A method for removing sulfur dioxide from contaminated sulfuric acid in copper smelter off-gas acid production

Abstract

The present application relates to the chemical technology field, especially to a kind of copper smelting flue gas for acid making method for removing sulfur dioxide in contaminated acid.The method is as follows: S1, contaminated acid containing sulfur dioxide is passed into the primary desorption tower along the contaminated acid input pipeline;S2, the primary desorption tower is atomized to the contaminated acid entering, and negative pressure airflow is applied to transport the desorbed sulfur dioxide out along the sulfur dioxide delivery pipeline at the top of the primary desorption tower;S3, contaminated acid enters the settling tank along the liquid discharge pipe at the bottom of the primary desorption tower for settling;S4, the supernatant at the top of the settling tank enters the secondary desorption tower along the secondary delivery pipe for secondary atomization, and the separated sulfur dioxide enters the sulfur dioxide delivery pipeline along the gas delivery pipe at the top of the secondary desorption tower;S5, the contaminated acid removed twice is uniformly recycled to the contaminated acid treatment tank.The method removes sulfur dioxide in contaminated acid twice, which can effectively remove sulfur dioxide in contaminated acid, and ensures the effect of contaminated acid treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to the chemical technology field, and in particular to a method for removing sulfur dioxide in contaminated acid for copper smelting flue gas acid production. BACKGROUND

[0002] A large amount of contaminated acid with sulfur dioxide concentration of 1mg / L or more is discharged in the flue gas purification process of sulfuric acid production industry, and sulfur dioxide will affect the subsequent waste liquid treatment, so it is necessary to remove sulfur dioxide in waste liquid. At present, the method of removing sulfur dioxide by separate desorption tower is limited by the content of sulfur dioxide in waste liquid, and the desorption efficiency is not high, and for contaminated acid with high solid content, the packing tower is prone to blockage. Therefore, it is urgent to solve.

[0003] The above content is only used to assist in understanding the technical solutions of the present application, and does not represent the acknowledgement of the above content as the closest prior art. SUMMARY

[0004] The technical problem to be solved by the present application is to provide a method for removing sulfur dioxide in contaminated acid for copper smelting flue gas acid production, which can effectively and stably remove sulfur dioxide in purified contaminated acid, and ensure the effect of treating contaminated acid by gas-liquid enhanced sulfidation method in the rear end, and has important popularization significance.

[0005] To achieve the purpose, the technical scheme of the present application is as follows: a method for removing sulfur dioxide in contaminated acid for copper smelting flue gas acid production, the method is as follows:

[0006] S1, the contaminated acid containing sulfur dioxide is introduced into the primary desorption tower along the contaminated acid input pipeline;

[0007] S2, the primary desorption tower atomizes the entering contaminated acid, and applies negative pressure airflow to transport the desorbed sulfur dioxide out of the primary desorption tower along the sulfur dioxide transport pipeline at the top of the primary desorption tower;

[0008] S3, the contaminated acid which has completed the first sulfur dioxide removal in the primary desorption tower enters the settling tank along the liquid discharge pipe at the bottom of the primary desorption tower for settling;

[0009] S4, the supernatant at the top of the settling tank enters the secondary desorption tower along the secondary transport pipe for secondary atomization, and the separated sulfur dioxide enters the sulfur dioxide transport pipeline along the gas transport pipe at the top of the secondary desorption tower;

[0010] S5, the contaminated acid which has completed twice removal is uniformly recycled to the contaminated acid treatment tank.

[0011] Preferably, the primary desorption tower is empty, and a top of a working cavity of the primary desorption tower is provided with a spray head, and a bottom of the working cavity of the primary desorption tower is provided with an impeller.

[0012] Preferably, a diameter of a liquid outlet of the spray head is greater than a diameter of a largest particle in the polluted acid.

[0013] Preferably, the secondary desorption tower adopts a tower tank integrated structure, an upper part of the secondary desorption tower is a packing tower body, a lower part of the secondary desorption tower is a liquid storage tank, and a diameter of the lower part of the secondary desorption tower is greater than a diameter of the upper part of the secondary desorption tower.

