A purification device for reducing arsenic in dilute acid

Abstract

The utility model discloses a kind of purification devices for reducing arsenic in dilute acid, by primary high-efficiency scrubber, gas cooling tower, secondary packing tower, accident high-level water tank, dilute acid settling tank, purification pressure filter, purification filtrate tank, primary reaction tower, secondary reaction tower, tertiary reaction tower, pump pit, reaction tower pressure filter, reaction tower filtrate tank composition, using reaction tower to increase the maximum circulating quantity of primary high-efficiency scrubber, through high-concentration sulfur dioxide reduction settlement pentavalent arsenic, effectively solve the problem of high arsenic content in dilute acid, high dilute acid processing cost, high resistance of primary high-efficiency scrubber, tower cleaning frequency, large overhaul workload. The device is safe and environmentally friendly, has low failure rate, can adapt to high-arsenic flue gas environment, is convenient for industrialized production and application, is suitable for chemical industry, environmental protection, non-ferrous metal smelting industry, belongs to sulfuric acid production equipment technical field.

Description

Technical Field

[0001] This utility model belongs to the technical field of sulfuric acid production equipment, specifically relating to a purification device for reducing the arsenic content in dilute acid. Background Technology

[0002] In the process of producing sulfuric acid from smelting flue gas, the complex flue gas undergoes a typical sulfuric acid purification system, which involves cooling and dust removal via a "high-efficiency scrubber-gas cooling tower-packed tower". During the purification of smelting flue gas, a large amount of arsenic dissolves in the dilute acid as arsenic acid, resulting in extremely high costs for the waste acid treatment system. Patent publication number "CN220758666U", with the utility model title "A High-Efficiency Scrubber for Reducing Arsenic Content in Dilute Acid", specifically discloses a high-efficiency scrubber for reducing the arsenic content in dilute acid. This device provides a method of repeatedly washing the dilute acid with circulating liquid within the high-efficiency scrubber under a sulfur dioxide reducing atmosphere in the purification system, thereby reducing the arsenic content. While this method can reduce the arsenic content in dilute acid, because it utilizes the system's own sulfur dioxide for reduction, the sulfur dioxide concentration is only about 10%. It mainly improves the pipeline and circulation method, but it still does not solve the problems of high resistance in the first-stage high-efficiency scrubber, relatively small circulation volume and reaction time, limited arsenic removal effect of dilute acid, frequent tower cleaning, and a large workload for maintenance. Utility Model Content

[0003] To address the aforementioned problems, this invention provides a purification device for reducing the arsenic content in dilute acid.

[0004] The technical solution of this utility model is implemented as follows: A purification device for reducing the arsenic content in dilute acid includes a primary high-efficiency scrubber, which is connected to a gas cooling tower via a pipeline. The gas cooling tower is connected to a secondary packed tower via a main flue gas pipeline. A dilute acid settling tank is provided below the primary high-efficiency scrubber. The dilute acid settling tank is connected to a purification filter press. The purification filter press is connected to a purification filter tank. The purification filter tank is connected to a primary reaction tower. The primary reaction tower is connected to a secondary reaction tower. The secondary reaction tower is connected to a tertiary reaction tower. The tertiary reaction tower is connected to a reaction tower filtrate tank and a reaction tower filter press, respectively. The reaction tower filtrate tank is connected to an emergency high-level water tank. The emergency high-level water tank and the flue gas inlet are connected to the primary high-efficiency scrubber via a pipeline. The bottom of the reaction tower filtrate tank is connected to the primary reaction tower via a drain pipe. The top of the primary reaction tower is connected to the main flue gas pipeline via a pipeline.

