic removal process for pretreatment of high-arsenic wastewater from rare and precious workshops according to claim 1, characterized in that, The purification tower is a packed tower, SO3 2- After removal, the liquid is sprayed into the purification tower from the top, and SO3 is removed from the purification tower. 2- After removal, the liquid flows from top to bottom and comes into contact with the air flowing from bottom to top. The air then acts as a stripping agent to further remove SO3. 2- Remove the dissolved gas components from the liquid.

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