[0014] Preferably, a top of a working cavity of the upper part of the secondary desorption tower is provided with a second spray head, and the second spray head is communicated with a secondary conveying pipe and sprays and atomizes supernatant entering the second spray head.

[0015] Preferably, a diameter of a liquid outlet of the second spray head is less than a diameter of the liquid outlet of the spray head.

[0016] Preferably, the sulfur dioxide in the sulfur dioxide conveying pipe is conveyed to the secondary power wave outlet and used for flue gas acid production.

[0017] Preferably, the bottom of the settling tank is provided with a polluted acid recovery pipe, and the polluted acid recovery pipe is communicated with a polluted acid treatment pool.

[0018] Preferably, the packing in the secondary desorption tower adopts 38mm plastic Heil rings, and the lower part of the secondary desorption tower is provided with a waste liquid pipe, and the waste liquid pipe is communicated with the polluted acid treatment pool.

[0019] Preferably, the bottom of the primary desorption tower and the bottom of the settling tank are both conical.

[0020] The beneficial effects of the present application are embodied in:

[0021] (1), the present application removes the sulfur dioxide in the polluted acid in two stages, solves the influence of a large amount of sulfur dioxide in the polluted acid on subsequent polluted acid treatment, reduces the cost of polluted acid treatment, and has important popularization significance.

[0022] (2), the two-stage desorption tower is a packed tower type structure with a Haier ring filler, the removal efficiency of sulfur dioxide can reach 95%, both times of desorption utilize the negative pressure of the purified flue gas to suck to the two-stage power wave outlet, the desorbed sulfur dioxide is used for flue gas acid making, after two times of desorption, the sulfur dioxide content in the waste acid is less than 1 mg / L. Compared with the method of removing sulfur dioxide by a single desorption tower, two times of desorption can further improve the desorption efficiency, for the waste acid with more impurity content and complex composition, the packing in the two-stage desorption tower can be prevented from being blocked, and the change of the sulfur dioxide content in the waste acid can be better coped with.

[0023] (3), the spray head and the impact impeller are arranged in the primary desorption tower, so that the entering waste acid can be sprayed and atomized, and the rotating impact impeller can not only generate airflow to accelerate the removal of sulfur dioxide along the sulfur dioxide conveying pipeline, but also can further atomize the liquid when colliding with the impact impeller, so that the waste acid can be sprayed and atomized multiple times in the primary desorption tower, and the removal effect of sulfur dioxide in the waste acid is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of the present application.

[0025] Reference signs:

[0026] 10, waste acid input pipeline; 20, primary desorption tower; 21, liquid discharge pipe; 22, spray head;

[0027] 30, settling tank; 31, waste acid recovery pipe; 32, secondary conveying pipe; 40, two-stage desorption tower;

[0028] 41, second spray head; 42, waste liquid pipe; 50, sulfur dioxide conveying pipeline. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, not all the embodiments. The embodiments in the present application and the features in the embodiments can be combined with each other without conflict. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0030] Embodiment 1

[0031] Referring to Figure 1 as shown:

[0032] The present application provides a method for removing sulfur dioxide in waste acid for copper smelting flue gas acid making:

[0033] The method is as follows:

[0034] S1, the sulfuric acid containing sulfur dioxide is introduced into the primary desorption tower 20 along the sulfuric acid input pipeline 10.

[0035] S2, the primary desorption tower 20 atomizes the entering sulfuric acid, and applies a negative pressure airflow to transport the desorbed sulfur dioxide out of the primary desorption tower 20 through the sulfur dioxide delivery pipeline 50 at the top of the primary desorption tower 20.

[0036] The primary desorption tower 20 is an empty tower, and the top of the working cavity of the primary desorption tower 20 is provided with a spray head 22, and the bottom of the working cavity of the primary desorption tower 20 is provided with an impeller.