[0005] Preferably, each reaction tower is connected in the middle by an overflow pipe and in the upper part by a degassing pipe. Each reaction tower is equipped with a spray pipe, which is connected to the bottom of each reaction tower through an external pipe. Each reaction tower is equipped with an air inlet pipe, which is connected to the regeneration separator of the ion liquid desulfurization system. The high-concentration sulfur dioxide generated by the regeneration separator of the ion liquid desulfurization system enters the spray pipes below the first-stage reaction tower, the second-stage reaction tower, and the third-stage reaction tower through the air inlet pipes and reacts with the dilute acid sprayed from the spray pipes. The desulfurized gas after the reaction passes through the degassing pipes in sequence through the reaction tower filtrate tank, the third-stage reaction tower, the second-stage reaction tower, and the first-stage reaction tower and is then directed to the main flue gas pipeline.

[0006] Preferably, the bottom of the three-stage reaction tower is provided with a pump pit, and the bottom of each reaction tower is connected to the sewage pipe through a pipe. The bottom of the filtrate tank of the reaction tower is connected to the pump pit through a pipe, and the pump pit is connected to the sewage pipe.

[0007] Preferably, the three-stage reaction tower is provided with a gas replenishment hole in the middle;

[0008] Preferably, each air intake pipe is equipped with a valve to control the air intake volume;

[0009] Preferably, hydraulic pumps are installed on the connecting pipes between the bottom of each reaction tower and the spray pipe, between the three-stage reaction tower and the reaction tower filter press, and between the reaction tower filtrate tank and the emergency high-level water tank.

[0010] The beneficial effects of this utility model are as follows: This utility model effectively solves the problems of high arsenic content in dilute acid and high cost of waste acid treatment by increasing the circulation volume through an external reaction tower and using high-concentration sulfur dioxide gas for reduction. The average arsenic content in the bottom dilute acid of the first-stage high-efficiency scrubber can be reduced by about 3000 mg / L. The solid arsenic pressing and separation system reduces the workload of tower cleaning. The device is safe and environmentally friendly, has a low failure rate, can adapt to flue gas environments with high arsenic content, and reduces the workload of system maintenance. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this utility model.

[0012] Parts Description: 1. Emergency High-Level Water Tank; 2. Primary High-Efficiency Scrubber; 3. Gas Cooling Tower; 4. Secondary Packed Tower; 5. Dilute Acid Settling Tank; 6. Purification Filter Press; 7. Purification Filtrate Tank; 8. Air Inlet Pipe; 9. Degassing Pipe; 10. Overflow Pipe; 11. Pump Pit; 12. Primary Reaction Tower; 13. Secondary Reaction Tower; 14. Sewage Discharge Pipe; 15. Tertiary Reaction Tower; 16. Air Injection Hole; 17. Reaction Tower Filter Press; 18. Reaction Tower Filtrate Tank; 19. Spray Pipe; 20. Main Flue Gas Pipe; 21. Flue Gas Inlet; 22. Hydraulic Pump. Detailed Implementation

[0013] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments.

[0014] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0015] See attached document Figure 1A purification device for reducing arsenic content in dilute acid includes a primary high-efficiency scrubber 2, which is connected to a gas cooling tower 3 via a pipeline. The gas cooling tower 3 is connected to a secondary packed tower 4 via a main flue gas pipeline 20. A dilute acid settling tank 5 is located below the primary high-efficiency scrubber 2. The dilute acid settling tank 5 is connected to a purification filter press 6. The purification filter press 6 is connected to a purification filter press 7. The purification filter press 7 is connected to a primary reaction tower 12. The primary reaction tower 12 is connected to a secondary reaction tower 13. The system is connected to a three-stage reaction tower 15, which is connected to a reaction tower filtrate tank 18 and a reaction tower filter press 17. The reaction tower filtrate tank 18 is connected to an emergency high-level water tank 1. The emergency high-level water tank 1 and the flue gas inlet 21 are connected to a primary high-efficiency scrubber 2 via a pipeline. The bottom of the reaction tower filtrate tank 18 is connected to a primary reaction tower 12 via a drain pipe 14. The top of the primary reaction tower 12 is connected to the main flue gas pipeline 20 via a pipeline. The reaction towers are connected in the middle via an overflow pipe 10 and at the top via a degassing pipe 9. Each reaction tower is equipped with... There is a spray pipe 19, which is connected to the bottom of each reaction tower via an external pipe. Each reaction tower is equipped with an air inlet pipe 8, which is connected to the regeneration separator of the ion liquid desulfurization system. The high-concentration sulfur dioxide generated by the regeneration separator of the ion liquid desulfurization system enters the spray pipes below the primary reaction tower 12, the secondary reaction tower 13, and the tertiary reaction tower 15 through the air inlet pipe 8, and reacts with the dilute acid sprayed from the spray pipe 19. The desulfurized gas after the reaction passes through the degassing pipe 9 sequentially through the reaction tower filtrate tank 18, the tertiary reaction tower 15, and the secondary reaction tower 13. The primary reaction tower 12 is connected to the main flue gas pipeline 20; the bottom of the tertiary reaction tower 15 is equipped with a pump pit 11, and each reaction tower is connected to the sewage pipe 14 through a pipe at its bottom. The bottom of the reaction tower filtrate tank 18 is connected to the pump pit 11 through a pipe, and the pump pit 11 is connected to the sewage pipe 14; the middle of the tertiary reaction tower 15 is equipped with an air replenishment hole 16; each air inlet pipe 8 is equipped with a valve to control the air intake; hydraulic pumps 22 are installed on the connecting pipes between the bottom of each reaction tower and the spray pipe, between the tertiary reaction tower and the reaction tower filter press tank, and between the reaction tower filtrate tank and the emergency high-level water tank.

[0016] Specifically, flue gas enters the primary high-efficiency scrubber 2 from flue gas inlet 21, and dilute acid enters the primary high-efficiency scrubber 2 from emergency high-level water tank 2 to scrub the flue gas. The scrubbed flue gas enters the gas cooling tower 3 for cooling, and then enters the secondary packed tower 4 through the main flue gas pipeline 20. After passing through the secondary packed tower 4, it enters the de-electrolysis and demisting device. The dilute acid underflow from the primary high-efficiency scrubber 2 enters the dilute acid settling tank 5, and is filtered by the purification filter press 6. The filter cake enters the smelting system for processing below the purification filter press. The dilute acid with high arsenic content filtered by the purification filter press 6 is pumped into the primary reaction tower 12, and then enters the secondary reaction tower 13 and the tertiary reaction tower 15 sequentially through the overflow pipe 10. Inside each reaction tower, it is circulated and sprayed through the spray pipe 19. The high-concentration sulfur dioxide generated by the regeneration separator of the ion liquid desulfurization system enters the spray pipes below the primary reaction tower 12, the secondary reaction tower 13, and the tertiary reaction tower 15 through the air inlet pipe 8, and comes into contact with the dilute acid to carry out a reduction reaction. When the liquid level in the primary reaction tower 12 is high, the liquid flows sequentially into the secondary reaction tower 13 and the tertiary reaction tower 14 through the overflow pipe. The dilute acid sprayed in the reaction towers comes into contact with the high-concentration sulfur dioxide introduced through the lower air inlet pipe 8, and a reduction reaction occurs to generate arsenic trioxide precipitate. This precipitate is then filtered by the underflow from the tertiary reaction tower 15. The arsenic-free dilute acid enters the emergency high-level water tank 1 and is supplied to the purification system for reuse. After the reaction, the gas and the sulfur dioxide dissolved in the liquid precipitate, and then pass through the degassing pipe 9 sequentially through the reaction tower filtrate tank 18, the tertiary reaction tower 15, the secondary reaction tower 13, and the primary reaction tower 12, and are connected to the main flue gas pipe 20. A gas injection hole 16 is set in the middle of the tertiary reaction tower 15 to control the system pressure. The underflow from the reaction tower filtrate tank 18, the primary reaction tower 12, the secondary reaction tower 13, and the tertiary reaction tower 15 is collected through the sewage pipe 14 and pumped into the tertiary reaction tower 15 for circulation. After the dilute acid from the bottom of the three-stage reaction tower 15 is filtered by the reaction tower filter press 17, the dilute acid with a lower arsenic content enters the reaction tower filtrate tank 18 for storage, and is then pumped into the emergency high-level water tank 1 for circulation. The arsenic trioxide that settles from the reduction reaction is pressed into filter cake and returned to the smelting system for ore blending.