[0037] The impeller is opposite to the spray head 22 and rotates under the impact of the liquid flowing out of the spray head 22, and the impeller generates a negative pressure airflow when rotating, which pushes the sulfur dioxide removed from the sulfuric acid into the sulfur dioxide delivery pipeline 50 from the primary desorption tower 20 and continuously transports it outward, thereby improving the removal efficiency of sulfur dioxide.

[0038] The diameter of the liquid outlet of the spray head 22 is greater than the diameter of the largest particles in the sulfuric acid. Through such a setting, it can avoid the blockage of the spray head 22 by the sulfuric acid, ensure the effect of spray atomization of the sulfuric acid, strengthen the stability of the working of the primary desorption tower 20, and improve the removal efficiency of sulfur dioxide.

[0039] The bottom of the primary desorption tower 20 is conical, and the bottom of the primary desorption tower 20 is provided with a liquid discharge pipe 21. The sulfuric acid solution that has completed the first removal of sulfur dioxide can quickly flow into the liquid discharge pipe 21 when passing through the bottom of the primary desorption tower 20, thereby accelerating the flow efficiency of the sulfuric acid.

[0040] S3, the sulfuric acid that has completed the first removal of sulfur dioxide in the primary desorption tower 20 enters the settling tank 30 along the liquid discharge pipe 21 for settling. The bottom of the settling tank 30 is also conical, and the top of the settling tank 30 is provided with a secondary delivery pipe 32 that communicates with the secondary desorption tower 40.

[0041] After the sulfuric acid entering the settling tank 30 is subjected to settling treatment, liquid layering occurs, and the upper part of the layered liquid forms supernatant containing sulfur dioxide, which is located at the top of the settling tank 30, and the top of the settling tank 30 is provided with the secondary delivery pipe 32 that communicates with the secondary desorption tower 40.

[0042] S4, the supernatant at the top of the settling tank 30 enters the secondary desorption tower 40 through the secondary delivery pipe 32, and the secondary desorption tower 40 adopts a tower tank integrated structure.

[0043] The upper part of the secondary desorption tower 40 is a packed tower body, and the internal packing of the secondary desorption tower 40 is 38mm plastic Heil rings.

[0044] The lower part of the secondary desorption tower 40 is a liquid storage tank, and the diameter of the lower part of the secondary desorption tower 40 is larger than the diameter of the upper part of the secondary desorption tower 40.

[0045] The top of the upper working chamber of the secondary desorption tower 40 is provided with a second nozzle 41, which is connected to the secondary conveying pipe 32 and sprays and atomizes the supernatant entering the second nozzle 41. The diameter of the liquid outlet of the second nozzle 41 is smaller than the diameter of the liquid outlet of the nozzle 22.

[0046] The waste acid is atomized a second time by using a secondary desorption tower 40. This setup makes the removal of sulfur dioxide from the waste acid more thorough and improves the removal efficiency of sulfur dioxide from the waste acid.

[0047] The sulfur dioxide separated from the supernatant enters the sulfur dioxide conveying pipeline 50 through the gas conveying pipe at the top of the secondary desorption tower 40, and is conveyed out under the influence of the negative pressure airflow in the sulfur dioxide conveying pipeline 50.

[0048] S5, the bottom of the settling tank 30 is provided with a waste acid recovery pipe 31; the waste acid recovery pipe 31 is connected to the waste acid treatment tank.

[0049] The lower part of the secondary desorption tower 40 is equipped with a waste liquid pipe 42, which is connected to the waste acid treatment tank, so that the waste acid removed in the two stages can be uniformly recycled to the waste acid treatment tank.

[0050] This setup allows for the step-by-step removal of sulfur dioxide from the waste acid, while also enabling its step-by-step recovery.

[0051] In addition, sulfur dioxide in sulfur dioxide conveying pipeline 50 is transported to the secondary power wave outlet for use in flue gas acid production. This setup achieves the recycling of sulfur dioxide, which not only reduces production costs but also improves the environmental impact of production.

[0052] It should be noted that if the embodiments of the present invention involve directional indicators such as up, down, left, right, front, back, etc., the directional indicators are only used to explain the relative positional relationship and movement of the components in a specific posture as shown in the attached figure. If the specific posture changes, the directional indicators will also change accordingly.

[0053] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the meaning of "and / or" throughout the text includes three parallel solutions; for example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied. Furthermore, "multiple" refers to two or more. Moreover, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent.

[0054] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for removing sulfur dioxide from waste acid used in copper smelting flue gas acid production, characterized in that, The method is as follows: S1, the waste acid containing sulfur dioxide is fed into the primary desorption tower (20) through the waste acid input pipe (10); S2, the primary desorption tower (20) atomizes the incoming waste acid and applies negative pressure airflow to transport the desorbed sulfur dioxide out along the sulfur dioxide conveying pipe (50) at the top of the primary desorption tower (20); S3, the waste acid that has completed the first sulfur dioxide removal in the first-stage desorption tower (20) enters the settling tank (30) through the drain pipe (21) at the bottom of the first-stage desorption tower (20) for settling; S4, the supernatant at the top of the settling tank (30) enters the secondary desorption tower (40) through the secondary conveying pipe (32) for a second atomization, and the separated sulfur dioxide enters the sulfur dioxide conveying pipeline (50) through the gas conveying pipe at the top of the secondary desorption tower (40) and is transported out. S5, the waste acid that has been removed twice is uniformly recycled to the waste acid treatment tank. After two desorption processes, the sulfur dioxide content in the waste acid is reduced to less than 1 mg / L. The primary desorption tower (20) is an empty tower, and a nozzle (22) is provided at the top of the working chamber of the primary desorption tower (20), and an impact impeller is provided at the bottom of the working chamber of the primary desorption tower (20); the nozzle (22) is connected to the waste acid input pipe (10) and sprays and atomizes the incoming waste acid; the impact impeller is opposite to the nozzle (22) and rotates under the impact of the liquid flowing out of the nozzle (22); The diameter of the outlet of the nozzle (22) is larger than the diameter of the largest particle in the waste acid; The upper working chamber of the secondary desorption tower (40) is provided with a second nozzle (41), and the second nozzle (41) is connected to the secondary conveying pipe (32) to spray and atomize the supernatant entering the second nozzle (41). The diameter of the outlet of the second nozzle (41) is smaller than the diameter of the outlet of the nozzle (22).

2. The method for removing sulfur dioxide from waste acid in copper smelting flue gas acid production according to claim 1, characterized in that, The secondary desorption tower (40) adopts an integrated tower and tank structure. The upper part of the secondary desorption tower (40) is a packed tower body, and the lower part of the secondary desorption tower (40) is a liquid storage tank. The diameter of the lower part of the secondary desorption tower (40) is larger than the diameter of the upper part of the secondary desorption tower (40).

3. The method for removing sulfur dioxide from waste acid in copper smelting flue gas acid production according to claim 2, characterized in that, The sulfur dioxide in the sulfur dioxide conveying pipeline (50) is conveyed to the secondary power wave outlet for use in flue gas acid production.

4. The method for removing sulfur dioxide from waste acid in copper smelting flue gas acid production according to claim 3, characterized in that, The bottom of the settling tank (30) is provided with a waste acid recovery pipe (31); the waste acid recovery pipe (31) is connected to the waste acid treatment tank.

5. The method for removing sulfur dioxide from waste acid in copper smelting flue gas acid production according to claim 4, characterized in that, The internal packing of the lower part of the secondary desorption tower (40) is made of 38mm plastic Heil rings, and the lower part of the secondary desorption tower (40) is provided with a waste liquid pipe (42), which is connected to the waste acid treatment tank.

6. The method for removing sulfur dioxide from waste acid in copper smelting flue gas acid production according to claim 5, characterized in that, The bottom of both the primary desorption tower (20) and the settling tank (30) is conical.

Images