[0017] Finally, it should be noted that the above examples are only used to illustrate the technical solution of this utility model and are not intended to limit it. Although the utility model has been described in detail through the above examples, those skilled in the art should understand that various changes or adjustments can be made to the above embodiments in detail and form without departing from the spirit and scope of this utility model, without deviating from the scope defined by the claims of this utility model.

Claims

1. A purification device for reducing the arsenic content in dilute acid, comprising a primary high-efficiency scrubber (2), wherein the primary high-efficiency scrubber (2) is connected to a gas cooling tower (3) via a pipeline, and the gas cooling tower (3) is connected to a secondary packed tower (4) via a main flue gas pipeline (20), characterized in that... The first-stage high-efficiency scrubber (2) is provided with a dilute acid settling tank (5), which is connected to a purification filter press (6). The purification filter press (6) is connected to a purification filter tank (7), which is connected to a first-stage reaction tower (12). The first-stage reaction tower (12) is connected to a second-stage reaction tower (13), which is connected to a third-stage reaction tower (15). The third-stage reaction tower (15) is connected to a reaction tower filtrate tank (18) and a reaction tower filter press (17), respectively. The reaction tower filtrate tank (18) is connected to an emergency high-level water tank (1). The emergency high-level water tank (1) and the flue gas inlet (21) are connected to the first-stage high-efficiency scrubber (2) through a pipe. The bottom of the reaction tower filtrate tank (18) is connected to the first-stage reaction tower (12) through a drain pipe (14), and the top of the first-stage reaction tower (12) is connected to the main flue gas pipe (20) through a pipe.

2. The purification device for reducing arsenic content in dilute acid as described in claim 1, characterized in that... Each reaction tower is connected in the middle by an overflow pipe (10) and at the top by a degassing pipe (9). Each reaction tower is equipped with a spray pipe (19), which is connected to the bottom of each reaction tower through an external pipe. Each reaction tower is equipped with an air inlet pipe (8), which is connected to the regeneration separator of the ion liquid desulfurization system. The high-concentration sulfur dioxide generated by the regeneration separator of the ion liquid desulfurization system enters the spray pipes below the first-stage reaction tower (12), the second-stage reaction tower (13), and the third-stage reaction tower (15) through the air inlet pipe (8) and reacts with the dilute acid sprayed from the spray pipe (19). The desulfurized gas after the reaction passes through the degassing pipe (9) in sequence through the reaction tower filtrate tank (18), the third-stage reaction tower (15), the second-stage reaction tower (13), and the first-stage reaction tower (12) and is then directed to the main flue gas pipe (20).

3. A purification device for reducing arsenic content in dilute acid as described in claim 1 or 2, characterized in that... The bottom of the three-stage reaction tower (15) is provided with a pump pit (11). Each reaction tower is connected to the sewage pipe (14) through a pipe. The bottom of the reaction tower filtrate tank (18) is connected to the pump pit (11) through a pipe. The pump pit (11) is connected to the sewage pipe (14).

4. A purification device for reducing arsenic content in dilute acid as described in claim 1 or 2, characterized in that... The three-stage reaction tower (15) is provided with a gas replenishment hole (16) in the middle.

5. The purification device for reducing arsenic content in dilute acid as described in claim 2, characterized in that... Each air intake pipe (8) is equipped with a valve to control the air intake volume.

6. A purification device for reducing arsenic content in dilute acid as described in claim 1 or 2, characterized in that... Hydraulic pumps (22) are installed on the connecting pipes between the bottom of each reaction tower and the spray pipe, between the three-stage reaction tower and the reaction tower filter tank, and between the reaction tower filtrate tank and the emergency high-level water tank.

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